Baichuan Company's monofilament production workshop

Chen Qinghua (left) and other experts are checking the zipper base fabric produced from waste fibers.

Baichuan's colored yarn display wall

Baichuan recycled cloth production workshop

Pengxiang recycled stone production workshop

Zhongke Sanjing rubber and plastic composite building materials production line

Waste fabrics, broken cowhide, waste stones... These industrial solid wastes that need to be paid for can become production raw materials with considerable economic value.

On January 14, the "Thirteenth Five-Year Plan" National Key R&D Plan "Solid Waste Resource Utilization" key project-"Southeast Light Industry Building Materials Characteristic Industrial Cluster Area Solid Waste Comprehensive Utilization Integrated Demonstration" project successfully passed the demonstration line on-site verification and indicator demonstration in Quanzhou.

The experts at the meeting unanimously stated that the project has created a "Quanzhou model" of green, tiered, high-quality utilization and coupled high-value utilization of multi-source solid waste, and achieved the goal of textile and clothing solid waste utilization rate > 70%, leather and shoemaking solid waste utilization rate > 80%, and stone processing solid waste utilization rate > 90%; driving the annual total solid waste consumption to increase by more than 1 million tons.

Why did the integrated demonstration project for comprehensive utilization of solid waste land in Quanzhou? How does the solid waste of a certain industry become the raw material of another industry through recycling and reuse, and achieve cross-industry "industrial symbiosis"? How to build a sustainable business model for the comprehensive utilization of solid waste in different industries? To this end, the reporter has an in-depth understanding.

Scene: "Rebirth" of the closed loop of solid waste

Just after New Year's Day in 2024, the sea breeze was blowing in Shishi City, Quanzhou, and the demonstration production line of Xingye Leather Technology Co., Ltd. was also booming.

Water vapor evaporates on the demonstration line, and the cowhide fiber slurry formed by the crushing of waste cowhide is sent to the high-pressure spunlace unit. Under a pressure of 200 to 350 kilograms, it is firmly "pierced" on the base cloth by water. After a series of processes such as rolling, drying, cooling, trimming, and polishing, it becomes a roll of cowhide fiber regenerated leather.

"These regenerated leathers are used in automotive interiors, uppers, clothing and other fields. A single production line can produce 200,000 to 300,000 meters per month. Because the size of regenerated leather is not restricted and the colors are rich, the product is in short supply and has entered the supply list of internationally renowned companies such as Adidas, Nike, and ZARA. At present, the second new production line has been installed and will be put into operation soon." Manager Cao, the person in charge of the production line, told reporters that Xingye Technology, as a large leather production plant, spends millions of yuan each year on the disposal of cowhide scraps. After the two regenerated leather production lines are fully put into production, it will not only save processing fees, but also bring nearly 200 million yuan in new output value each year.

In addition to cowhide, cow hair is also a major solid waste generated by Xingye Technology. On another production line, the cow hair removed before leather tanning is washed, dried, pretreated, hydrolyzed, concentrated and other processes to become two products. "One is a modified keratin retanning agent, which is used in the leather tanning process to save tanning agents; the other product is keratin powder, which can be used as a raw material for feed." Professor Lin Wei of Sichuan University, the person in charge of the third project topic, said that valuable components can be extracted from waste materials to turn cow hair into treasure. Liu Bowen, the head of the R&D department of Xingye Technology, said, "The production line has completed small and medium tests and applied for three national invention patents." At this time, the factory of Fujian Baichuan Resource Recycling Technology Co., Ltd. in Quangang is also in full swing. Here, waste plastic bottles, waste cloth, waste fiber, etc. are experiencing several "rebirths".

The commonly seen waste PET (polyester resin) plastic bottles, on Baichuan's demonstration production line, go through a series of processes such as sorting, crushing, and washing to become ultra-clean recycled bottle flakes, which can be used as raw materials to produce polyester filaments, which are the raw materials for various fabrics such as clothing, shoe uppers, hats, school bags, blankets, etc. "The waste yarn and weaving scraps generated in the production process of the textile and clothing industry are pelletized to become this gray-black granule, commonly known as bubble material." Zhang Feipeng, chairman of Baichuan Company, said that the bubble material is reused after viscosity enhancement and granulation - part of it can replace recycled bottle flakes, and after mixing, homogenization, spinning, waterless coloring and other processes, it will eventually become a piece of dye-free recycled colored yarn with different colors; the other part is directly made into recycled polyester monofilament for zipper teeth.

