Rai Singh Dahiya of Rajasthan has developed an efficient biomass gasifier where he has changed the conventional design, especially of the filters and cooling unit to get clean gas, ensuring smooth operation of engine at low operational cost. The unit consists of a gasifier, which generates producer gas from bio-waste just to run an engine. The gasifier is conical in shape, compact in design and surrounded by a water jacket with the capability to handle multiple fuel sources. Fuel wood or briquettes from agricultural residues can be fed to this gasifier. The air inlet is provided at the bottom. The system has two stages for removing ash, charred residue and tar. The primary filter unit comprises a series of rows of filtration units; each series consists of a rod over which semicircular baffles having perforation are welded. Perforation becomes progressively smaller from the first to the third filtration unit. The filter can easily be cleaned by pulling out the rod with the baffles. It is surrounded by a water jacket. The secondary filter has layers of different sizes of sieves ranging from 2 inches to very fine size, with the cleaning gate at the bottom. This product was invented in the year 2006.