-
8/8/2019 13_4_NEW YORK_09-69_0151
1/9
\
\
'\
15i
CHEMICALS FROM COAL
Howard R. BatchelderBattelle 'Memorial Institute, Columbus Lab
orat orie s
Columbus, Ohio
Introduction
This paper is intended a s a review up to 1 9 6 2 of the hist
ory of chem icalsfro m coal, the controlling influences in the
past, and what ma y be expected inthe future. The te rm "chemicals"
c ov ers pr im ari ly ammonia, the light aro -ma tic s (benzene,
toluene, and xylene), t a r acids, t a r bas es and t a r o r
pitch,gas , and coke.
In the United States, thes e chem icals have been derived fr om
c oalalmost exclusively through high-tempera ture byproduct
carbonization. InEngland and in Europe, thes e and other chem icals
have been obtained to som eextent through various low-temperature
carbonization pr oc es se s and by coalhydrogenation in England and
Germany for a few years.to tra ce the periodic efforts to establish
low-temperature carbonization in theUnited States. In no cas e did
these res ult in significant com me rci al chemica lproduction.
No attempt will be made
In this country, the production of coke was clo sely linked to
the demandsof the iron and st ee l industry . Up to the tim e of
World War 11, in periods ofhigh industrial activity with good mar
ke ts fo r steel , coke-oven capacity andoutput inc rea sed and the
coal chem icals we re in good supply. When demandfor s te el
decreased, oven operation slowed down and the supply of c hem
icalsfel l also. Markets fo r the chemicals other than coke wer e
nev er st ron g enoughto justify oven operation fo r the se
alone.
In 1910, coke-ma king capacity amounted to about 70 million tons
pe ryear--sub stantially al l in beehive ovens with no chemicals
recover y. Coal t a rderivatives w er e obtained prim arily by
importatio n fr om Germany. During andimmediately aft er World War
I with the Ger man s upplies cut off, the marketsfor ch emicals
obtainable fr om coal we re s tron g enough to supp ort the
construc -tion of byproduct ovens and s t a r t the d isplacem ent
of beehive ovens. A t the endof the war (1919), total carbonizing
capacity had r is en to 97 million tons p eryear, of which 407' was
in byproduct ovens. A t no subsequent ti me did the tot alcapacity
in cr ea se above the 97 million tons, but by 1944 alm os t 90% of
th e tot alcapacity was in byproduct ovens.in beehive ovens.
In 1962, only 270of the t ot al coke was produced
-
8/8/2019 13_4_NEW YORK_09-69_0151
2/9
W o r l d War I1 brough t imp erat ive demand s for toluene,
ammonia, andothe r ch emicals that could not be m et by the coke
plants. ' Petroleu m andnatural gas were used a s r a w ma ter ial
s, and since that time they have dominated.In a very re al sense,
the e r a of significance for chemicals from coal was theperi od
from 1920 to 1940.
Let us co nsid er now som e of the most im portant chemicals to
s ee howthe production fro m coal rel ate s t o the production from
other raw m aterials.
Ammonia
The co mm erc ial syn thes is of amm onia was well establish ed
by 1925,F ro m that time , byproduct ammonia
and by 1940 had r ea ch ed a production rat e twice a s grea t a
s the ammoniarecovered from byproduct operations.held i n the
neighborhood of 200,000 to 250,000 ton s pe r ye ar until 1957.
Duringthe next five years, it dropped to about 175,000 tons p er ye
ar.of synth etic ammonia has doubled ev ery five o r six y e ar s
and by 1962 it hadreached almost, 6 million tons per year.
The production
Figure 1 'shows the production ra te fo r each. Fig ure 2 shows
the by-product ammonia a s a perc enta ge of the total.3% of th e
total ammonia produ ction in the United States.
In 1962, thi s repr esen ted only
Benzene
Until 1950, b enzene w as obtained alm ost exclusively fro m the
prod uctsof c oal carbon ization- -ei the r scrubbe d from the gas
a s "light oil" o r distilledfrom the ta r s t ream. By 1940,
production had ri se n fr om the dep ress ion lowsto around 150
million gallons per year . During the fift ies it reached a peak
ofalmo st 200 million gallo ns pe r ye ar and h as dropped
significantly since.1950, petroleum benzene w as included in the
production sta tis tic s for the firs tt ime at 10 million gallon
s.Figure 3 shows the dr am at ic r is e of this production and the
relation to benzenederived from coal. Actually, much of the benzene
for me rly derived from coalwould not be sal able in to da y' s
marke t. It has been only by improved methodsof recovery and
purification that coke-oven benzene has been able to withstandthe
competition of petroleum -derived benzene a s well as i t has.
