A method for conversion of food waste to biofuel can include a first fermentation in which food waste is converted C.sub.2-C.sub.4 short-chain carboxylic acids, and a second fermentation in which the C.sub.2-C.sub.4 short-chain carboxylic acid are elongated into C.sub.5-C.sub.8 medium-chain carboxylic acids. Medium-chain carboxylic acids can undergo hydrogenation-dehydration of the medium-chain carboxylic acids into C.sub.5-C.sub.8 linear olefins. The C.sub.5-C.sub.8 linear olefins are then oligomerized to a C.sub.10-C.sub.25 mixture comprising olefins, paraffin, cycloparaffins, and aromatics through dimerization; and saturated to C.sub.10-C.sub.25 mixture by hydrogenation to produce the biofuel.

A supported catalyst for reducing CO.sub.2 is provided. The supported catalyst includes a plurality of support particles; and a plurality of catalyst particles disposed over each support particle. Characteristically, the catalyst particles has formula PdH.sub.x/C wherein x is 0.3 to 0.7. Methods for making the support particles and using the support particles to reduce carbon dioxide are also provided.

A supported catalyst for reducing CO.sub.2 is provided. The supported catalyst includes a plurality of support particles; and a plurality of catalyst particles disposed over each support particle. Characteristically, the catalyst particles has formula PdH.sub.x/C wherein x is 0.3 to 0.7. Methods for making the support particles and using the support particles to reduce carbon dioxide are also provided.

A multipurpose fuel composition is disclosed which contains a petroleum derived jet fuel component and a renewable jet fuel component, wherein the multipurpose fuel composition has a freezing point of −40° C. or below, and an exemplary cetane number more than 40, preferably more than 45, more preferably more than 50.

A system for producing ethanol comprises a rectifier column that receives a first process stream comprising from about 42% to about 60% ethanol, wherein the rectifier column purifies the first process stream to provide an ethanol product stream that is at least about 90% ethanol, and one or more evaporators configured to evaporate water from a second process stream, wherein the one or more evaporators generate vapor, and wherein at least a portion of the vapor supplies heat energy for separation of ethanol from water in the rectifier column.

A system for producing ethanol comprises a rectifier column that receives a first process stream comprising from about 42% to about 60% ethanol, wherein the rectifier column purifies the first process stream to provide an ethanol product stream that is at least about 90% ethanol, and one or more evaporators configured to evaporate water from a second process stream, wherein the one or more evaporators generate vapor, and wherein at least a portion of the vapor supplies heat energy for separation of ethanol from water in the rectifier column.

Systems and methods to provide renewable transportation fuels for internal combustion engines by converting renewable feedstocks into two or more intermediate hydrocarbon blend stocks and blending at least two of the two or more intermediate hydrocarbon blend stocks to produce the renewable transportation fuel. Methods and/or processes may include selecting sugar from a sugar source and introducing the sugar into one or more reactors. The sugar may be converted into an intermediate renewable hydrocarbon blend stock and sent to a separation unit to separate out an intermediate renewable gasoline unit. The process may include selecting and converting a lipid from a lipid source into a renewable diesel product. The renewable diesel product may be sent to a second separation unit to separate out renewable diesel and a low-grade naphtha. The low-grade naphtha and intermediate renewable gasoline may be blended to define a finished renewable gasoline.

Hydroprocessed residual fuel and/or fuel blending components are provided that have a sulfur and nitrogen level comparable to liquefied natural gas (LNG). Because of the low starting level of sulfur and/or nitrogen, the severity of the hydroprocessing that is needed for the crude oil or bottoms fraction in order to remove sulfur to a level that is comparable to LNG is reduced or minimized. This can allow the resulting marine residual fuels to have low carbon intensity, low SOx and NOx emission and high energy density. Since the hydroprocessed fractions correspond to a fuel oil product, the resulting marine fuel can be used in existing fleets, and can be distributed in existing bunkering systems.

Hydroprocessed residual fuel and/or fuel blending components are provided that have a sulfur and nitrogen level comparable to liquefied natural gas (LNG). Because of the low starting level of sulfur and/or nitrogen, the severity of the hydroprocessing that is needed for the crude oil or bottoms fraction in order to remove sulfur to a level that is comparable to LNG is reduced or minimized. This can allow the resulting marine residual fuels to have low carbon intensity, low SOx and NOx emission and high energy density. Since the hydroprocessed fractions correspond to a fuel oil product, the resulting marine fuel can be used in existing fleets, and can be distributed in existing bunkering systems.

Separation of carbon dioxide from the exhaust of an internal combustion engine, the production of hydrogen from water, and reformation of carbon dioxide and hydrogen into relatively high-octane fuel components.