Process for the preparation of polyaddition products of isocyanates and denatured biomasses, their use as reactive fillers and as plant nutrients and a process for the production of sheets or shaped articles using the polyaddition products

The instant invention is directed to a process for the production of denatured polyaddition products of biomasses and isocyanates, comprising reacting PA1 (A) from 5 to 98%, by weight, based on (A)+(B), of a biomass based on microorganisms or derivative and decomposition products thereof with PA1 (B) from 95 to 2%, by weight, based on (A)+(B), of a compound containing isocyanate groups, at temperatures of at least 50.degree. C. with complete denaturing of component (A).

BACKGROUND OF THE INVENTION 
This invention relates to a process for irreversibly denaturing and, at the 
same time, deodorizing biomasses containing microorganisms and the 
secondary products thereof, particularly biological clarified sludges, by 
reaction with compounds containing isocyanate groups. According to the 
present invention, the thus-obtained substantially odorless, denatured 
polyaddition products are used as reactive fillers or molding compositions 
in the production of plastics or as long-term fertilizers in agriculture. 
In biological purification plants, organochemical effluent impurities are 
degraded, i.e. biologically eliminated, by means of microorganisms. Under 
the conditions applied, the microorganisms multiply to a particularly 
marked extent. The quantity of the biomass consists mainly of bacteria in 
the so-called "activated sludge basin" of the purification plant 
increasing daily by from about 3 to 4%, by weight, so that, although some 
of the microorganisms die, the quantity of bacteria would double in from 3 
to 4 weeks. Accordingly, some of the biomass has to be continuously 
removed from the activated sludge basin in the form of so-called "surplus 
activated sludge" in order to maintain the optimal conditions for 
microbial effluent purification. For this reason, biomasses accumulate 
worldwide in extremely large and ever-increasing quantities in the fully 
biological purification of industrial and communal effluents. In the 
Federal Republic of Germany alone, about 2 million metric tons (expressed 
as dry weight) per year of these protein-containing biomasses are at 
present either being dumped or burned. Even today, the necessary removal 
of the water from the activated sludges is still a problem because, under 
the sedimentation conditions normally applied in the purification plants, 
the activated sludge to be removed contains only about 1%, by weight, of 
microbial dry mass. In conventional centrifuges, the solids content of the 
sludge may only be concentrated to from 7 to 9%, by weight. Even where 
polyelectrolytes are added and centrifugal decanters used, it may only be 
increased to from 12 to 15% by weight. 
Even in these low concentrations, the activated sludges have a pronounced 
gel structure and a relatively high viscosity on account of the pronounced 
chemical and physical binding of the water to the microorganisms. For this 
reason, normal filtration is impossible without certain treatment. 
Filtration is also complicated by the fact that the bacteria cells attract 
one another and form common, slimy shells, resulting in the formation of 
tacky flakes. In practice, therefore, inorganic primary sludges are added 
to the surplus activated sludges in from substantially the same to twice 
the quantity in order to facilitate removal of the water on an industrial 
scale by means of filter presses. In this way, a filter cake having a very 
high content of inorganic constituents and a water content of about 50%, 
by weight, based on the mass as a whole, is obtained. On the other hand, 
burning may only be carried out using surplus activated sludge powders 
having a very high content of organic mass. This is done either under 
substantially anhydrous conditions with the disadvantage that the drying 
process requires far more energy than may be obtained as heat equivalent 
during burning, or aqueous activated sludge is burned with an addition of, 
for example, heavy oil as energy carrier in a quantity sufficient to 
evaporate the quantities of water entrained. 
Another problem is that, as soon as it is isolated from the settling basin, 
the excess bacterial sludge immediately begins to rot and gives off an 
unbearable odor. Even anhydrous activated sludge powder dried at 
110.degree. C. has a very unpleasant odor and continues to rot on becoming 
moist. The presence of pathogenic germs cannot be ruled out. 
For these reasons, the composting of the treated sludge or its direct use 
as a fertilizer in agriculture is possible only to a limited extent. The 
elimination and utilization of treated sludges involve considerable 
ecological problems which have not been solved in a satisfactory manner. 
Known processes for working-up biomasses of microorganisms and the 
disadvantages and inadequacies thereof are discussed in detail in U.S. 
patent application Ser. No. 84,002, now abandoned. 
According to the estimates of the Federal Ministry of the Interior of the 
Federal Republic of Germany (1975 Waste Economy Program of the Federal 
Government; Environmental Letter 13, 1976), the annual accumulation of 
treated sludge will have increased by 1985 to about 50 million cubic 
meters from communal plants plus another 30 million cubic meters from 
industrial plants, which for a water content of 95% represents 
approximately 4 million metric tons of dry purified sludge per year. 
Accordingly, it is urgently necessary both for ecological reasons and also 
for economic reasons to find improved processes for working up surplus 
activated sludges with elimination of harmful impurities. It is also 
necessary to enable the purified sludges consisting mainly of high-quality 
proteins, nucleic acids enzymes and other valuable organic compounds to be 
utilized without endangering the environment by recycling on an industrial 
scale. 
It has now surprisingly been found that various biomasses based on 
microorganisms or metabolism and/or decomposition products thereof, 
including in particular the above-described purified sludges from 
biological purification plants, may be worked-up in a simple and 
considerably improved manner. This is accomplished by reacting the 
biomasses with compounds containing isocyanate groups. The reaction may 
take place optionally in the presence of organic solvents, carbonyl 
compounds, compounds capable of aminoplast or phenoplast formation and/or 
other additives, optionally at elevated temperature and/or elevated 
pressure. In the context of the present invention "working-up" is to be 
understood to mean that the biomasses are concentrated, irreversibly 
deodorized and, in this way, made available for utilization in the 
plastics-processing industry and in agriculture. The biomass polyaddition 
products obtained in accordance with the present invention are sterile, 
completely odorless in most cases and contain the biomass used in 
chemically bound and completely denatured form. The products are not tacky 
in aqueous phase, may be filtered without difficulty and dried in 
energy-saving manner. They are completely stable in storage and free from 
pathogenic organisms. The total enzyme deactivation and complete cell 
death of the biomasses completely suppress decomposition and putrefaction 
processes, fermentation and unpleasant odor formation of enzymatically or 
microbiologically degradable cell ingredients. Accordingly, the process 
products may be indefinitely stored both in dry and also in moist form 
without giving off unpleasant odors and without undergoing further 
enzymatic degradation. 
It is known that isocyanates may be reacted with other starting materials 
of the type commonly encountered in polyurethane chemistry in the presence 
of biologically active substances to form high molecular weight compounds. 
In contrast to the present invention, whose object is to denature 
biomasses based on microorganisms with complete destruction of living 
cells and active enzymes present therein, the known processes seek to fix 
selected biologically active compounds in polyurethanes with full 
retention of the bioactivity. 
Thus, in German Offenlegungsschriften Nos. 2,612,138 and 2,625,544, for 
example, describe the fixing of enzymes, antigens, antibodies or 
antibiotics by means of prepolymers containing isocyanate groups. In this 
case, the polyaddition reaction has to be carried out very carefully to 
avoid destruction of the bioactive substances. The thus obtained products 
are used as biospecific catalysts, antigens or antibodies. Various 
biologically fully active or even activated substances fixed to a 
polyurethane matrix may be similarly produced in accordance with German 
Offenlegungsschriften Nos. 2,319,706 and 2,625,471 and U.S. Pat. Nos. 
3,574,062; 3,705,084; 3,791,927; 3,672,955; 3,929,575; and 3,905,920. As 
mentioned above, the process according to the present invention differs 
from these known processes not only in regard to the starting materials 
used (microbial biomasses of extremely heterogeneous composition which 
still contain virtually all the cell constituents and, in general, even 
have a largely undamaged cell structure and also contain living cells are 
used instead of isolated biochemically active individual compounds), but 
also in regard to the reaction conditions so that the biomasses treated in 
accordance with the present invention are completely changed physically, 
chemically and biologically in relation to the starting material. 
DESCRIPTION OF THE INVENTION 
Accordingly, the present invention relates to a process for the preparation 
of denatured polyaddition products of biomasses and isocyanates, 
comprising reacting 
(A) from 5 to 98%, by weight, preferably from 20 to 90%, by weight, based 
on (A)+(B), of a biomass based on microorganisms or derivative and 
decomposition products thereof; with 
(B) from 95 to 2%, by weight, preferably from 80 to 10%, by weight based on 
(A)+(B), of a compound containing isocyanate groups; optionally in the 
presence of 
(C) water and/or an organic solvent; and optionally in the presence of 
(D) organic and/or inorganic additives; at temperatures of at least 
50.degree. C., preferably from 50.degree. to 200.degree. C., and, with 
particular preference, from 80.degree. to 150.degree. C., and are thus 
completely denatured. 
In one particular embodiment of the present process, condensation reactions 
may be carried out with the biomasses before, after or during the 
isocyanate polyaddition reaction. This may be done optionally with partial 
hydrolytic decomposition of the biomasses, by reacting them with suitable 
carbonyl compounds, particularly aldehydes or compounds capable of 
aminoplast and/or phenoplast formation. 
In the context of the present invention, "biomasses" are understood to be 
various biosystems of microorganisms, such as prokaryontae and 
eurkaryontae, for example bacteria, yeasts, protozoae and other 
single-cell microorganisms, fungi, algae, etc., which are present in the 
divided state, dormant state, in a state of partial or complete cell death 
or which are already in the process of enzymatic decomposition or 
decomposition by foreign cultures. 
Examples of such biosystems include biomasses of microorganisms or 
biological purification plants and other microbial or bacterial biomasses 
of the type which accumulate: 
(a) in processes for recovering products of the primary metabolism, i.e., 
for example, in the biotechnical production of ethanol, butanol, acetone, 
citric acid, lactic acid, tartaric acid, simple aliphatic carboxylic 
acids, amino acids, etc.; 
(b) in technical fermentation processes for the production of products of 
the secondary metabolism, for example in the production of antibiotics, 
vitamins, growth hormones, steroid hormones, alkaloids, etc.; 
(c) in processes for recovering cell constituents, such as enzymes, nucleic 
acids or polysaccharides; and 
(d) in processes for producing yeast, for example for baking purposes, for 
alcoholic fermentation or for recovering proteins from methane, petroleum 
and methanol. 
Biomasses of the type which accumulate in biotransformation processes 
include processes where microorganisms are used as catalysts for 
organochemical reactions, such as oxidation, reduction, decarboxylation, 
phosphorylation, amination, deamination, acetylation, de-acetylation, etc. 
Biomasses preferably used in the process of the present invention are: 
(a) Biomasses from biological plants for the purification of industrial and 
communal effluents. Such biomasses consist of numerous types of bacteria, 
algae and fungi which function optimally at a P:N:C ratio of about 1:5:100 
and which are known as "omnivores". The biomasses emanating from 
purification plants, which are also known as "purified sludges" or 
"activated sludges", may be used in the process according to the present 
invention even when they contain traces of mercury, cadmium, zinc, iron, 
chromium and/or lead ions. 
(b) Digested sludges and biosludges of various types and also biomasses 
containing large amounts of Escherichia coli and/or various suspended 
vegetable substances. 
(c) Biomasses from anaerobic (intensive) digestion processes, 
refuse/purified sludge composting products. Examples include biomasses 
from thermophilic digestion processes (aerobic-thermophilic processes), 
products obtained by the aerobic composting of purified sludge by the 
quick-rotting process, microbially infested fibrous sludges, sludges from 
the food and luxury-food industries, for example sludges from dairies and 
abattoirs, and biosludges which have been dried and dumped. 
(d) A variety of yeasts (fungi) from technical processes, for example from 
alcoholic fermentation processes. 
(e) Biomasses from the production of acetic acid lactic acid, citric acid 
or tartaric acid, also bacterial cultures fermenting by enzymatic 
processes. 
(f) Defective parts of yeast cultures. 
(g) Biomasses from the production of proteins based on various hydrocarbon 
sources, such as petroleum, paraffin cuts, methane or methanol. 
Particularly suitable biomasses of this type are biomasses based on 
certain yeast cells from industrial installations for the production of 
protein from petroleum fractions and defective parts of such biomasses. In 
this connection, particularly suitable biomasses are also biomasses of 
single-cell microorganisms consisting of bacterial mixed cultures, of the 
type used in the production of proteins from natural gas (methane). Other 
suitable biomasses are biomasses or pseudomonas bacteria which are 
cultivated in fermenters at about 37.degree. C. and from which 
high-protein feeds may be produced using methanol as the carbon source. 
(h) Biomasses from the production of penicillin, for example Pencillium 
notatum and Pencillium chrysogenum. 
