Process for producing renewable jet fuel compositions
Processes for producing jet fuel are disclosed. In one embodiment, syngas is converted to methanol, and a first portion of the methanol is converted to olefins using a methanol-to-olefins catalyst. The olefins are then oligomerized under conditions that provide olefins in the jet fuel range. The olefins can then optionally be isomerized and/or hydrotreated. A second portion of the methanol is converted to dimethyl ether, which is then reacted over a catalyst to form jet fuel-range hydrocarbons and aromatics. All or part of the two separate product streams can be combined, to provide jet fuel components which include isoparaffins and aromatics in the jet fuel range. The syngas is preferably derived from biomass or another renewable carbon-containing feedstock, thereby providing a biorefining process for the production of renewable jet fuel. In another embodiment, the process starts with methanol, rather than producing the methanol from syngas.
1. A process for producing a mixture comprising aromatics and hydrocarbons in the C 5-15 range, comprising:
(a) generating or providing syngas by gasifying a feedstock selected from the group consisting of coal, methane, glycerol, biomass, black liquor, municipal solid waste, and lignin;
(b) converting the syngas to methanol over an appropriate methanol-synthesis catalyst;
(c) separating the methanol into at least a first stream and a second stream;
(d) converting the methanol in the first stream to dimethyl ether;
(e) reacting the dimethyl ether with ZSM-5 or H-ZSM-5 to one or more jet fuel range hydrocarbons and aromatics;
(f) converting the methanol in the second stream to olefins using a methanol-to-olefins catalyst;
(g) oligomerizing the olefins under conditions which produce olefins in the jet fuel range;
(h) isomerizing and hydrotreating the olefins in the jet fuel range formed during the olefin oligomerization step to form paraffins in the jet fuel range;
(i) isolating products in the jet fuel range obtained from step (h), and combining said isolated products with the one or more jet fuel range hydrocarbons and aromatics from step (e) to provide a mixture comprising aromatics and hydrocarbons in the C 5-15 range; and
(j) blending said mixture comprising aromatics and hydrocarbons in the C 5-15 range as a blendstock with JP8, JPA, JP4, or JP1.
2. The process of claim 1 , wherein said syngas is derived from biomass.
3. The process of claim 1 , wherein said syngas is derived from coal.
4. The process of claim 1 , wherein said syngas is derived from methane.