The New York herald., 1870-01-25
THE METHODS OF PURIFICATI0N.
How Drs. Smith and Harris Found
a Nuisance.
What the Manhattan and New York GaSlight
Companies Did and What the Mtiropoli
tan Company WOnld Not llo.
HISTORY OF THE GAS CONTROVERSY

The following s the Official report or Professor
Chandler 10 the Metropolitan Board OF Health Oh the
SUBJECT OF the manufacture ANA publication OF llu-
nanatng gas, and, embracing as IL does the methods
Of avoiding OF nuisance as well as the stand taken
" secure better quality OF gas, and at the same
time obviate the evils TO which the public has been
subjected, 1t wll be found OF particular INTEREST,":
O0louel EAiMoNs CLARK, Secretary OF the Metropol-
tan Board OF Health:--
Sm-ln answer to the resolution OF The Board OF
HEALTH directing the chemist 10 make statements IA
e1tenso o! the methods OF puri1ca.on employed BY
the several gas companies OF New York, have the
honor TO submit the following report:-
I.-METHoDs or PURiFIcArioS IN GENERAL USE.
OF blLumin0us coal 10 a bright red heat m clay or
IRON rctorts, Is freed, during It's passage through the
nyurauiic MAN, the condenser and the washer, from
the tar whicl It contains and from portion OF It's
wafer and ammoniacal compounds II st.ll contains,
however, objectionable impurities, which must be
removed by process OF purincaiion. These are
Huiphuretted hydrogen, supbide OF ammonium, cya-
moe OF ammonium sulphocyanlde OF ammonium.
bisulphlde OF carbon certain other sulphur COM
pounds whose exact nature Is not known, and car
bonJc acld. The sulphur compounds are all very
objectionable; they give Tie gas a very offensive
smell, and. when burned. produce sulphurous
acld, which, II produced In any consider
air OF room unfit for human lie.
and seriously injure furniture and goods exposed 10
ls action. These sulphur compounds must there
lore be removed The carbonic acid gas Is oDjec-
t0nabe only III as far as 1t dinnishes the unilnat-
Ing power OF the gas when present IN appreeable
DonIc acid for perfectly puri1ed gas would produce
wheo burned, great many times as much car
bonlc acid as exists IN the most Impure crude gas
The presence OF ammonia III Gas IN appreclaDle guam
Is Objectionable, but a. all the methods o putt
ncation at present used remove the compounds Oh
ammonia very enectually we may connne The dls
cusslon 10 the sulphur compounds ana the carbonic
acid 1nere are four methods or purifying gas now
j. me vet Lime Process.
This process involves passing the gas through
mix OF lime. lt is the Oldest process IN use and
~ very elective I'D removing both the sulphur
compounds ana the carb0mc acid. 1t has been
generally abandoned. however, on account or the
diliculty of disposing OF the ioal milk Of htne
called 'Diue nilly.n Occurring as liquid the blue
billy is not easily transported, and 1t does not
Tor use as fertilizer. Runnlng lt INTO rivers aud
streams has been forbidden by law as the pollution
VI the waters by IT was inioeraole, white the ex-
ncmcly offensive smell when II enlts makes It
impossible TO store II unul II becomes dry enough
JOr transportation
2. ne Dry Lime Process.
In tins process dry OF Sight, moist hydrate OF
lime Is placed on trays or IRON boxes through winch
Lne gas made pass. THIS process very effec
tive and has very generally superseded the wet lime
ine carDonc acld equally well When the foul lime
removed however. II evolves the same odor which
caused the wet lime process 10 be abandoned. When
exposed TO the air IL RAPIDLY undergoes oxidation.
becoming heated In consequence. During TINS pro-
cess 1t evolves suphide OF ammonium and some
other compounds whose exact nature Is not known,
out whose odor Ls extremely offensive. Ins Is the
of the 'gas nuisance SO loud y complained OF a
lew years ago, when all the New YORK companies
employed tins process Of purl1cation. After the
oxidation or the foul lime Is completed IL To
be specially Offensive the peculiar stencil being
evolved uuring The first hour two OF exposure.
The ofrenslvcness OF this foul lime became such a
constant Cause OF complaint in the large cities OF
Europe that the gas companies were compelled 70
abandon The process, as they had previously aDan-
doned the wet lime. Nsystem oil venuating the
I0nl lime has been invented and IS now in use at
both the stations OF the Manhattan Company in tis
city, which effects ITS oxidation such manner
that the offensive gases eyON cd NOT permitted 10
escape into the atmosphere, but are passed through
washing apparatus ana finally through SPECIAL
pnr.iier by wnicn tney are rendered comparatively
lnO7ensivs. THIS invention seems 10 obyIate the
nuisance Of dry lime purincaton.
= 3. The LafHGltg f1Dcess.