(i) Biomasses from the final stage of the production of tetracycline 
(streptomycetes), biomasses from filament-like bacteria from the 
production of sisomycin (micromonospora) and other types of streptomyces. 
(j) Biomasses based on various other bacteria and fungi, of the type 
described in detail in U.S. patent application Ser. No. 84,002, now 
abandoned and numerous other microbial biomasses of the type described in 
the literature (cf. Synthesis 4, 120-134 and 147-157 (1969)). These 
biomasses may consist of pure culture and of mixed cultures, i.e. of 
cultures which have been infected during fermentation processes and are 
therefore unuseable, and may contain, for example, even in admixture, dead 
cells of vegetable origin or cell ingredients, such as hemi-celluloses. 
(k) Algae, such as blue algae, green algae (for example chlorella), 
diatoms, conjugate, flagellar algae, brown algae and red algae, and also 
protozoate. 
(1) Mixed cultures of various bacteria, fungi and algae and also cultures 
of biomasses which are infected with other types of fungi, bacteria, etc. 
and which have a complex composition. Examples of such mixed cultures are 
mixed cultures of the type grown on spent residues in the process of 
decomposition, nutrient media (such as gelatin, molasses, starches and 
other polysaccharides), in the open air and in moist form and also on 
protein-containing, still living or even already decomposing algae. 
Mixtures of different biomasses may also be used in the process according 
to the present invention. The present process may also be used in cases 
where the biomasses contain a variety of different impurities. In this 
connection, reference is made by way of example to biomasses containing 
heavy metal salts, plant protection agents, antibiotics or other organic 
or inorganic chemicals. 
It is particularly preferred to use the aqueous or dried powder-form 
purified sludges from industrial and communal purification plants 
described in detail above for the isocyanate polyaddition reactions 
according to the present invention. These purified sludges do not have a 
defined composition, but instead consist of many types of bacteria, fungi 
and protozae, depending on the contamination of the effluent and the 
biological conditions. Of these many types of bacteria, fungi and 
protozae, the following few are mentioned by way of example: Aerobacter 
aerogenes, Corynebacterium laevaniformas, Paracolobactrum aerogenoides, 
Escheria intermedium, Escheria faecale, Flavobacteria, Pseudomonas, 
Nitrosomonas and Nitrobacter geni, also Shaerotilus natens and white 
sulfur bacteria. In addition, enzymes, ferments and algae are also 
present. 
The biomasses used in the process according to the present invention 
contain a variety of compounds containing H-acid groups which are capable 
of entering into polyaddition reactions with isocyanates (cf. for example 
"Handbuch der Frischwasser and Abwasserbiologie", Vol. II, page 620 (1960) 
by H. Lubmann). Examples of these compounds are inter alia proteins, (for 
example lipoproteins, glycoproteins) as constituents of enzymes; the 
enzymes themselves (such as glucose oxidase, catalase, glucose isomerase, 
invertase, lactase, naringinase, lipases, asparaginases, .alpha.-amylases 
and glycoamylases, cellulases, lysozymes, proteases, etc.); 
nucleoproteins; ribonucleic acids and deoxyribonucleic acids; 
phosphatides, (particularly inositol phosphatide, colamine cephalin and 
serine sephalin; lipoids or plasmalogens providing they contain colamine 
bound in the form of a phosphoric acid ester as base); sugars and 
polysaccharide-like cell reserve substances and cell ingredients, 
hemi-celluloses, starches, pectins and lignins: constituents of the cell 
walls of bacteria, for example, polymers of amino sugars (acetyl 
glucosamine+N-acetyl muramic acid) which are cross-linked by way of 
polypeptides in the N-acetyl muramic acid component; cell wall 
constituents of fungi and algae, (such as celluloses, hemi-celluloses and 
other polysaccharides) and chitine fractions with acetyl gluosamine and 
acetyl galactosamine fractions. 
Component (B) in the process according to the present invention may in 
principle be formed by various low molecular weight or high molecular 
weight monoisocyanates or polyisocyanates which are liquid or soluble in 
an organic solvent at the processing temperatures. According to the 
present invention, however, it is also possible to use products containing 
isocyanate groups which are infusible or insoluble. For example, it is 
possible to use aliphatic, cycloaliphatic, araliphatic, aromatic and 
heterocyclic polyisocyanates of the type described, for example, by W. 
Siefken in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136. 
Examples include those corresponding to the following general formula: 
EQU Q(NCO).sub.n 
wherein 
n=2 to 4, preferably 2; and 
Q represents an aliphatic hydrocarbon radical containing from 2 to 18 
carbon atoms, preferably from 6 to 10 carbon atoms, a cycloaliphatic 
hydrocarbon radical containing from 4 to 15, preferably from 5 to 10 
carbon atoms, an aromatic hydrocarbon radical containing from 6 to 15 
carbon atoms, preferably from 6 to 13 carbon atoms or an araliphatic 
hydrocarbon radical containing from 8 to 15 carbon atoms, preferably from 
8 to 13 carbon atoms. Specific examples include ethylene diisocyanate, 
1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 
1,12-dodecane diisocyanate, cyclobutane-1,3-diisocyanate, 
cyclohexane-1,3-and 1,4-diisocyanate and mixtures of these isomers, 
1-isocyanato-3,3,5-trimethyl-5-isocyanatomethyl cyclohexane (German 
Auslegeschrift No. 1,202,785 or U.S. Pat. No. 3,401,190), 2,4- and 
2,6-hexahydrotolylene diisocyanate and mixtures of these isomers, 
hexahydro-1,3- and/or 1,4-phenylene diisocyanate, perhydro-2,4' and/or 
-4,4'-diphenyl methane diisocyanate, 1,3- and 1,4-phenylene diisocyanate, 
2,4 - and 2,6-tolylene diisocyanate and mixtures of these isomers, 
diphenyl methane-2,4' and/or -4,4'-diisocyanate and 
naphthylene-1,5-diisocyanate. 
According to the present invention, it is also possible to use triphenyl 
methane-4,4',4"-triisocyanate; polyphenyl polymethylene polyisocyanates of 
the type obtained by condensing aniline with formaldehyde, followed by 
phosgenation (British Pat. Nos. 874,430 and 848,671); m- and 
p-isocyanatophenyl sulfonyl isocyanates (U.S. Pat. No. 3,454,606); 
perchlorinated aryl polyisocyanates (German Auslegeschrift No. 1,157,601 
or U.S. Pat. No. 3,277,138); polyisocyanates containing carbodiimide 
groups (German Pat. No. 1,092,007, U.S. Pat. No. 3,152,162 and German 
Offenlegungsschriften Nos. 2,504,400; 2,537,685; and 2,552,350); 
norbornane diisocyanates (U.S. Pat. No. 3,492,330); polyisocyanates 
containing allophanate groups (British Pat. No. 994,890, Belgian Pat. No. 
761,626 and Dutch Patent Application 7,102,524); polyisocyanates 
containing isocyanurate groups (U.S. Pat. No. 3,001,973, German Pat. Nos. 
1,022,789; 1,222,067; and 1,027,394 and German Offenlegungsschriften Nos. 
1,929,034 and 2,004,048); polyisocyanates containing urethane groups 
(Belgian Pat. No. 752,261 or U.S. Pat. Nos. 3,394,164 and 3,644,457); 
polyisocyanates containing acylated urea groups (German Pat. No. 
1,230,778); polyisocyanates containing biuret groups (U.S. Pat. Nos. 
3,124,605; 3,201,372; and 3,124,605 and British Pat. No. 889,050); 
polyisocyanates produced by telomerization reactions (U.S. Pat. No. 
3,654,106); polyisocyanates containing ester groups (British Pat. Nos. 
965,474 and 1,072,956, U.S. Pat. No. 3,567,763 and German Pat. No. 
1,231,688); reaction products of the above-mentioned isocyanates with 
acetals (German Pat. No. 1,072,385); and polyisocyanates containing 
polymeric fatty acid esters (U.S. Pat. No. 3,455,883). 
It is also possible to use the isocyanate-containing distillation residues 
obtained in the commercial production of isocyanates, optionally in 
solution in one or more of the above-mentioned polyisocyanates. It is also 
possible to use mixtures of the above-mentioned polyisocyanates. 
In general, it is particularly preferred to use the commercially readily 
available polyisocyanates. Examples include 2,4- and 2,6-tolylene 
diisocyanate; also mixtures of these isomers ("TDI"); polyphenyl 
polymethylene polyisocyanates of the type obtained by condensing aniline 
with formaldehyde, followed by phosgenation ("crude MDI"); and 
polyisocyanates containing carbodiimide groups, urethane groups, 
allophanate groups, isocyanurate groups, urea groups or biuret groups 
("modified polyisocyanates"); particularly modified polyisocyanates of the 
type derived from 2,4- and/or 2,6-tolylene diisocyanates or from 4,4'- 
and/or 2,4'-diphenyl methane diisocyanate. 
According to the present invention, component (B) may also comprise 
NCO-groups containing reaction products of the above-mentioned 
polyisocyanates and the high molecular weight and/or low molecular weight 
polyhydroxyl compounds known from polyurethane chemistry (so-called 
"NCO-prepolymers"). Monoisocyanates, such as methyl, benzyl, phenyl or 
tolyl isocyanates, are also suitable for the process according to the 
present invention. 
For denaturing biomasses in accordance with the present invention, it is of 
particular economic advantage to use the distillation residues 
accumulating in the commercial production of isocyanates for which it has 
not yet been possible to find practical use, as explained above in 
connection with the biomasses, and whose elimination has hitherto also 
involved considerable problems (cf. in this connection, for example, 
German Offenlegungsschriften Nos. 2,846,815 and 2,846,809 and U.S. patent 
application Ser. Nos. 88,800 and 89,322). Distillation residues 
particularly suitable for the purposes of the present invention are the 
substantially monomer-free, cross-linked distillation residues which are 
insoluble in inert organic solvents and which cannot be melted without 
decomposing. These are of the type which accumulate as slag in the removal 
of monomeric tolylene diisocyanates by distillation from crude 
phosgenation products of tolylene diamines, optionally after stirring into 
water, and which before use are ground into a powder and, optionally, 
chemically modified simultaneously and/or subsequently by reaction with 
compounds reactive with the functional groups of the distillation residue, 
particularly the isocyanate groups. 
As mentioned above, the distillation residues used in the process according 
to the present invention automatically accumulate in the conventional 
process for the production of 2,4- and/or 2,6-tolylene diisocyanate on an 
industrial scale. They are in the form of relatively high molecular weight 
residue slags crosslinked by way of main valency bonds which are generally 
formed in a quantity of more than 10%, by weight, based on the calculated 
quantitative yield of monomeric diisocyanates. To make them easier to 
handle they are generally introduced into water at a temperature above 
150.degree. C., resulting in the formation of a coarse-grained, 
irregularly shaped insoluble slag in which a large number of the free 
isocyanate groups have reacted to form polyurea groups. Although this slag 
still has a small content of free NCO-groups (generally less than 15%, by 
weight and, in most cases, from 1 to 10%, by weight), it is substantially 
free from monomeric diisocyanates. In addition to the NCO-groups, the TDI 
residue slags contain urea, biuret, uretdione isocyanurate, carbodiimide, 
uretone imine and, in some cases, even methyl benzimidazolone groups and 
the biuretization products thereof in varying quantitative ratios. The 
slags are so highly cross-linked by way of these various functional groups 
that, even after size-reduction to a mean particle size of less tha 5 
.mu.m, they are substantially insoluble in inert organic solvents, such as 
methylene chloride, cyclohexane, cyclohexanone, toluene, xylene or 
dichlorobenzene, even at boiling temperature. Even in boiling dimethyl 
formamide, the residue powders are only partly swollen, but not dissolved. 
On heating, only a very small proportion, if any, of the TDI distillation 
residues used in accordance with the present invention softens at 
temperatures above about 250.degree. C., although beyond about 280.degree. 
C. the distillation residues decompose without melting, giving off gases 
in the process. 
Some of the above-mentioned groups in the TDI slag, for example, uretdione 
and carbodiimide groups, may additionally react chemically with the 
biomasses at elevated temperatures. 
The very coarse-grained TDI residue slag is preferably first pre-comminuted 
to less than 3 mm in a comminuting machine, for example, a cutting 
granulator or a hammer mill, and is then brought to the final particle 
size required at any stage using known wet or dry grinding processes. 
