4 June 1994

Since the 1960s. the U. S. Gov­ern­ment (and now many oth­er coun­tries) required auto­mo­bile man­u­fac­tur­ers con­trol the emis­sion of nitro­gen oxides (NOx), car­bon monox­ide (CO), and hydro­car­bons pro­duced by gaso­line pow­ered auto­mo­biles. Emis­sions reg­u­la­tions estab­lished for 1982 and lat­er vehi­cles led to the devel­op­ment of the cur­rent three-way cat­a­lyst that simul­ta­ne­ous­ly con­trols all three pol­lu­tants to the required lev­els. In the late 1980s, this was already a $500 million/year busi­ness in the U. S.*

Typ­i­cal three way cat­a­lysts con­tain rhodi­um, plat­inum, and/or pal­la­di­um met­als with oth­er addi­tives that are all sup­port­ed on an alu­mi­na sup­port.# Gen­er­al­ly, the sup­port­ed cat­a­lyst is dis­trib­uted onto a ceram­ic hon­ey­comb that is then encased with­in a steel con­tain­er mount­ed under the pas­sen­ger com­part­ment. Exhaust gas­es then dif­fuse into the pores and react with a cat­a­lyst and exit as non-pol­lu­tants. The cat­a­lyst reduces the pol­lu­tants with­in about 0.5 sec­ond and oper­ates at about 1000°F. These durable sys­tems oper­ate effi­cient­ly for the life of the vehi­cle. Nev­er­the­less, new changes to the reg­u­la­tions will demand fur­ther cat­a­lyst improve­ments. Improved cat­a­lysts are need­ed for con­trol­ling cold start emis­sions from lean fuel oper­at­ed engines. Recent­ly, B. J. Coop­er summarized@ some of the tech­ni­cal chal­lenges remain­ing in auto-emis­sion con­trol catal­y­sis. Also, cat­a­lysts are need­ed for con­trol­ling emis­sions from diesel engines, espe­cial­ly with regard to soot con­trol.

John N. Armor, PhD
Group Head
Catal­y­sis Skill Cen­ter

* B. F. Greek, Chem­i­cal & Engi­neer­ing News, (May 29, 1989) 29–56.
# K. C. Tay­lor, Chemtech, (Sep­tem­ber 1990) 551–555.
@ B. J. Coop­er, Plat. Met. Rev. 38 (1994) 2–10.

Patent No. 2,451,804 Method of and Appa­ra­tus for Con­tact­ing Solids and Gas­es

Over half the world’s gaso­line is cur­rent­ly pro­duced by a process devel­oped in 1942 by a group called the “Four Horse­men” of Exxon Research and Engi­neer­ing Com­pa­ny. The world’s first com­mer­cial Flu­id Cat­alyt­ic Crack­ing facil­i­ty began pro­duc­tion for Exxon on May 25, 1942. The Flu­id Cat Crack­ing process rev­o­lu­tion­ized the petro­le­um indus­try by more effi­cient­ly trans­form­ing high­er boil­ing oils into lighter, usable prod­ucts.

The four Exxon inven­tors respon­si­ble for this crack­ing process are Don­ald L. Camp­bell, Homer Z. Mar­tin, Eger V. Mur­phree, and Charles Wes­ley Tyson.

When Exxon’s first com­mer­cial cat crack­ing facil­i­ty went on-line in 1942, the U.S. had just entered World War II and was fac­ing a short­age of high-octane avi­a­tion gaso­line. This new process allowed the U.S. petro­le­um indus­try to increase out­put of avi­a­tion fuel by 6,000% over the next three years. Flu­id Cat Crack­ing also aid­ed the rapid buildup of buta­di­ene pro­duc­tion, which enhanced Exxon’s process for mak­ing syn­thet­ic butyl rubber–another new tech­nol­o­gy vital to the Allied war effort.

In the 1930s, Exxon began look­ing for a way to increase the yield of high-octane gaso­line from crude oil. Researchers dis­cov­ered that a fine­ly pow­dered cat­a­lyst behaved like a flu­id when mixed with oil in the form of vapor. Dur­ing the crack­ing process, a cat­a­lyst will split hydro­car­bon mol­e­cule chains into small­er pieces. These small­er, or cracked, mol­e­cules then go through a dis­til­la­tion process to retrieve the usable prod­uct. Dur­ing the crack­ing process, the cat­a­lyst becomes cov­ered with car­bon; the car­bon is then burned off and the cat­a­lyst can be re-used.

