IMPROVEMENTS IN THE MODE OF PURIFYING GAS
Year: 1879

page_text: LETTERS PATENT to Herbert John Haddan, of the Firm of Herbert and
Company, Solicitors of Patents, of 67, Strand, in the City of Westminster, Civil
Engineer, for the Invention of "IMPROVEMENTS IN THE MODE OF PURIFYING
GAS" A communication from abroad by Orazio Lugo, Chemist, of Flushing,
Queen's County, and William T. Lees, Gas Engineer and Chemist, of Brooklyn
City, King's County, all in the United States of America.
Sealed the 28th May 1880, and dated the 19th December 1879
COMPLETE SPECIFICATION filed by the said Herbert John Haddan at the
Office of the Commissioners of Patents on the 19th December 1879.
HERBERT JOHN HADDAN, of the Firm of Herbert and Company, Solicitors of
Patents, of 67, Strand, in the City of Westminster, Civil Engineer
"IMPROVE
MENTS IN THE MODE OF PURIFYING GAS." A communication from abroad by
Orazio Lugo, Chemist, of Flushing, Queen's County, and William T Lees, Gas
Engineer and Chemist, of Brooklyn City, King's County, all in the United States
of America.
The chemistry of illuminating gas has been sufficiently developed by chemists to
enable the gas manufacturer to apply intelligently those economical improvements
which produce a gas free from deleterious substances. Illuminating gas is manu-
factured generally by the destructive distillation of carbonaceous materials containing
a large percentage of volatile matter. The distillate consists of several compounds
differing in their nature and quantity according to the substance submitted to
distillation, as well as to the degree of heat used during the operation. Bituminous
coal is largely used for the manufacture of illuminating gas, but it produces, besides
gaseous hydrocarbons, several deleterious substances, such as sulphur and animoniacul
compounds, which should be totally extracted before the gas is delivered to the
consumer, The object of the Invention is to enable the gas manufacturer thoroughly
to extract from the illuminating gas sulphur, and ammoniacal compounds in a
Price 1 1

page_text: We
practical and economical manner, and to this end the Invention consists generally
in heating the crude gas before it is scrubbed or washed, and particularly with a
gas mixture, vapor or vaporizable substance, which will form with the sulphur of
the gas soluble sulphur compounds, upon the application of heat. The Invention
consists specifically in introducing atmospheric air or caustic ammonia into the gas,
preferably at a point between the condenser and scrubber, heating the mixture
and then washing, that is heating before the gas is either scrubbed or passed through
a purifying substance To carry the Invention into effect, in as much as crude gas
already contains a substance, to wit, ammonia, which converts sulphur and its
insoluble compounds into soluble sulphur compounds when heated is applied, we may
simply heat such gas and convert much of the sulphur contained into soluble com-
pounds of sulphur, the conversion being dependent upon the quantity of ammonia
present or we may heat the gas with any gas, mixture, vapor, or wholly or partly
vaporizable substance which will convert the sulphur or its insoluble compounds
into soluble sulphur compounds, or introduce about one to two per cent of
atmospheric air into the gas at any convenient place between the retorts and the
condenser, and between the condenser and the scrubber, we superheat the mixture
to a temperature of about 250° C., by passing it through a heated chamber
prefer to pass the gas through a tubular iron vessel, kept at the required temperature
by superheated steam. After passing through the heated chamber (which we will
call the gas superheater), the gas is scrubbed with water, and then passed through
a purifying material in order to take out the last traces of impurities We have
also tried caustic ammonia, introduced into the gas after being passed through the
condenser, then superheating the mixture to about 250°-270° C. The results were
very satisfactory; the gas when thus treated needed only to be washed with water
to render it sufliciently free from sulphur and ammoniacal compounds. We may
employ a substance or substances from which ammonia can be generated upon the
application of heat
By this process the purifying of the gas is done by the water
used, as the sulphur compounds contained in the crude gas are modified during the
superheating process, and become soluble in water When the mixture of crude
gas and atmospheric air is superheated to about the temperature above mentioned,
a large quantity of free sulphur is deposited as the gas becomes cool. In connection
with this reaction, we have noticed the total decomposition of the very objectionable
naphthalene. We could not detect a trace either of naphthalene or any other solid
hydrocarbon in the gas purified by our process. The crude gas we operated upon
contained 180 grams of sulphur (S) and 333 grains of ammonia (NHI) to the 100
cubic feet. The same gas after being purified by our method contained only
3 grains of sulphur (S) to the 1000 cubic feet, and not a trace of ammonia
found most of the sulphur compounds in the water coming from the washer and
scrubber in the form of sulpho-carbonate of ammonia, sulphocyanate of ammonia,
and sulphide of ammonium. We also found a considerable quantity of sulphate of
ammonia deposited with the free sulphur in the cooler pipes between the gas super-
heater and scrubber. A small quantity of sulphide of hydrogen escapes the reaction
during the superheating of the gas, but is easily retained by passing the gas through
bone black or any other suitable substance, such as lime, iron, or manganese.
method above described can be applied to the purification of coal gas, water gas,
and all other kinds of gas containing sulphur. What is claimed and desired to be
secured by Letters Patent is:-1st. In purifying gas, the process of converting the
sulphur contained in crude gas into soluble sulphur compounds, for removal which
consists in superheating the crude gas by itself between the place of its generation
and the washer 2nd In the purification of gas, the process of converting the
sulphur or sulphur compounds contained therein into soluble compounds of sulphur
readily removable from the gas, which consists in introducing into the gas a gas,
vapor, or vaporizable substance which will form with the sulphur of the gas soluble
sulphur compounds upon the application of heat, and then heating the mixture.
3rd. The process of purifying illuminating gas, freeing it from sulphur and ammonia
We
The

page_text: which consists in introducing into the gas a gas or vapor such as air or caustic
ammonia, which will form with the sulphur of the gas soluble sulphur compounds,
beating the mixture, and then washing, substantially as set forth.
In witness whereof, I, the said Herbert John Haddan, have hereunto set my
hand and seal, this Nineteenth day of December, A.D. 1879.
H. J. HADDAN. (1. s.)