Important variables which influence the efficiency of a hydrodynamic separation of dense materials using a hydrocyclone are the dynamic viscosity at the inflow of the hydrocyclone and the number of passes through the hydrocyclone. According to the invention, the method and the device allow a control of the viscosity in the hydrocyclone as well as the number of passes through the hydrocyclone when separating dense materials from a slurry in conjunction with an anaerobic fermentation of the constituents of the slurry which can be fermented. By fermenting the constituents of the slurry which can be fermented, the content of a fermentation reactor has a lower viscosity than the slurry being fed. The viscosity in the inflow of the hydrocyclone is set by means of a controlled return flow from a fermentation reactor, and the number of passes is set by a controlled return flow from the outflow of the hydrocyclone. The slurry is pumped into a return flow from the fermentation reactor. The viscosity in the inflow of the hydrocyclone is controlled by the throughput of the return pump on the basis of the content of solids of the slurry. The number of passes through the hydrocyclone is controlled via the ratio of the feed of the hydrocyclone to the feed of the fermentation reactor from which dense materials are removed. Because the process of diluting the slurry with the content of the fermentation reactor does not have an influence on the hydraulic dwell time in the fermentation reactor, the fermentation reactor can be designed for a smaller accumulation of slurry.

A system comprising a collocated thermal plant, water source, CO.sub.2 source and biomass growth module is disclosed. A method of improving the environment by utilizing the system is disclosed.

A process and apparatus for sequestering carbon and converting it to fuel, such as methane, and/or materials, such as fermentation substrates, biopolymers, bioplastics, oils, pigments, biochar, metals, such as mercury, chromium and arsenic, fibers, proteins, vitamins, fertilizers and animal feed. The apparatus comprises a deep well carbon-sequestering bioreactor coaxially located within a deep well anaerobic bioreactor. Carbon is sequestered into a photosynthetic biomass or a heterotrophic biomass, which is subsequently digested by an anaerobic biomass containing methanogenic microbes, whereby methane is a digestion product. Alternatively, the biomass can be subjected to physical-chemical treatment to produce oil and other useful byproducts.

A process and apparatus for sequestering carbon and converting it to fuel, such as methane, and/or materials, such as fermentation substrates, biopolymers, bioplastics, oils, pigments, biochar, metals, such as mercury, chromium and arsenic, fibers, proteins, vitamins, fertilizers and animal feed. The apparatus comprises a deep well carbon-sequestering bioreactor coaxially located within a deep well anaerobic bioreactor. Carbon is sequestered into a photosynthetic biomass or a heterotrophic biomass, which is subsequently digested by an anaerobic biomass containing methanogenic microbes, whereby methane is a digestion product. Alternatively, the biomass can be subjected to physical-chemical treatment to produce oil and other useful byproducts.

Methods of capturing atmospheric carbon-dioxide gas by generating energy via combustion of a biomass feedstock and providing at least a portion of the energy to a bioprocessing facility. The combustion of the biomass feedstock produces a flue gas having carbon-dioxide gas that can be captured. Related facilities.

Method and apparatus for the production of hydrogen and other gaseous or liquid substances (such as 2,3-butanediol) formed with the help of microbes in conditions where the normal microbial metabolism (catabolism and anabolism) has been restricted by pH or temperature, for example. Then carbon is not liberated into gaseous phase as fast as in more common microbial reactions. Carrier gas directed into organic waste or other biomass is helping in liberating molecular hydrogen into gaseous phase with the aid of microbial enzymes or electric phenomena at the same time when new hydrogen is binding into the biomass from water. Removed gases or combustion gases from the incineration plants can be directed back into bioprocess in some process alternatives, together with lowering total carbon emission by these means. The production plant is planned in such a way that it can be situated in the midst of inhabitation.

Improved methods for anaerobic digestion of organic matter to produce biogas. Among the improvements given are including ferric iron in a hydrolysis reactor to increase the rate and efficiency of anaerobic hydrolysis to provide substrates for methanogenesis. A solids separation step is added after hydrolysis and before methanogenesis to improve the efficiency of the methanogenesis step. Other improvements involve using separate tanks for the hydrolysis and methanogenesis stages and using two (or more) methanogenesis tanks in sequence, and switching the order of the two (or more) methanogenesis tanks periodically.

Improved methods for anaerobic digestion of organic matter to produce biogas. Among the improvements given are including ferric iron in a hydrolysis reactor to increase the rate and efficiency of anaerobic hydrolysis to provide substrates for methanogenesis. A solids separation step is added after hydrolysis and before methanogenesis to improve the efficiency of the methanogenesis step. Other improvements involve using separate tanks for the hydrolysis and methanogenesis stages and using two (or more) methanogenesis tanks in sequence, and switching the order of the two (or more) methanogenesis tanks periodically.

Improved methods for anaerobic digestion of organic matter to produce biogas. Among the improvements given are including ferric iron in a hydrolysis reactor to increase the rate and efficiency of anaerobic hydrolysis to provide substrates for methanogenesis. A solids separation step is added after hydrolysis and before methanogenesis to improve the efficiency of the methanogenesis step. Other improvements involve using separate tanks for the hydrolysis and methanogenesis stages and using two (or more) methanogenesis tanks in sequence, and switching the order of the two (or more) methanogenesis tanks periodically.

Improved methods for anaerobic digestion of organic matter to produce biogas. Among the improvements given are including ferric iron in a hydrolysis reactor to increase the rate and efficiency of anaerobic hydrolysis to provide substrates for methanogenesis. A solids separation step is added after hydrolysis and before methanogenesis to improve the efficiency of the methanogenesis step. Other improvements involve using separate tanks for the hydrolysis and methanogenesis stages and using two (or more) methanogenesis tanks in sequence, and switching the order of the two (or more) methanogenesis tanks periodically.