ASSESSMENT OF SYNGAS PRODUCED FROM GASIFICATION OF OLIVE TREE PRUNING IN A DOWNDRAFT REACTOR

Gasification of biomass is a widely used technique for renewable energy production from agricultural residues that allows both to reduce the environmental impacts of agroforestry sector and to obtain products such as syngas and biochar. The aim of this work is to assess the energy characteristics of syngas obtained from gasification, with air, of olive tree prunings through a downdraft fixed bed reactor. Results showed that the composition of syngas is strongly influenced by the air flow rate. The hydrogen and carbon monoxide contents reached values of about 16%v/v and more than 13%v/v, respectively. The methane content was less than 3%v/v while nitrogen content was more than 50%v/v as consequence of the use of air as oxidizing agent. The lower heating value of syngas ranged between 3.6 MJ Nm(-3) and 4.6 MJ Nm(-3). The biochar produced during the gasification process showed a carbon content of about 74%w/w. By results of biomass characterization and of gasification tests, it is possible to state that olive tree prunings are a suitable biomass for gasification in downdraft fixed bed reactor and hence for production of syngas and biochar.