In
By 1962, thi s had ris en t o 418 million gallons.
Most of th e benze ne produced h as been used as intermedia te
in themanufacture of chem icals that have only come to significance
sinc e the timeof World War 11. St yr ene , cyclohexane, and phenol
account for almos t th re e-fourths of the benzene consumption.
Since 1950, t he sp eci fic addition of benzene
-
8/8/2019 13_4_NEW YORK_09-69_0151
3/9
153
to gasoline has been negligible in te r m s of the othe r
uses.recove ry of benzene fr om petroleum so ur ces has been in
resp onse to a demandthat did not exist in the earlier days, but
which is la rg e enough s o that benzenefr om coal could not have
begun to sa tisf y it .
Thus it is that the
The economics of the production of benzene from pet rol eum so
ur cesdet erm ine the pri ce at which benzene fr om co al can be
sold. Th e coke-ovenbenzene production is mo re o r le ss fixed by
the demands of the st ee l industryfo r coke. The benzene so
produced mus t be sold, but the production f ro mpetroleum can be
flexible and can respond in volume to the pr ic e situation.
TolueneA s the demands of the first world w ar led to the
production of toluene
from byproduct ovens, s o the gr ea te r demands of the second
world wa r led tot h e fi rs t significant production fr om
petroleum. During the whole hist ory ofcoke-oven operatio n in the
United States, the production of toluene f ro m coaldid not re ac h
50 million gallons per year . During the war, the production
oftoluene f rom petroleum in only five ye ar s r os e fr om nothing
to o ve r 160 milliongallons pe r year . A t the end of the wa r,
it dropped to le ss than 10 milliongallons, the n sta rte d a climb
that ha s not yet slowed down. Fig ur e 4 shows th eproduction fr
om coal and fro m petroleum.
The very drama tic rise during the wa r and sh ar p drop in 1946
a r eevidence of th e flexibility of the supply from petroleum.tha
t let s the coke-oven production se t a floor under the p rice
range and thepetroleum supply se t a ceiling.mate r ia l w i l l
come into the ma rke t-- to withdraw if the pri ce declines.
It is this flexibilityA s price increases , more and mor e
petroleum
Much of the toluene produced is used fo r the hydrodealkylation
to benzene,th er ef or e a significant amount of benzene from
petroleum is via toluene. Motorgasoline, solvents, and aviation
gasoline ar e other maj or uses, and it is probablyin these ma rk
ets that most of the toluene from coal is used.
Xylenes fr om coa l have not been of gr eat imp ort anc e in the
past. Duringthe fifties, production ro se t o above 10 million
gallons per yea r for seven ye ar s ,after which it dropped.fro m
petroleum.This dropped after the.war, but in 1948 star ted an incre
ase that ca rr ied productionto almost 350 million gallons in 1962
.
PriQr o World War I1 th er e was no significant productionIn
1944 , almost 50 million gallons was re cov ere d from
petroleum.
-
8/8/2019 13_4_NEW YORK_09-69_0151
4/9
154
This is shown in Fi gur e 5. A substantial part of the
production issepa rated into the i s o m e r s fo r production of
phthallic anhydride, isophthallicand terephthallic acids.
Phenol
The synthesis of phenol was established as a comm ercial
practicemany ye ar s ago, and by 1940 the synt hetic production
alread y amounted tothr ee o r four t imes the amount recov ered fr
om coke-oven operations.fro m coa l stayed in the rang e of 2 t o 3
million gallons per yea r until 1 9 5 5 whenit rose to 4 to 6
million gallons.fro m about 8 million gallons in 1940 to over 80
millio n gallons in 1962 .
PhenolSynthetic phenol ha s increa sed r at he r stea dily
These a re shown in Figure 6.
Naphthalene
Coke-oven op eratio ns have been the p rim ary o r exclusive sou
rce ofnaphthalene through su bst ant iall y al l of the pe rio d
under consideration. However,som e naphthalene w as mad e fro m p
etroleum by hydrodealkylation in 1961 , andby 1964 th is accounted
for over 40% of the to ta l production. It ha s been est ima
tedthat the maximum amount available fro m coal tar would be app
roxim ately 6 5 0million pounds pe r yea r. The total 1964
production (including petronaphthalene)was 7 4 0 million pounds.