In 1S49 MI. Laming introduced the hjdrated ses
guloXlde Oi iron us substitute for llnb FOR purify
ing gas, preparing IT OF suitable quality by mixing
copperas tsnlphate of lron) with SACKED lime and
sawdust, ana exposing the mixture to the air to
oxidlze the protoxide OF iron 10 the sesquioxiae.
Jnc resulting mixture contains migrated sesquioX.
lie OF iron, suiphate OF lime, sawdusi.
When an excess OF hydrate OF lime Is employed
the resulting mixture contains tins substance also.
Ihis material very effective removing the sui
phur compounds from the gas. There Is however,
sone difference OF opinion az 10 tho completeness
perhaps w variations IN the proportions Of the
gradients. Two important advantages attend The
OF TINS mixture; first when fouied IT. does mol
evolve offensive odors on exposure 10 the ar: see
ond by exposure I'D alt the scsquioxde OF iron,
which has Deen changed to sulphide Of IRON IN the
purifier, Is regenerated. the sulphur being bereted
ana EesquloXde of iron agaiu formed. The mix
turc may therefore, he used aguin aud again
.lll 1t becomes clogged with the sulphur dber-
ated thai IT does nos act promptly on the sa4. II s
tnen found 10 contain rom forty 70 sixty per Gem Of
sulphur, and may be used for the manufacture OF
suiphurlc acid. | have seen mixtures which had
been Ia use twelve mouths.
4. me AO! one Process
few months after iauing introduced the artificial
bydrated sesqui02ldc Df IRON in France Nj. j. NJ. Hills
applied the natural hydrated so sau1oxide OF iron or
.bog iron ore nEngland THIS material, Ike the
Laining mixture, may De used,again and again ana
dues not evolve offensive odors Wnen exposed ~
the air. A modification OF tliS process ls now used
by the New York Gas Light Company ol this city.
1t was invented by MeSsrs Sr. John and CarGwright.
and mas been IN use nearly two years giving entire
satisfaction As the Dog iron ores OF mis- nughoor-
hood are not sufficiently pulvcfuienl to act promptly
oil the gas Messis ST. John and Cartwright add tu
the ore a quaiiIty ol iron behring's or turnngs.
which they then convert ino IN artificial hyaratel
sesquoxide OF IRON by lnoisiening the Whole with
aLnm0naca liquor and exposing IL TO The uir. The
resulting MIXTURE OF natural AMI artificial oxide re.
ceiyes an addifion OF coarsey pulverzed charcoal.
This mixture is always aprinklcd Win AmniOnlacai
waler before IL IL placed IN the puriBer.
The material now in daily use at the works OF
In Aprll. is6s. occasional additions of Iroa
borings have been made 10 ~; otherwise the
material is the same. When last tested II contained
thirty per cent or sulphur. IN Germany several
varieties OF sesquloxlde Ur IRON are now In Use,
prominent among which are The Oberuseler NIX
silren an iron ore containing some oxide OF man.
ganese; the "Manhein oxIde,n ana Deckes 3
oxide very pure artificial oxides OF iron,
U-kxrENr no WHICH the DIFFERENT METHODS OF
PuRiFnArioN ARA EMPLoyEp.
ihe wet iitle mtthod has been almost entirely
abandoned. ihe only works at which know 1t 10
oe used 81 present are Al Cork. III Ireland. These
WORKS are of moderate slze ana are situated out or
the cify- moreover, Tue Vas * freed from ammonia
10y means t supnurlr acui before II cones In con
tact with TIE lime. The fonl ltue does not there
fore evolve aulphlde ol amInonium when exposed 10
the air. The dry lime process though s IN genera
use IN this country, las oeen almost universally
abandoned III Europe. Ap1nuoned. nrsty, because
the foul lime was al intOifrape nuisance: srcopdlv
bec3 use the process 100 expensive the line can
DE nxed but once and wien exhausted has hui a
trirEg value ~ fertilizer
The i,aming mixture Is new 'isei ID many 81 the
European gas works. All the gas supplied TO PARIS
is purified by rbis maieria. Ihe German gHa en-
gneers have found that thid lixtl"e owes ITS en-
cacy entirely to The oxide Of iron wucl It contains
and that the sulphate and hyIrate ~ lime present
do not take any appreaaole pHrb IN the putiheatoh.
Hence Llcy ABANDONING tbs mixture Tor tbe
natlral0r srt,ncaI oxNes or iron which cheaper
and more efGcient
The IRON ore method Ia row most generally nsed
an Europe and na5 obtained 1UDthUld IN ths
country beng used by the New York Gas night Com
pany ln this city, as already described, and by TWO
or three companies ju HassacnusetL6. All the
Liverpool gas, niuch II not AL or the Lcndon
gas, and tliat " most or rho German ciHes IL