The description describes the integration of a gas fermentation process with a gasification process whereby effluent from the gas fermentation process is recycled to the gasification process. The one or more effluents which can be recycled include a stream comprising microbial biomass, a product stream comprising at least a portion of the at least one fermentation product, a by-product stream comprising fusel oil, and a waste water stream comprising microbial biomass. The stream comprising biomass can be dried before it is passed to the gasification zone. At least a portion of the waste water stream can be passed to the gasification process where one use is to replace at least a portion of the process water. The waste water stream can be further processed to produce a clarified water stream and a biogas stream comprising methane either or both of which can be passed to the gasification process.

A method for providing a fuel includes providing a partially purified biogas at a first processing site, where the partially purified biogas is produced by multiple biogas sources and/or from multiple feedstock sources. The partially purified biogas is compressed, fed to a mobile tank, and transported by vehicle to a second processing site. At the second processing site, which may also receive biogas from a plurality of biogas sources, the partially purified biogas is further processed to produce a fuel or fuel intermediate.

A method for providing a fuel includes providing a partially purified biogas at a first processing site, where the partially purified biogas is produced by multiple biogas sources and/or from multiple feedstock sources. The partially purified biogas is compressed, fed to a mobile tank, and transported by vehicle to a second processing site. At the second processing site, which may also receive biogas from a plurality of biogas sources, the partially purified biogas is further processed to produce a fuel or fuel intermediate.

There are provided systems and methods for using fuel-rich partial oxidation to produce an end product from waste gases, such as flare gas. In an embodiment, the system and method use air-breathing piston engines and turbine engines for the fuel-rich partial oxidation of the flare gas to form synthesis gas, and reactors to convert the synthesis gas into the end product. In an embodiment the end product is methanol.

A method for producing a synthetic fuel from hydrogen and carbon dioxide comprises extracting hydrogen molecules from hydrogen compounds in a hydrogen feedstock to produce a hydrogen-containing fluid stream; extracting carbon dioxide molecules from a dilute gaseous mixture in a carbon dioxide feedstock to produce a carbon dioxide containing fluid stream; and processing the hydrogen and carbon dioxide containing fluid streams to produce a synthetic fuel. At least some thermal energy and/or material used for at least one of the steps of extracting hydrogen molecules, extracting carbon dioxide molecules, and processing the hydrogen and carbon dioxide containing fluid streams is obtained from thermal energy and/or material produced by another one of the steps of extracting hydrogen molecules, extracting carbon dioxide molecules, and processing the hydrogen and carbon dioxide containing fluid streams.

A method for producing a synthetic fuel from hydrogen and carbon dioxide comprises extracting hydrogen molecules from hydrogen compounds in a hydrogen feedstock to produce a hydrogen-containing fluid stream; extracting carbon dioxide molecules from a dilute gaseous mixture in a carbon dioxide feedstock to produce a carbon dioxide containing fluid stream; and processing the hydrogen and carbon dioxide containing fluid streams to produce a synthetic fuel. At least some thermal energy and/or material used for at least one of the steps of extracting hydrogen molecules, extracting carbon dioxide molecules, and processing the hydrogen and carbon dioxide containing fluid streams is obtained from thermal energy and/or material produced by another one of the steps of extracting hydrogen molecules, extracting carbon dioxide molecules, and processing the hydrogen and carbon dioxide containing fluid streams.

A cement clinker producing system, capable of providing a gas containing a carbon dioxide gas at a high concentration by increasing a carbon dioxide gas concentration for a part of an exhaust gas, includes a cyclone preheater to preheat a cement clinker raw material, a rotary kiln to burn the preheated cement clinker raw material so as to provide cement clinker, a calcination furnace to promote decarbonation of the cement clinker raw material, a clinker cooler to cool the cement clinker, a kiln exhaust-gas discharge passages to discharge an exhaust gas generated in the rotary kiln, a combustion-supporting gas supply device to supply a combustion-supporting gas having a higher oxygen concentration than air, a combustion-supporting gas supply passage to guide the combustion-supporting gas to the calcination furnace, and a calcination furnace exhaust-gas discharge passage to discharge a carbon dioxide gas-containing exhaust gas generated in the calcination furnace.

Processes for converting methane and/or other hydrocarbons to synthesis gas (i.e., a gaseous mixture comprising H.sub.2 and CO) are disclosed, in which at least a portion of the hydrocarbon(s) is reacted with CO.sub.2. At least a second portion of the methane may be reacted with H.sub.2O (steam), thereby improving overall thermodynamics of the process, in terms of reducing endothermicity (ΔH) and the required energy input, compared to “pure” dry reforming in which no H.sub.2O is present. Such dry reforming (reaction with CO.sub.2 only) or CO.sub.2-steam reforming (reaction with both CO.sub.2 and steam) processes are advantageously integrated with Fischer-Tropsch synthesis to yield liquid hydrocarbon fuels. Further integration may involve the use of a downstream finishing stage involving hydroisomerization to remove FT wax. Yet other integration options involve the use of combined CO.sub.2-steam reforming and FT synthesis stages (optionally with finishing) for producing liquid fuels from gas streams generated in a number of possible processes, including the hydropyrolysis of biomass.

Processes for converting methane and/or other hydrocarbons to synthesis gas (i.e., a gaseous mixture comprising H.sub.2 and CO) are disclosed, in which at least a portion of the hydrocarbon(s) is reacted with CO.sub.2. At least a second portion of the methane may be reacted with H.sub.2O (steam), thereby improving overall thermodynamics of the process, in terms of reducing endothermicity (ΔH) and the required energy input, compared to “pure” dry reforming in which no H.sub.2O is present. Such dry reforming (reaction with CO.sub.2 only) or CO.sub.2-steam reforming (reaction with both CO.sub.2 and steam) processes are advantageously integrated with Fischer-Tropsch synthesis to yield liquid hydrocarbon fuels. Further integration may involve the use of a downstream finishing stage involving hydroisomerization to remove FT wax. Yet other integration options involve the use of combined CO.sub.2-steam reforming and FT synthesis stages (optionally with finishing) for producing liquid fuels from gas streams generated in a number of possible processes, including the hydropyrolysis of biomass.

A synthetic product production system is provided with: a synthesis plant for producing a synthetic product by synthesizing a hydrogen-containing gas and carbon dioxide; and a carbon dioxide supply line for supplying the carbon dioxide to the synthesis plant from a recovery and storage plant including a recovery device for recovering the carbon dioxide from a carbon dioxide-containing gas and an injection facility for fixing the recovered carbon dioxide into a stratum.