Syngas production from citrus residues through catalytic BFB gasification

The exploitation of the biomass as renewable energy have resulted to be a significant solution for the growing trend of the worldwide energies market. In these last years, many attentions have been addressed toward use/valorization of agro-industrial residues and waste[1]. Only in Italy, every year the juice industries produce about 1 million tons of citrus peels, involving significant environmental problem related to disposal of solid wastes. Hence, the conversion of these by-products represent a significant source of energy that could be valorized by gasification technology [2]. In this context, aim of this work is to evaluate the feasibility to convert citrus residues in syngas by catalytic steam gasification process. Thus, thermo-gravimetric analysis (TGA/DTG) were carried out on citrus peels samples, both under nitrogen and steam atmosphere, in order to individuate the suitable operative temperature range and to maximize the citrus peels oxidation reaction-step. Successively, gasification experimental tests were carried out in a bubbling fluidized bed reactor at 720°C, 1 bar and various steam to biomass inlet ratios. Different kind of fluidized bed materials, as silica send and solid volcanic lava were used for the tests. Therefore, effect of different parameters were investigated in order to evaluate the gasification performances in terms of: i) syngas yields ii) hydrogen selectivity iii) effect of gasify agent on syngas composition, mainly in terms of H2/CO ratio iv) catalytic bed materials role, especially of volcanic lava, on citrus peels steam gasification yield. References [1] M. Volpe, D. Panno, R. Volpe, A. Messineo, "Upgrade of citrus waste as a biofuel via slow pyrolysis", J. of Analytical and Applied Pyrolysis 115 (2015) 66-76. [2] A. Galvagno, M. Prestipino, G. Zafarana, V. Chiodo, "Analysis of an integrated agro-wast gasification and 120kW SOFC CHP system: modeling and experimental investigation", Energy Procedia 101 (2016) 528-535.