This study presents the engineering design and assessment of a model biomass thermal decomposition fuel generating system to be utilized in small applications, with a capacity of around 10 kW. To guarantee the suitability of the syngas for utilization in a reciprocating engine, the setup includes a gas filtration treatment system in conjunction with a small-sized downdraft gasifier. The configuration of the downdraft gasifier model is based on existing literature, but the methodology has been adapted for smaller gasifiers. To prepare the producer gas for use in the internal combustion engine (ICE), a three-stage gas cleaning system was developed. The first stage involves a hot gas clean-up using a cyclone to remove particles and compounds, continued by a heat exchanger to cool the gas and condense tars and moisture. To sum up, the purification of cooled gases involves the implementation of two filtration phases, with the first phase utilizing organic material and the second phase utilizing a polypropylene cartridge filter.