Biomass Group, Nanjing Agricultural University, PO Box 68, 40 Dianjiangtai Road, Nanjing 210031

碱颗粒球磨预处理: Efficient saccharification of wheat straw pretreated by solid particle-assisted ball milling with waste washing liquor recycling

Recently, PhD student Miss Xiao-le Liu supervised by Prof. Zhen Fang published a research article in Bioresource Technology about ball milling pretreatment with NaOH solid particles for enzymatic hydrolysis of wheat straw.

Wheat straw was pretreated using ball milling (BM) promoted by solid particles (NaOH, NaCl, citric acid). NaOH showed the best synergistic interaction effect, due to the breakage of β-1,4-glycosidic bonds among cellulose molecules by the alkali solid particles induced by BM. NaOH-BM pretreatment decreased the straw crystallinity from 46% to 21.4% and its average particle size from 398.3 to 50.6 μm in 1 h. After 4 h milling, the reducing-end concentration of cellulose increased by 3.8 times from 12.5 to 60.2 μM, with glucose yield increased by 2.1 times from 26.6% to 82.4% for 72 h enzymatic hydrolysis at cellulase loading of 15 FPU/g dry substrate. The pretreatment washing liquor was recycled for the re-treatment of partially pretreated biomass at 121 °C for 30 min, resulting in 99.4% glucose yield by enzymatic hydrolysis. BM assisted with alkali particles was an effective approach for improving biomass enzymatic saccharification.

Related results were published in Bioresource Technology:

XL Liu, CY Dong, SY Leu, Zhen Fang* (Supervisor), ZD Miao, Efficient Saccharification of Wheat Straw Pretreated by Solid Particle-Assisted Ball Milling with Waste Washing Liquor Recycling, Bioresource Technology, 347, 126721, https://doi.org/10.1016/j.biortech.2022.126721 (2022).

Wheat straw was ball milling pretreated with NaOH particles for 4 h with 82.4% glucose yield after 72 h enzymatic hydrolysis. The pretreatment washing liquor was recycled for the re-treatment of partially pretreated biomass at 121 °C for 30 min, resulting in 99.4% glucose yield. （球磨辅助NaOH颗粒预处理小麦秸秆4 h。酶水解72 h，预处理后小麦秸秆酶解率为82.4%。预处理后的水洗液循环利用，在121°C下，对预处理4 h后的小麦秸秆再预处理30 min，酶解率提高到99.4%）

球磨辅助固体颗粒预处理小麦秸秆的高效糖化及水洗废液的循环利用

最近，博士生刘小乐（女）在方真教授的指导下，在国际学术期刊Bioresource Technology （Q1, IF 9.6）发表一篇关于球磨辅助NaOH颗粒预处理小麦秸秆用于酶解的研究性论文。

通过球磨辅助固体颗粒(NaOH、NaCl，柠檬酸)预处理小麦秸秆。其中，球磨辅助NaOH颗粒预处理的协同作用最好，这可能是由于球磨可以使NaOH破坏纤维素分子间的β-1,4-糖苷键。球磨辅助NaOH颗粒预处理1 h后，纤维素结晶度从46%降为21.4%，平均粒径从398.3 μm降到50.6 μm。球磨辅助NaOH颗粒预处理4 h后，在15 FPU/g干底物的条件下酶解72 h，酶解率从26.6%提高到82.4%，酶解率较原始小麦秸秆提高2.1倍。对预处理后的水洗液进行循环利用，在121 ℃下对预处理4 h后的秸秆再预处理30 min，酶解率提高为99.4%。

结果发表在Bioresource Technology：

XL Liu, CY Dong, SY Leu, Zhen Fang* (Supervisor), ZD Miao, Efficient Saccharification of Wheat Straw Pretreated by Solid Particle-Assisted Ball Milling with Waste Washing Liquor Recycling, Bioresource Technology, 347, 126721, https://doi.org/10.1016/j.biortech.2022.126721 (2022).

还原胺化Synergistic catalysis of Co-Zr/CN_x bimetallic nanoparticles enables reductive amination of bio-based levulinic acid

Recently, PhD student Mr Pei-dong Wu supervised by Profs. Hu Li and Zhen Fang published a research article in Advanced Sustainable Systems about bimetallic synergistic catalysis for reductive amination of bio-based levulinic acid.

