Production of bio-based liquefied petroleum gas
The disclosure provides methods for the production of liquefied petroleum gas from sustainable feedstocks, including methods comprising conversion of alcohols produced by gas fermentation for the production of propane and/or butane.
1. A method of producing liquefied petroleum gas comprising:
a) producing a dehydration feed stream comprising a C3 alcohol and/or a C4 alcohol by microbial fermentation of a gaseous substrate comprising CO, CO 2 , CH 4 , or any mixture thereof, wherein the dehydration feed stream has a water content of less than 30 wt %;
b) contacting, in a dehydration reactor, the dehydration feed stream with a dehydration catalyst to produce a first reactor effluent stream comprising a C3 alkene and/or a C4 alkene; and
c) contacting, in a hydrogenation reactor, the first reactor effluent stream comprising the C3 alkene and/or the C4 alkene with hydrogen and a hydrogenation catalyst to produce a product stream comprising propane and/or butane.
2. The method of claim 1 , wherein:
(a) the C3 alcohol comprises isopropanol and/or 1-propanol; and
(b) the C4 alcohol comprises butanol or an isomer of butanol.
3. The method of claim 1 , wherein the dehydration catalyst is selected from acidic alumina, aluminum phosphate, silica-alumina phosphate, amorphous silica-alumina, aluminosilicate, zirconia, sulfated zirconia, tungstated zirconia, tungsten carbide, molybdenum carbide, titania, sulfated carbon, phosphated carbon, phosphated silica, phosphated alumina, acidic resin, heteropolyacid, inorganic acid, and any combination thereof.
4. The method of claim 1 , wherein the hydrogenation catalyst comprises a Ni-alumina, Pd—C, Raney-Ni, Co, or Pt catalyst, or any combination thereof.
5. The method of claim 1 , wherein:
(a) the C3 alkene comprises propene; and
(b) the C4 alkene comprises butene, an isomer of butene, and/or butadiene.
6. The method of claim 1 , wherein the dehydration reactor operates at a temperature of from 100° C. to 500° C., of from 350° C. to 450° C., or of from 375° C. to about 425° C.
7. The method of claim 1 , wherein the dehydration reactor operates at a pressure of from 0.2 MPa to 2 MPa, of from 0.2 MPa to 1 MPa, or of from 0.2 MPa to 0.7 MPa.
8. The method of claim 1 , wherein the dehydration reactor operates at a weight hourly space velocity (whsv) of from 1 h −1 to 10 h −1 , of from 2 h −1 to 8 h −1 , or of from 0.5 h −1 to 2 h −1 .
9. The method of claim 1 , wherein the hydrogenation reactor operates at a temperature of less than 400° C., of less than 250° C., or of 100° C. to 150° C.
10. The method of claim 1 , wherein the hydrogenation reactor operates at a pressure above 1.7 MPa, of 0.7 MPa to 8.2 MPa, of 0.7 MPa to 2.0 MPa, or of 1.0 MPa to 2.0 MPa.