Institute of Natural Products Chemistry - Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam.
Refinery and Petrochemicals Technology Research Center (RPTC), Ho Chi Minh City University of Technology (HCMUT), 268 Ly Thuong Kiet Street, Ho Chi Minh City, Vietnam.
Sci Rep. 2020 Dec 4;10(1):21263. doi: 10.1038/s41598-020-77867-5.
Difficulties in the production of lignin from rice straw because of high silica content in the recovered lignin reduce its recovery yield and applications as bio-fuel and aromatic chemicals. Therefore, the objective of this study is to develop a novel method to reduce the silica content in lignin from rice straw more effectively and selectively. The method is established by monitoring the precipitation behavior as well as the chemical structure of precipitate by single-stage acidification at different pH values of black liquor collected from the alkaline treatment of rice straw. The result illustrates the significant influence of pH on the physical and chemical properties of the precipitate and the supernatant. The simple two-step acidification of the black liquor at pilot-scale by sulfuric acid 20w/v% is applied to recover lignin at pH 9 and pH 3 and gives a percentage of silica removal as high as 94.38%. Following the developed process, the high-quality lignin could be produced from abundant rice straw at the industrial-scale.
由于回收木质素中含有高硅含量，导致从稻草中生产木质素存在困难，这降低了其作为生物燃料和芳香化学品的回收产量和应用。因此，本研究的目的是开发一种更有效和选择性地降低稻草木质素中硅含量的新方法。该方法通过监测在不同 pH 值下对稻草进行碱性处理得到的黑液进行单级酸化时沉淀行为以及沉淀的化学结构来建立。结果表明 pH 值对沉淀和上清液的物理和化学性质有显著影响。通过在中试规模下用 20w/v%硫酸进行简单的两步酸化黑液，可在 pH 9 和 pH 3 下回收木质素，硅去除率高达 94.38%。采用所开发的工艺，可从丰富的稻草中在工业规模上生产出高质量的木质素。
