Abstract

Press mud (PM), generated from sugar mills, and poultry droppings (PD) are treated as waste materials and may be a solution for a country’s energy deficit in that their anaerobic co-digestion can produce high-value bio-energy in the form of biogas. Both a batch experiment and continuous experiments in continuous stirred tank reactor (CSTR) were conducted to determine the optimal temperature from the mesophilic temperature regimes in terms of methane yield. Also studied was the variability of other major parameters at varying temperatures with co-digestion of PM and PD in microbial consortia. The average highest ultimate methane yield and specific methane yields were 325 and 260 normalized litre per kg volatile solids (NL kg⁻¹ VS) for the batch and continuous experiments, respectively. The maximum average specific methane yields were obtained at 35–45 °C, as expected, but yields did not differ significantly. The rate of methane production was relatively lower at temperatures of less than 35 °C and significant yield differences were found among temperatures of 35, 30, 25 and 20 °C. The results show that the temperature influenced the anaerobic digestion performance significantly. The optimum temperature was predicted using MINITAB-18 software according to the best-fit regression models, and modeling showed the optimal temperature was 44 °C.

摘要

制糖厂产生的压榨泥 (PM) 和家禽粪便 (PD) 被视为废物，可能是解决国家能源短缺问题的方法，因为它们的厌氧共消化可以产生高价值的生物能源形式沼气。在连续搅拌釜反应器 (CSTR) 中进行分批实验和连续实验，以确定甲烷产率方面的中温温度范围的最佳温度。还研究了其他主要参数在不同温度下与微生物群落中 PM 和 PD 的共同消化的变化。平均最高最终甲烷产量和特定甲烷产量分别为 325 和 260 标准化升/kg 挥发性固体 (NL kg ^-1VS) 分别用于批量和连续实验。正如预期的那样，在 35-45 °C 时获得了最大平均特定甲烷产量，但产量没有显着差异。在低于 35°C 的温度下，甲烷的产生率相对较低，并且在 35、30、25 和 20°C 的温度之间发现了显着的产量差异。结果表明，温度对厌氧消化性能有显着影响。使用MINITAB-18软件根据最佳拟合回归模型预测最适温度，建模显示最适温度为44℃。