Effect of equivalence ratio on the performance of the downdraft gasifier – An experimental and modelling approach

Abstract

This paper deals with experimental and modelling studies carried out for different Equivalence Ratio (ER). Seven different ER (0.24–0.386) were selected to investigate the downdraft gasifier performance. The lignite and sawdust briquette (70:30, %wt.) were used as feedstock in a 10 kWe atmospheric pressure downdraft gasifier. The fuel consumption and air consumption were observed to exist in the range of 0.54 kg h−1 to 11.1 kg h−1 and 0.59 kg h−1 to 19.5 kg h−1 respectively. The Lower Heating Value (LHV) and gas yield were found to be 4.91 MJ Nm−3 and 2.99 Nm3 kg−1 respectively at 0.386 ER. Tar and Particulate Matter (PM) were found in the range of 516.3 mg Nm−3 to 565.23 mg Nm−3 and 47.86 mg Nm−3 to 57.29 mg Nm−3 respectively for different ER. The CGE observed was 80.03% whereas the tar and PM were reported as 516.3 mg Nm−3 and 47.86 mg Nm−3 respectively at ER of 0.386. A thermo-equilibrium model was developed to estimate the producer gas compositions and LHV. The results were compared with the experimental results from the literature and good agreement between the two was observed.