Abstract

Municipal waste has the potential to be a significant source of energy production. This study investigated pretreatment methods such as NaOH, hydrothermal, and ozonation to increase biomethane production from municipal waste. In addition, these pretreatments were further evaluated using ultrasonic pretreatment after achieving optimal conditions by RSM CCD methods. The optimum pretreatment conditions were observed to be 8% NaOH concentration, 132 °C hydrothermal temperature, and O₃ equal to 0.19 g/g TS. The maximum biomethane produced and achieved during the tests was 394 mL/kg TS, which increased to 410 mL/kg TS after ultrasonic pretreatment. The best sCOD reduction in the optimal pretreatment conditions and after the ultrasonic pretreatment was 87% and 91%, respectively. Also, in the absence of ozone pretreatment, the highest yields of biomethane and biogas occurred at a 6.4% concentration of NaOH and a temperature of 135 °C; however, in the presence of ozone, the yield of biomethane and biogas produced was greater and the inhibitory effect of sodium hydroxide also occurs in higher amounts. Experiments have shown that ozonation increases biomethane production rather than increasing biogas production (hence the ratio of methane to biogas).

摘要

城市垃圾有可能成为能源生产的重要来源。本研究调查了 NaOH、水热和臭氧等预处理方法，以提高城市垃圾中的生物甲烷产量。此外，在通过 RSM CCD 方法达到最佳条件后，使用超声波预处理进一步评估了这些预处理。最佳预处理条件为 8% NaOH 浓度、132 ℃水热温度和 O ₃等于 0.19 g/g TS。测试期间产生和达到的最大生物甲烷为 394 mL/kg TS，在超声预处理后增加到 410 mL/kg TS。最佳预处理条件下和超声预处理后的最佳 sCOD 降低率分别为 87% 和 91%。此外，在没有臭氧预处理的情况下，生物甲烷和沼气的最高产量出现在 6.4% 的 NaOH 浓度和 135 °C 的温度下；然而，在臭氧存在的情况下，产生的生物甲烷和沼气的产量更大，氢氧化钠的抑制作用也更多地出现。实验表明，臭氧化增加了生物甲烷的产量，而不是增加了沼气的产量（因此甲烷与沼气的比例）。