In cases where the TDI residues accumulate in water or are wetted with 
water, it is particularly economical environmentally desirable to subject 
the coarse TDI slag to wet grinding in the aqueous biomass suspension in 
batch-type or continuous machines optionally arranged one behind the other 
in two stages. The solids content of these mixtures during grinding 
preferably amounts to from 10 to 45%, by weight. Depending on the required 
grain size, the wet grinding may be done in tube and ball mills, toothed 
colloid mills, trigonal gear ring mills, corundum disc mills and 
stirrer-equipped ball mills. 
In certain cases, some or all of the water may be replaced during grinding 
by another liquid. 
The TDI residue slags obtained after wet grinding which contain different 
quantities of free NCO-groups, depending on the procedure adopted, are 
used either in the form of very finely divided suspensions or pastes or 
(after isolation of the suspending agent) in the form of powders in the 
same way as the TDI residue powders obtainable by dry grinding. 
TDI residue slags which have been pre-ground to less than from 2 to 3 mm 
and pre-dried, preferably at temperatures below 50.degree. C., and which 
have a moisture content of not much more than 20%, by weight, and 
preferably less than 10%, by weight, are used for dry grinding. The choice 
of the particular machines used for dry grinding is essentially governed 
by the final particle size and particle size distribution required and by 
the grinding costs. In comparison with plastics, the residue slags used in 
accordance with the present invention are very hard. By virtue of the high 
degree of cross-linking, they may be ground without softening at 
temperatures up to about 200.degree. to 300.degree. C. in conventional 
size-reducing machines free from cooling problems, which is of particular 
importance for obtaining very fine particle sizes. 
Grinding may be carried out, for example, in pinned-disc mills, ball mills, 
baffle plate mills, air-stream mills, cross-beater mills, gear ring mills 
or turbine mills. It is preferred to use steam-jet or air-jet mills 
because, in mills of this type, size-reduction is primarily obtained by 
inter-particle collisions and secondarily by wall collisions. Very fine 
particle sizes may thus be obtained in a single passage. 
Dry grinding may also be carried out by single-stage and multi-stage, 
batch-type or continuous grinding processes. 
As a result of wet or dry grinding, the residual reactive groups of the 
above-mentioned type which are included in the residue slag are made 
available for a variety of chemical reactions with the biomasses. 
The residue powder should have a particle size of less than 2 mm preferably 
less than 0.8 mm, more preferably less than 0.4 mm and, with particular 
preference, less than 0.1 mm, to enable the polyaddition reactions with 
the biomasses to take place substantially quantitatively. 
Further particulars on the production of the TDI residue powders used in 
the process according to the present invention may be found in German 
Offenlegungsschrift No. 2,846,815 and U.S. Pat. No. 4,297,456. The earlier 
disclosure also contains a detailed description of possible modification 
reactions on the TDI residue powders (for example by means of carbonyl 
compounds or compounds containing Zerewitinoff-active hydrogen atoms) 
which may optionally be carried out before the powders are used in 
accordance with the present invention. 
The present process may be carried out in various ways, depending on 
whether dried biomasses or biomasses dispersed in water are used as the 
starting material. Where the process is carried out in the aqueous phase, 
biomasses having a solids content of from 0.3 to 20%, by weight, 
preferably from 1 to 15%, by weight, are generally used. The aqueous 
surplus activated sludges from biological purification plants generally 
have a solids content of from 0.3 to 3%, by weight, more particularly from 
0.7 to 1.5%, by weight. The quantity in which the isocyanate is used where 
the process is carried out in the aqueous phase amounts to from about 2 to 
95%, by weight, preferably from 3 to 80%, by weight, (based on the sum of 
the dry weight of the biomass and the weight of the isocyanate) and is 
also governed by the type of isocyanate used. Low molecular weight 
monoisocyanates and polyisocyanates (molecular weight up to about 500), of 
the type described in detail above, are preferably used in quantities of 
from 3 to 20%, by weight, while relatively high molecular weight 
polyisocyanates (including in particular the TDI residue powders) are 
preferably used in quantities of from about 20 to 80%, by weight, (based 
in each case on the sum of the isocyanate and the dry weight of the 
biomasses). If the isocyanate is present in a stoichiometric excess in 
relation to the H-acid groups of the biomass, biomass-isocyanate 
polyadditon products containing free NCO groups, which may be of 
particular advantage for some applications of the products (for example as 
reactive fillers), are obtained in accordance with the present invention. 
In cases where isocyanates which are liquid under the reaction conditions 
or which are dissolved in an organic solvent are used, the denaturing 
reaction is preferably carried out at temperatures of from 50.degree. to 
200.degree. C. and, with particular preference, from 80.degree. to 
120.degree. C. Denaturing using the above-described TDI residue powders 
generally required somewhat higher temperatures, for example from 
70.degree. to 200.degree. C., and preferably from 90.degree. to 
150.degree. C. In cases where a solvent is used, the reaction temperature 
may generally be reduced by about 20.degree. to 30.degree. C. in relation 
to the solvent-free procedure. 
In cases where biomasses dispersed in water are used as the starting 
material in accordance with the present invention it is advantageous, 
particularly if the starting material is relatively coarse, to also use an 
organic solvent in a quantity of from 1 to 30%, by weight, preferably from 
5 to 10%, by weight, based on the dispersion, in order to facilitate the 
reaction between the generally hydrophobic isocyanates and the aqueous 
biomass. The organic solvent used is preferably at least partly miscible 
with water. Solvents suitable for use in the process according to the 
present invention, which may also contain isocyanate-reactive groups, are 
for example, acetone, methyl ethyl acetate and mixtures thereof. 
Where the process is carried out in the aqueous phase, it is preferred to 
apply temperatures of from 80.degree. to 130.degree. C. Pressure may also 
be applied, for example, an excess pressure of from 2 to 100 bars. The pH 
value is generally from 1 to 10, preferably from 4 to 8. If necessary, the 
pH may be adjusted to the required range by the addition of acids or 
alkali or ammonia. The application of high temperatures and low pH values 
during the isocyanate polyaddition reaction promotes plasmolysis, i.e. 
shrinkage of the protoplasma, and partial hydrolysis of the cell material. 
The polyaddition reaction in the aqueous phase may be carried out both in 
batches in conventional reaction vessels and also (optionally in 
combination therewith) continuously. Straight-flow mixers, of the type 
described, for example in German Pat. No. 2,513,815 (U.S. Pat. No. 
4,089,835), or multiphase reaction tubes according to German 
Offenlegungsschrift No. 2,719,970 (U.S. Pat. No. 4,119,613) and the 
apparatuses described in the literature cited therein may be used. In the 
continuous processes, the average residence time of the reaction mixture 
of concentrated aqueous biomass, isocyanate and, optionally, solvent 
preferably amounts to from between about 2 to 20 minutes and, with 
particular preference, from 1 to 5 minutes for temperatures near the 
boiling point. It is of particular advantage to use a multiphase flow-type 
reaction tube because substantially quantitative drying of the 
polyaddition product is also obtained in this way. Where the polyaddition 
reaction according to the present invention is carried out in batches in 
conventional reaction vessels, the surplus activated sludge from 
biological purification plants is denatured and flocculated by the 
polyaddition reaction to such an extent that the process products may be 
isolated by filtration resulting in a solids content of more than 50%, by 
weight, (even without the otherwise necessary filtration aids). 
In cases where substantially anhydrous powders of biomasses are used for 
the process according to the present invention, it may be assumed that the 
cells have died, leaving only a small residue of living cells. As 
mentioned above, however, an activated sludge powder, for example, is 
still attended by an intolerable odor. In the same way as the latent 
residual activity, this odor may be completely eliminated by the 
isocyanate polyaddition reaction of the present invention. To this end, 
the powder-form biomass may be intensively mixed with a large excess (of 
NCO groups) of a liquid or dissolved monoisocyanate or polyisocyanate. The 
addition reaction takes place at temperatures as low as room temperature, 
albeit over a period of a few days. It is preferable to briefly heat the 
mixture (preferably for from 3 minutes to 3 hours, depending on the 
temperature) to a temperature of from about 50.degree. to 200.degree. C., 
preferably from 80.degree. to 150.degree. C., and, after reaching a 
constant NCO content, to remove the excess, unused low molecular weight 
isocyanate, optionally by means of a solvent, such as acetone. A 
powder-form insoluble biomass polyisocyanate having an NCO content which 
may amount to more than 15 %, by weight, is obtained. The reaction of the 
dry biomass with an equivalent or sub-equivalent quantity of isocyanates 
leads to NCO-free sterilized biomass polyaddition products. In this 
embodiment of the process, too, the isocyanate is used in a quantity of 
from 2 to 95%, by weight, preferably from 3 to 80%, by weight, (based on 
the total quantity of biomass and isocyanate). The reaction may be carried 
out either as such or in the above-mentioned organic solvents (in which 
case the solvent is used in a quantity of from 1 to 50%, by weight, 
preferably from 5 to 20%, by weight, based on the reaction mixture). Where 
substantially anhydrous biomasses and a liquid organic solvent are used, 
the process may again be carried out in batches in conventional reaction 
vessels and also continuously in straight-flow mixers, multiphase reaction 
tubes or in reaction screw extruders. 
It is of particular technical significance, above all when, in addition to 
the biomasses, the reaction mixture contains only small quantities of 
liquid components (for example solvents or liquid reactants for the 
biomasses) and when the powder-form TDI residues slags described in detail 
above are used as the isocyanate component, to apply two processes which 
may optionally be coupled with one another. For the first process, the 
known centrifuging and fluidizing technique carried out by means of 
mechanically active mixers or mixing tools and/or for the second, the 
fluidized-bed technique. For the first technique, it is best to use 
commercially available heatable and coolable mixers in which 
plowshare-like blades arranged on a rotatable shaft and, optionally, 
independently movable cutter heads are mounted in the mixing drum. 
Providing the process conditions under which a substantially powder-like 
form is maintained during the polyaddition reaction according to the 
present invention (temperature; residence time) are determined first by 
laboratory tests and then by semi-technical tests in from 100 to 200 liter 
mixers, it is possible without major difficulties to use large-capacity 
mixing units optionally arranged one behind the other for producing 
commercial quantities of biomass isocyanate polyaddition products. 
For applying the second technique, namely the fluidized bed technique, the 
optimal state of fluidization in the fluidized bed is difficult to 
calculate and, for given solids data, such as density, particle sizes and 
distribution, and the selected flow medium (for example air or nitrogen), 
is essentially determined by the difference between the loosening rate and 
the rate of flow of the flow medium. The optimal state of fluidization may 
readily be determined by a few preliminary tests carried out in a small 
laboratory fluidized bed. The optional use of liquid or gaseous reaction 
components should be taken into account in these preliminary tests. 
In cases where the fluidity of a packing proves to be inadequate during the 
process (i.e. where a certain tackiness occurs), it is possible in certain 
cases to use a granular material of higher specific gravity (for example 
quartz sand) and to isolate the polyadduct in a cyclone. 
In fluidized beds characterized by high through-flow rates, fine 
size-reduction may be obtained by vigorous agitation of the solids, 
possibly even during the reactions according to the present invention. 
As mentioned above, it is also possible in one particular embodiment of the 
present invention to carry out condensation reactions with carbonyl 
compounds and, optionally, compounds suitable for aminoplast and/or 
phenoplast formation in the biomasses before, after or during the 
isocyanate polyaddition reaction according to the present invention. Such 
condensation reactions are only the subject of the present invention 
insofar as they are used in combination with isocyanate polyaddition 
reactions in the manner described above. 
The simplest modification is to allow formaldehyde to act on the biomasses. 
Depending on the pH value, the biomasses initially only undergo 
methylolation or cross-linking reaction (preferably in the strongly acid 
range) which results in the formation of methylene bridges. In addition to 
a carbonyl compound suitable for condensation with the biomasses, it is 
also possible, as mentioned above, to add other compounds capable of 
condensation. In addition, however, compounds capable of condensing with 
carbonyl compounds are also formed during the isocyanate polyaddition 
reaction itself. It is of particular advantage to add urea or to form urea 
groups capable of condensation and also to use azulmic acid (cf. for 
example the summary by Th. Volker in Angewandte Chemie 1960, pages 
379-384) which, as a polymeric hydrocyanic acid, contains numerous amino 
groups. In addition, azulmic acid, which is also reactive to isocyanates, 
is also capable of complexing heavy metal ions. Accordingly, biomass 
azulmic acid polyisocyanate polyaddition products modified in accordance 
with the present invention are particularly suitable for use as plant 
nutrients. In addition, they considerably increase the nitrogen content of 
the products. 
Suitable carbonyl compounds, which may optionally be used as reaction 
components for carrying out the process according to the present 
invention, are any of the conventional carbonyl compounds containing 
sufficiently reactive carbonyl groups. Preferred carbonyl compounds are 
aldehydes and ketones. 
