Lomunyak George, Osodo Booker, Njoka Francis, Kombe Emmanuel
Department of Energy, Gas and Petroleum Engineering, Kenyatta University, P. O. Box 43844 00100, Nairobi, Kenya.
Heliyon. 2024 Dec 5;10(24):e40991. doi: 10.1016/j.heliyon.2024.e40991. eCollection 2024 Dec 30.
Utilization of loose waste biomass such as charcoal dust remains popular in low-to mid-income countries due to increased energy demands, poverty and heighten efforts to mitigate climate change. This study sought to investigate the effects of starch, paper and algae binders on the physical, mechanical and combustion characteristics and emission levels of manually-made acacia charcoal dust briquettes. Acacia charcoal dust is collected and mixed with different binders at binder proportions of 10 %, 15 %, 20 %, 25 % and 30 % of the total weight for individual samples. Briquette samples are produced using a manually-operated briquetting machine. Briquettes are dried, characterized, and analyzed. Response Surface Methodology is used to investigate the effect of binder type and binder proportions on calorific value, ignition time and burning rate of the briquettes. Results show that the density of the produced briquettes from Charcoal-Starch (CS), Charcoal-Paper (CP) and Charcoal-Algae (CA) samples ranged between 571.5 kg/m- 678.1 kg/m, 495.8 kg/m-534.4 kg/m, 535.6 kg/m-578.2 kg/m, respectively. A mean shatter resistance of 91.3 %, 97.9 % and 95.2 % is obtained for CS, CP and CA briquettes, respectively. Moisture content, volatile matter, ash content and fixed carbon for all the samples ranged between 4.7 % and 7.1 %, 30 % and 46 %, 14 % and 32 %, 23 % and 56 %, respectively. Moreover, optimization response results show that a 30 % starch binder proportion gives the best calorific value, ignition time and burning rate. The highest emissions for CO, NOx and SO are, respectively, 389 ppm, 2.86 ppm and 2.26 ppm for CS samples, 345.3 ppm, 5.46 ppm, and 2.66 ppm for CP, and 422.1 ppm, 5.46 ppm 3.06 ppm for CA samples. Those results show that it is practically feasible to manually-make quality acacia charcoal dust briquettes with starch, paper and algae as binders. Such briquettes hence provide a quality source of fuel curbing deforestation and waste dumping, reducing fuel shortages in cities and forming a source of livelihood especially in developing countries.
由于能源需求增加、贫困以及减缓气候变化的力度加大，诸如木炭粉尘等松散废弃生物质在低收入和中等收入国家的使用仍然很普遍。本研究旨在调查淀粉、纸张和藻类粘结剂对人工制作的相思木炭粉尘压块的物理、机械和燃烧特性以及排放水平的影响。收集相思木炭粉尘，并将其与不同的粘结剂按单个样品总重量的10%、15%、20%、25%和30%的粘结剂比例混合。使用手动压块机制备压块样品。对压块进行干燥、表征和分析。采用响应面法研究粘结剂类型和粘结剂比例对压块热值、着火时间和燃烧速率的影响。结果表明，木炭 - 淀粉（CS）、木炭 - 纸张（CP）和木炭 - 藻类（CA）样品制成的压块密度分别在571.5 kg/m³ - 678.1 kg/m³、495.8 kg/m³ - 534.4 kg/m³、535.6 kg/m³ - 578.2 kg/m³之间。CS、CP和CA压块的平均抗碎强度分别为91.3%、97.9%和95.2%。所有样品的水分含量、挥发物、灰分和固定碳分别在4.7%至7.1%、30%至46%、14%至32%、23%至56%之间。此外，优化响应结果表明，30%的淀粉粘结剂比例给出了最佳的热值、着火时间和燃烧速率。CS样品中CO、NOx和SO的最高排放量分别为389 ppm、2.86 ppm和2.26 ppm，CP样品分别为345.3 ppm、5.46 ppm和2.66 ppm，CA样品分别为422.1 ppm、5.46 ppm和3.06 ppm。这些结果表明，以淀粉、纸张和藻类作为粘结剂人工制作高质量的相思木炭粉尘压块在实际中是可行的。因此，这种压块提供了一种优质的燃料来源，可抑制森林砍伐和废物倾倒，减少城市燃料短缺，并成为特别是在发展中国家的一种生计来源。