The remaining part of the waste is transported to the surrounding areas and will shine again on the production lines of different companies.

80 kilometers away from Baichuan is Fujian Pengxiang Industrial Co., Ltd., a Chinese artificial stone enterprise. Chairman Wang Shaofang has been engaged in the manufacture of recycled stone for nearly 20 years. Previously, he never thought that he would have a relationship with the textile industry, but now the fiber source waste from Baichuan has become his favorite.

In Pengxiang's factory, giant "tofu"-like artificial marble blocks are waiting to solidify and slice. "We have two products that use waste fibers. One is the recycled organic artificial stone, which is made by coupling natural stone processing waste such as recycled crushed stone with unsaturated resin, mixing, vacuum oscillation pressing, room temperature curing to obtain square materials, and then cutting, grinding and polishing." Li Jiancheng, head of the production department, introduced that the newly developed "recycled fiber source unsaturated resin" is made from fiber waste from Baichuan through controlled alcoholysis and polycondensation preparation by upstream enterprises. This not only reduces the cost of raw materials, but also the produced artificial marble has good performance in compression resistance, flexural resistance, linear thermal expansion coefficient and other properties.

Another product is recycled inorganic artificial stone, which is made of natural stone processing waste after screening, adding waste fiber debris or recycled polyester monofilament for reinforcement, mixing with cement binder, vacuum oscillation molding, room temperature curing, cutting, surface grinding and polishing. In Pengxiang's product exhibition hall, the recycled stone with different aggregates such as agate, labradorite, mica flakes and even glass beads is colorful and made into various ornaments and decorative paintings. It has become a new favorite for home decoration and is popular outside China.

The person in charge of the fourth project subject, Professor Dai Zilin of the Guangdong Academy of Sciences, said that the original reinforced inorganic stone was added with glass fiber, but now it is fiber waste. "After testing, the flexural resistance of terrazzo products is better than before."

"Artificial organic stone and inorganic stone are originally the reuse of crushed stone waste generated by the local stone industry." Wang Shaofang said that she did not expect that the combination of solid waste from the stone industry and solid waste from the textile industry would not only produce high-quality recycled stone, achieve cost reduction and increase efficiency, but also contribute to the disposal of solid waste and circular economy.

This "regeneration road" has not yet reached its end. At Fujian Zhongke Sanjing Environmental Protection Co., Ltd. in Anxi County, Quanzhou, the hard-to-regenerate solid waste is melted in one furnace to make use of the waste heat.

On the demonstration production line of Zhongke Sanjing, fiber scraps from Baichuan, leather shoe material waste from Xingye Technology, fiber-source polyester precursors from waste textiles... are aggregated, crushed, and ground into "rubber-plastic composite building materials" in the reactor for the construction of rubber-plastic runways. Pan Bifeng, general manager of Fujian Zhongke Sanjing Environmental Protection Co., Ltd., proudly said that the products of this production line have been used in the construction of runways in eight schools, including Zhangzhou Jinfeng Experimental Primary School, Quanzhou Buxin Primary School, and Anxi Zhuotao Middle School; in addition, the ground powder produced in the processing of organic artificial stone can be combined with biomass nanofibers to make high-strength cement mortar.

So far, the solid wastes of the three major industries of textile and clothing, footwear and leather, and stone processing have been "eaten up and squeezed out" one after another, serving as raw materials for each other and flowing in a closed loop, forming an "industrial symbiosis" chain. This is exactly the goal of the "Integrated Demonstration of Comprehensive Utilization of Solid Waste in Southeast Light Industry and Building Materials Characteristic Industrial Cluster" project (hereinafter referred to as the "Integrated Demonstration Project of Comprehensive Utilization of Solid Waste") to achieve.

Background: Joint research

It is no accident that the Integrated Demonstration Project of Comprehensive Utilization of Solid Waste was landed in Quanzhou.

