Experimental assessment of pine wood chips gasification at steady and part-load performance

Abstract

The trend towards decentralised electricity generation and combined heat and power (CHP) is continuously increasing. The transition towards a decentralised power system relies on small-scale and often intermittent generation, bringing new challenges such as matching the demand with supply. A possible solution is the use of renewable energy technologies able to accommodate the demand profile, such as biomass gasification. However, operation at part-load is required and thus limiting the gasification performance efficiency. In this paper, a novel experimental assessment and performance results of a biomass gasification system are presented, consisting on the evaluation of the system performance for steady-state conditions at different loads. Gasifier performance at steady-state conditions showed relatively stable reduction and throat temperatures, with average values of about 729 °C and 915 °C, respectively. These high temperatures assure a producer gas LHV of about 5.5 MJ/kg. Decreasing the gas flow rate resulted in a decrease of both reduction and throat temperatures. Nonetheless, the gas LHV increased until 62.5% where a maximum of about 6 MJ/kg was measured. Concerning the equivalence ratio, it decreased with load, attaining a minimum value at 80%, where the best cold gas efficiency results were found (74%).