Moreda Geleta Afessa, Teklemariyem Debela Alema, Tolasa Sorome Deresa, Gutata Gamachis Ragasa
Department of Mechanical Engineering, College of Engineering and Technology, Dambi Dollo University, Dambi Dollo, Ethiopia.
Thermal Engineering, Jimma Institute of Technology, Jimma University, Jimma, Ethiopia.
Heliyon. 2024 Oct 10;10(20):e39097. doi: 10.1016/j.heliyon.2024.e39097. eCollection 2024 Oct 30.
This study explores the potential of Khat waste as a biofuel through a detailed analysis of its physical properties and pyrolytic behavior, employing both laboratory and simulation techniques. Biomass, including Khat waste, is a valuable renewable energy source with potential applications in reducing waste and CO2 emissions, especially in rural areas of developing countries like Ethiopia. The physical properties of the Khat waste were thoroughly examined, including moisture content, ash, volatile matter (VM), fixed carbon (FC), and elemental composition. The apparent density of the pyrolyzed khat waste was found to be 0.9688 g/cm³. The TGA results showed a moisture loss of 6.7 %, volatile matter of 4.7 %, fixed carbon of 6.78 %, and ash content of 5.55 %. Notably, Khat waste exhibited unique thermal behavior with a downward shift in TG curves above 220 °C. DTGA identified three decomposition peaks: moisture evaporation at 100 °C, hemicellulose breakdown at 210 °C, and cellulose degradation at higher temperatures. Fourier Transform Infrared Spectroscopy (FTIR) provided insights into the functional groups present in Khat waste, including alkene functional groups and O-H bonds, which are crucial for biofuel properties. Simulation using Aspen Plus software modeled the pyrolysis process, highlighting how varying heating rates affect volatile matter and fixed carbon content. Increasing heating rates decreased volatile matter and moisture but increased fixed carbon content. These findings offer valuable insights for optimizing Khat waste as a biofuel, emphasizing the need for tailored pyrolysis conditions to enhance biofuel production efficiency.
本研究通过对阿拉伯茶废料的物理性质和热解行为进行详细分析，采用实验室和模拟技术，探索其作为生物燃料的潜力。包括阿拉伯茶废料在内的生物质是一种宝贵的可再生能源，在减少废物和二氧化碳排放方面具有潜在应用，特别是在埃塞俄比亚等发展中国家的农村地区。对阿拉伯茶废料的物理性质进行了全面检查，包括水分含量、灰分、挥发物（VM）、固定碳（FC）和元素组成。热解后的阿拉伯茶废料的表观密度为0.9688 g/cm³。热重分析（TGA）结果显示，水分损失为6.7%，挥发物为4.7%，固定碳为6.78%，灰分为5.55%。值得注意的是，阿拉伯茶废料表现出独特的热行为，在220°C以上热重曲线向下移动。导数热重分析（DTGA）确定了三个分解峰：100°C时水分蒸发，210°C时半纤维素分解，以及较高温度下纤维素降解。傅里叶变换红外光谱（FTIR）提供了有关阿拉伯茶废料中存在的官能团的见解，包括烯烃官能团和O-H键，这些对生物燃料性质至关重要。使用Aspen Plus软件进行的模拟对热解过程进行了建模，突出了不同加热速率如何影响挥发物和固定碳含量。提高加热速率会降低挥发物和水分，但会增加固定碳含量。这些发现为优化阿拉伯茶废料作为生物燃料提供了有价值的见解，强调了需要定制热解条件以提高生物燃料生产效率。
