基于离散元法的玉米秸秆球磨预处理放大仿真研究

Investigation of Scale-up Simulation for Corn Straw Ball Milling Pretreatment Utilizing Discrete Element Method

摘要:

为了更好地推动秸秆球磨预处理技术应用，评估球磨预处理工艺实现放大生产的可行性，通过离散元法仿真模拟预测规模放大的秸秆球磨预处理中的能耗，并验证球磨规模放大后的预处理效果。将实验室规模的CJM-SY-B型振动球磨机筒体尺寸按容积放大24倍后建立三维几何模型，导入EDEM软件，通过输入玉米秸秆初始和球磨后的物理属性参数仿真模拟得到球磨机内部的碰撞能量耗散情况，来估算放大后的球磨能耗；同时，对比了两种规模下仅球磨预处理的玉米秸秆粒径及酶解产糖浓度，验证了秸秆球磨工艺放大后的预处理效果。结果表明仿真预测能耗为1.48kW·h/kg，实际能耗为1.65kW·h/kg，预测相对误差为10.3%，实验室规模与规模放大后的球磨玉米秸秆粒径跨度仅相差0.8%，酶解产生的总单糖质量浓度分别为85.5g/L和88.5g/L，表明玉米秸秆的酶解效果未因球磨规模放大而发生明显变化。本研究证明利用离散元法对玉米秸秆球磨进行放大仿真是可行的，为实现秸秆球磨工艺放大应用提供一定的理论参考和技术支持。

Abstract:

Aiming to enhance the promotion of straw ball milling pretreatment technology and assess the feasibility of scaling up the ball milling pretreatment process, the energy consumption during straw ball milling pretreatment was predicted at a larger scale by using discrete element simulation, followed by verification of the pretreatment efficacy post-scaling. After increasing the cylinder size of the CJM-SY-B vibrating ball mill in laboratory conditions to 24 times its original volume, a three-dimensional geometric model was constructed. The EDEM software was employed to simulate impact energy dissipation within the ball mill by inputting physical property parameters for corn stalks both at initial stages and after milling, thereby estimating energy consumption for scaled-0up operations. Concurrently, particle size distribution and sugar production concentration from corn straw subjected to ball milling were compared across two different scales, validating the effectiveness of straw ball milling treatment. Results indicated that predicted energy consumption was 1.48kW·h/kg of straw while actual consumption measured at 1.65kW·h/kg with a relative prediction error of 10.3%. The difference in particle size span between laboratory-scale and scaled-up corn stalks was merely 0.8%, with total monosaccharide concentrations resulting from enzymatic hydrolysis recorded as 85.5g/L and 88.5g/L respectively;these findings suggested that enzymatic hydrolysis efficiency for corn straw remained largely unchanged despite scale enlargement in milling processes. This research substantiated the viability of utilizing discrete element methods for scaling up corn stalk processing and offered theoretical insights along with technical support for broader applications in stalk milling.