NOVELTY - Biomass gasification system comprises: reactor (16) to gasify biomass feedstock (44) to convert to producer gas, where reactor comprises enclosure disposed about gasification chamber (50), and having side walls (68) between inlet (52) and outlet (70), and several fluid injectors (66) disposed along length of side walls to inject fluid into gasification chamber; and control system (67) communicatively coupled to several fluid injectors and configured to independently control each fluid injector of several fluid injectors to independently control flow of fluid through each fluid injector.    USE - As biomass gasification system to form producer gas, which is used to generate methanol, ammonia, and/or diesel fuel (claimed).    ADVANTAGE - The biomass gasification system has controllable injection nozzles that inject air and/or oxygen into chamber of thermal conversion device, compared to current biomass gasification systems. Unfortunately, many current biomass gasification systems generate producer gas with high levels of undesirable particulates, such as tar. Accordingly, prior to use in power generation system, producer gas needs to be cleaned to generate gas mixture with desired composition. The incorporation of cleaning components, such as scrubbers and filters, for removing these undesirable particulates can add cost and complexity to biomass gasification system, thus reducing its efficiency. The system is capable of relatively generating clean producer gas while overcoming the drawbacks. The controllable fluid injectors facilitate conversion of biomass into producer gas by injecting air and/or oxygen into combustion zone of biomass gasification chamber. The controllability of fluid injectors enables selective activation and deactivation of subsets of several fluid injectors, with respect to operational parameter of biomass gasification process or power generation system, such as type of biomass feedstock, length of pyrolysis zone of gasification chamber, length of combustion zone of biomass gasification chamber, operational parameter of engine that receives producer gas from reactor, and/or tar content of producer gas. The system thus offers distinct advantages over traditional biomass gasification systems that do not include controllable fluid injectors, such as enables activation of subsets of fluid injectors that are capable of injecting air and/or oxygen into combustion zone and deactivation of subsets of fluid injectors that are less suitable for injecting fluid into combustion zone; and renders single biomass gasifier suitable for use with variety of types of feedstock, which may be associated with different combustion and pyrolysis zone lengths.    DETAILED DESCRIPTION - A biomass gasification system comprises: reactor (16) configured to gasify biomass feedstock (44) to thermally convert biomass feedstock into producer gas, where reactor comprises enclosure disposed about biomass gasification chamber (50), enclosure has inlet (52), outlet (70), and side walls (68) disposed between inlet and outlet, and several fluid injectors (66) disposed along length of side walls and configured to inject fluid into gasification chamber; and control system (67) communicatively coupled to several fluid injectors and configured to independently control each fluid injector of several fluid injectors to independently control flow of fluid through each fluid injector. The fluid comprises air, and/or oxygen. The several fluid injectors comprise several subsets of fluid injectors, and each fluid injector within subset of fluid injectors is configured to be activated and deactivated concurrent with activation and deactivation of each other fluid injector in subset. The control system is configured to selectively control each fluid injector based on operational parameter of reactor. The operational parameter comprises type of biomass feedstock, approximate length of pyrolysis zone (56) of gasification chamber, approximate length of combustion zone (58) of biomass gasification chamber, operational parameter of engine that receives producer gas from reactor, and/or tar content of producer gas. The biomass gasification system comprises air delivery system (69) configured to supply several fluid injectors with air, and/or oxygen. The biomass gasification system comprises: reactor configured to gasify biomass feedstock in biomass gasification chamber to thermally convert biomass feedstock into producer gas, where several nozzles are disposed along length of reactor and configured to inject air and/or oxygen into biomass gasification chamber; and control system configured to determine approximate location of combustion zone in gasification chamber and to selectively deactivate each nozzle of several nozzles not capable of injecting air and/or oxygen into combustion zone. The air delivery system comprises air source, oxygen source, and/or flow controller. The biomass gasification system comprises cyclone configured to separate particulates from producer gas; scrubber system configured to clean producer gas; and power generation system (20) configured to receive producer gas and utilize producer gas to generate at least one of methanol, ammonia, and diesel fuel. An INDEPENDENT CLAIM is included for method for selectively activating several controllable fluid injectors based on operational parameter of biomass gasification process, involving: receiving data corresponding to operational parameter of biomass gasification process or power generation system that receives producer gas from biomass gasification process; activating, based on received data, subset of several air and/or oxygen injectors disposed along length of biomass gasification chamber; and controlling air delivery system to supply activated subset of several air and/or oxygen injectors with air and/or oxygen for injection into biomass gasification chamber.    DESCRIPTION OF DRAWING(S) - The figure shows block diagram of biomass gasification system including biomass gasifier having several controllable fluid injectors.    Gasifier/reactor (16)    Power generation system (20)    Biomass-derived feedstock (44)    Gasification chamber (50)    Inlet (52)    Pyrolysis zone (56)    Combustion zone (58)    Fluid injectors (66)    Control system to control supply of air to fluid injectors (67)    Side walls of gasification enclosure (68)    Air delivery system (69)    Outlet (70)