Process and Apparatus for the Production of Heating Gases, Poor in Nitrogen from Combustible Materials Containing Hydrocarbons.
Year: 1899

page_text: Date of Application, 22nd Aug., 1899-Accepted, 3rd Mar., 1900
Process and Apparatus for the Production of Heating Gases, Poor in
Nitrogen from Combustible Materials Containing Hydrocarbons.
I, EDUARD BLASS, of Essen on the Ruhr, in the Empire of Germany, Civil
Engineer, do hereby declare the nature of this invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
This invention has for its object the economical generation of gas from and
the gasification of combustible materials containing hydrocarbons, such as
bituminous coal and the like, in such a manner as to obtain, broadly speaking,
a heating gas poor in nitrogen.
According to this invention not only is a portion of the carbon converted into
heating gas poor in nitrogen but all the hydrocarbons are obtained either as CmHn
in form of gas, or as tar and the like or after their decomposition into CO and H
as hydrogen-gas.
This is effected by distilling the fresh combustible material by the aid of hot
non condensible hydrogen gas and converting the coke resulting therefrom into
hydrogen gas. In order to ensure the distillation to be complete a special
arrangement has to be adopted for supplying the coal constantly with freshly
re-heated hydrogen gas until the coking is complete.
In the accompanying drawing which illustrates the invention;
Figure 1 shows a general arrangement of the apparatus.
Figure 2 is a detail view.
Figure 3 is a modification of the arrangement shown in Figure 1.
The apparatus for carrying out the process consists mainly of the following
parts. A single sheet metal cover encloses the chamber E for drawing off the
gas and the chamber V for distilling. Above the apparatus is fitted a charging
funnel F adapted to communicate with the chamber E through an opening
normally closed by a valve G.
The valve G serves for the purpose of cutting off the chamber E for drawing
off the gases from the hopper F whenever this hopper is to be filled with fresh
coal. As soon as the hopper is charged the lid or cover of the same is closed and
the valve G is opened, so that the coal can drop into the chamber E. To prevent
the collection of any noxious and explosive gases in the hopper above the valve G
an annular passage A¹ is provided which communicates by pipe B with the
exit L for water gas or generator gas, so that this passage A is filled with these
gases, which are here in absence of air inexplosive. Below the distilling chamber
is an inlet nozzle Z for the admission of an air-blast or mixture of gas and stean:.
At the junction of the two chambers about the middle of the apparatus an annular
hollow space R is arranged free of the combustible material and the gas there
collected is led off through channels and delivered into a circular channel K and
thence into the pipe L which latter is fitted with a closed outlet S and with a
branch leading into the scrubber W. Below the charging funnel F is an open-
ing through which the gases are drawn off by the exhauster X so as to pass
either along the shortest route through the open valve Y or when the said valve Y
TD 077

