New approach for integral treatment of OFMSW: Comparative analysis of its methane performance versus a conventional continuously stirred tank reactor

To develop this comparative, in this study was necessary to determine experimentally the HRT in which maximum methane production was reached (optimum HRT) using UFAF technology. Bio-hydrogen effluents resulting of the dark fermentation of OFMSW coming from a full-scale mechanical-biological treatment plant was used as feedstock. To determine the optimum HRT, a sequential decreasing of this operational parameter from 7.5 to 1.5 days was established. The results obtained indicate that the maximum specific methane yield, 0.26 and 0.28 LCH4/g CODr respectively, were obtained at 3 days HRT in mesophilic (35 °C) and thermophilic (55 °C) regime of temperature. Finally, the comparative analysis showed that the methane production of the new scheme based on methanogenic-thermophilic UFAF reactor is approximately 4 times higher than methanogenic-thermophilic CSTR (2.00 versus 0.48 LCH4/L/d respectively) and, in addition, higher methane percentage on biogas is reached (75.9% versus 70.6% respectively).