NOVELTY - The method involves selecting a downdraft gasifier (14) in which apertures of an upper manifold aligns with apertures of an intermediate section to form columnar cavities to be extended from the upper manifold to a lower manifold and to place the upper manifold in communication with the lower manifold. A feedstock (16) is placed into the upper manifold. Temperature of each columnar cavity is measured. Flow of gas e.g. oxygen, oxygen enriched air and air, is adjusted to a particular columnar cavity to maintain the temperature of the particular columnar cavity within a particular range.    USE - Method for performing gasification of feedstocks using a downdraft gasifier in a gasification industry. Uses include but are not limited to tire, used motor oil, sewage sludge, municipal solid waste, agricultural waste, coal fines, petroleum sludge, landfill gas and natural gas.    ADVANTAGE - The method enables providing a semi permeable barrier by bed of moving and mixing balls for permitting synthesis gas and small particles to work or pass while blocking passage of larger particles and increasing the flow to raise the temperature within the columnar cavity or decreasing the flow to lower the temperature within the columnar cavity by a control system to maintain the temperature of the columnar cavity within the particular range, so that down time and accumulation associated with down time can be minimized or eliminated while permitting shafts to be formed of materials with less tolerance to heat in an inexpensive and more readily available manner. The method allows the feedstock to enter into the downdraft gasifier through a feedstock inlet and travel down through the downdraft gasifier toward a waste outlet such that the gasifier with drying zone, tar-formation zone, oxidation zone and reduction zone functioning in unison to simultaneously process the feedstock can efficiently generate clean synthesis gas while receiving a wide variety of inputs or feedstocks.    DETAILED DESCRIPTION - The intermediate section is a lower intermediate section, middle intermediate section or upper intermediate section.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic block diagram of a downdraft gasifier system with material flow.    Preprocessor (12)    Downdraft gasifier (14)    Feedstock (16)    Geo-polymer block plant (48)    Sulfur-free fuel (82)