Particularly preferred aldehydes are saturated, aliphatic (optionally 
halogen- or hydroxy-substituted monoaldehydes), such as formaldehyde, 
acetaldehyde, butyraldehyde, isobutyraldehyde, pivalic aldehyde, chloral, 
hydroxy acetaldehyde, hydroxy pivalic aldehyde, glyceric aldehyde, hydroxy 
aldehydes of the type present in formose-sugar mixtures and hydroxy 
aldehydes formed from other aldehydes by aldol condensation reactions. 
Other particularly preferred aldehydes are unsaturated aliphatic aldehydes 
(such as acrolein and crotonaldehyde), cycloaliphatic aldehydes (such as 
cyclohexane aldehyde, aliphatic dialdehydes, such as glyoxal, methyl 
glyoxal, glyoxal sulfate and glutaric dialdehydes), aromatic aldehydes 
(such as benzaldehyde, 4-methyl benzaldehyde, salicylic aldehyde and 
terephthalic dialdehyde), and aldehydes derived from heterocycles (such as 
furfurol and hydroxy methyl furfurol). It is also possible with advantage 
to use "masked aldehydes", i.e. compounds which either release aldehydes 
or react like aldehydes under the reaction conditions. In this connection, 
particular reference is made to paraformaldehyde, trioxane, chloral 
hydrate, hexamethylene tetramine and semi-acetals of aldehydes, in 
particular formaldehyde with monofunctional, difunctional or higher 
polyfunctional alcohols, such as methanol, ethanol, butanol, ethylene 
glycol and diethylene glycol. 
Particularly preferred ketones are hydroxy acetone, dihydroxy acetone, 
methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and 
acetophenone and quinones, such as benzoquinone. 
It is also possible to use mixtures of aldehydes and/or ketones. Mixtures 
of formaldehyde and other aldehydes or ketones are particularly preferred. 
Hydroxy aldehydes and hydroxy ketones may be formed in situ by aldol 
condensation reactions from mixtures such as those of formaldehyde with 
aldehydes or ketones containing hydrogen atoms in the .alpha.-position. 
The hydroxy aldehydes and polyhydroxy ketones readily enter into addition 
reactions with, for example, urea and numerous aminoplast formers during 
formation thereof, particularly in the mildly to strongly alkaline range, 
to form N-alkylol compounds which in turn represent condensation partners 
for the above-mentioned biomasses. 
Suitable thiocarbonyl compounds, which may be used as reaction compounds 
for carrying out the process according to the present invention, are 
conventional thiocarbonyl compounds containing sufficiently reactive 
thiocarbonyl groups. Preferred such thiocarbonyl compounds are 
thioaldehydes and thioketones. Particularly preferred thioaldehydes and 
thioketones are those derived from the aldehydes and ketones which are 
mentioned above as being particularly preferred. 
It is also advantageous to use "masked thioaldehydes", i.e. compounds which 
release thioaldehydes under the reaction conditions. Reference is made in 
particular to trimeric thioformaldehyde (trithian) which decomposes into 
thioformaldehyde at elevated temperatures in the presence of acids. 
Carbonyl compounds which are in dissociation equilibrium with low molecular 
weight uncondensed N-alkylol compounds are, preferably, simple aldehydes, 
particularly formaldehyde, which is in equilibrium with the corresponding 
N-methylol compounds. Such N-methylol compounds include, in particular, 
N-methylol urea, N,N'-dimethylol urea, methylolated dicyanodiamide, 
methylolated oxamide, N-methylol thiourea, N,N'-dimethylol thiourea and 
methylolated melamines. Examples of methylolated melamines include 
hexamethylol melamine and tris-hydroxy methyl melamine corresponding to 
the following formula: 
##STR1## 
Reference is also made to monomethylol ethylene urea corresponding to the 
following formula: 
##STR2## 
to monomethylol ethylene thiourea corresponding to the following formula: 
##STR3## 
and to tetramethylol acetylene diurea corresponding to the following 
formula: 
##STR4## 
It is also possible to use alkylol compounds of the type derived from 
simple aldehydes, preferably those containing up to 5 carbon atoms. 
The following compounds are used with particular preference as carbonyl 
compounds for carrying out the process according to the present invention: 
formaldehyde, acetaldehyde, isobutryaldehyde, crotonaldehyde, glyoxal, 
furfurol, hydroxy methyl furfurol, salicylic aldehyde and semi-acetals 
thereof. Polymers of formaldehyde (such as paraformaldehyde and trioxane) 
hexamethylene tetramine and thioaldehydes (such as thioformaldehyde) may 
also be used. The uncondensed (low molecular weight) N-alkylol compounds 
preferred for use in the present invention are N-methylol urea, dimethylol 
urea, trimethylol melamine, hexamethylol melamine, monomethylol ethylene 
urea, monomethylol ethylene thiourea and tetramethylol acetylene diurea. 
As mentioned above, aminoplast formers may also be used in the process 
according to the present invention for modifying the biomasses. In the 
context of the present invention, aminoplast formers are understood to be 
nitrogen compounds which are capable of forming N-oligocondensation and 
N-polycondensation products with reactive carbonyl compounds. 
Aminoplast formers which correspond to this definition are nitrogen 
compounds. Examples include ureas (for example urea itself, acetylene 
urea, dimethyl acetylene urea and N-methylene urea), thioureas (such as 
unsubstituted thiourea), diureas (such as hexamethylene diurea, 
tetramethylene diurea and ethylene diurea), polyureas (such as the type 
obtained by reacting aliphatic, cycloaliphatic or araliphatic 
diisocyanates, triisocyanates or biuret-polyisocyanates with ammonia, 
primary amines, or polycarboxylic acid amines, such as oxalic acid 
diamide, succinic acid diamide and adipic acid diamide), monourethanes, 
diurethanes and higher polyurethanes (such as the reaction products of 
aliphatic, cycloaliphatic, araliphatic and aromatic mono- or 
bis-chloroformic acid esters with ammonia or primary amines), biurets, 
melamines (such as melamine itself), amidines (such as dicyanodiamidine), 
guanidines (such as aminoguanidine), guanazoles, guanamines, cyanamide, 
dicyanodiamide, primary monoamines, secondary monoamines, arylamines, 
ammonia, diamines, triamines, hydrazines and carboxylic acid hydrazines 
(such as hydroazodicarbon amide, carbazinic acid esters and 
hydrazodicarboxylic acid esters), also similar nitrogen compounds capable 
of aminoplast formation, preferably the derivatives containing N-alkylol 
groups, preferably N-methylol groups, corresponding to the above-mentioned 
nitrogen compounds and the corresponding C.sub.1 -C.sub.4 alkyl ethers of 
these N-alkylol derivatives may be used. 
Other preferred aminoplast formers are .alpha.,.omega.-diureas of 
relatively high molecular weight, N-methylol derivatives thereof and 
N-methylol alkyl ethers. .alpha.,.omega.-bis-alkoxy methyl urethanes 
containing polyether, polythioether, polyacetal, polyester amide or 
polycarbonate residues having an average molecular weight of from 400 to 
10,000 and, optionally, additional urethane or substituted urea groups 
between the functional groups in the .alpha.,.omega.-position are also 
preferred. In this respect, particularly preferred relatively high 
molecular weight nitrogen compounds capable of aminoplast formation are 
compounds which may be dissolved or dispersed in water. Examples include 
compounds which, between the functional urethane or urea groups in the 
.alpha.,.omega.-position, contain polyethylene oxide residues or residues 
of copolymers of ethylene oxide with propylene oxide or tetrahydrofuran or 
of water-soluble polyacetals produced from di-, tri- or tetraethylene 
glycol and formaldehyde. 
These aminoplast formers suitable for use as starting compounds are known 
or may be produced by methods known in principle (cf. Houben-Weyl 
"Methoden der Organischen Chemie", Vol. XIV, Part 2 (1963), pages 319-402, 
Georg Thieme-Verlag, Stuttgart). 
"Modified aminoplast formers" may also be used as aminoplast formers in the 
process according to the present invention. Modified aminoplast formers 
are aminoplast formers which contain additional groups readily capable of 
incorporation. Examples of modified aminoplast formers are compounds which 
may be rapidly and easily incorporated by mixed condensation. Such 
compounds are preferably polyurethanes and polyureas containing terminal 
NH.sub.2 groups, polyamides of poly-(.beta.-alanine) having molecular 
weights of up to 2000, N-methylol methyl ethers of polycaprolactam, 
polythiolactams, polypeptides of N-carboxy-.alpha.-aminocarboxylic acids, 
low molecular weight polyamides of aliphatic dicarboxylic acids and 
diamines, polyamides of cycloaliphatic components and aromatic components, 
polyamides containing O- and S- or N- as heteroatoms, and polyester 
amides. Mixed condensates which, in addition to amide groups, also contain 
ester, urethane or urea groups; ethoxylated and propoxylated monoamides 
and polyamides; polyhydrazides; polyaminotriazoles; polysulfonamides; 
formaldehyde mixed condensates with urea, melamine and dicyanodiamide; low 
molecular weight aniline formaldehyde condensates; sulfonic acid amides; 
mononitriles and dinitriles; acrylonitrile; urotropin; hexahydrotriazines 
of primary amines and formaldehyde; Schiff's bases and ketimines or 
polyketimines, for example those from 1 mole of hexamethylene diamine and 
2 moles of cyclohexanone; polyaddition products and polycondensation 
products of melamine and other aminoheterocycles with aldehydes and 
alcohols; polyaddition and polycondensation products of nitriles with 
aldehydes; reaction products of phosphorous acid and dialkyl phosphates 
with carbonyl compounds and amines or polyamines may also be used. In this 
connection, other suitable compounds capable of aminoplast formation are 
the compounds which are described on pages 7 to 12 of German 
Offenlegungsschrift No. 2,324,134. 
Other modified aminoplast formers which may be used in the process 
according to the present invention are N-alkylol compounds and, in 
particular, N-methylol compounds which are partly etherified with 
polyhydroxyl compounds. 
The proportion of alcohols or polyhydric-alcohols in these products may 
amount, depending on the component, to 60%, by weight, based on the sum of 
the percentages of nitrogen compounds and alcohols. 
The following compounds inter alia are particularly suitable for use as 
aminoplast formers in the process according to the present invention: 
urea, thiourea, diureas, such as hexamethylene diurea, tetramethylene 
diurea, ethylene urea, acetylene urea, dimethyl acetylene urea, oxalic 
acid diamide, succinic acid diamide, adipic acid diamide, mono- or 
bis-hydrazines (such as hydrazodicarbonamide, carbazinic acid methyl and 
ethyl esters), hydrazodicarboxylic acid esters, monourethanes and, in 
particular, diurethanes (such as the reaction products of aliphatic, 
cycloaliphatic, araliphatic and aromatic mono- or bis-chloroformic acid 
esters with ammonia and primary amines), aniline melamine, dicyanodiamide, 
cyanamide, aminoguanidine, dicyanodiamidine, guanamines, guanazoles, 
polyureas and polybiurets (particularly the type obtained by reacting 
aliphatic, cycloaliphatic, araliphatic diisocyanates or triisocyanates) 
and biuret polyisocyanates with an excess of ammonia or primary amines. 
Other aminoplast formers which may be used in the process according to the 
present invention are substantially defect-free azulmic acids, 
defect-containing so-called "modified azulmic acids", azulmic acids 
stabilized by condensation with carbonyl compounds, azulmic acids 
stabilized by condensation with carbonyl compounds and aminoplast formers 
or low molecular weight condensation products thereof and also metal salt 
complexes of the above-mentioned azulmic acids. These compounds are 
preferably used together with other aminoplast formers, particularly urea, 
in the process according to the present invention. 
These various azulmic acids are known and are described in detail in 
Houben-Weyl, Methoden der Organ. Chemie (1952), Vol. 8, page 261; in 
Angewandte Chemie 72, (1960), pages 379-384; in German Pat. Nos. 662,338 
and 949,600 and in German Offenlegungsschriften Nos. 2,806,019 and 
2,806,020 and U.S. patent application Ser. Nos. 11,554; 84,002; and 82,839 
and U.S. Pat. No. 4,252,919. 
Phenoplast formers suitable for use in the process according to the present 
invention are the known phenols and derivatives thereof, such as phenol, 
cresol, bisphenol A, nitrophenol, pyrocatechol, hydroquinone and naphthol 
sulfonic acid. Other aminoplast and phenoplast monomers suitable for use 
as modifying agents are described in German Offenlegungsschriften Nos. 
2,324,134; 2,713,198 and 2,738,532. 