page_text: "
is closed they pass to the refrigerator T-through the nozzle J. The pipe D is a steam
supply pipe. The object of the valves M, C, N and P will be hereinafter explained.
The operation is as follows: The coke in the distilling chamber V (distilled
coal and the like from above) is heated by the air from the inlet nozzle Z.. The
gas then generated rises up into the circular channel K and is either allowed to
escape into the atmosphere by opening the valve S or to be led off to any suitable
place for use. The slide valve M is in this case set to the position "hot blast'
Figure 2, so that the fan can only draw in air. After the combustible material
is sufficiently hot the valve is reversed and thereupon the gas production com-
mences for the generation of the heating gases poor in nitrogen. The valves S, P
and C are closed, valves N and Y open while the slide valve M is set to
gas-
generation" Figure 1. By using two blasts, one for air-blast and one for draw-
ing off the gases, the said slide valve M is not required. The fan thereupon
draws off the gases of distillation which together with the steam from the pipe 1)
pass through the nozzle Z into the coke. The mixture of gas and steam passes
through the burning coke and is decomposed into hydrogen gas. The hot
hydrogen gas thus produced is drawn off through the chamber E and during its
passage upwards it degasifies the fresh combustible material, while at the same
time a certain amount of this gas passes up the passages into the circular channel k
and through the pipe L to the scrubber Wand finally into the gasometer.
<
If now the temperature in the coke chamber sinks so far that the generation
of hydrogen gas is very small that is to say that the decomposition of the steam
becomes unprofitable by reason of a large portion of the steam escaping un-
decomposed through the coke while the percentage of carbonic acid in the
generated gases rises unduly, the steam supply is stopped but the fan is kept
working. This is the commencement of the second phase of the gas production.
The circulation of the gas mixture by means of the fan wheel X, now however
without steam, continues and the heat from the coke which is still fairly high is
communicated to the circulating gases and these in turn give the heat up to the
incompletely distilled coal. This circulation is kept up until the coal has
practically given up all gas, so that not only all the distillation products are made
use of from the yield of gas, but at the same time all the necessary coke for
conducting the process is obtained from the distilled coal.
After the coking of the coal is completed the apparatus is reversed by setting
the valve M to warm blast."
During the process the tar and ammonia may be extracted from the circulation
gas mixture which contains all the products of distillation. To this end the
valve is screwed down, slide S and P must be closed and C and N must be
open. Thus the gas mixture is caused to pass through the pipe J into the
refrigerator T where it deposits tar and ammonia. The fan or exhauster draws
the gas now freed from tar and ammonia and causes it to circulate after mixing
steam with it for the first. working period, or alone for the second working period.
The gas thus produced is bydrogen gas which in some instances may con-
tain CH. If it is desired to produce a mixture of hydrogen gas with non
decomposed distillation products (illuminating gas) the excess of gas is not allowed
to pass off from the annular space. but is caused to mix and ascend with the
circulating gas current through the fresh charge of combustion material for re-
heating and there become further charged with the products of distillation. This
is effected by closing the valves S. N and C and having valves Y and P open.
portion of the gas mixture is drawn up by the fan or exhauster and circulated
while the other portion enters through the pipe J into the refrigerator T so as to
be freed from tar and ammonia whence it passes through the pipe H immediately
into the gasometer.
The hot hydrogen gas looses most of its heat during its passage through the
generating chamber, and therefore a scrubber is not required.
If it is desired to obtain as much as is possible of the by-products, tar and
ammonia, the process last described is so far altered as to obtain the tar and

page_text: For this
ammonia not only from that portion of the gas which finally passes into the
gasometer but from all the gas which ascends through the pipe 0.
purpose the valve C is opened and valve Y closed so that the whole of the gas
must pass into the refrigerator T any excess being led off through the pipe H into
the gasometer.
Having now regard to the nature of the product obtained by this improved
process there are four ways of operating during the gas generating period, riz.:
to produce hydrogen gas without extraction of by products; the same with complete
extraction of the by products; to produce mixed gas with a partial extraction of
by-products; the same with complete extraction of by product.
This process and the apparatus used therefore are however defective in so far
as the gas mixture with or without steam is introduced from below into the
combustion material and at the same place where the air is introduced. The
mixture naturally greatly cools the layer of material with which it first comes
into contact but this layer may again be brought into incandescence by re-heating
providing the cooling has not been excessive. Therefore the gas-generation must
neither be kept up too long nor at starting must the air blast be too strong, other-
wise the combustible material will become cold and the working interrupted.
This may be obviated by causing the mixture to enter alternately below and above
the combustion material. By so doing however the working depends too much
upon the vigilance of the attendant while moreover loss of heat occurs by intro-
ducing the mixture at the upper part owing to it coming into contact with the
coal whereby the steam, tar-vapours and so on condense. The gas produced leaves
under high temperature at the hottest part of the combustion column whichi
entails great loss of heat. The above mentioned defects are obviated by the use
of the apparatus shown in Figure 3 of the accompanying drawings.
The two hearths of the kilns are in direct communication with each
other. Centrally below the hearths there is arranged an inlet nozzle Z for the
air blast common to both kilns. 4 and 3 designate four and three-way valves
and D¹ and D² are steam- supply-pipes.
The operation in this apparatus is as follows:-
Both hearths are filled half-way with coke and above that with fresh coal and
the coke is then heated by the air blast entering by the nozzle Z. The gases of
combustion escape through R' and R2 and through the open slides S and S2 intó
the air, the said slides being particularly adjusted each to regulate the volume
of air for each kiln. At the finish of the warm blast the two columns of com-
bustion material are hottest at the base while at R1 and R2 the coke is only
moderately hot and the coal supply at E1 and E2 is relatively cold. Hereupon
the gas generation may be started. For producing hydrogen gas the valves C
and P are closed and Y and N opened and furthermore the air-blast Z and the two
slides S&S are also closed. The fan or exhaust X or any other convenient
draw-off mechanism is set in motion while at the same time allowing steam to
enter at D. This steam passes through the hot circular channel K and then
issuing at R it passes between the coal E¹ and coke V whereby it becomes heated
through contact with the moderately hot coke until decomposed it passes in form
of hot hydrogen gas into the hearth V2, distilling the coal in E2 then passing
through the disc valve 3 into the exhauster and dise valve 4 and returning to K¹
where laden with the products of distillation it is, or not, mixed with steam at 1)¹
and then again circulates in the same manner as before. The mixture always
enters the materials in the kiln at the junction between the burning coal and
coke and the fresh coal so that not only condensation of the mixture is prevented
but the same becomes heated and so enables the temperature of the burning coke
to be kept unimpaired during the decomposition of the gas mixture. By causing
the mixture to enter at the top so that it can only cool the materials located at
the opposite side to the air blast, it will be practically impossible for the coke to
become extinguished by the blast.
The mixture during circulation gives up its excess in form of hydrogen gas