Camp­bell, Mar­tin, Mur­phree, and Tyson began think­ing of a design that would allow for a mov­ing cat­a­lyst to ensure a steady and con­tin­u­ous crack­ing oper­a­tion. The four ulti­mate­ly invent­ed a flu­idized solids reac­tor bed and a pipe trans­fer sys­tem between the reac­tor and the regen­er­a­tor unit in which the cat­a­lyst is processed for re-use. In this way, the solids and gas­es are con­tin­u­ous­ly brought in con­tact with each oth­er to bring on the chem­i­cal change.

This work cul­mi­nat­ed in a 100 bar­rel-per-day demon­stra­tion pilot plant locat­ed at Exxon’s Baton Rouge facil­i­ty. The first com­mer­cial pro­duc­tion plant processed 13,000 bar­rels of heavy oil dai­ly, mak­ing 275,000 gal­lons of gaso­line.

Con­sid­ered essen­tial to refin­ery oper­a­tion, Flu­id Cat Crack­ing pro­duces gaso­line as well as heat­ing oil, fuel oil, propane, butane, and chem­i­cal feed­stocks that are instru­men­tal in pro­duc­ing oth­er prod­ucts such as plas­tics, syn­thet­ic rub­bers and fab­rics, and cos­met­ics. Dur­ing today’s Flu­id Cat Crack­ing process, a box­car load of cat­a­lyst is mixed with a stream of oil vapor every minute. It is this mix­ture, behav­ing like a flu­id, that moves con­tin­u­ous­ly through the sys­tem as crack­ing reac­tions take place.

Flu­id Cat Crack­ing cur­rent­ly takes place in over 370 Flu­id Cat Crack­ing units in refiner­ies around the world, pro­duc­ing almost 1/2 bil­lion gal­lons of gaso­line dai­ly. It is con­sid­ered one of the most impor­tant chem­i­cal engi­neer­ing achieve­ments of the 20th cen­tu­ry. Flu­id Cat Crack­ing tech­nol­o­gy con­tin­ues to evolve as clean­er high-per­for­mance fuels are explored.

Don­ald L. Camp­bell was born August 5, 1904 in Clin­ton, Iowa. He has always been fas­ci­nat­ed by invent­ing and solv­ing prob­lems. He first attend­ed Iowa State Uni­ver­si­ty, then MIT and the Har­vard Busi­ness School. Dur­ing his 41 years at Exxon, 25 were spent in Exxon Research & Engi­neer­ing. At his retire­ment in 1969, he held 30 patents and was the assis­tant to the vice pres­i­dent of New Areas of Research.

Homer Zettler Mar­tin was born on Novem­ber 20, 1910 in Chica­go, Illi­nois. He received his B.S. in chem­i­cal engi­neer­ing from the Illi­nois Insti­tute of Tech­nol­o­gy and his M.S. and Ph.D. from Michi­gan. After join­ing Exxon in 1937, he became one of its most pro­lif­ic inven­tors, with 82 patents upon his retire­ment in 1973. Mar­tin died in Sun City, Ari­zona on Sep­tem­ber 1, 1993.

Eger Vaugh­an Mur­phree, born Novem­ber 3, 1898 in Bay­onne, New Jer­sey, moved as a young­ster with his fam­i­ly to Ken­tucky. At Ken­tucky Uni­ver­si­ty, he grad­u­at­ed with degrees in chem­istry and math­e­mat­ics (1920), then went on for his mas­ter’s in chem­istry (1921). After work­ing as a high school teacher and foot­ball coach for a peri­od of time, he attend­ed MIT for two years. In 1924, he went to work at Solvay Process Com­pa­ny as a chem­i­cal engi­neer, and in 1930, joined what was then Stan­dard Oil of New Jer­sey. From 1947 to 1962, he served as pres­i­dent of the Stan­dard Oil Devel­op­ment Co., which was renamed Esso Research & Engi­neer­ing in 1955. In 1956, he was giv­en the job of direct­ing mil­i­tary projects relat­ed to the guid­ed-mis­sile pro­gram; he served one year as spe­cial assis­tant to Defense Sec­re­tary Charles Wil­son. Mur­phree, who was also a mem­ber of the com­mit­tee that orga­nized the Man­hat­tan Project, was wide­ly rec­og­nized as a leader in the fields of syn­thet­ic toluene, buta­di­ene and hydro­car­bon syn­the­sis, flu­id cat­alyt­ic crack­ing, flu­id hydro­form­ing, and flu­id cok­ing. He died of a heart attack in 1962.

Charles Wes­ley Tyson, known as Wes to his friends, was born in 1900. In 1930, after receiv­ing his bach­e­lor’s and mas­ter’s degrees in chem­i­cal engi­neer­ing from MIT, he joined Esso. In 1961, he was appoint­ed spe­cial assis­tant to the vice pres­i­dent of Exxon Research & Engi­neer­ing, and at his retire­ment in 1962, he held 50 patents. Tyson died in 1977.

