Process characteristics and products of olive kernel high temperature steam gasification (HTSG)

Exploitation of olive kernel for bioenergy production, with respect to the green house gases (GHGs) mitigation, is the main aim of this work. In this study, olive kernels were used as a solid biofuel, and high temperature steam gasification (HTSG) was investigated, in the fixed bed unit at KTH Sweden, with regard to hydrogen maximization in the produced gasification gas. Experiments were carried out in a temperature range of 750–1050 °C, with steam as the gasifying agent. The behaviour of olive kernels, under residence times from 120 up to 960 s, has been studied. At 1050 °C, a medium to high calorific value gas was obtained (LHVgas = 13.62 MJ/Nm3), while an acquired H2/CO molar ratio equal to four proved that olive kernel HTSG gasification could be an effective technology for a hydrogen-rich gas production (∼40%vv H2 in the produced gasification gas at 1050 °C). The produced char contained 79%ww of fixed carbon, low chlorine and sulphur content, which enables it for further re-use for energetic purposes. Tar content in the produced gas at 750 °C was 124.07 g/Nm3, while a 1050 °C at 79.64% reduction was observed and reached the value of 25.26 g/Nm3.