Improved Fischer-Tropsch Slurry Reactors

Andrew Lucero

关键词: ALCOHOLS;    BOILING;    CATALYSTS;    COALESCENCE;    DISULFIDES;    ETHANE;    EVAPORATION;    HEAT TRANSFER;    HOT SPOTS;    HYDROCARBONS;    MASS TRANSFER;    METHANE;    MIXTURES;    MOLYBDENUM;    PROPANE;    SLURRY REACTORS;    SYNTHESIS;    SYNTHESIS GAS;    TEMPERATURE CONTROL;   

DOI  :  10.2172/993519
RP-ID  :  WRI-09-R005
PID  :  OSTI ID: 993519
Others  :  TRN: US1008139

美国|英语

来源: SciTech Connect

【 摘 要 】

The conversion of synthesis gas to hydrocarbons or alcohols involves highly exothermic reactions. Temperature control is a critical issue in these reactors for a number of reasons. Runaway reactions can be a serious safety issue, even raising the possibility of an explosion. Catalyst deactivation rates tend to increase with temperature, particularly of there are hot spots in the reactor. For alcohol synthesis, temperature control is essential because it has a large effect on the selectivity of the catalysts toward desired products. For example, for molybdenum disulfide catalysts unwanted side products such as methane, ethane, and propane are produced in much greater quantities if the temperature increases outside an ideal range. Slurry reactors are widely regarded as an efficient design for these reactions. In a slurry reactor a solid catalyst is suspended in an inert hydrocarbon liquid, synthesis gas is sparged into the bottom of the reactor, un-reacted synthesis gas and light boiling range products are removed as a gas stream, and heavy boiling range products are removed as a liquid stream. This configuration has several positive effects for synthesis gas reactions including: essentially isothermal operation, small catalyst particles to reduce heat and mass transfer effects, capability to remove heat rapidly through liquid vaporization, and improved flexibility on catalyst design through physical mixtures in addition to use of compositions that cannot be pelletized. Disadvantages include additional mass transfer resistance, potential for significant back-mixing on both the liquid and gas phases, and bubble coalescence. In 2001 a multiyear project was proposed to develop improved FT slurry reactors. The planned focus of the work was to improve the reactors by improving mass transfer while considering heat transfer issues. During the first year of the project the work was started and several concepts were developed to prepare for bench-scale testing. PowerEnerCat was unable to raise their cash contribution for the project, and the work was stopped. This report summarizes some of the progress of the project and the concepts that were intended for experimental tests.