Cai Lun might not have thought that the papermaking technique he improved would turn green!

In recent years, the world's papermaking industry has made rapid technological progress. Due to constraints in resources, environment and other aspects, papermaking enterprises have stepped up their efforts in energy conservation and consumption reduction, environmental protection, improving product quality and economic benefits. They are developing continuously in the direction of a modern large-scale industry with high efficiency, high quality, high benefits, low consumption and low emissions, showing a trend of enterprise scale, technological integration, product diversification, cleaner production, resource conservation, forest and paper integration and industrial globalization.

Previously, the development of my country's chemical mechanical pulp industry faced many problems, such as reliance on imports for core equipment, mixed sources of raw materials, high chemical consumption, high power consumption for pulping, unstable pulp quality, and high pollution load, which seriously affected the development of the industry. In response to these problems, Fang Guigan, a researcher at the Institute of Forest Products Chemical Industry of the Chinese Academy of Forestry, led a team to innovatively carry out research work such as homogenization and softening of mixed materials, low-temperature directional dissociation of fibers, reduction of chemicals, and efficient treatment of wastewater, as well as technical research and core equipment creation, namely the "Key Technology and Industrialization of High-yield Clean Pulping of Mixed Materials" project. The project provides technical support for expanding the range and proportion of chemical mechanical pulp products, improving product grades and corporate economic benefits, and achieving low-carbon, green and sustainable development, and won the second prize of the National Science and Technology Progress Award in 2019.

The project "Key Technologies and Industrialization of High-Yield Clean Pulping of Mixed Materials" has overcome a series of key industrialization technologies such as variable pressure impregnation softening, fiber directional dissociation, energy-saving pulping, clean pulp bleaching and production wastewater treatment and reuse; it has created core equipment such as multi-stage differential kneading variable pressure impregnation, functional zoning high-efficiency pulping, dual-function softening and bleaching and high-efficiency wastewater treatment, achieving the goal of high-value utilization of low-quality raw materials and overall improving my country's high-yield pulping technology and equipment level.

The project has been widely promoted and exported in 15 provinces and regions including Shandong and Jiangsu. More than 40 high-yield pulp lines have been built and upgraded, covering more than 70% of production capacity. It saves 5 million cubic meters of wood, 180 million cubic meters of water, and 6.96 billion kWh of electricity every year, with significant economic, social and ecological benefits. It has laid a solid foundation for China's clean pulping technology with independent intellectual property rights to go global.

Fang Guigan's team is continuing to expand the relevant technologies of the "Key Technologies and Industrialization of High-Yield Clean Pulping of Mixed Materials" project to the field of clean and efficient pulping of agricultural straw residues such as rice and wheat straw, corn straw, and cotton stalks, thereby improving the utilization value of grass fiber raw materials and enhancing the risk resistance of my country's papermaking industry in response to the shortage of fiber resource supply.

(Guideline expert: Fang Guigan, researcher at the Institute of Chemical Industry of Forest Products, Chinese Academy of Forestry)

China Association for Science and Technology Department of Science Popularization

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