IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICAL FUEL AND IN THE PRODUCTION OF GAS FOR ILLUMINATING AND HEATING PURPOSES
Year: 1873

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lanc,
in the County of Middlesex, Patent Agent, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICAL FUEL AND IN THE
PRODUCTION OF GAS FOR ILLUMINATING AND HEATING PURPOSES."-A com-
munication from abroad by Louis Jacques Martin, of Paris,
France.
Sealed the 9th April 1874, and dated the 16th October 1878.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 16th October 1873.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the County
of Middlesex, Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MANUFACTURE OF ARTIFICIAL Fuel and
IN THE PRODUCTION OF GAS FOR ILLUMINATING AND HEATING PURPOSES," to be as
follows:
:―
T1 •
-

page_text: where rich or poorer gas may be obtained from lignite and other matters
hitherto deemed valueless simultaneously with the production of a cheap
fuel for household and manufacturing uses free from smell, and
possessing a calorific power at least equal to wood charcoal. By thu
combining the manufacture of gas with the production of fuel in existin
works and apparatus an immense economy in labour and expense may
be effected.
Agglomerated fuel made of the ingredients above indicated will pro-
duce a gas of richer or poorer quality, according to the proportion of
boghead or cannel coal contained in the mixture; but as this gas varies
in density and illuminating power with the quality of the elements of
the composition I prefer to employ peat in which there is but little
essential variation while it is readily obtainable in large quantities at but
little expense. Moreover peat is a spongy matter highly penetrable and
contains but 50 to 60 per cent. of carbon with however a much larger
proportion of hydrogen than is found in coal.
In employing this natural product for the manufacture of illuminating
gas I have profited by the affinity possessed by hydrogen gas, either pure
or proto-carbonated, for bi-carburet of hydrogen in decomposition. For
this purpose I immerse the peat for 24 hours in a bath of hydrocarburet
at a temperature of from about 120 to 140 degrees Fahrenheit in order
that it may be thoroughly penetrated. This bath should be composed
of hydrocarburcts containing more or less carbon, according to the
desired illuminating quality of the gas to be obtained. On leaving the
bath the peat is dried which occupies at least 24 hours, and then ground
up, and from four to five per cent. of lime is next added, as also a binding
material, after which it is formed into blocks.
By simply sprinkling the peat with the 5 or 10 per cent. of lime a rich
quality of gas may be obtained in existing apparatus, leaving a residue
of carbonized peat such as is generally used. I prefer however after
the peat has been saturated to grind it up with the necessary quantity
of lime, and then agglomerate the same with the assistance of rosin or
pitch and mould it into blocks or sticks. I then obtain as residue a
fuel suited for domestic use and ready for immediate sale.
I may also although with less advantage pulverize ordinary peat and
add the requisite quantity of hydrocarburet, rosin, and vegetable pitch,
then agglomerate the same, sprinkle it with 5 to 10 per cent. of lime,

page_text: and finally mould it into blocks of any form with the aid of pressure.
Thus prépared the peat absorbs from 10 to 15 per cent. in weight of the
carburet of hydrogen employed. I then place it in a sheet iron
receptacle which is introduced into an ordinary gas retort, well luted
and heated to a cherry red. An illuminating gas of rich quality may in 6
this manner be obtained in much less time than when coal or other
materials are employed, requiring little if any purification, and free
from any of the objections applying to other rich gases which are liable
to condense in the pipes and cause obstructions.
.Peat may also be employed, such as it is obtained from the bogs, 1
provided it is sufficiently dry; it is first immersed in the bath before
referred to, and then introduced direct into the retort without being
placed in a receptacle as previously described.
A minimum of 10,000 cubic feet of gas per ton, may be obtained
by the above process, and from 30 to 35 per cent. of residue possessing 1
great density and high calorific power.
The retorts may be heated either with coke or coal or with tar by
adapting the furnace accordingly.
I also reserve the right of utilizing coal tars and products of
condensation resulting from the manufacture of portable gas, so as to 2
form with the peat, lignite, or other substances a material analogous to
boghead or cannel coal, but possessing the advantage over these natural
products of furnishing at a cheap rate a valuable fuel in addition to the
illuminating gas.
I may also treat desiccated wood, in a similar way to peat, in a bath 2
of hydrocarburet at a suitable temperature, so as to impart to it the
necessary equivalent of carbon for producing a rich gas. The hydro-
carburet may be caused to penetrate the pores both of the compressed
peat and the wood (but more particularly the latter) by the aid of
pressure or of a vacuum.
In selecting the hydrocarburets with which to impregnate the peat
for the purpose of producing gas it has been found that certain of them,
such as for example, gas tars and heavy oils resulting from the
distillation of the same are after the benzole and pitch have been
extracted unsuited for manufacturing gas by the aid of heat in the
2