In addition, biomasses which have been denatured by the process according 
to 
U.S. Patent Application Ser. No. 84,002 now abandoned, may also be used in 
the process according to the present invention. Such biomasses are 
obtained by condensing them in aqueous medium with carbonyl compounds, 
thiocarbonyl compounds and/or carbonyl compounds which are in dissociation 
equilibrium with low molecular weight, uncondensed N-alkylol compounds, 
optionally in the presence of a catalyst and optionally in the presence of 
additives, in a first reaction phase, optionally with hydrolytic 
degradation or denaturing of the cell walls present in the biomasses. The 
unreacted carbonyl compounds, thiocarbonyl compounds and/or carbonyl 
compounds which are in equilibrium are reacted with low molecular weight, 
uncondensed N-alkylol compounds with aminoplast formers optionally 
containing N-alkylol groups or with phenoplast formers in a second 
reaction phase carried out in aqueous medium optionally in the presence of 
a catalyst, optionally in the presence of chain-terminators and optionally 
in the presence of additives. The thus-obtained modified biomasses may 
optionally be freed from undesirable substances still present and/or 
subjected to an after-treatment. 
The polyaddition products of denatured biomasses, isocyanates and, 
optionally, aminoplast or phenoplast formers produced in accordance with 
the present invention may be after-treated by treating them with a variety 
of reagents at temperatures of from 0.degree. to 200.degree. C., 
preferably from 10.degree. to 140.degree. C. and, with particular 
preference, from 30.degree. to 120.degree. C., optionally in the presence 
of diluents, such as anhydrous organic solvents. In this way, chemical 
reactions take place essentially on the surface of the products so that 
chemically surface-modified products are obtained. 
This chemical surface modification of the polyaddition products obtainable 
by the process according to the present invention is preferably obtained 
by treatment with urea melts; treatment with acylating agents, such as 
formic acid, acetic acid anhydride or mixed acid anhydrides of acetic acid 
and oleic acid (preferably in the presence of sodium or potassium 
acetate); cyclic acid anhydrides, such as maleic acid anhydride, phthalic 
acid anhydride or hexahydrophthalic acid anhydride; melts of dicarboxylic 
acids, such as adipic acid, phthalic acid, hexahydrophthalic acid or 
trimellitic acid; inorganic acid chlorides, such as cyanogen chloride, 
phosgene, thionyl chloride, sulfur chlorides, phosphorus oxychloride, 
phosphorous pentachloride, silicon tetrachloride, antimony trichloride or 
titanium tetrachloride; inorganic acid chlorides, such as acetyl chloride, 
benzoyl chloride, chloroformic acid esters, benzene sulfonic acid 
chlorides, phosphoric acid ester chlorides, chloromethane sulfochloride or 
cyanuric acid chloride; treatment with alkylating agents, such as dimethyl 
sulfate, methyl iodide or methyl bromide, dichloroethane, glycol 
chlorohydrin, chloroacetic acid ethyl ester, dichloroacetic acid ethyl 
ester, chloroacetaldehyde diethyl acetal, allyl chloride, benzyl chloride, 
trichloromethyl isocyanide dichloride or other isocyanide dichlorides; 
treatment with .epsilon.-caprolactam, .epsilon.-caprolactone, hydroxy 
pivalic acid lactone, cyclic 6-membered or 8-membered siloxanes, 
azalactams of the type known from German Offenlegungsschrift No. 
2,035,800, glycol carbonate, ethylene oxide, propylene oxide, butylene 
oxide, styrene oxide, epichlorohydrin, butyrolactone, valerolactone, 
oxazolidines, oxazolines, imidazolidines, isatoic acid anhydride or 
Leuch's anhydrides of aminoacids and phosgene; treatment with 
acrylonitrile or other vinyl monomers, such as acrylic acid, methacrylic 
acid or methyl, ethyl, .beta.-hydroxy ethyl or propyl esters thereof; 
treatment with hydroxy alkane phosphonic acid esters or the parent acids, 
particularly with hydroxy methyl phosphonic acid esters or with the free 
hydroxy methyl phosphonic acid; treatment with chloromethyl alkoxy 
silanes; treatment with a variety of mononitriles or polynitriles, 
preferably hydroxy methyl nitrile, under the conditions of Thorpe's 
reaction catalyzed by hydroxy anions; treatment with polyisocyanates of 
the above-mentioned type in the presence of isocyanate-reactive compounds 
known from polyurethane chemistry (particularly polyols having a molecular 
weight of from 62 to 500). In this way, the denatured biomass may be 
surrounded by a polyurethane shell without the material losing its 
powder-form consistency. A similar effect is obtained by after-treating 
the above-mentioned denatured biomass still containing free NCO-groups 
with polyols or by subjecting them to carbodiimide formation. 
Other suitable after-treatment reagents include sodium hydroxide, potassium 
hydroxide, calcium hydroxide, sodium sulfide, rongalite ammonium 
polysulfides, diethyl phosphite and dimethyl phosphite. 
During these after-treatment reactions, it is also possible to carry out a 
variety of copolymerization or polymerization reactions involving vinyl 
monomers. In this case, the biomass mixed condensates are surrounded or 
microencapsulated by the polymers formed. The "shell materials" may, of 
course, also be used in a large excess. 
In the same way as the polyurethane-coated products mentioned above, 
biomasses modified in this way may be directly molded under heat (i.e. 
without the addition of further binders) to form shaped articles. 
In certain cases, the modification reactions on the biomasses discussed 
above under the generic heading of "after-treatment" may even be carried 
out before or at the same time as the polyaddition reaction according to 
the present invention. It is also possible, after the polyaddition 
reaction, to produce from the products, polymethylene ureas, 
polyalkylidene ureas and other substantially insoluble or completely 
insoluble compounds, for example highly cross-linked aminoplast 
condensates which, on account of their insolubility, show virtually no 
covalent bonds to the biomass. Such mixtures, in which the quantity of the 
non-covalently bound fraction of aminoplast condensates or phenoplast 
condensates may be varied as required, represent extremely interesting 
flameproofing agents for a variety of plastics, particularly where they 
are charged with polymethylene thioureas, cross-linked polymethylene 
melamine powders, urea hydrazodicarbonamide formaldehyde-condensates and 
dicyanodiamide or oxamide condensates. 
It is also advantageous to subsequently charge the products with 
substantially insoluble melamine phosphate, substantially insoluble urea 
oxalate, urea nitrate or substantially insoluble ammonium magnesium 
phosphate. The addition of alumina hydrates, aluminum oxides, 
alumosilicates, calcium carbonate, quartz powder and the addition of 
linear or cross-linked polymethylene ureas, powdered melamine formaldehyde 
condensates, urea hydrazodicarbonamide condensates and high molecular 
weight polyammonium polyphosphates are also of importance. The products 
obtained in this case are eminently suitable for use as flameproofing 
agents for plastics. 
In addition, other additives which may advantageously be used in the 
process according to the present invention, particularly in cases where 
azulmic acids are used, are sugars, such as cane sugar and other sugars 
which do not contain free aldehyde groups or even formose-sugar mixtures 
produced from formaldehyde. These various types of sugars may be fixed in 
passages and pores of the azulmic acid. In addition, the various sugars 
may even be attached to the mixed condensates in the form of the generally 
substantially insoluble calcium complexes thereof. 
In addition, it is always possible when the polyadducts according to the 
present invention contain azulmic acids to simultaneously gas the products 
with ammonia and carbon dioxide after production. In this case, the small 
molecules of ammonia and carbon dioxide penetrate into the azulmic acid 
skeleton to a considerable extent. 
In addition to the reactive aminoplast, phenoplast and vinyl monomers and 
other reactive low molecular weight compounds which have been described in 
detail, it is possible to add to the biomasses in the process according to 
the present invention a variety of different fillers and additives. 
Examples include organic naturally occurring substances and products 
obtained therefrom, inorganic naturally occurring substances and products 
obtained therefrom, synthetic organic products, synthetic inorganic 
products and/or mixed organic/inorganic products. 
Preferred organic natural substances and products obtained therefrom are 
wood powder or chips, lignin powder, lignin sulfonic acids, ammoniated 
lignin sulfonic acids, humus, huminic acids, ammoniated huminic acids, 
peat, proteins and the degradation products thereof. Other examples 
include polypeptides, wool, gelatin, fish meal, bone meal, pectins, 
polysaccharides (such as starch and cellulose), hemicelluloses, 
homogenized materials of vegetable and animal origin, active carbon and 
ashes obtained by the incineration of organic substances formed by 
photosynthesis or conventional fuels. 
Preferred inorganic natural substances and products obtained therefrom are 
silicates (such as aluminum silicates, calcium silicates, magnesium 
silicates and alkali silicates), silicas (particularly disperse silicas 
and silica gels), clay minerals, mica, carbonates (such as calcium 
carbonate), phosphorite and phosphates (such as calcium phosphate and 
ammonium magnesium phosphate), and sulfates (such as calcium sulfate). 
In addition to natural or synthetic rubbers, polyamides and epoxide resins, 
preferred synthetic organic products are the aminoplast and phenoplast 
resins described in detail above. 
Other particularly suitable additives are powder-form TDI residue slags of 
the type described above, the NCO groups of which have been quantitatively 
removed by reaction with water or other H-acid compounds (TDI distillation 
residues modified in this way are also described in the above-mentioned 
German Offenlegungsschriften 2,846,809 and 2,846,815 and U.S. Pat. Nos. 
4,251,638 and 4,297,456). Even if they are free from NCO groups, such 
powders still contain numerous reactive groups (for example urea, 
urethane, carbodiimide and/or uretdione groups) which may participate in 
the polyaddition and polycondensation reactions taking place in the 
process according to the present invention. 
Preferred synthetic inorganic products are fertilizers (such as super 
phosphate, Thomas slag, rhenania phosphate, phosphorite, calcium 
cyanamide, calcium ammonium nitrate, Leuna saltpeter, potassium 
phosphates, potassium nitrate and ammonium nitrate), pigments (such as 
iron oxides and titanium dioxides), and in particular the inorganic 
primary sludges from biological purification plants. 
The polyaddition products of denatured biomasses, isocyanates and, 
optionally, additives produced in accordance with the present invention 
are eminently suitable for use as agrochemicals, particularly when they do 
not contain free NCO groups. Agrochemicals are chemicals which may be used 
for a variety of purposes in agriculture and gardening. 
Thus, the substances produced in accordance with the present invention may 
be used, for example, as fertilizers both for supplying plants with 
macronutrients and also for supplying plants with micronutrients. They are 
particularly suitable for use as long-term nitrogen fertilizers. Of 
particular interest in this respect are those substances usable in 
accordance with the present invention which contain ions required by 
plants, such as ammonium ions, lithium, sodium, potassium, beryllium, 
magnesium, calcium, strontium, barium, aluminum, zinc, manganese, nickel, 
cobalt and iron ions. 
Those substances usable in accordance with the present invention which 
contain anions, such as chloride, nitrate, sulfate and/or phosphate, are 
also of particular interest as fertilizers. 
Those substances according to the present invention which contain several 
of the above-mentioned types of ions alongside one another are 
particularly preferred as fertilizers. Such substances, are for example, 
substances which contain both potassium and/or ammonium ions and also 
nitrate and/or phosphate ions. 
In addition, those substances according to the present invention which, 
optionally in addition to nutrient ions, contain the organic additives 
described in detail above are of particular interest as fertilizers. 
The substances of the present invention, optionally in addition to 
containing nutrient ions, may be used in combination with commercial 
fertilizers may be used as fertilizers. Particularly suitable commercial 
fertilizers are super phosphate, Thomas slag, rhenania phosphate, 
phosphorite, calcium cyanamide, calcium ammonium nitrate, Leuna saltpeter, 
potassium phosphates, potassium nitrate and ammonium nitrate, urea 
formaldehyde condensates, urea crotonaldehyde condensates, urea 
isobutyraldehyde condensates and condensates of dicyanodiamide, melamine 
or octamide with aldehydes (such as formaldehyde, acetaldehyde, 
crotonaldehyde or isobutyraldehyde) are also suitable. 
Those substances according to the present invention which, optionally in 
addition to nutrients, also contain biologically active garden soil may 
also be used as fertilizers. 
In cases where compounds according to the present invention produced from 
biomasses containing heavy metal salts are used as fertilizers, it is 
necessary to add azulmic acids, thiourea or other compounds having a 
strong complexing action as aminoplast formers during the production of 
these products. In this way, heavy metal ions present in the biomasses 
(for example, ions of lead, copper, mercury, cadmium or zinc) are bound so 
firmly that no plant damage occurs. 
