Disclosed are methods and systems for producing a gas from a combustible material. In particular, disclosed are methods and systems for batch-type production of a gas from a combustible material. The methods and systems include igniting at least a portion of the combustible material loaded in the sealed containment structure to form a thermally affected layer, wherein the step of feeding the oxidant into the sealed containment structure is carried out so that conversion of the combustible material to a gas at one point in the sequence is initiated prior to complete conversion of the combustible material at a previous point in the sequence.