Bimetallic synergy and carbon-nitrogen doping can contribute to enhanced catalytic activity due to the strong electronic state and unique geometrical structure. In this work, a series of biomass-derived Co-M bimetallic C-N doped catalysts (Co-M@Chitosan-X; M = Zr, Ni, Fe, Cu, In; X denotes the molar percentage of M) were prepared via simple oil bath reflow and annealing. The Co-Zr@Chitosan-X catalysts were determined to contain alloy (Co-Zr), metal-carbon bond (Co-C, Zr-C), metal-nitrogen bond (Co-N, Zr-N) and metal oxide (Co₃O₄, ZrO₂) through a series of characterizations, in which graphite-coated alloys and metal oxides were catalytically active species. The doping of the second metal results in a significant enhancement for the number of active sites in the catalyst, and the d-band center is shifted toward a deviation from the Fermi energy level. Among the tested catalysts, Co-Zr@Chitosan-20 exhibited superior catalytic activity for the reductive amination of bio-based levulinic acid to 5-methyl-2-pyrrolidone in 99.3% selectivity and 92.8% yield. This non-noble metal bimetallic synergistic catalytic protocol opens an avenue for efficiently producing biomass-derived nitrogenous chemicals.

Related results were accepted in Advanced Sustainable Systems:

Pei-dong Wu, Hu Li *, Zhen Fang *, Synergistic catalysis of Co-Zr/CN_x bimetallic nanoparticles enables reductive amination of bio-based levulinic acid, 2022, 2100321. https://doi.org/10.1002/adsu.202100321

Non-noble bimetallic nanoparticles (Co-Zr/CN_x) were efficient for direct conversion of bio-based levulinic acid (LA) to 5-methyl-2-pyrrolidone (5-MP) in water at 130 °C. Synergistic role was found in the reductive amination process with high activity over a long period of time in one-pot reactions. 非贵金属双金属纳米粒子（Co-Zr/CN_x）在130℃的水中能有效地将生物基乙酰丙酸（LA）直接转化为5-甲基-2-吡咯烷酮（5-MP）。在单锅反应中还原胺化过程中发现双金属催化剂长时间具有高活性。

博士生吴培栋在李虎教授和方真教授的指导下，在国际学术期刊Advanced Sustainable Systems发表研究性论文:

具有协同作用的Co-Zr/CN_x双金属纳米颗粒催化

还原胺化生物质基乙酰丙酸

最近，博士生吴培栋在李虎教授和方真教授的指导下，在国际学术期刊Advanced Sustainable Systems (Q1; Impact factor: 6.271)上发表了一篇关于双金属协同催化生物基乙酰丙酸还原胺化的研究性论文。

双金属协同作用和碳氮掺杂有助于提高催化剂的催化活性，因为掺杂后催化剂的强电子态和独特的几何结构。在这项工作中，通过简单的油浴回流和高温退火制备了一系列生物质衍生的双金属碳氮掺杂催化剂（Co-M@Chitosan-X；M = Zr, Ni, Fe, Cu, In；X表示M的摩尔百分比）。通过一系列的表征，Co-Zr@Chitosan-X催化剂的组分被确定为含有合金（Co-Zr）、金属-碳键（Co-C、Zr-C）、金属-氮键（Co-N、Zr-N）和金属氧化物（Co₃O₄、ZrO₂），其中石墨包覆的合金和金属氧化物是催化活性物种。第二种金属的掺入使催化剂的活性位点数量明显增加，并且d带中心向偏离费米能级的方向移动。在催化剂活性测试中，Co-Zr@Chitosan-20在还原胺化生物基乙酰丙酸为5-甲基-2-吡咯烷酮的过程中表现出卓越的催化性能，其中选择性为99.3%，收率为92.8%。这种非贵金属的双金属协同催化作用为有效生产生物质衍生的含氮化学品开辟了一条新的途径。

详情可见：

Pei-dong Wu, Hu Li *, Zhen Fang *. Synergistic catalysis of Co-Zr/CN_x bimetallic nanoparticles enables reductive amination of bio-based levulinic acid, 2022, 2100321. https://doi.org/10.1002/adsu.202100321