The seventh day of the Chinese New Year in 2022 is the first day of construction, but it is not yet the day of school, and the university town is very quiet. However, the teachers of the lignocellulose high-value utilization team of Guangdong University of Technology started a day's work early, and many of them entered the "start- work" state two days ago.
In the laboratory of the Lignocellulose High Value Utilization Team of Guangdong University of Technology, bags of coffee-colored powder substances are stored. These substances are industrial lignin, which is derived from the waste liquid produced by the pulping process of papermaking. Turning industrial lignin into treasure is the team's main research direction.
(Lignin)
In plants, lignin is the second largest component after cellulose. Plants can provide more than 150 billion tons of lignin per year through photosynthesis, but this rich and valuable renewable natural resource is far from being fully utilized efficiently. For example, China's pulp and paper industry and cellulosic ethanol industry also produce 20 million tons of industrial lignin every year, but at present, more than 90% is concentrated and burned or discharged, which wastes resources and pollutes the environment.
"Our research object mainly focuses on industrial lignin, hoping to achieve hierarchical gradient utilization of lignin like oil. Through chemical modification and microstructural regulation, lignin can play its role in suitable application areas. Dr. Lin Xuliang, a member of the team and associate professor, told reporters. The industrial lignin researched by his team is very wide-ranging, and more than ten products involving agriculture, construction, energy, plastics and other fields can be derived from the three research directions of phenol platform small molecules, micro-nano functional materials, and surfactants.
(The research object of the lignocellulose high-value utilization team of Guangdong University of Technology mainly focuses on industrial lignin)
Lin Xuliang's research direction is mainly the basic research of lignin as a catalyst carrier. In his laboratory, an in-line detection system for high-temperature, high-pressure photocatalytic miniature reactions is constantly testing the effectiveness of various catalysts. Electrolyzing water to produce hydrogen is an important way to produce hydrogen in green, but the cost is high, mainly due to the fact that electrocatalysts for electrolyzing water are very expensive.
"The catalyst for electrolysis of water to hydrogen mainly requires the use of precious metals such as platinum, palladium and ruthenium, and its characteristics of small reserves, expensive price and low stability limit its large-scale application." We use functional lignin rich in lignin to coordinate with inexpensive transition metals, and dop carbonization to prepare lignin as a carbon carrier electrocatalyst, which has the same effect as or exceeds that of commercial catalysts for precious metals. Lin Xuliang said that the substitution of electrocatalysts in this way will greatly improve the cost performance of electrolyzed water to produce hydrogen.
(In Lin Xuliang's laboratory, an online detection system for high-temperature and high-pressure photocatalytic miniature reactions is constantly testing the efficiency of various catalysts.)
Lin Xuliang already has a long-term goal in mind, and he hopes to continue to study the application of lignin carbon-based materials in the field of catalysts. "At present, the catalyst we have developed has good performance, but it can only produce a few hundred milligrams at a time in the laboratory, which cannot meet the needs of industrial applications. We hope to continuously improve the catalytic activity and applicability of such catalysts by figuring out its mechanism of action, and strive to reduce their costs, strive to achieve pilot tests, and lay a good foundation for their industrialized large-scale application. He said.
"There's always not enough time, and we want to use the weekends and winter and summer vacations to do more." Lin Xuliang told reporters that the realization of high-value resource application of industrial lignin will contribute to the sustainable development of mankind and will also greatly help China achieve the goal of "double carbon". Therefore, they dare not have a slack, and have been with the enthusiasm of waiting for no time and only racing against the clock to promote the "best use of lignin".
Text, photo/Guangzhou Daily, New Flower City Reporter: Long Kun
Video/Guangzhou Daily Xinhuacheng Reporter: Long Kun
Guangzhou Daily New Flower City Editor: Lin Chuanling