Liquefaction of pistachio shells and analysis of the products

LIQUEFACTION OF PISTACHIO SHELLS AND ANALYSIS OF THE PRODUCTSSUMMARYAs a result of the rapid increase of world population, and the developing technology, most ofthe increasing need for energy is met by primary fossil energy resources such as petroleum,natural gas and coal that are non-renewable and cause environmental problems.Today the usage of clean, easy to find and renewable alternative energy sources rapidlybecomes more important. Biomass, among the alternative energy sources, is anenvironmentally-friendly renewable energy resource, always present in almost all parts of theworld in a great potential.In this study, the effects of various experimental parameters on the liquefaction yields of abiomass waste material, namely pistachio shells, were investigated. Temperature, pressureand tetralin/(tetralin+creosote oil) ratio were the parameters whose effects were studied indetail. The experiments were carried out in a magnetically stirred autoclave of 250 mlcapacity. Tetralin+creosote oil mixture and hydrogen were used during the experiments assolvent and gas medium, respectively. The reaction time at reaction conditions was taken as45 minutes. The oil, asphaltene, preasphaltene and residue fractions of liquefaction productswere seperated by Soxhlet extraction.The individual effects of temperature and tetralin/(tetralin+creosote oil) ratio on liquefactionof pistachio shells were investigated in the fırst part of this study. In the second part, theeffects of temperature, pressure and tetralin/(tetralin+creosote oil) ratio were investigatedbased on an experimental design work. The studied ranges for temperature, pressure andtetralin/(tetralin+creosote oil) ratio were 325-375ºC, 10-30 atm., 0-1, respectively. In the thirdand last stage, the model equations for oil+gas, asphaltene and preasphaltene yields, totalconversions were developed and an optimization study was done.As a result of the models obtained for the liquefaction yields, the optimum conditions are; fortotal conversion, 370,5ºC, 22,6 atm and 0,08 tetralin/(tetralin+creosote oil) ratio; for oil+gasyield, 370,8ºC, 19,9 atm and 0,96 tetralin/(tetralin+creosote oil) ratio; for asphaltene yield,361,9ºC, 19,5 atm and 0,03 tetralin/(tetralin+creosote oil) ratio; for preasphaltene yield,355,4ºC, 19,1 atm and 0,01 tetralin/(tetralin+creosote oil) ratio.Keywords: Biomass waste material, pistachio shells, liquefaction, experimental design.1