Abstract

Biorefineries from paddy residues (rice straw and rice husk) have a high potential to satisfy human society’s need for sustainable fuel and chemical production. Biorefinery systems should be created in a sustainable and eco-friendly manner, accompanying the safe disposal of waste stream produced during processing. This study developed a pilot-scale biorefinery, whose bioethanol production from rice straw was an integrated recovery system for lignin, silica, and nutrient recovery. The recovery yield of silica and lignin from the black liquor of alkaline pretreatment was up to 96%, and the lignin purity reached 79% without the existence of carbohydrate fiber. After the recovery, the final liquid waste mainly contained inorganic matters and has a potential to be reused in the acidification step. The distillation residue was a nitrogen source for simultaneous saccharification and fermentation equivalent to corn steep liquor with the final ethanol concentration of 1.6 wt% in 160 h. The new process can be considered as a zero-waste biorefinery model. The material flow indicated that more valued products produced by the simple method increase the profits of this process. Also, the energy efficiency of the process was 0.53 that demonstrated the process’s economy and sustainability. The proposed system was feasible to foster the sustainable integration of local agricultural development and biomass industry shortly.

Graphic abstract

中文翻译：

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试点规模的稻田残留物可持续地生产生物乙醇和增值化学品

摘要

稻渣（稻草和稻壳）的生物精炼厂具有很高的潜力，可以满足人类社会对可持续燃料和化学生产的需求。伴随安全处理过程中产生的废物流，应以可持续和生态友好的方式创建生物精炼系统。这项研究开发了中试规模的生物精炼厂，其稻草秸秆生产的生物乙醇是木质素，二氧化硅和营养物回收的综合回收系统。从碱性预处理黑液中回收二氧化硅和木质素的产率高达96％，木质素纯度达到79％，而没有碳水化合物纤维的存在。回收后，最终的废液主要包含无机物，并有可能在酸化步骤中再次使用。蒸馏残余物是氮源，用于同时糖化和发酵，相当于玉米浆，在160小时内最终乙醇浓度为1.6 wt％。新工艺可以被视为零废物生物精炼厂模型。物料流表明，通过简单方法生产的更有价值的产品增加了此过程的利润。同样，该过程的能源效率为0.53，这证明了该过程的经济性和可持续性。拟议的系统在短期内促进当地农业发展与生物质能产业可持续融合是可行的。物料流表明，通过简单方法生产的更有价值的产品增加了此过程的利润。同样，该过程的能源效率为0.53，这证明了该过程的经济性和可持续性。拟议的系统在短期内促进当地农业发展与生物质能产业可持续融合是可行的。物料流表明，通过简单方法生产的更有价值的产品增加了此过程的利润。同样，该过程的能源效率为0.53，这证明了该过程的经济性和可持续性。拟议的系统在短期内促进当地农业发展与生物质能产业可持续融合是可行的。

图形摘要