Abstract: Energy consumption has an important influence on the process of forming of biochar-based fertilizer. From the view of reducing energy consumption and ensuring product quality, this study chose biochar and bentonite as slow-release materials, soluble starch as binder, and urea, ammonium dihydrogen phosphate, muriate as raw materials for the slow-release fertilizer, and carried out forming experiments to investigate the effect of different speed, moisture content, aspect ratio and ratio of slow-release materials and fertilizer on specific energy consumption and compressive strength. On the basis of single factor test, considering lower energy consumption and high compressive strength, the optimal process parameters was obtained from respond surface model. Results showed that the influence of each factor on energy consumption was as follows: aspect ratio > moisture content > speed > ratio of slow-release materials and fertilizer. the strength order of the related factors to compressive strength was moisture content> ratio of slow-release materials and fertilizer > speed > aspect ratio. The optimal process parameters were: 50 mm/min for speed,3.5 for aspect ratio,14.16% for moisture content,4 for ratio of slow-release materials and fertilizer. Under this condition, specific energy consumption of the extrusion process is 20.541 kJ/kg, compressive strength of pellet is 35.013 N. These results were expected to provide references for upgrading pelleting process and designing of equipment.

Key words: specific energy consumption, biochar-based fertilizer, compression, optimization

摘要： 针对生物炭基肥成型过程中单位产品能耗高的问题，从降低能耗、保证产品质量的角度出发，以生物炭和膨润土为基质材料，可溶性淀粉为粘结剂，尿素、磷酸二氢铵、氯化钾作为基础肥料进行挤压成型试验,研究了不同压缩速度、含水率、长径比和基肥比（基质材料与基础肥料的比值）对比能耗和抗压强度的影响。在单因素试验的基础上，以最低比能耗、最高抗压强度为目标，采用响应面试验优化工艺参数。结果表明各因素对比能耗影响作用大小依次为长径比>含水率>压缩速度>基肥比；各因素对抗压强度影响作用大小依次为含水率>基肥比>压缩速度>长径比。最佳工艺参数为:压缩速度为50 mm/min，长径比为3.5，含水率为14.16%，基肥比为4，该条件下单位产品比能耗为20.541 kJ/kg，颗粒抗压强度为35.013 N。该研究可为制粒工艺以及成型设备的改进提供一定参考。

关键词: 比能耗, 炭基肥, 成型, 工艺优化