Almond residues gasification plant for generation of electric power. Preliminary study

In this work, the results of the gasification process of almond residues (almond shell, almond tree pruning, and almond shell peel) generated by an industry (PASAT SAT) are presented. This study was performed in a laboratory fixed-bed reactor. The objective was the obtaining of low/medium heating value gases, which could be burnt in a gas engine to generate electric energy. The effects of varying the air flow rate (50–400 cm3 min− 1) and the temperature (650–800 °C) in the gasification process of the almond shell peel were discussed. An air flow rate of 200 cm3 min− 1 and temperature of 800 °C were the optimal conditions with respect to the quality of the gas. At these conditions, the gasification processes of almond shell and almond tree pruning were also studied. The molar fractions of the fuel components reached their maximum values at these conditions with an average gas composition of 2.9% O2, 52.2% N2, 13.3% H2, 14.3% CO, 11.3% CO2, 4.8% CH4 and 1.2% C2H2, C2H4 and C2H6. The gas yield obtained was 1.66, 1.85 and 1.71 N m3/kg of residue for almond shell peel, almond shell and almond tree pruning, respectively. The higher heating value (HHV) of the gas obtained at these conditions (5.8, 6.5 and 6.4 MJ N m− 3 for almond shell peel, almond shell and almond tree pruning, respectively) are comparable with the published data by other researchers. The carbon conversion was in the range between 81% and 90%. From the residues generated by the industry, with an average processing capacity of 1400 kg of residue/h, an energy potential of 3.99 MW thermal could be obtained. The design of a gasification plant for generation of electric energy with an alternator of 1.99 MW, considering a global efficiency of the process of 25%, could be performed.