A low-cost pyrogas cleaning system for power generation: Scaling up from lab to pilot

An effective pyrogas cleaning system is necessary for downstream application of biomass pyrolysis technology for power generation. Particularly, tar must be lowered to a satisfying level in order to avoid the problem of tar blockage for preventing damage to the engine and to prolong the engine lifetime. This research was carried out from previous successful research on oil scrubbers and char adsorption for tar removal. Further lab scale experimentation was done to find the appropriate quantity of oil to be used in the scrubber; the results were used for scaling up and showed that the optimum system needed for 0.045 m3/h pyrogas the quantity of 1 l, during a test lasted 30 min. The 1 l oil scrubber was combined with a 41 g char adsorption bed and 97.6% gravimetric tar removal efficiency was obtained. The combination of the oil scrubber and the char adsorption bed was scaled up and installed into the IPRP (Integrated Pyrolysis Regenerated Plant) at the University of Perugia, with chestnut wood (Castanea Sativa Miller) as feedstock, and connected to a 6 kWe Lombardini engine with a power generator and electric load. Pyrogas was sampled at 0.7 m3/h and connected to the cleaning system, consisting of a 15 l oil scrubber combined with a 922 g char adsorption bed. The demonstrating test was successfully accomplished with 98.7% gravimetric tar removal at the exit of the char adsorption bed. The engine ran smoothly and the electric load was constant.