(151c) Medium Chain Alcohol Production Using Alkali Promoted Mo-Sulfide Fischer-Tropsch Catalysts

Today’s chemical industry is very complex with most commodity chemicals being produced from some variation of petroleum feedstocks. From transportation fuels to polymers, petroleum is truly the largest source of basic hydrocarbons for which many of the common household products used by consumer. Along with this, stems many industrial and environmental issues which must be addressed for long-term stability of the petroleum and chemical industry. The upgrading of petroleum feedstocks, which are bulky, hydrogen deficient molecules, generally requires vast amounts of hydrogen gas during upgrading. Hydrogen is typically produced via methane steam reforming reactions. Carbon dioxide, noted for its climate change potential, is produced as a byproduct of methane steam reforming. CO₂ sequestration and/or utilization is a growing concern and is at the forefront of many political and environmental policies that are being introduced worldwide. One avenue to combat the growing release of CO₂ into the atmosphere is to convert CO₂ to syngas via dry reforming or trireforming. Furthermore, recent developments in Dry Reforming and Trireforming processes, both of which yield syngas, has opened up new revenue streams for carbon dioxide produced from large point sources. These large point sources include refineries as well as natural gas and coal-based electric power generators.

Fischer – Tropsch synthesis has long been a well-recognized process for the conversion of syngas (H₂ and CO) to commodity and fuel compounds such as methanol and long chain hydrocarbons. In this work, a series of Fischer - Tropsch Molybdenum-Sulfide catalysts have been prepared for the purpose of producing medium chain (C6 – C8) alcohols. Using a hydrothermal synthesis technique, alkali-promoted MoS2 catalysts were developed with the addition of cobalt. Catalysts were characterized using SEM, TEM, XRD, and BET to identify possible structural and chemical characteristics leading to their influence on activity and selectivity. Furthermore, the catalyst materials were evaluated for their formation of higher alcohol compounds. Reaction results indicated that cesium alkali and cobalt promoters were the most stable, active, and selective for the formation of medium chain alcohols. The Cs_0.3Co_0.5MoS₂ catalyst (reacted at 3.2 MPa, 300 °C, and H₂/CO = 0.8) favored C6 – C8 alcohols (93 wt % total mass of products). Complete details on catalyst synthesis, characterization, and reactions will be presented.