An integrated biomass conversion system and a method of starting and shutting down the system are disclosed. The integrated biomass conversion system comprises a syngas generator, such as a gasifier, a cleanup engine and a syngas utilization system, which could be a power producing engine or a chemical reactor for chemical or fuel synthesis. The cleanup engine operates rich and at high temperatures so that the tars exhausted by the syngas generators are destroyed and not allowed to foul other components. An orderly sequence to start and shut down the integrated biomass conversion system is disclosed.

An integrated biomass conversion system and a method of starting and shutting down the system are disclosed. The integrated biomass conversion system comprises a syngas generator, such as a gasifier, a cleanup engine and a syngas utilization system, which could be a power producing engine or a chemical reactor for chemical or fuel synthesis. The cleanup engine operates rich and at high temperatures so that the tars exhausted by the syngas generators are destroyed and not allowed to foul other components. An orderly sequence to start and shut down the integrated biomass conversion system is disclosed.

A method of producing a gas from a combustible material is provided. The method comprises the steps of loading the combustible material into a containment structure and sealing it therein. An oxidant is fed into the sealed containment structure with a controlled flow rate and a controlled rate of movement such that the combustible material is partly converted, thereby leaving behind thermally affected layers of combustible material after the injection point has passed through the material. At least some of the combustible material is converted into molten slag and or char that accumulates as the bottom-most thermally affected layer and subsequently cools and solidifies. The method is characterised in that it further includes the step of discharging solid slag and or char in the bottom-most thermally affected layer from under material that remains in the containment structure to remove solid slag and or char from the containment structure.