Synthesis hydrocarbons

Fischer-Tropsch Process. The Hterature on the hydrogenation of carbon monoxide dates back to 1902 when the synthesis of methane from synthesis gas over a nickel catalyst was reported (17). In 1923, F. Fischer and H. Tropsch reported the formation of a mixture of organic compounds they called synthol by reaction of synthesis gas over alkalized iron turnings at 10—15 MPa (99—150 atm) and 400—450°C (18). This mixture contained mostly oxygenated compounds, but also contained a small amount of alkanes and alkenes. Further study of the reaction at 0.7 MPa (6.9 atm) revealed that low pressure favored olefinic and paraffinic hydrocarbons and minimized oxygenates, but at this pressure the reaction rate was very low. Because of their pioneering work on catalytic hydrocarbon synthesis, this class of reactions became known as the Fischer-Tropsch (FT) synthesis. 

In the mid-1930s Universal Oil Products reported (33,34) that gasoline of improved quaHty could be produced by cracking the high boiling fractions of Fischer Hquids, and a consortium, the Hydrocarbon Synthesis, Inc., entered into an agreement with Ruhrchemie to Hcense the Fischer synthesis outside Germany. 

Other synthetic methods have been investigated but have not become commercial. These include, for example, the hydration of ethylene in the presence of dilute acids (weak sulfuric acid process) the conversion of acetylene to acetaldehyde, followed by hydrogenation of the aldehyde to ethyl alcohol and the Fischer-Tropsch hydrocarbon synthesis. Synthetic fuels research has resulted in a whole new look at processes to make lower molecular weight alcohols from synthesis gas. 

After reduction and surface characterization, the iron sample was moved to the reactor and brought to the reaction conditions (7 atm, 3 1 H2 C0, 540 K). Once the reactor temperature, gas flow and pressure were stabilized ( 10 min.) the catalytic activity and selectivity were monitored by on-line gas chromatography. As previously reported, the iron powder exhibited an induction period in which the catalytic activity increased with time. The catalyst reached steady state activity after approximately 4 hours on line. This induction period is believed to be the result of a competition for surface carbon between bulk carbide formation and hydrocarbon synthesis.(6,9) Steady state synthesis is reached only after the surface region of the catalyst is fully carbided. 

The steady state rates of hydrocarbon synthesis over the carbided iron surface are given in Table I. The reaction rates have been normalized to the physical surface area of the starting iron powder [18 M /g] and are reported in molecules/cm sec. A turnover... 

Hydrocarbon Synthesis and Rearrangement over Clean and Chemically Modified Surfaces... 

The poor regioselectivity of alkyne insertion in our polycychc aromatic hydrocarbon synthesis (Scheme 17) suggested to us that perhaps the palladium intermediate in that process was actually undergoing migration from one aromatic ring to the other, perhaps by a Pd(IV) hydride intermediate, to establish an equilibrium mixture of two regioisomeric arylpalladium intermediates under our reaction conditions (Scheme 18). This, indeed, appears to be true as... 

This section covers recent advances in the application of three-phase fluidization systems in the petroleum and chemical process industries. These areas encompass many of the important commercial applications of three-phase fluidized beds. The technology for such applications as petroleum resid processing and Fischer-Tropsch synthesis have been successfully demonstrated in plants throughout the world. Overviews and operational considerations for recent improvements in the hydrotreating of petroleum resids, applications in the hydrotreating of light gas-oil, and improvements and new applications in hydrocarbon synthesis will be discussed. 

The overall reaction of the desired hydrocarbon synthesis is thus... 

McDonald, M.A., Storm, D.A., and Boudart, M. 1986. Hydrocarbon synthesis from carbon monoxide-hydrogen on supported iron Effect of particle size and interstitials. J. Catal. 102 386 -00. 

Weller, S. E. 1947. Kinetics of carbiding and hydrocarbon synthesis with cobalt Fischer-Tropsch catalysts. J. Am. Chem. Soc. 69 2432-36. 

Arcuri, K. B., andLeviness, S. C. 2003. The regeneration of hydrocarbon synthesis catalyst, a partial review of the related art published during 1930 to 1952. Paper presented at the AIChE Spring National Meeting, New Orleans, April 2. www.fischer-tropsch.org. 

Lapidus, A., Krylova, A., Kazanskii, V., Borovkov, V., and Zaitsev, A. 1991. Hydrocarbon synthesis from carbon monoxide and hydrogen on impregnated cobalt catalysts. Part I. Physico-chemical properties of 10% cobalt/alumina and 10% cobalt/ silica. Appl. Catal. 73 65-81. 

Kravtsov, A.V., Moizes, O.E., Usheva, N.V., and Yablonskii, G.S. 1988. Kinetic model for hydrocarbon synthesis from CO and H2 accounting for its intragroup distribution. React. Kinet. Catal. Lett. 36 201-6. 

Bechara, R., Balloy, D., and Vanhove, D. 2001. Catalytic properties of Co/Al203 system for hydrocarbon synthesis. Appl. Catal. A 207 343-53. 

The Friedel-Crafts hydrocarbon synthesis appears to be a similar process in which (usually) a proton is displaced, but the actual reagent is... 

R. Madon and E. Iglesia, Hydrogen and CO intrapellet diffusion effects in ruthenium-catalyzed hydrocarbon synthesis, J. Catal., 1994, 149, 428 137. 

F. Hershkowitz, Hydrocarbon Synthesis Process Using Pressure Swing Reforming, US Patent 7,053,128 B2 (2006). 

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