United Gas Improvement Co.'s cyclic catalytic reforming process, schematically shown here, now used in 17 installations. It produces carrier gas from feed stocks of natural gas through kerosine, and offers substantial cost advantages by Using existing installations
1 Eliminating need for
coke fuel.
I-
C. G. MILBOURNE and C. 8. GLOVER United Engineers & Constructors, Inc., Philadelphia, Pa.
Cyclic Catalytic Reforming Process
WHEN
NATURAL gas was delivered to the Eastern Seaboard in 1948, gas utility companies were faced with the problem of how to utilize this new supply of energy. At that time most of the companies were distributing manufactured g a s - c o a l gas, carbureted water gas, or a mixture of the two-at a calorific value of about 530 B.t.u. per cubic foot. Some utilities decided to convert their systems to the use of straight natural gas; others elected to remain on a mixed gas basis, and utilize natural gas essen-
tially as one of the raw materials component of the sendout mixture. As additional supplies of natural gas became available, it was found that the daily contract amount would supply all sendout requirements for a t least 9 months of the year. Therefore, those companies on a mixed gas basis began to look for a means of reforming a portion of the natural gas to a carrier gas to obtain a source of hydrogen for controlling burning characteristics, and reenriching with additional natural gas to sendout calorific-value requirements.
A commercially developed process for reforming natural gas a t that time is both thermal and cyclic; natural gas is passed through a n incandescent coke fuel bed of a standard water gas' set, and cracked to hydrogen and carbonthe carbon essentially adheres to particles of coke fuel and hydrogen passes off in the gas stream. Thermal reforming was not economical because higher price coke fuel was required. Therefore, it became apparent that a process for reforming natural gas without using coke fuel had VOL. 49, NO. 3
MARCH 1957
387
Advantages of CCR Process
Two UGI cyclic catalytic reforming sets installed in a gas utility plant
the advantage of substantiall!. lo\vci. production cost. T h e principle of the methane-steam reaction, using a nickcl catalyst at elevated temperatures, is \vel1 kno\vn : the catalyst, contained in special al1o)tubes (6, 8-70) and externally heated, produces a reformed gas consisting essentially of hydrogen, carbon monoxide, and some carbon dioxide. T h e United Gas Improvemenr Co. (CGI) Philadelphia, Pa., in collaburacion \vith the gas division of United Engineers Pr Constructors, Inc.. buildrrs of gas production apparatus. developed the UGI cyclic catalytic reforming process (7, 3-5, 7, 7 7 , 7.3) to rrform natural gas catalytically to a carrier gas. This \vas done on the basis of lonq experience in using cyclic equipment for producing blue gas and carbureted ivatcr gas from solid fuels and oil. Further, ir \\'as felt that existing gas plant production equipment could be adapted to cyclic catalytic reforming ivitli corisiderahlc savings in capital cost.
Description of Process Design of apparatus for c a r q i n g out principles of the UGI cyclic catalytic reforming process (CCR process): foli o \ ~the~ general basic design of rvater gas apparatus. T h e set consists essentially of two refractory-lined cylindrical vessels with auxiliaries. T h e combustion shell is of steel plate, 1-7 feet in outside diameter by 24 feet
388
high, lined \vith refractory t u a n insicit. diameter of 10 feet. It is equipped l v i r h a supply of air and hydrocarbon feed for heating, and steam for process requirernents. In the lo\ver portion of the combustion chamber, rrfracrory chrckers comprising a preheat section ai^ installed. The reforming shell is of sterl plate'. 1 2 fc:ct i n outside diameter by 17 feet I i n c h e s liigli, lined \\,ith refractory to a n iiisidr diameter of 10 frrt. ; I sinqlr statiunar!. bed of nickel catalyst is located in t h t , ruppei- portion. ?'his shcll and the c~onibustion shell arc connectrd a t thr hast, by means of a rrfractory-lincd runnt.1 eqtiipped with a source of supply c'f natural gas and '(ir other liydrocarhons fur process requirements. I'ollo\ving the rcl'urixin3 shell is 'I vertical tvastc-hcat boiler> through \\-liich pass all producrs o f combustion from the heating portion of the c!-clr. and all reformed carrier gas from t h e crackirq portion. T h e aniount of high prcssure steam produced from the \Taste-heat boiler c x c e r d s total process requirrments. Auxiliary equipment includes a \ v a t u sealed \\-ash box. w \ \ w scrubber for cooling reformed gas? stcam turbinedriven air blower.. steam accurnulator, and h>-draulic pumping system. I n addition, cyclic materials floxv is aclmittcd to the set by means of an automatic control machine h a t causes hydraulic valves to open and close at preset intervals. Rate of materials Ho\v is controlled by hand- or motor-operated dampers. ?'lie lieatinq ~xirtiori of thc.
INDUSTRIAL AND ENGINEERING CHEMISTRY
This pt'r~ccss is an adaptatii~ri111 tlie cyclic principle u s c d fur years i n ~iriiducing b l u r gas and carbureted \vCitri. p. This rnrthod ~ l 'storing w i t l i i i i i i relativci). short tinir, a large qiidritity ( i l heat i n the catalyst bed f O l ' ri~leasc t t i catal\.lic rcforininq of hydrcicarh,ns lias many advaritaqrs. :\Iternatel>. 1ic.atinq a n d making dirc*rtl>.through t l i t . ('iitiilyst bed tend t o L i x p tlic c a t a l i s t c t i ~ a n and activc; in normal operatii~ri,rai.bon i s not deposited. Sickcl catal! s i b drt' usuall\ I c,titlcrcd inacti\.c I)!. sulfur. \\'hilr ii lil'i, tcst has not been made, i t is brlievcd [tiat siilistantiai riili'ur coiict~iitratio~~s iii t11e f w r i s t ~ c kcan he tcileratrd \ v i t h o i t 1 c ~ d \ T r s r l ~ . affecting activity. Otic. 1)I1itit ~ i s r d 7OO.f)flO gdllons 01' Iierosirir ~ ~ ~ n r a i n i n g 0 . 0 1 ~sulfur \ v i t I i o i t t an) indii ~ i r i o nr ) I loss in ciititl!-st activit!.. I,o\v sulfur content feed S L I j < . k S , 5iic11 as liquefied p c t r o l e u ~ n(I,€') j i d s t ' s ? ~ a s u line. naphtha. and kcrosinr, liavt. been used in normal c o ~ n ~ n r r c i arjp*t~iticins. l 1)iesc.l and hriiv). oils having a sulfur r o n t c n t of(i.3 to ? , . 5 ( ' ; , respceti\.clv. l~:iv(, been succrssiiill~Lisrd in thc~?-loot pi101 plant s r t and. IO a l i i n i t t d i , \ t i , n t i n co inmr IT i ii 1 o p e r a t i u n s. This c!-clic p r i r r s s can l x ~( 1i111r111led so