Particularly preferred fertilizers are products based on biomasses free 
from heavy metals of the type which accumulate, for example, in 
fermentation processes in the pharmaceutical, enzyme, food and luxury food 
industries. Also biomasses free form heavy metals emanating from 
biological or fully biological purification plants for industrial and 
communal effluents are particularly preferred. 
Biomass mixed condensates according to the present invention which, by the 
use of isobutyraldehyde, also contain segments corresponding to the 
following structure: 
##STR5## 
as linking elements within the fused or added polymethylene urea groups 
may also advantageously be used as fertilizers. The site indicated by the 
arrow is considerably more prone to hydrolysis than methylene-linked urea 
segments. The substances in question may be very effectively used as 
fertilizers from which nitrogen is released quickly and uniformly over 
long periods. 
Those substances according to the present invention which have been 
produced using various azulmic acids may also be used with advantage as 
fertilizers. By virtue of the manifold chemical reactivity and absorbency 
of the azulmic acids, such products are distinguished by particularly high 
structural variability. For example, relatively large quantities of acids, 
preferably phosphoric acid and nitric acid, may be bound. Acids present in 
excess may be neutralized, for example by gassing with ammonia. Such 
products are capable of supplying plants both with organically bound and 
also with inorganically bound nitrogen. 
Products which still contain aldehydes, for example formaldehyde, after 
production are best treated with amines or ammonia before they are used as 
nitrogen fertilizers. Formaldehyde treated with ammonia, for example, is 
converted into hexamethylene tetramine which is a very effective nitrogen 
fertilizer. 
In cases where azulmic acids (crude azulmic acids, modified azulmic acids 
and/or stabilized azulmic acids) are used in the production of the 
biomasses modified in accordance with the present invention, normally 
highly water-soluble cell ingredients of the biomasses (such as 
polysaccharides), water-dispersible or soluble glycolipids, lipoproteins, 
degraded proteins, nucleic bases, degraded, but uncondensed nucleic acids, 
may be completely adsorbed onto azulmic acids so that these substances 
(which are valuable humidifiers and plant nutrients) do not enter the 
effluent, but instead are available to the plants as nitrogen fertilizers. 
Those isocyanate-free products which have been produced from biomasses free 
from heavy metal salts and rich in proteins and, optionally, 
physiologically compatible additives may be used as animal feed 
supplements. 
In addition, the modified heavy metal-free biomasses produced in accordance 
with the present invention are suitable for use as soil improving agents. 
To this end, it is preferred to use those products, according to the 
present invention, which contain wood powder or powdered vegetable 
material. Those modified biomasses usable in accordance with the present 
invention which have been produced using azulmic acids may also be used 
with advantage as soil-improving agents. 
Those modified biomasses usable in accordance with the present invention 
which contain fault-rich azulmic acids in bound form have a certain 
polyelectrolyte character and may act as ion-exchanging nitrogen 
fertilizers in the soil. In this case, the ions required by the plants, 
for example, potassium and/or ammonia ions, are given off to the soil or 
to the substrate, while other ions are bound. 
By virtue of the high absorbency and high complex-forming capacity thereof, 
modified biomasses usable in accordance with the present invention which 
contain azulmic acids or other compounds capable of complex formation may 
also be used for fixing harmful substances in soil. For example, it is 
possible to bind undesirable heavy metal ions present in soil, such as 
lead and mercury ions, by means of the substances containing azulmic acid 
usable in accordance with the present invention so firmly that there is no 
longer danger of plant damage. In addition, oil impurities, overdosages of 
plant protection agents or excessive salt concentrations in substances may 
be eliminated by adding such substances suitable for use in accordance 
with the present invention. 
Substances usable in accordance with the present invention which, in 
addition to other plant nutrients, also contain peat may readily be used 
for the production of molded peat pots for gardening purposes by the 
addition of binders, such as starch, degraded celluloses, alginates and 
pectins. In this case, it is best for the ratio, by volume, of white peat 
to black peat in the substrate be about 1:1. 
Modified biomasses usable in accordance with the present invention which, 
in addition to nitrogen and other plant nutrients contain from about 20 to 
40%, by weight, of peat are also especially suitable for covering soil and 
substrates and also rows of seeds because the dark color of the substrates 
according to the present invention guarantees a good earth-like 
appearance, prevents soil encrustation and promotes quicker germination of 
the seeds. 
Peat-containing substances usable in accordance with the present invention 
are also suitable for preventing or reducing the release of odors during 
decomposition processes. 
Substances useable in accordance with the present invention which, in 
addition to other plant nutrients, also contain peat may be converted by 
the addition of starch adhesives, hemi-celluloses or alginates into 
shaped, air-permeable and moisture-retaining materials which are suitable 
for use as packaging material for transporting plants. 
The substances usable in accordance with the present invention may be used 
either as such or in formulations for supplying plants with nitrogen and, 
optionally, other nutrients and also as soil-improving agents. 
In this respect, the substances usable in accordance with the present 
invention may be converted into the conventional formulations, such as 
emulsions, spraying powders, suspensions, powders, dusting agents, foams, 
pastes, granulates, suspension-emulsion concentrates, seed powders, 
natural and synthetic substances impregnated with active principles or 
microencapsulations in polymeric substances and in coating compositions 
for seeds. 
These formulations are produced in known manner, for example by mixing the 
active ingredients with diluents (i.e., liquid solvents), and/or solid 
carrier substances, optionally using surface-active agents (i.e., 
emulsifiers, and/or dispersants and/or foam-forming agents). Where water 
is used as the diluent, it is also possible, for example, to use organic 
solvents as auxiliary solvents. Suitable liquid solvents are, in general, 
aromatic hydrocarbons (such as xylene, toluene, or alkyl naphthalenes), 
chlorinated aromatic or aliphatic hydrocarbons (such as chlorobenzenes, 
chloroethylenes or methylene chloride), aliphatic hydrocarbons (such as 
cyclohexane or paraffins, for example petroleum fractions), alcohols (such 
as butanol or glycol), and ethers and esters thereof, ketones (such as 
acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone), 
strongly polar solvents (such as dimethyl formamide, dimethyl sulfoxide, 
and water). Suitable solid carrier materials are natural powdered minerals 
(such as kaolins, aluminas, talcum, chalk, quartz, attapulgite, 
montmorillonite or diatomaceous earths), and synthetic powdered minerals 
(such as highly disperse silica, aluminum oxide and silicates). Suitable 
solid carrier materials for granulates are broken and fractionated natural 
minerals (such as calcite, marble, pumice, sepiolite, dolomite and 
synthetic granulates of inorganic and organic powders) and granulates of 
organic material (such as sawdust, coconut shells, corn cobs and tobacco 
stalks). Suitable emulsifiers and/or foam-forming agents are non-ionic and 
anionic emulsifiers, such as polyoxyethylene fatty acid esters, 
polyoxyethylene fatty alcohol ethers (for example, alkyl aryl polyglycol 
ether), alkyl sulfonates, alkyl sulfates, aryl sulfonates and protein 
hydrolysates. Suitable dispersants are, for example, lignin sulfite waste 
liquors and methyl cellulose. 
Adhesives, such as carboxymethyl cellulose, natural and synthetic polymer 
powders, granulates or latices, such as gum arabic, polyvinyl alcohol and 
polyvinyl acetate, may also be used. 
Dyes (such as inorganic pigments, for example, iron oxide, titanium oxide 
and Prussian blue), and organic dyes (such as alizarin dyes and azometal 
phthalocyanine dyes), and trace nutrients (such as salts of iron, 
manganese, boron, copper, cobalt, molybdenum and zinc), may also be used. 
The formulations generally contain from 0.1 to 95%, by weight, preferably 
from 0.5 to 90%, by weight, of active ingredient. 
The substances according to the present invention may be present in the 
formulations in admixture with other fertilizers or pesticides. 
They may be applied by the methods normally used in agriculture and 
horticulture, i.e., for example by direct introduction into soil, by 
pouring, spraying, scattering, dusting, etc. Specialized forms of 
application include root application, leaf application, stalk injection 
and bark application. In the case of root application, the fertilizer may 
either be mixed with the substrate used for cultivation or may be 
introduced into furrows in the ground. In addition, the fertilizer may be 
introduced into the deeper root zones by means of a so-called "fertilizer 
lance" and also through punched or drilled holes. 
The quantity in which the substances according to the present invention are 
used may be varied within relatively wide limits. Where the substances 
according to the present invention are used as a fertilizer or 
soil-improving agent, the quantity in which they are used is essentially 
determined by the type of soil and also by the nutrient demand of the 
particular plants. In general, the active ingredient is used in quantities 
of from 0.1 to 200 kg/ha, preferably from 1 to 100 kg/ha. Where the 
substances according to the present invention are used for other purposes, 
for example, for covering substrates, for the production of packaging 
materials for plants, for protecting plants or parts of plants, for the 
production of molded peat pots or for binding undesirable odoriferous 
substances, the quantity in which the active ingredient is used is adapted 
to the particular demand. 
The dried and powdered polyaddition products of denatured biomasses, 
isocyanates and, optionally, additives produced in accordance with the 
present invention are especially suitable for use as a reactive filler for 
a variety of polyaddition, polycondensation and/or polymerization 
reactions, particularly where they contain free isocyanate groups, for 
which they may be used in a quantity of from 2 to 95%, by weight, 
preferably from 10 to 70%, by weight, and, in particular, from 15 to 40%, 
by weight, based on the total quantity of modified plastic. (The use as a 
filler for polyurethane plastics is covered by a co-pending Application 
filed by the present Applicants and does not form part of the present 
invention). 
As mentioned above, certain coated denatured biomass powders may be used 
directly (i.e. without additional binder) as heat-formable molding 
compositions. 
The powders obtained in accordance with the present invention are 
preferably incorporated as filler in aminoplast and phenoplast resins. In 
this case they are advantageously present during the actual production of 
these resins in known manner from carbonyl compounds (particularly 
formaldehyde) and aminoplast or phenoplast monomers (preferably urea, 
melamine and/or phenol) and are chemically incorporated into the polymer 
during its formation through the numerous reactive groups thereof. 
Carbonyl compounds and aminoplast or phenoplast monomers suitable for this 
purpose are described, for example, in German Offenlegungsschriften Nos. 
2,324,134; 2,639,254 and 2,713,198. 
The biomasses worked-up in accordance with the present invention may also 
be used as a reactive component in the production of epoxide resins. 
Isocyanate groups present in the modified biomass may react both with the 
hydroxyl groups (present in epoxide resins) and also, at elevated 
temperatures, preferably above 160.degree. C., with the epoxide groups to 
form oxazolidone rings. 
The powdered modified biomasses are preferably mixed homogeneously with 
liquid diepoxides at room temperature or elevated temperature and reacted 
under known process conditions, optionally in the presence of a hardener 
(for example, an amino compound, dicarboxylic acid or dicarboxylic acid 
anhydride). In numerous cases (particularly at hardening temperatures 
above 100.degree. C., as mentioned above), the polyfunctional biomasses 
may partly react both with the epoxide resin and also with the hardener 
during the epoxide polyaddition reaction so that the reactive filler is 
incorporated into the hardened cast resin by main valency bonds. 
The biomasses added in total quantities of up to about 50%, by weight, 
based on the end product, reduce in particular the inflammability of the 
resins produced from epoxides and, in addition, restrict shrinkage. In the 
case of large castings, the increase in temperature which occurs 
internally during hardening is lower than that which occurs in the case of 
unfilled castings. 
However, the biomasses worked-up in accordance with the present invention 
may also be used as a reactive filler in the production of cyanate resins, 
for example from the starting compounds described in German 
Offenlegungsschrift No. 2,260,487. 
Biomasses into which optionally copolymerizable, unsaturated groups have 
been introduced may also be used with advantage in the production of 
plastics in known manner by the polymerization or copolymerization of 
monomers containing olefinically unsaturated groups. Examples of such 
monomers are acrylonitrile, styrene, butadiene, acrylic acid, methacrylic 
acid, vinyl chloride, vinyl acetate and unsaturated polyesters. The 
polymerization reactions are preferably carried out in a liquid medium, 
for example in water or an organic solvent, in the presence of the very 
finely divided biomasses. 
The modified biomasses optionally containing free NCO groups produced in 
accordance with the present invention may readily be coated by 
polymerization reactions in which monomeric or oligomeric vinyl compounds 
are (co)polymerized in the presence of the finely ground biomasses, 
optionally in a solvent which is inert to isocyanate groups. 
The biomasses worked-up in accordance with the present invention are also 
particularly important as binders or as fillers in the production of 
boards or moldings in hot presses by binding lignocellulose-containing 
fibers, chips or layers. In this case, additional binders are preferably 
the condensation products of formaldehyde with urea, melamine or phenol 
known for this purpose, particularly in the form of aqueous solutions or 
dispersions thereof. It is known from German Offenlegungsschrift No. 
