Steam co-gasification of horticultural waste and sewage sludge: Product distribution, synergistic analysis and optimization

In this study, horticultural waste (HW) and sewage sludge (SS) with different mass ratios were co-gasified with steam at different temperatures to investigate the product distribution, gas synergistic interaction, and optimal design for gas products from co-gasification process. Results showed that with the increase of SS ratio in blends, the H-2 content was increased and the syngas yield was decreased. The synergistic interaction was more significant at higher temperature which promoted the H-2 production probably due to the reduction and steam oxidation of Fe species in SS during co-gasification process. The optimized highest effective gas content (82.92 vol%) was achieved with the highest HHV (11.40 MJ/m(3)) at the conditions of SS ratio = 0.80 and temperature of 900 degrees C. It indicates that steam co-gasification of HW and SS is a promising technology to produce desired syngas towards a clean and efficient waste management process.