Otieno Edwin Ochieng, Kiplimo Robert, Mutwiwa Urbanus
Pan African University Institute for Basic Sciences, Technology and Innovation, P. O. Box 62000-00200, Nairobi, Kenya.
Department of Marine Engineering and Maritime Operation, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000 - 00200, Nairobi, Kenya.
Heliyon. 2023 Feb 27;9(3):e14041. doi: 10.1016/j.heliyon.2023.e14041. eCollection 2023 Mar.
The demand for energy has been growing over the years to match development and population growth. The current sustainable development model advocates for the use of renewable (green) energy sources with an aim of lowering carbon emissions thereby mitigating the effects of climate change. A circular economy aspires to keep materials in use for as long as possible thus the reuse of agricultural waste especially in energy generation is a step in this direction. This study reports on the optimization of anaerobic digestion parameters for biogas production when wastes from pineapple are co-digested with those from livestock. The volume of biogas yield was optimized with regards to temperature, pH value, and mixing ratio of the substrates using Box Behnken Design (BBD), a class of Response Surface Methodology (RSM). This was achieved through a software package, Design Expert 13.The experiments were performed using Rehau home gas systems of 6 m in Jomo Kenyatta University of Agriculture and Technology. Pineapple wastes were co-digested with livestock waste in the ratio of 1:1, 1:2 and 1:3. The numerical optimization results revealed that the maximum biogas yield was 1.98 m when the pH was set at 6.0, temperature at 30 °C and pineapple mixing ratio at 62.5%. The results from this study can form a basis for policy makers in formulating strategies to guide adoption of biogas generated from agricultural waste as a key green energy for the economy.
多年来，能源需求一直在增长，以适应发展和人口增长。当前的可持续发展模式提倡使用可再生（绿色）能源，目的是降低碳排放，从而减轻气候变化的影响。循环经济致力于尽可能长时间地保持材料的使用，因此农业废弃物的再利用，特别是在能源生产中的再利用，是朝着这个方向迈出的一步。本研究报告了菠萝废弃物与牲畜废弃物共消化时沼气生产厌氧消化参数的优化情况。使用响应面法（RSM）中的Box Behnken设计（BBD），对沼气产量在温度、pH值和底物混合比例方面进行了优化。这是通过一个名为Design Expert 13的软件包实现的。实验在乔莫·肯雅塔农业技术大学6米长的瑞好家用气体系统上进行。菠萝废弃物与牲畜废弃物按1:1、1:2和1:3的比例共消化。数值优化结果表明，当pH值设定为6.0、温度为30℃且菠萝混合比例为62.5%时，沼气产量最高为1.98立方米。本研究结果可为政策制定者制定战略提供依据，以指导采用农业废弃物产生的沼气作为经济的关键绿色能源。
