The embodied invention is directed toward capturing air sources that contain higher concentrations of CO.sub.2 and directing the air to a controlled crop growing environment where a crop will be able to benefit from the higher amounts of CO.sub.2. The air is preferably filtered for dust, monitored for CO.sub.2 levels, and a mixer is used to control the CO.sub.2 level to a desirable amount.

A fermenter for biogas plants, including a submersible motor-driven stirrer that can be vertically adjusted by means of a motor. During operation of the biogas plant, the fermenter is filled, to a level, with substrate that is to be fermented, and the agitator blades of the submersible motor-driven stirrer are fully immersed in the substrate. According to the invention, a level gauge is provided, by means of which the level of the substrate is detected and a corresponding level measuring signal is generated as an actual level signal. Furthermore, a control device is provided, to which the level measuring signal is fed and which controls the vertically adjusting motor for the submersible motor-driven stirrer in such a way when a lower level is detected that the stirrer is lowered and the agitator blades continue to be fully immersed in the substrate.

A tempering device for tempering of biomass contained in a container, including at least one tempering mechanism, and at least one conveying device for conveying a mass flow of biomass in a main flow direction. The at least one conveying device includes at least one agitator, and wherein the at least one tempering mechanism is arranged in the main flow direction generated by the at least one conveying device. The at least one tempering mechanism is tubular with an inner tube and with an outer tube arranged coaxially to the inner tube. The inner tube and the outer tube form an intermediate space through which a tempering medium may flow. The tempering mechanism is oriented relative to the conveying device such that, in operation of the heating device, at least 40% of the delivery volume of the mass flow generated by the conveying device flows through the inner tube.

Agitating device (10) for a digester (1) of a biogas plant (100) having a housing (11) and a driving device (12) for rotatably driving the agitator blades (13-15). The driving device (12) comprises a drive shaft (16) and an electric drive motor (20) wherein the drive motor (20) is accommodated sealed in the housing (11). The drive motor (20) comprises an outer, hollow stator (21) and a rotary rotor (22) which is centrally accommodated therein and is configured at least partially hollow. The rotor (22) is rotatably supported at the housing (11) and comprises a coupling device (23) for non-rotatable coupling with the drive shaft (16) to drive the at least one agitator blade (13-15) by means of the drive shaft (16).

Height adjusting device (1) for adjusting the height of an agitating device (2) in a digester (101) of a biogas plant (100), biogas plant (100) comprising a digester (101), a support unit (10), a displacement member (6), an agitating device (2), and a height adjusting device, and method for operating an agitating device (2). The height adjusting device comprises a housing unit (4), a drum device (5) rotatably accommodated on the housing unit (4), and a displacement member (6). The displacement member (6) is in functional connection with the drum device (5) and the agitating device (2) and the displacement member (6), depending on the direction of rotation of the drum device (5), can be wound onto the drum device (5) or unwound from the drum device (5) in sections, so that the agitating device (2) can be displaced upwardly or downwardly. Furthermore a fixing device (7) is provided which is suitable and configured to fix the drum device (5) at least temporarily to prevent the displacement member (6) from unwinding if the displacement member (6) is not retained tautly between the drum device (5) and the agitating device (2).

A process comprising (i) providing a gaseous stream including greater than 1% by volume carbon dioxide; (ii) providing water; (iii) converting the carbon dioxide and the water to an organic intermediate and oxygen gas in the presence of light; (iv) separating the oxygen gas from the organic intermediate; and (v) converting the organic intermediate to ethylene and carbon dioxide after said step of separating the oxygen gas from the organic intermediate.

An arrangement (1) for the cultivation of plants and for the utilization of biomass waste and a system (1000) of at least one arrangement (1) for the cultivation and utilization of biomass are disclosed. The arrangement (1) comprises a modular greenhouse (100) and a modular, two-stage biogas plant (200). The system (1000) has at least one arrangement (1) wherein a control and monitoring unit (101) of the modular greenhouse (100) and a further a control and monitoring unit (201) of the two-stage biogas plant (200) are communicatively connected to a central control and monitoring unit (55).

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.

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.

Systems and methods for integrating thermochemical processing of biomass and anaerobic digestion are provided. Light oxygenated organic compounds are produced as byproducts of thermochemical biomass processing e.g. by torrefaction and/or pyrolysis, and are converted to methane by anaerobic digestion. Thermochemical processing units may or may not be co-located with the anaerobic digestion units, with co-location providing benefits for e.g. rural agricultural enterprises.