A process for the production of a methane-enriched gas including the steps of providing a bioreactor having at least one device for supplying a gas, and at least one outlet for removing the methane-enriched gas generated in the bioreactor; providing a device for determining the proportion of carbon dioxide in the methane-enriched gas removed from the bioreactor; specifying a target value S for the proportion of carbon dioxide in the methane-enriched gas removed from the bioreactor; supplying carbon dioxide-containing gas to the bioreactor; supplying hydrogen-containing gas to the bioreactor; forming methane-enriched gas in the bioreactor; removing the methane-enriched gas formed in the bioreactor from the bioreactor; determining an actual value for the proportion of carbon dioxide in the methane-enriched gas removed from the bioreactor; comparing the target value S with the determined actual value; regulating the quantity of supplied carbon dioxide-containing gas and/or regulating the quantity of supplied hydrogen-containing gas in a manner such that the determined actual value corresponds to the specified target value S, wherein the target value S specified for the proportion of carbon dioxide in the methane-enriched gas removed from the bioreactor satisfies the condition 0 vol% < S ≤ 5 vol%.

According to the present invention, organic material is converted to biogas through anaerobic digestion and the biogas is purified to yield a combustible fluid feedstock comprising methane. A fuel production facility utilizes or arranges to utilize combustible fluid feedstock to generate renewable hydrogen that is used to hydrogenate crude oil derived hydrocarbons in a process to make transportation or heating fuel. The renewable hydrogen is combined with crude oil derived hydrocarbons that have been desulfurized under conditions to hydrogenate the liquid hydrocarbon with the renewable hydrogen or alternatively, the renewable hydrogen can be added to a reactor operated so as to simultaneously desulfurize and hydrogenate the hydrocarbons. The present invention enables a party to receive a renewable fuel credit for the transportation or heating fuel.

Compositions and methods for a hybrid biological and chemical process that captures and converts carbon dioxide and/or other forms of inorganic carbon and/or CI carbon sources including but not limited to carbon monoxide, methane, methanol, formate, or formic acid, and/or mixtures containing CI chemicals including but not limited to various syngas compositions, into organic chemicals including biofuels or other valuable biomass, chemical, industrial, or pharmaceutical products are provided. The present invention, in certain embodiments, fixes inorganic carbon or CI carbon sources into longer carbon chain organic chemicals by utilizing microorganisms capable of performing the oxyhydrogen reaction and the autotrophic fixation of CO.sub.2 in one or more steps of the process.

A system for digesting biodigestible feed that preferably includes the steps of comminuting the feed, introducing feed, an oxygen-containing gas, an accelerant, and bacteria into a digestion zone, the bacteria being suitable for digesting the feed under aerobic, anaerobic, and anoxic conditions. The contents of the digestion zone can be changed from aerobic operation to either anoxic or anaerobic operation, or vice versa, without changing the bacteria in the digestion zone.

The present invention belongs to the field of treatment of urban organic wastes, and specifically relates to a high-value treatment system or method for urban wet garbage. According to the present invention, through the steps such as oil extraction, high-efficiency hydrolysis, high-value biological conversion, simultaneous recovery of released nitrogen and phosphorus and deep utilization of residues, urban wet garbage is converted into acetic acid by high-value treatment, produced by-products including carbon dioxide and hydrogen are biologically converted into acetic acid, released nitrogen and phosphorus are recycled into slow-release fertilizers, and solid residues are used to prepare materials capable of promoting conversion of the wet garbage into acetic acid through high-value treatment. According to the present invention, not only can high-value treatment of the urban wet garbage be realized, but also produced waste gases and waste residues are recycled.

The present invention relates to methods and apparatus for microbial conversion of carbon dioxide, carbon monoxide and hydrogen to methane, and to the microbial populations, and the media comprising the microbial populations, that may be used in such methods and apparatus.

In alternative embodiments, provided are genetically or recombinantly engineered nitrogen-fixing, nitrogenase expressing bacteria capable of enzymatically synthesizing hydrocarbons, and methods for making and using them. In alternative embodiments, provided are genetically or recombinantly engineered nitrogen-fixing, nitrogenase expressing bacteria including nitrogen-fixing diazotrophs such as nitrogen-fixing bacteria of the family Pseudomonadaceae, or the genus Azotobacter, for the whole cell synthesis of hydrocarbons and carbon-carbon bonds. In alternative embodiments, nitrogen-fixing, nitrogenase-expressing bacteria used to practice the invention are genetically or recombinantly engineered to express an exogenous nitrogenase express more endogenous nitrogenase or have increased nitrogenase, activity. In alternative embodiments, nitrogen-fixing, nitrogenase-expressing bacteria used to practice the invention are genetically or recombinantly engineered to lack or have decreased molybdenum transporter activity. In alternative embodiments, provided are culture systems, fermenters and bioreactors using nitrogen-fixing, nitrogenase-expressing bacteria for enzymatically synthesizing hydrocarbons.

A nutrient composition for enhancing biogenic methane production from a carbonaceous material is described. The nutrient composition comprises a source of phosphorus (P) and a source of nitrogen (N), wherein the molar ratio of phosphorus to nitrogen (P/N) is greater than 1.5, and the nitrogen concentration is at least 0.1 m M and less than 1.7 m M. A process for enhancing biogenic methane production from a carbonaceous material is also described. The process involves contacting the nutrient composition of the invention with the carbonaceous material for a period of time to biogenically produce methane and subsequently collecting methane from the carbonaceous material. The process may further comprise contacting the carbonaceous material with a second nutrient composition, wherein the second nutrient composition has a P/N molar ratio greater than the P/N molar ratio of the former nutrient composition.

A system and method for converting waste and secondary materials into synthesis gas (syngas) through the use of a molten metal bath gasifier for the initial breakdown of waste feeds and an A/C plasma reactor for complete dissociation of waste feeds into syngas, and an anaerobic digester. The system includes a heat recovery and steam power generation process for the production of electricity. The system produces a net output of electricity above plant load sufficient for the co-production of renewable Hydrogen and Oxygen. The process does not require the use of fossil fuels or fossil feedstocks during normal operations, and it eliminates combustion produced stack emissions or landfill residuals.

Systems and processes of providing novel thermal energy sources for hydrothermal liquefaction (HTL) reactors are described herein. According to various implementations, the systems and processes use concentrated solar thermal energy from a focused high-energy beam to provide sufficient energy for driving the HTL biomass-to-biocrude process. In addition, other implementations convert biowaste, such as municipal biosolids and grease and food waste, to biocrude using anaerobic digesters, and a portion of the biogas generated by the digesters is used to produce the thermal and/or electrical energy used in the HTL reactor for the biomass-to-biocrude process. Furthermore, alternative implementations may include a hybrid system that uses biogas and solar radiation to provide sufficient thermal energy for the HTL reactor.