TITLE: Appendix B. Interim Progress Report, October 1, 1978-December 31, 1979 (for the Massachusetts Institute of Technology)

AUTHOR: C. N. Satterfield;   J. P. Longwell;   G. A. Huff.

INST.  AUTHOR: Massachusetts Inst. of Tech., Cambridge.

SPONSOR: Department of Energy, Washington, DC.

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  1979,  19p.

NTIS REPORT NO.: DE84009345

ABSTRACT:

We can make some comments about the overall rate constant based on our experimental work and on previous work on the Fischer-Tropsch synthesis in the vapor phase for an iron catalyst, and founded on our experience with mass transfer in general. First, the intrinsic component reportedly has an activation energy of 17 to 27 kcal/mole (appendix A) while the mass transfer term should be around 5 kcsl/mole. In other words, there is a striking difference for the temperature dependency of mass transfer and of the intrinsic reaction that make up the overall rate constant. As is often the case, intrinsic kinetics dominate at lower temperatures but mass transfer at higher temperatures. Second, when only the degree of agitation is changed, the mass transfer term will vary while the intrinsic rate component remains constant. Specifically, for our experimental apparatus, gas bubble size decreases and gas hold-up increases as the shear-rate increases with more rapid stirring speeds. As a result, there is more gas in the slurry with a larger surface area for mass transport, and, hence, the mass transfer component diminishes as agitation increases. For this report, we dwell on the rate of synthesis gas disappearance. However, preliminary evidence is presented to suggest that mass transfer also markedly affects the product distribution. (ERA citation 09:019873)

REPORT  NUMBER: DOE/ET/13376-T1

CONTRACT  NUMBER: AT01-76ET13376