page_text: which escapes at R2 the coldest part of the coke column and then passes through
the disc valve 4 into the scrubber W and thence into the gasometer. By closing
the valve Y and opening valve C the gas is caused to pass through the
refrigerator T for the purpose of depriving it of its tar and ammonia. For the
next following period of gas generation, or even during the same period the two
disc-valves, advantageously coupled together, are reversed and steam is allowed to
enter at D2 so that now the gas passes in the reverse direction through the
kilus.
For producing gas mixture the valves P and Y are open but S, C and N closed
as in this case the scrubber is not required. After sufficient warm blast steam is
supplied through D¹ or D2 and the exhauster started. The hydrogen gas then
generated passes through the two kilns but an excess of gas is not allowed to
escape at R2 and the whole of the gas is obliged to ascend through the fresh coal
in E. The gas then passes direct through the fan or exhaust X and disc valve 4
and re-enters K either in its present state or mixed with steam. The excess
passes in form of gas mixture to the refrigerator T to be freed from tar and
ammonia and thence by the pipe H into the gasometer.
For the purpose of obtaining the by-products from the whole of the gas in
circulation it will be necessary to close the valve Y and open C so as to cause all
the gas and not only the excess of gas. to pass into the refrigerator.
The advantages accruing from the improved process are in short the following:
Higher output for the same amount of combustion material, in that the
hydrocarbons are completely extracted from the materials and that the com-
bustion gas thereby produced, whether it be hydrogen gas or gas mixture, is
drawn-off at the coldest part of the apparatus so saving in heat and cooling water
expended.
Greater safety from the danger of an explosion for by the improved process no
air can possibly enter the gasometer. In only one possible way could air enter
the gaspipes, i.c., after it has passed through the coke when it may pass in the
form of generator gas. In none of the processes heretofore in use is there an
arrangement of a protecting incandescent coke-column between the air blast and
the gasometer.
The gas mixture produced by this process is particularly valuable because it
has not only greater heating effect, but for use as an illuminating gas it requires
much less of a carburetter than the pure hydrogen gas. In addition to this the
gas contains less CO than the hydrogen gas, therefore it is less poisonous and
has moreover the characteristic odour of ordinary illuminating gas, while the
hydrogen-gas is nearly odourless.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is—
1. The process for the manufacture of heating combustible gas, either in the
form of hydrogen gas, or as a gas mixture (mixture of hydrogen gas and
illuminating gas) from hydrogenous combustion materials and characterized in
that an exhauster is used for producing circulation of the gas so that after shutting
off steam the circulation of the gas may be continued for the purpose of producing
the required amount of coke for the continuation of the process, from the fresh
combustion material while simultaneously therewith generating and collecting
the distillation products either as hydrogen gas or gas mixture (mixture of
hydrogen gas and illuminating gas), substantially as and for the purpose described.
2. A manner of carrying out the process claimed in Claim 1, characterized in
that the gas, or the gas mixture and steam, is introduced between the burning
coke and the fresh combustible material and that the gas generated is drawn off
at the coolest part, whereby the same is not only prevented from, being condensed,
but is preliminarily heated, substantially as and for the purpose described.
3. A form of process as claimed in Claim 1, in which the gas, for the purpose

page_text: of extracting tar and ammonia may be led into a tar and ammonia-separator
before introducing it, either mixed with hydrogen gas or alone, into the burning
coke, or before drawing it off for consumption, substantially as and for the purpose
described.
Dated 100-1
e
1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.