page_text: ordinary manner, that is to say, by being introduced in a thin stream in
the gas retort. I therefore dissolve from 5 to ten per cent. of rosin in
these dead oils in order to increase their consistency and heat them to a
temperature of from 190 to 212 degrees Fahrenheit, and then immerse
the peat, either moulded or not, therein for about 15 or 20 minutes.
In order the better to understand the object of this mode of treatment,
it should be considered that peat in its original condition contains
from 15 to 20 per cent. of water besides being hygrometric and very
friable. Hence if gas is obtained from it in this condition, the 15 or 20
per cent. of water it contains will be decomposed and resolved into
oxygen and hydrogen, forming oxide of carbon, which is very deleterious
and prejudicial to the illuminating power of the gas, rendering it
impossible to obtain proto-carbonated hydrogen from ordinary peat, and
from this cause the manufacture of gas from peat has practically
speaking hitherto failed. When on the contrary the peat is treated after
the before described method it forms a product similar to gas coal and
may be used either for heating the retorts or for producing gas. The
blocks of articifical fuel will also, owing to the cheapness with which
they can be produced, form an excellent substitute for coal for heating
purposes.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 15th April 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Sixteenth day of October, in the year of
our Lord One thousand eight hundred and seventy-three, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Alexander Melville Clark, Her special
licence that I, the said Alexander Melville Clark, my executors, adminis-
trators, and assigns, or such others as I, the said Alexander Melville
Clark, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,

page_text: but I modify the composition when it is desired to obtain a rich gas,
similar to that obtained from boghead.
The following are the approximate proportions in each case :—
but I modify the composition when it is desired to obtain a rich gas,
similar to that obtained from boghead.
The following are the approximate proportions in each case:
For ordinary quality gas,-
Lignite pounded fine
Tan or wood sawdust pounded fine
Heavy tar from rich gas
For rich quality gas,-
1000 lbs.
200
"
100 "
Lignite (pounded)
Tan (pounded)
Petroleum tar (disacidified)
cotton or other seed
Tar, residue of the purification of oil of
1000 lbs.
200 "
100 "
->
100 ”
The several matters are first worked up in a mixer, and heated if
necessary, and then moulded into cylindrical or other shaped lumps.
The lumps are next placed in a retort and heated for obtaining gas
therefrom, and after being extinguished in "etouffoirs" and cooled they
are ready for use as fuel for domestic purposes. Or the lumps after
merely being moulded may be supplied to existing gasworks, where rich
or poor gas may be obtained from lignite and other matters, hitherto
deemed valueless, simultaneously with the production of a cheap fuel for
household and manufacturing uses; free from smell and possessing a
calorific power at least equal to wood charcoal. By thus combining
the manufacture of gas with the production of fuel in existing works
and apparatus an immense economy in labor and expense may be
effected.
Agglomerated fuel made of the ingredients above indicated will
produce a gas of richer or poorer quality, according to the proportion of
boghead or cannel coal contained in the mixture, but as this gas varies
in density and illuminating power, according to the quality of the
elements of the composition, I employ peat by preference, as in this
material there is but little essential variation, and it is readily obtainable
in large quantities at moderate cost. Moreover peat is a spongy matter,
highly penetrable, and contains but 50 to 60 per cent. of carbon, with
however a much larger proportion of hydrogen than is found in coal.

page_text: In employing this natural product for the manufacture of illuminating
gas I desire to profit by the affinity of pure hydrogen gas, or proto-
carbonate of hydrogen for bi-carburet of hydrogen under decomposition.
For this purpose I immerse the peat for 24 hours in a bath of hydro-
carbuet, at a temperature of from about 120 to 140 degrees Fahrenheit,
in order that it may be thoroughly penetrated. This bath should be
composed of hydrocarburets richer or poorer in carbon, according to the
desired illuminating quality of the gas to be obtained. . On leaving the
bath the peat is dried upon screens, which occupies at least 24 hours,
and then ground up, and from four to five per cent. of lime is next
added, as also a binding material, after which it is formed into blocks.
By simply sprinkling the peat with five or ten per cent. of lime a rich
gas may be obtained in existing apparatus, leaving a residue of car-
bonized peat like that generally in use. I prefer however; after the peat
has been saturated, to grind it up with the necessary quantity of lime,
and then agglomerate the same with the assistance of rosin or pitch, and
mould it into blocks or sticks like the fuel known in France as Paris
charcoal. In that case I obtain as residue a fuel suited for domestic use,
and ready for immediate sale.
I may also, although with less advantage, pulverize ordinary peat and
add the requisite quantity of hydrocarburet, rosin, and vegetable pitch,
then agglomerate the same, sprinkle it with 5 to 10 per cent. of lime,
and finally mould it into blocks of any form with the aid of pressure.
Thus prepared the peat absorbs from ten to fifteen per cent. of its weight
of the carburet of hydrogen employed. I then place it in a sheet-iron
receptacle, which is introduced into an ordinary gas retort, well luted,
and heated to a cherry red. A rich illuminating gas may in this manner
be obtained in much less time than from coal or other materials,
requiring little if any purification, and free from all of the objections
applying to other rich gases, which are liable to condense in the pipes a
and cause obstructions.
Peat may also be employed such as it is obtained from the bogs, pro-
vided it is sufficiently dry. It is first immersed in the bath before
referred to, and then introduced direct into the retort without being
placed in a receptacle, as previously described.
A minimum of ten thousand cubic feet of gas per ton may be obtained
by the above process, and from thirty to thirty-five per cent. of residue,
possessing great density and high calorific power.