Copy­right 1999, Nation­al Inven­tors Hall of Fame, Akron, Ohio.

Cat­a­lysts, in the def­i­n­i­tion devel­oped by Berzelius and oth­ers in the last cen­tu­ry, are mate­ri­als which change the rate of attain­ment of chem­i­cal equi­lib­ri­um with­out them­selves being changed or con­sumed in the process.

Catal­y­sis is an aston­ish­ing phe­nom­e­non. Some cat­a­lysts achieve aston­ish­ing activ­i­ties, so that very small quan­ti­ties of cat­a­lyst can con­vert thou­sands or mil­lions of times their own weight of chem­i­cals. Equal­ly sig­nif­i­cant, how­ev­er, is selec­tiv­i­ty; usu­al­ly thought of in terms of a cat­a­lyst accel­er­at­ing one of a num­ber of com­pet­ing reac­tions, but also pos­si­ble by virtue of a cat­a­lyst select­ing one reagent out of a com­plex mix­ture.

Catal­y­sis is the key to both life and lifestyle. It is an essen­tial tech­nol­o­gy for chem­i­cal and mate­ri­als man­u­fac­tur­ing, for fuel cells and oth­er ener­gy con­ver­sion sys­tems, for com­bus­tion devices, and for pol­lu­tion con­trol sys­tems. Cat­a­lysts are wide­ly used in food pro­cess­ing, and enhance the per­for­mance of oth­er con­sumer prod­ucts such as laun­dry deter­gents. The pos­si­bil­i­ty of analysing and ulti­mate­ly manip­u­lat­ing genes rests on the cat­alyt­ic prop­er­ties of RNA to repli­cate mol­e­cules con­tain­ing bio­log­i­cal infor­ma­tion. New sen­sor sys­tems use cat­alyt­ic sur­faces to detect spe­cif­ic mol­e­cules and announce their pres­ence through the heat of a vig­or­ous cat­alyt­ic reac­tion. And while the ten­den­cy is to think of catal­y­sis as a phe­nom­e­non for mak­ing things hap­pen, the basis of many valu­able drugs is the oppo­site phe­nom­e­non; Via­gra and Quinapril com­bat impo­tence and hyper­ten­sion by inhibit­ing enzymes, respec­tive­ly PDE‑V, a phos­pho­di­esterase which breaks down the NO mes­sen­ger cGMP, and ACE, the Angiotensin-Con­vert­ing Enzyme.

The eco­nom­ic con­tri­bu­tion from catal­y­sis is as remark­able as the phe­nom­e­non itself. Esti­mates from just four years ago that 35% of glob­al GDP depends on catal­y­sis missed much of the emer­gent genet­ic busi­ness. Con­fin­ing the analy­sis to the chem­i­cals indus­try, with glob­al sales of per­haps US$1.5 x 1012 the pro­por­tion of process­es using cat­a­lysts is 80% and increas­ing. The cat­a­lyst mar­ket itself is US$1010, so that catal­y­sis costs are much less than 1% of the sales rev­enue from the prod­ucts which they help cre­ate. Small won­der that the cat­a­lyst mar­ket is increas­ing at 5% per annum.

The terms “cat­a­lyst” and “catal­y­sis” have also trans­lat­ed from the world of sci­ence to every­day cliché. Our west­ern soci­ety places a high val­ue on the pow­er to induce change, under the descrip­tor “progress”, and it is small won­der that “cat­a­lyst” is a trade­name cho­sen for wine, per­fume, mag­a­zines, man­age­ment con­sul­tan­cies and adver­tis­ing agen­cies. There is even a breed of com­ic-book super­heroes.

The east­ern tra­di­tion is dif­fer­ent. Rather than depict­ing a cat­a­lyst as an agent of rapid break­down and change, the Chi­nese char­ac­ters for “cat­a­lyst” also apply to “mar­riage bro­ker”.

This is a sub­tle and per­cep­tive appre­ci­a­tion of how cat­a­lysts work. It also seems most appro­pri­ate giv­en that the suc­cess­ful cre­ation and appli­ca­tion of cat­alyt­ic process­es is gen­uine­ly mul­ti­dis­ci­pli­nary. On a tech­ni­cal lev­el it requires skills in chem­istry, chem­i­cal engi­neer­ing, mate­ri­als tech­nol­o­gy, as well as the eco­nom­ics and prac­ti­cal­i­ties of man­u­fac­tur­ing process­es. And it can best be induced by active and strate­gic col­lab­o­ra­tion between indus­try, uni­ver­si­ties and gov­ern­ment.

Chris Adams
Insti­tute of Applied Catal­y­sis
Chris@xef6.demon.co.uk
See also: “Catalysing Busi­ness” by C J Adams, Chem­istry and Indus­try, 1999, pp740-743