Cheap, locally produced natural minerals such as dolomite, zeolite (clinoptilolite) and calcium carbonate were used as catalysts for in-situ pyrolysis of pecan nut shells collected from local crops. In order to explore the effect of calcination on biomass pyrolysis, tests were performed with both non-calcined and calcined catalysts. Results show a general improvement of pyrolysis performance when catalysts were used. Higher biogas yields were obtained for calcined catalysts (except CaO). On the other hand, non-calcined catalysts always promoted higher condensate yields. Bio-oil characterization with GC-MS showed guaiacol was the main formed product, and results suggest catalyst calcination promotes catalytic cracking. From analysis with GC-TCD, it was observed the mixture of biomass with CaO prominently promoted hydrogen production.
