Potentials for New Reactor Configurations for Fischer-Tropsch Synthesis and Methods of Design

Abstract

Gas-to-Liquid (GTL) technology represents a major pathway for the production of easily-transportable liquid hydrocarbons and value-added chemicals from abundant natural resources (coal, natural gas, and biomass). The Fisher-Tropsch synthesis (FTS) reaction is the principal route for GTL processes. It was developed in early 1923 and within only a few years after its discovery, eight industrial plants for fuel production using FTS technology were operating in Germany. Even though more than hundred plants of different capacities were built since then, only three main designs for the reactor bed found their way to commercial scale plants (tubular fixed-bed reactors, fluidized fixed-bed reactors, and slurry reactors). Challenges related to the optimization of existing commercial reactors or to the consideration of alternative designs for FTS processes still exist. These challenges can be attributed to many fundamental reasons including the complex nature of the synthesis process/reactions as well as certain technical difficulties in controlling the thermophysical characteristics of the reaction in conventional reaction media (i.e. gas-phase or liquid-phase). This paper summarizes the challenges facing existing commercial reactors and the potentials for proposed new designs (micro-reactors, supercritical fluid FTS process based on fixed-bed reactors, monolith reactor, etc.). A configuration of a novel FTS reactor technology that combines the advantages of slurry reactor and fixed-bed reactor and at the same time overcomes many of their limitations will be presented. Simulation of performance of the novel reactor will be compared to existing commercial reactors and others under typical industry operating conditions of standard cobalt-based catalyst.

Related Publications:

1. Elbashir, N. O., Bao, B., and El-Halwagi, M. M., "An Approach to the Design of Advanced Fischer-Tropsch Reactor for Operation in Near-Critical and Supercritical Phase Media", H. E. Alfadalla, G. V. Reklaitis, M. M. El-Halwagi Editors "Advances in Gas Processing: Proceedings of the 1st Annual Symposium on Gas Processing. Elsevier, Amsterdam, The Netherlands 2009,Volume 1, 423-433.

2. Elbashir, N. O. "Advancement in the design of Fischer-Tropsch reactor technology and the potentials for nonconventional reaction media" ACS Fuel Chemistry Division Preprint 54 (2), in press.

3. Elbashir, N. O. , C. B. Roberts (2005) "Enhanced Incorporations of Ą-olefins in the Fischer-Tropsch Synthesis Chain-Growth Process Over an Alumina Supported Cobalt Catalyst in Near-Critical and Supercritical Hexane Medium" Industrial & Engineering Chemistry Research. 44, 505-521.