1,669,759 and from German Auslegeschrift No. 1,653,169 that 
polyisocyanates may also be used instead of or in addition to such binders 
in the production of molded materials based on vegetable 
lignocellulose-containing starting materials. 
It has now been found that the biomasses modified in accordance with the 
present invention are eminently suitable for this purpose (above all where 
they contain free NCO groups or where additional isocyanates are used). In 
this case, they are used in a quantity of from 2 to 90%, by weight, 
preferably from 10 to 60%, by weight, based on the total weight of the 
molding. 
Suitable lignocellulose-containing starting materials which may be bound in 
this way are, for example, wood, bark, cork, bagasse, straw, flax, bamboo, 
alfa grass, rice husks, sisal and coconut fibers. The material may be in 
the form of granulates, chips, fibers or powder and may have a water 
content of from 0 to 35%, by weight, preferably from 5 to 25%, by weight. 
From 1 to 50%, by weight, preferably from 5 to 20%, by weight, of a 
polyisocyanate and/or a formaldehyde resin (expressed as solids, based on 
the total weight of the molding) and the above-mentioned quantity of 
modified biomass are added to it, followed by pressing (generally under 
the effect of heat and pressure) to form panels or moldings. 
Laminated panels or moldings may also be produced in the same way from 
veneers, papers or fabrics. Laminated boards or moldings may also be 
produced in this way from veneers and strip-form, bar-form or rod-form 
center layers (so-called "cabinet making boards") by treating the veneers 
as described above with the modified biomass and, optionally, the 
conventional binder and subsequently pressing them with the center layers, 
generally at elevated temperature and pressure. In this connection, it is 
preferred to apply temperatures from 100.degree. to 250.degree. C. and, in 
particular, from 130.degree. to 200.degree. C. The initial pressure 
applied is preferably from 5 to 150 bars. The pressure subsequently falls, 
generally towards zero, in the course of the pressing operation. It is, of 
course, also possible to use known organic or inorganic fungicides, 
insecticides or flameproofing agents in quantities of from about 0.05 to 
30%, by weight, preferably from 0.5 to 20%, by weight. 
Accordingly, the present invention also relates to a process for the 
production of panels or moldings by the hot pressing of 
lignocellulose-containing starting materials which is characterized in 
that from 2 to 90%, by weight, based on the total weight of the molding, 
of the biomasses modified in accordance with the present invention and, 
optionally, conventional formaldehyde resins are used as binder. 
The biomasses worked-up in accordance with the present invention may also 
be generally added as reactive filler to lacquers and coatings of various 
types (in quantities of from about 2 to 70%, by weight, preferably from 5 
to 40%, by weight, based on the total solids content). Examples of such 
lacquers and coatings are roof or floor coverings, gap-filling and 
surfacing compounds, optionally using bitumen or tar compositions. Another 
potential application is in the modification of thermoplastic plastics. In 
this case, the biomasses are mixed with the thermoplast in a quantity of 
from 3 to 200%, by weight, preferably from 10 to 100%, by weight, based on 
thermoplast, using known techniques (for example co-extrusion) and the 
resulting mixture optionally subjected to thermoplastic forming, for 
example by injection molding or press-molding. 
Materials of this type may be used, for example, in the production of 
structural components or furniture.

The present invention is illustrated by the following Examples in which the 
quantities quoted represent parts and percentages by weight, unless 
otherwise indicated. 
A from 7 to 12% aqueous surplus activated sludge ("BS"), which had been 
formed by the multiplication of microorganisms, particularly bacteria, 
fungi, and protozoae, from industrial and communal effluents in a fully 
biological purification plant and obtained by centrifuging a clarified 
sludge originally containing approximately 1%, by weight, of organic 
matter, was used as the biomass in Examples 1 to 15 below. The surplus 
activated sludge parts used had a gel-like character, could not be 
filtered and, even in the fresh, biologically still active state, gave off 
an unbearable odor. On standing, the untreated biomass putrefied in a few 
days, giving off gases. The dry mass had a nitrogen content of from 7.8 to 
8.5%, by weight, and an ignition loss of from 81 to 87%, by weight. 
In practice, these surplus aqueous purified sludges are mixed with 
inorganic primary sludges in from the same to twice the quantity, based on 
solids, in the purification plant in order to make them filterable, 
filtered in filter presses to form an approximately 50% filter cake and 
transported to dumps. 
Examples 1 to 12 below illustrate the working-up of the biomasses by 
isocyanate polyaddition in aqueous or organo-aqueous, disperse phase. 
Formulations and test results are shown in Table 1. 
TABLE 1 
______________________________________ 
Dry Mass 
Iso- Nit- 
Ex- Biomass cyan- Sol- %, by tro- 
am- Conc. Type pH ate vent weight 
gen Odor 
ple 1 2 3 4 5 6 7 8 
______________________________________ 
1 12.1 BSD 1.4 10 Bz 
5 Ac 25 7.5 slight 
2 12.1 BSD 1.9 10 T1 
5 Ac 26 7.4 slight 
3 12.1 BSD 6.5 10 H 30 Ac 41 11.2 very 
slight 
4 12.1 BSD 2.8 10 30 Ac 42 8.3 very 
D44 slight 
5 6.7 BSA 2.5 50 5 Ac 37 8.7 very 
D44 slight 
V20 
6 6.7 BSA 3.5 100 30 To 49 12.2 none 
T80 
7 11.4 BSA 6.8 100 5 Ac 35 12.5 none 
T80-R1 
8 12.1 BSD 1.7 100 20 Ac 51 12.6 very 
T80-R2 slight 
9 11.4 BSA 6.8 100 10 To 45 12.7 none 
T80-R2 
10 11.4 BSA 3.0 200 5 Ac 48 14.2 none 
T80-R2 
11 12.1 BSD 1.7 100 10 To 39 12.8 none 
T80-R3 
______________________________________ 
Explanation of Table 1: 
Column 1: 
Concentration of the aqueous surplus 
activated sludge (BS) used in percent, 
by weight. 
Column 2: 
Type of surplus activated sludge used: 
BSA = biologically fully activated, i.e. 
centrifuged BS run off fresh from 
the settling tank in the form of a 
1% sediment. Viscosity at 25.degree. C.: 
580 cP. 
BSD = biologically deactivated BS. The 
BS was denatured by refluxing for 
2 hours with 2.5%, by weight, of a 
38% aqueous formaldehyde solution 
at pH from 6.5 to 7, the biomass 
being partially hydrolyzed. 
BSA and BSD are unfilterable starting 
materials. 
Column 3: 
pH = pH value during the isocyanate 
polyaddition reaction; the end 
products are each adjusted to pH 
from 6 to 7. 
Column 4: 
Parts, by weight, of isocyanate, based on 
100 parts of BSA or BSD-solids. 
Bz = benzyl isocyanate 
T1 = 4-tolyl isocyanate 
H = 1,6-hexamethylene diisocyanate 
D44 = 4,4'-diphenyl methane diisocyanate 
(pure) 
D44 V20 = 
Technical crude phosgenation 
products of an aniline/ 
formaldehyde condensate; NCO-- 
content: 29%. 
T80 = 2,4-/2,6-tolylene diisocyanate; 
monomer mixture in a ratio of 80:20. 
The isocyanates T80-R1, R2 and R3 are 
granulated isocyanate residue slags from the commercial 
production of 2,4-/2,6-tolylene diisocyanate (isomer 
ratio: 80:20) which were obtained in accordance with 
German Offenlegungsschrift 2,846,815 or U.S. Pat. 
Application Serial No. 88,800,4,297,456 by denaturing the NCO-- 
containing, from about 150 to 200.degree. C., viscous tar-like 
sump phase (distillation residue) with from about 4 to 
5 times the quantity of water and which, depending on 
the drying temperature (from 40 to 70.degree. C.), have the 
indicated residual isocyanate content which was deter- 
mined in acetone at 50.degree. C. 
T80-R1 NCO--content: 
14.2%; particle size 20- 250 .mu.m 
T80-R2 NCO--content: 
9.9%; particle size 30-500 .mu.m 
T80-R3 NCO--content: 
5.0%; particle size 100-800 .mu.m 
Column 5: 
Parts, by weight, of solvent, based on 
100 parts of the aqueous surplus 
activated sludge used. 
Ac = Acetone; Tol = toluene. 
Colunm 6: 
Percent, by weight, of dry mass in the 
filter cake after removal of the water 
and solvent by filtration under suction. 
Column 7: 
Nitrogen content of the dry mass in 
percent, by weight. 
Column 8: 
Odor qualification of the product produced 
in accordance with the present invention. 
______________________________________ 
COMISON TESTS 
When the activated sludges mentioned in Column 2 were exposed to the 
process and reaction conditions according to the present invention, as 
described in the following, but without the addition of the 
monoisocyanates, diisocyanates or higher polyisocyanates mentioned, the 
unbearable odor persisted in the case of BSD and, in the case of BSA, was 
considerably intensified on storage with vigorous evolution of gas (inter 
alia elimination of hydrogen sulfide), so that spreading as a plant 
nutrient, for example, was impossible. Process and reaction conditions for 
Examples 1 to 11 and the Comparison Tests without isocyanate polyaddition: 
The surplus activated sludge was introduced at room temperature into a 
vessel of VA steel equipped with a reflux condenser, after which the 
quantity of monoisocyanate or polyisocyanate indicated in Table 1 was 
stirred in. The solvent was either combined with the isocyanate before the 
addition (Examples 1 to 4) or separately introduced (Examples 5 to 11). 
The contents of the vessel were heated under reflux to boiling point and 
maintained at boiling temperature for from 1 to 3 hours. Where an acid pH 
value is indicated in Table 1, it was adjusted with sulfuric acid, 
generally before the isocyanate was added. When no more free isocyanate 
could be detected, the contents of the vessel were neutralized with sodium 
triphosphate or alkali metal hydroxide and, after cooling, were compressed 
in a conventional pressure filter or filter press. To reduce the water 
content, the moist filter cake was dried in a recirculating air heating 
cabinet (Examples 1 to 8, 9 and 11) or by spreading out in air (Examples 7 
and 10) until the required water content was reached. Where the product is 
to be used as an odorless long-term fertilizer for horticultural and 
agricultural purposes, it is preferably dried to a water content of from 
about 10 to 40%, by weight, and reduced to a grain size of from 1 to 4 mm. 
EXAMPLE 12 
2000 parts of a 12.1%, deactivated aqueous sludge, 10 parts of an 
emulsifier of 1 mole of oleyl alcohol and 400 moles of ethylene oxide and 
242 parts of the powdered tolylene diisocyanate residue tar T80-R2 were 
thoroughly mixed and the resulting mixture heated for 1 hour to 
145.degree. C. in a pressure vessel. After cooling, the mixture was 
filtered under suction. The moist filter cake had a solids content of 38%. 
The odorless dry mass had a nitrogen content of 12.7%. 
Examples 13 to 15 below describe the production of biomass 
polyaddition-polycondensation products in accordance with the present 
invention simultaneous isocyanate polyaddition and aminoplast condensation 
reactions in aqueous-organic phase. 
EXAMPLE 13 
Formulation: 
880 parts, by weight, of an 11.4%, aqueous biologically fully active 
purified sludge adjusted to pH 2.1 using sulfuric acid, 
100 parts, by weight, of powdered tolylene diisocyanate residue slag T80-R2 
having an NCO content of 9.9%; 
40 parts, by weight, of a 30% aqueous formaldehyde solution, 
30 parts, by weight, of urea and 
100 parts, by weight, of toluene. 
Reaction conditions: 
The above-mentioned components were combined at room temperature in a 
stirrer-equipped vessel provided with a reflux condenser and heated with 
stirring to the boiling temperature. The mixture was then refluxed for 
from about 2 to 3 hours until no more free isocyanate could be detected. 
It was then neutralized with calcium hydroxide solution until the pH 
remained constant at 6.5 to 7. After cooling, the mixture was compressed 
in a pressure filter at from 0.5 to 2 bars. 
The odorless filter cake had a solids content of 47%. The dry mass had a 
nitrogen content of 18.4%. 
EXAMPLE 14 
The procedure is as in Example 13, except that 10 parts of monomeric 
tolylene diisocyanate (2,4-/2,6-isomer=80:20) were used instead of 100 
parts of isocyanate residue slag. 
An odorless filter cake having a solids content of 34% was obtained under 
the same reaction conditions. 
The nitrogen content amounted to 19.1%, based on dry mass. 
