TITLE: Coal Liquefaction Research, October 1, 1978-September 30, 1981.

AUTHOR: H. Heinemann.

INST.  AUTHOR: California Univ., Berkeley. Lawrence Berkeley Lab.

SPONSOR: Department of Energy, Washington, DC.

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  Sep 81,  51p.

ABSTRACT:

Progress reports are presented for the following two areas: catalytic cracking studies with water-wet silica-alumina catalysts; and Fischer-Tropsch reactor studies where similarities and differences between fixed bed and slurry type reactors are investigated and further experiments conducted to measure mass transfer coefficients and reaction kinetics which are to be used in a model slurry reactor. The following are some of the conclusions. (1) The premise that the presence of liquid water might increase catalytic cracking activity was found to be invalid. It was demonstrated that cracking can occur at previously unobserved low temperatures (though at low conversions) and that an anomaly exists in that one of the catalysts tested shows an entirely different cracking behavior and probably follows a different cracking mechanism. (2) the diameter of a fixed-bed Fischer-Tropsch reactor critically affected the resistance of the reactor to plugging caused by the build up of carbonaceous or waxy deposits. Plugging was very likely due to local nonuniformity in the catalyst temperature. Decreasing the reactor diameter at a fixed gas space velocity, should improve temperature uniformity by decreasing the length of the thermal conduction path and increasing the extent of convective heat transfer from each catalyst particle.  Suppression of plugging at higher H sub 2 /CO ratios is likely due to a reduction in the product average molecular weight and the reaction with hydrogen of carbon deposited via the Boudouard reaction. A slurry bed reactor with its much greater isothermicity can be expected to behave similarly to very small diameter fixed bed reactors and therefore have a higher tolerance of lower H sub 2 /CO ratio feed gas. (ERA citation 06:034218)

REPORT  NUMBER: LBL-13238

CONTRACT  NUMBER: W-7405-ENG-48;   FG22-78ET1143