Eger Murphree and the Four Horsemen: FCC, Fluid Catalytic Cracking

Don­ald Camp­bell, Homer Mar­tin, Eger Mur­phree and Charles Tyson, who were known for their devel­op­ment of a process still used today to pro­duce more than half of the world’s gaso­line. These “Four Horse­men” were part of the Exxon Research Co. The world’s first com­mer­cial Flu­id Cat­alyt­ic Crack­ing facil­i­ty began pro­duc­tion for Exxon in 1942. The Flu­id Cat­alyt­ic Crack­ing process rev­o­lu­tion­ized the petro­le­um indus­try by more effi­cient­ly trans­form­ing high­er boil­ing oils into lighter, usable products.

Their notable US Patent No. 2,451,804: A Method of and Appa­ra­tus for Con­tact­ing Solids and Gas­es describes their mile­stone inven­tion. Over half the world’s gaso­line is cur­rent­ly pro­duced by a process devel­oped in 1942 by 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. 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. By 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.
 
Con­tributed by Nation­al Inven­tors Hall of Fame website
1999