page_text: The retorts may be heated either with coke or coal, or with tar, by
adapting the furnace accordingly.
This Invention presents great advantages to commercial and private
gasworks at a time when the price of coal is so high as to render it
absolutely necessary to find a natural or artificial substitute.
1
I also reserve the right of utilizing coal tars and products of con- .
densation resulting from the manufacture of portable gas so as to form
with the peat, lignite, or other substances a material analogous to
boghead or cannel coal but possessing the advantage over these natural
products of furnishing at a cheap rate a valuable fuel in addition to an
illuminating gas.
I may also treat desiccated wood in a similar way to peat in a bath of
hydrocarburet at a suitable temperature so as to impart to it the
necessary equivalent of carbon for producing a rich gas. The hydro-
carburet may be caused to penetrate the pores both of the compressed
peat and the wood (but more particularly the latter) by mechanical 'or
atmospheric pressure.
'
In selecting the hydrocarburets with which to impregnate the peat for
the purpose of producing gas, it has been found that certain of them,
such as for example gas tars and heavy oils resulting from the distillation
of the same are, after the benzole and pitch have been extracted, unsuited
for manufacturing gas by distillation in the ordinary manner, that is to
say, by introducing them in a thin stream in the retort. I therefore
dissolve from five to ten per cent. of rosin in these dead oils in order to
increase their consistency, and heat them to a temperature of from one
hundred and ninety to two hundred and twelve degrees Fahrenheit, and
then immerse the peat, either moulded or not, therein for about fifteen or
twenty minutes. In order to better understand the object of this mode
of treatment, it should be considered that peat in its original condition
contains from fifteen to twenty per cent. of water besides being hygro-
metric and very friable; hence if gas is obtained from it in this condition
the fifteen or twenty per cent. of water it contains will be decomposed
and resolved into oxygen and hydrogen, forming oxide of carbon, which
is very deleterious and prejudicial to the illuminating power of the gas.
It is thus impossible to obtain proto-carbonate of hydrogen from ordinary
peat, and from this cause the manufacture of gas from peat on a com-
mercial scale has hitherto been a failure. When on the contrary the

page_text: therefrom:-I dry the tan in a suitable apparatus whereby all traces of
moisture are expelled without however raising the temperature beyond
two hundred and twelve degrees, and when it is well dried I place it in
an openwork cylinder and cause it to absorb twenty to twenty-five per
cent. of a hydrocarburet suitably prepared, either by simple immersion
therein or by pressure as when peat is employed. After having thus
obtained a carbonized tan I agglomerate with it wood pitch, preferably
mixed with a small quantity of coal tar, thus forming what I term
"braisette", from which material I obtain gas and a product or residue
which may be used as fuel for domestic purposes.
When it is desired to mould the residue I proceed in a slightly
different manner, that is to say, I grind the tan after it is dried and mix
it with fifteen per cent. of wood pitch, and after moulding it either into
lumps similar to Paris charcoal or into blocks or brignettes it is car-
buretted, as above explained, and the gas is then extracted; the product
whether in one or other form burning exactly the same as wood
charcoal.
Spent dye woods as well as sawdust may also be similarly treated with
a view to obtain gas and fuel for domestic uses.
Having described the nature of the Invention, and the manner of per-
forming the same, I declare that what I claim as the Invention to be
protected by the herein-before in part recited Letters Patent is, impreg-
nating peat, lignite, desiccated wood, tan, and other ligneous substances
generally with a prepared hydrocarburet at given temperatures, whereby
to form a product similar to gas coal, which may be used either directly
as a rich quality fuel for heating furnaces, or distilled for obtaining gas
for illuminating and heating, as well as a carbonized peat or wood residue
forming a substitute for wood charcoal for domestic uses.
In witness whereof, I, the said Alexander Melville Clark, have here-
unto set my hand seal, this Fifteenth day of April, in the
year of our Lord One thousand eight hundred and seventy-
fanm