In a premixing apparatus that mixes a fuel gas with air and supplies an air-fuel mixture to a burner through a fan, includes a main valve, a zero governor, and a variable throttle valve which are interposed from an upstream side downward in sequence in a gas supply passage, of which an downstream end is connected to a gas suction part that is provided in an air supply passage on an upstream side of a fan, and carries out a first control that regulates an opening degree of the variable throttle valve so that an excess air ratio of the air-fuel mixture, which is indexed based on a flame current that is detected by a flame rod which is exposed in flames of the burner, and a second control that, at time of a post-purge operation, if the flame rod detects the flame current, it will be decided that an open trouble of the main valve occurs and the opening degree of the throttle valve will be tightened till a minimum opening-degree which is set so that the burner is extinguished.

In a premixing apparatus that mixes a fuel gas with air and supplies an air-fuel mixture to a burner through a fan, includes a main valve, a zero governor, and a variable throttle valve which are interposed from an upstream side downward in sequence in a gas supply passage, of which an downstream end is connected to a gas suction part that is provided in an air supply passage on an upstream side of a fan, and carries out a first control that regulates an opening degree of the variable throttle valve so that an excess air ratio of the air-fuel mixture, which is indexed based on a flame current that is detected by a flame rod which is exposed in flames of the burner, and a second control that, at time of a post-purge operation, if the flame rod detects the flame current, it will be decided that an open trouble of the main valve occurs and the opening degree of the throttle valve will be tightened till a minimum opening-degree which is set so that the burner is extinguished.

A process for producing products from biomass comprises pyrolysing biomass at a selected temperature and producing a bio-syngas, processing bio-syngas from pyrolysis step (a) to remove condensable constituents from the bio-syngas, and processing the non-condensable bio-syngas from bio-syngas processing step (b) and producing one or more than one product, such as bio-fuels, bio-chemicals, bio-solvents and bio-plastics.

A process for producing products from biomass comprises pyrolysing biomass at a selected temperature and producing a bio-syngas, processing bio-syngas from pyrolysis step (a) to remove condensable constituents from the bio-syngas, and processing the non-condensable bio-syngas from bio-syngas processing step (b) and producing one or more than one product, such as bio-fuels, bio-chemicals, bio-solvents and bio-plastics.