EXAMPLE 15 
Formulation: 
880 parts, by weight, of the same 11.4% surplus activated sludge as in 
Example 13, 
100 parts, by weight, of black powdered azulmic acid produced by the 
polymerization of hydrocyanic acid in accordance with German 
Offenlegungsschrift No. 2,806,019 or U.S. patent application Ser. No. 
11,542, 
20 parts, by weight, of a 30% aqueous formaldehyde solution, 
100 parts, by weight, of 4,4'-diphenyl methane diisocyanate and 
100 parts, by weight, of acetone. 
The reaction took place under the conditions described in Example 13. The 
NCO-free odorless filter cake had a solids content of 56.5% and a nitrogen 
content of 21.2%, based on dry substance. 
Foul-smelling surplus activated sludge powders dried at about 110.degree. 
C. were used as biomass in Examples 16 to 27 below. These surplus 
activated sludge powders, which emanate from fully biologically, 
industrial and communal purification plants, are normally stored in dumps 
or, in rare cases, are burned. Once they had become moist, these activated 
sludge powders underwent biological reactivation in a few days and 
continued to putrefy, giving off an increasingly intense odor. 
In the following Examples, these biomasses were denatured in accordance 
with the present invention by isocyanate polyaddition in predominantly 
organic, disperse phase or simply wetted with organic solvents. 
Formulations and test results are shown in Table 2. 
TABLE 2 
______________________________________ 
Dry mass 
Ex- Iso- Nit- 
am- Pro- cyan- tro- NCO 
ple cess ate Solvent 
Additions 
gen Odor content 
1 2 3 4 5 6 7 8 
______________________________________ 
16 I 200 100 Tol 
-- 13.7 none 3.5 
T80 
17 I 200 100 Tol 
-- 11.3 none 0 
T80R2 
18 I 100 80 Tol 
-- 13.0 none 0 
T80R3 
19 I 100 80 Ac 100 Az 23.4 none 0 
T80R2 
20 I 100 80 Ac 100 Az 21.3 none 0 
D44 
21 I 50 100 Ac -- 9.3 none 0 
D44 
22 I 50 100 Ac -- 11.0 none 0 
H 
23 I 50 100 Ac -- 10.3 none 0 
IPDI 
24 I 50 100 Ac -- 9.2 none 0 
L 
25 II 50 25 Ac -- 9.3 none 0 
D44 
26 II 100 20 Tol 
-- 12.8 none 0 
T80R2 
27 II 100 25 Ac 20 Uro 15.5 none 0 
T80R2 
28 III 100 -- -- 12.8 none 0 
T80R3 
29 I 100 100 Ac 100 ABS 
9.7 none 0 
T80R2 
______________________________________ 
Explanation of Table 2: 
Column 1: 
Example No. 
Column 2: 
Process used (see following description) 
Column 3: 
Diisocyanates and isocyanate residue slags 
as explained in Table 1 (parts, by weight, 
based 100 parts, by weight, of surplus 
activated sludge powder). T80 = tolylene 
diisocyanate (80% 2,4-; 20% 2,6-isomer). 
IPDI = Isophorone diisocyanate 
L = Tris-urethane isocyanate of 1 mole 
of 1,1,1-trimethylol propane and 
3 moles of 2,4-tolylene diisocya- 
nate (used in the form of a 75% 
solution in ethyl acetate). 
Column 4: 
Solvent in parts, by weight, based on 
total solids. 
Ac = acetone; Tol = toluene. 
Column 5: 
Additions (parts, by weight, based on 
100 parts, by weight, of surplus 
activated sludge powder) 
Az = Azulmic acid produced by the poly- 
merization of hydrocyanic acid in 
accordance with German Offenlegungs- 
schrift 2,806,019 or U.S. Pat. 
Application Serial No. 11,542 
(particle size: 10-100 .mu.m), 
Uro = Urotropin in the form of a 30% 
solution in water (with a catalytic 
quantity of sulfuric acid), 
ABS = Graft copolymer of butadiene- 
styrene-acrylonitrile; added in the 
form of a 33% aqueous dispersion. 
Column 6: 
Nitrogen content of the dry mass in 
percent, by weight. 
Column 7: 
Odor qualification of the product produced 
in accordance with the present invention. 
Column 8: 
NCO content of the dried process products. 
Process and reaction conditions for Examples 16 to 27: 
Process I: 
The components combined at room temperature in a stirrer-equipped vessel 
provided with a reflux condenser were heated with stirring for from 2 to 4 
hours to boiling temperature until the NCO-content remains constant 
(Example 16) or is zero (in the other Examples). 
The solvent was either completely distilled off with stirring, in which 
case the temperature was increased by 30.degree. to 40.degree. C. towards 
the end and the powder-form process products were discharged from the 
vessel under excess pressure or pneumatically removed therefrom, or the 
biomass polyaddition products dispersed in the organic medium were allowed 
to cool, the dispersant was filtered off and the product subsequently 
dried. 
Process II: 
(a) Batch embodiment: 
The components mentioned in Table 2 were wetted with the small quantity of 
acetone or toluene indicated in a kneader and heated for from 30 to 90 
minutes to from 110.degree. to 140.degree. C. in a pressure vessel under 
the autogenous reaction pressure. Upon completion of the isocyanate 
polyaddition reaction, the reaction mixture was left to cool to about the 
boiling temperature of the solvent which was then quantitatively disilled 
off. 
The products were isolated cold in the form of odorless, sterile powders 
which no longer putrefied, even on moistening with water and prolonged 
storage. 
(b) Continuous embodiment (preferred): 
With the same result, the reaction components were introduced into a 
twin-screw evaporation extruder, with toluene as the wetting agent, in 
which the isocyanate polyaddition reaction was carried out over a period 
of from 10 to 30 minutes at from 140.degree. to 170.degree. C. Before the 
powder-form products emerged from the extruder, the wetting agent was 
completely recovered by distillation. 
Process III (particularly preferred): 
The powder-form starting compounds were continuously introduced into a 
fluidized bed and reacted for an average of from 10 to 20 minutes at a 
temperature of from 145.degree. to 180.degree. C. The odorless activated 
sludge residue polyisocyanate polyaddition product was continuously 
removed from the reactor by forced upward flow. 
EXAMPLE 28 
1000 g of a bacterial activated sludge (solids content approximately 8.5%) 
emanating from a fully biological purification plant for industrial and 
communal effluents and consisting of a variety of microorganisms with 
traces of the following plant protection agents (herbicides): 
N-methyl isopropyl carbamate (0.5 g) 
4-amino-6-t-butyl-3-methyl thio-4,5-dihydro-1,2,4-triazine-5-one (0.5 g) 
N-(3-benzthiazolyl)-N,N'-dimethyl urea (0.5 g), 
were initially heated with intensive stirring to 80.degree. C. with 100 g 
of 30% formalin (1 mole) and 25 g of 85% phosphoric acid in a ground glass 
flask. The cell walls of the bacteria were thus ruptured and the plant 
protection agents present deactivated and hydrolyzed by reaction of the 
NH.sub.2 - or NH-functions thereof with formaldehyde by N-methylolation 
(&gt;N--CH.sub.2 --O--CH.sub.2 N&gt;) or methylene linkage (&gt;N--CH.sub.2 --N&lt;). 
After this primary reaction, samples were taken and centrifuged. By 
titrating the formaldehyde in the filtrates, it was analytically 
determined that 0.05 mole of formaldehyde has been consumed. A solution of 
60 g of urea (1 mole) in 100 g of water and 10 g of 30% formalin (0.1 
mole) were then added to the reaction mixture. After condensation for 15 
minutes at 70.degree. C., the mixture was cooled over a period of 30 
minutes to a temperature of 45.degree. C. and a readily filterable, 
powder-form biomass mixed condensate was obtained. This biomass mixed 
condensate was neutralized with calcium hydroxide, as a result of which 
substantially insoluble calcium phosphate precipitated in very finely 
divided form in the biomass condensate dispersion. The powder-form product 
was filtered off and washed with a 2% aqueous ammonia solution. The 
product was then dried under reduced pressure at 70.degree. C., giving a 
substantially odorless powder in an amount of 176 g. The nitrogen content 
amounted to 13.4%. 
Based on the mixture of condensed proteins, enzymes nucleic acids and other 
cell ingredients, the process product contained about 39%, by weight, of 
polymethylene ureas having the following idealized constitution: 
##STR6## 
wherein x is unknown and the fraction of (K) fused to functional groups of 
the biomass could not be analytically determined on account of the 
insolubility of the biomass mixed condensate. 
100 g of the dried product were mixed with 20 g of hexamethylene 
diisocyanate and 100 g of toluene and the resulting mixture maintained for 
6 hours at 150.degree. C. in a pressure vessel. It was then washed with 
methanol. 106 g of a biomass isocyanate polyaddition product which was 
completely odorless and sterile were obtained after drying. 
EXAMPLE 29 
Quantities of 1000 g of a bacterial activated sludge (dry matter content 
approximately 8.4%) emanating from a fully biologically purification plant 
for industrial and communal effluents were methylolated or condensed for 
10 minutes at 70.degree. C. with 1 mole of formaldehyde (100 g of 30% 
formalin), followed by the addition of each of the following isocyanates 
which, were reacted with the reactive groups of the biomass or with water, 
to form in situ polyurea derivatives which immediately co-condensed with 
the formaldehyde (0.85 mole) and N-methylol compounds of proteins still 
present following the addition of 16 g of concentrated sulfuric acid: 
(a) 0.2 mole of 2,4-tolylene diisocyanate dissolved in 40 g of acetone, 
(b) 0.2 mole of hexamethylene diisocyanate dissolved in 40 g of acetone, 
(c) 0.2 mole of 4,4'-diisocyanatodiphenyl methane dissolved in 40 g of 
acetone, 
(d) 0.2 mole of lysine ester methyl isocyanate dissolved in 40 g of 
acetone, 
(e) 44 g of a tolylene diisocyanate residue isocyanate having an NCO 
content of 16.2%, by weight, dissolved in methylene chloride, 
(f) 40 g of a higher polyisocyanate of aniline formaldehyde condensates 
dissolved in 40 g of acetone, 
(g) 0.4 mole of methoxy methyl isocyanate, 
(h) 34 g of biuret polyisocyanates (dissolved in 40 g of acetone) based on 
hexamethylene diisocyanate having an NCO content of 22.3%, this mixture 
contained approximately 33%, by weight, of triisocyanatohexyl biuret 
having the following idealized constitution 
##STR7## 
in addition to biuret polyisocyanates of higher molecular weight and 
polyisocyanato-polybiurets, 
(i) 48 g of uretone imine triisocyanate (dissolved in 40 g of acetone) 
corresponding to the following idealized formula: 
##STR8## 
(j) 42 g of the following idealized tris-urethane triisocyanate 
##STR9## 
The particular isocyanate added reacted with the biomass or with the water 
to form polyureas of relatively high molecular weight which contained 
highly reactive thermal NH.sub.2 -groups and numerous NH-groups which 
co-condensed with the formaldehyde present and the resulting N-methylol 
compounds or N,N-aminals of the proteins and cell ingredients. The 
reaction mixture was then neutralized using calcium hydroxide and washed 
with 2% aqueous NH.sub.3 -solution. 
In the case of reactions (a) to (i) readily filterable biomass mixed 
condensates were obtained. Yields: 
(a) 120 g, N-content: 8.6%, calcium sulfate content: 12.8% 
(b) 116 g, N-content: 9.4% 
(c) 140 g, N-content: 7.9% 
(d) 120 g, N-content: 9.1% 
(e) 139 g, N-content: 8.5% 
(f) 132 g, N-content: 8.5% 
(g) 118 g, N-content: 7.8% 
(h) 141 g, N-content: 11.6% 
(i) 123 g, N-content: 9.8% 
0.1 mole of ethylene glycol, diethylene glycol, 1,4butane diol or 
water-immiscible diols, such as hexane diol and 2-ethyl-1,3-hexane diol, 
may be added to the aqueous starting biomass dispersion, resulting in the 
formation not only of polyureas, but also of polyurethane segments which, 
through the high NH-content thereof, again contain functional groups for 
co-condensation with the aldehydes and the methylol groups of the proteins 
and N-methylolated cellular constituents of the biomass. 
The powder-form filtered biomass mixed condensates obtained were 
quantitatively freed from traces of formaldehyde by heating to 50.degree. 
C. in 2% ammonia solution, resulting in the formation of water-soluble 
hexamethylene tetramine, and were obtained in the form of completely 
odorless powders after extraction with acetone. Even after storage for 
lengthy periods, these powders remained odorless because the entire enzyme 
spectrum of the biomasses was completely deactivated.