One of the major end-products of lignocellulosic biorefining chain is the solid residues containing various compounds. The present approach to solid residues treatment is combustion for generation of heat and electricity. This study investigated the potential for recycling of the combustion ash from the solid residues after lignocellulosic dry biorefining process. A range of characterizations showed that the combustion ash contained a high amount of calcium carbonate. By recycling the ash as the neutralizer in biorefining process, the waste calcium carbonate in the ash was efficiently utilized for pretreated biomass neutralization and can replace 40 % of calcium hydroxide for lactic acid production. The chiral L-lactic acid titer reached 102.4 ± 3.6 g/L from 20 % (w/w) solids loading of wheat straw. Three feasible strategies of ash recycling for the investigated biorefinery concept were further proposed base on the rigorous calcium mass calculation, which can efficiently reduce the consumption of neutralizers.

木质纤维素生物精炼链的主要最终产品之一是含有各种化合物的固体残渣。目前处理固体残渣的方法是燃烧以产生热量和电力。本研究调查了木质纤维素干法生物精炼过程后从固体残渣中回收燃烧灰分的潜力。一系列特征表明燃烧灰中含有大量碳酸钙。通过回收灰渣作为生物精炼过程中的中和剂，有效利用灰渣中的废碳酸钙用于预处理生物质中和，可替代40%的氢氧化钙生产乳酸。当麦秆固体含量为 20%（w/w）时，手性 L-乳酸滴度达到 102.4 ± 3.6 g/L。基于严格的钙质量计算，进一步提出了针对所研究的生物炼制概念的三种可行的灰回收策略，可以有效减少中和剂的消耗。