The present invention provides a gas conditioning system for processing an input gas from a low temperature gasification system to an output gas of desired characteristics. The system comprises a two-stage process, the first stage separating heavy metals and particulate matter in a dry phase, and the second stage including further processing steps of removing acid gases, and/or other contaminants. Optional processes include adjusting the humidity and temperature of the input gas as it passes through the gas conditioning system. The presence and sequence of processing steps is determined by the composition of the input gas, the desired composition of output gas for downstream applications, and by efficiency and waste minimization.