Obviously, future increases in naphthalene supply willnecessarily
be of petroleum origin.
T a r B a se s
Of the t ar ba se s, pyridine until the middle fifties was
available onlyfro m coal t a r , a s w er e som e of the homologs.
The production of syntheticpyridine, the picolenes, and othe rs has
made for a mor e stable market .andmay in the future lead to the
development of mo re wides pread us es.estim ated that the pr ese
nt synthetic pyridine capacity is adequate to supply th eto ta l
demand. It s e e m s evident that, if the consumption of pyridine
and othe rbas es expands, synthetic ma ter ial wi l l supply this
increase-,-not increasedproduction from c oal carbonization.
It is
-
8/8/2019 13_4_NEW YORK_09-69_0151
5/9
1 5 5
Coke-Oven Gas
A t one period, gas was a significant byproduct of coal
carbonization,too valuable to be used in underfiring the ovens.gas
we re used fo r underfiring to make the coke-oven ga s available
for sal e.addition, a significant amount of coke was consumed in
the manufacture ofcarburetted water ga s and water gas fo r ammonia
synthesis.
Blast furnace gas and producerIn
The increased availability of natural gas has substantially
eliminatedboth of these so tha t coke-oven gas now finds its
principal use a s a captiveplant fuel. Under any normal
circumstances, i t see ms certain that futureincreases in fuel
needs wil l be supplied by methane whether of na tu ra l ori gino r
synthesized.
Coke-Coke itself, the pr im ar y product of carbonization, has
exp erien ced
also the erosion of its ma rke ts by inc rea sed utilization of
petroleum o r natu ralgas. As stated above, coke for wate r ga s
production is no longer necess ary toany extent. Even in the blast
furnace, the use of oil o r gas injection, togetherwith oth er
changes, ha s reduced the coke req uir ed pe r ton of
iron.improvements in the blas t furn ace contributed to the
reduction in coke r ate ,but the ov erall effect is striking.
Many
In 1962, 66 million.tons of pig i ro n wer e produced. At the av
erag e cokera te of 1920, t hi s would have req ui re d ov er 68
million tons of coke. Actualcoke usage in 1962 was only 46 million
ton s-- a difference of 22 million tons.
Conclusions
Fr om the foregoing, it se em s evident that chemicals fro m
coke-ovenoperation--no ma tt er how importa nt t o tha t
operation--cannot be expected to bea significant fact or in the
future. If chem icals fr om coal a r e to be important,they must be
derived fro m s ome other means of coal conversion on a
massivescale.
Work to be repo rted in thi s symposium may lead to the
establishmentof an industry fo r the conversion of c oal to
products such a s liquid fuels o n ama jor scale. In that cas e,
the simultaneous production of vario us chem icalsmay be of a
magnitude to challenge the dominance of petroleum and natur al
gas,and the income from chemicals production may be a significant
part of theeconomic justification of such plan ts
-
8/8/2019 13_4_NEW YORK_09-69_0151
6/9
156I
In making the economic calculations, it must be rememb ered that
in
plant, presumably, will not have this freedom, and the projected
chemi cals
11any cases t h e production of chemicals from petroleum is very
flexible, withfreedom to enter or withdraw from ma rke ts a s pri
ce s fluctuate. The coal
income must not be calc ula ted on the ba si s of a pr ic e
higher than that whichw i l l induce the fi rs t pe trole um
competition into the mar ket.
1,)!
-
8/8/2019 13_4_NEW YORK_09-69_0151
7/9
. . -157
\.
1
\\
\\\
\\
a4
Y
I0 00 (Y
a20L5
-a
0dI
DIp
0mL0dzI * 1
0 0 0 0 0 00 0 0 0 s(Y00
(Y
0 0 00 0 0
o m CD eq m C D dc90. 0.
i
-
8/8/2019 13_4_NEW YORK_09-69_0151
8/9
158I
aLL \\
1 I 10 0 0 0 0 0 0 0 0O D 0 d N0 0 0 0 ZOD" d N
SNOl lVO NOI l l IMI
4 , I 1 I I:0 0 0 0 0 0 0 0O D Q * N0 0 0 0 ? O D " d (YSNOllVD
NO1111W
I' 1
-
8/8/2019 13_4_NEW YORK_09-69_0151
9/9
i
L,
159
I 1 I 10 0 0 0 g w c d N - -Q D Q d hl
.SNOllVD NOl l l IW
E0aY
0(0
S N O ll V D NO1111MI