Quanzhou, as a cluster of textile and clothing, leather and footwear, and stone processing, produces nearly 10 million tons of solid waste every year. For a long time, it has been mainly solved by incineration and landfill.

"At present, there are problems such as large output, low utilization efficiency, and improper treatment in solid waste treatment, which have caused environmental problems and waste of resources, and restricted the green and sustainable development of our province's characteristic industries." Professor-level senior engineer and vice president of Fujian Normal University Chen Qinghua told reporters that industries, research institutions, and localities are actively seeking better solutions for solid waste disposal.

"Solid waste from various industries has complex composition, different quality and is difficult to dispose of. It is a common problem that industrial agglomeration areas need to solve urgently. Establishing a complete set of technical systems for solid waste resource utilization is the preferred way to solve the solid waste problem in light industrial agglomeration areas." He believes.

In 2019, Fujian Normal University and well-known Chinese universities and institutes jointly carried out core technology research and development, built a demonstration project in Quanzhou, explored the way to cascade utilization of cross-industry solid waste in agglomeration areas, and was approved as a key special project of "solid waste resource utilization" in the National Key R&D Program.

The project follows the concept of "industrial coupling and symbiosis", that is, an ecological network with reasonable resource allocation, efficient energy use and comprehensive waste utilization is formed between various industrial systems. The by-products or waste resources generated by a certain industry can be used as energy or raw and auxiliary materials required for the production of another industry, so that multiple industries can form an integrated symbiotic ecological network.

Chen Qinghua described the process of building such a network as "breaking the wall". First of all, we must find out the bottom line and form a technical roadmap.

"Based on the industry type, scale, structure and other characteristics of the three major industries of Quanzhou City, namely textile and garment, leather and shoe making, and stone processing, we simulated and analyzed the raw materials, equipment, process technology system and product structure of each enterprise." Professor Wang Yajun of China University of Petroleum, the person in charge of the first project topic, said that the research team sorted out the industrial symbiosis technology chain of 12 types of typical wastes such as polyester fabrics, blended fabrics, pre-tanned cow hair, leather solid waste, shoe scraps, stone grinding powder, etc. in the three industries, and constructed a multi-source solid waste database and material metabolism simulation analysis model in Quanzhou.

Based on the database and material metabolism simulation analysis model, the scientific research team "attacked each one" and developed key technologies such as high-quality utilization of solid waste in the textile and garment industry, extraction and recycling of valuable components of solid waste in the leather and shoe making industry, high-value utilization of solid waste coupled with stone processing and light textile industry, and "near-zero" emission of three wastes, forming the "Quanzhou model" of high-value utilization of multi-source solid waste coupled regeneration, and obtained more than 50 patents, and relying on leading enterprises in the industry to build demonstration projects.

"After the introduction of key technologies, based on the stable operation data of the demonstration line and calculated by a third party, the solid waste utilization rate of textile and clothing was 92.3%, the solid waste utilization rate of leather and shoe making was 91.5%, and the solid waste utilization rate of stone processing was 90.8%. Based on the research and development of innovative technologies, a green technology integration solution was proposed, which made it possible to "eat up and squeeze out" the difficult-to-regenerate polymer solid waste. The three major industries formed a closed-loop flow, further improving the solid waste utilization rate, and the solid waste utilization rate of the technical integration solution reached 93.2%. " said Professor Luo Yongjin of Fujian Normal University, the person in charge of the fifth project subject. This set of technologies has achieved the goal of a solid waste utilization rate of >70% for textile and clothing, >80% for leather and shoe making, and >90% for stone processing, and has promoted the comprehensive utilization rate of solid waste in the integrated demonstration base to >80%.

"Based on the characteristics of solid waste and the green technology integration plan for comprehensive utilization of solid waste, a commercial operation model was proposed. The technology promotion has effectively driven the total amount of solid waste consumed in Quanzhou to exceed 1 million tons per year." Luo Yongjin said that if the business model is promoted and policies and standards are promoted, in theory, the integrated demonstration base can utilize 2.196 million tons of waste in 2022, which will be of great benefit to the construction of a "zero-waste city".

Will the birth of new processes and new products bring new pollution problems? How to control them? This is also the research focus of the project.

At Zhongke Sanjing, the newly developed integrated mobile waste gas treatment equipment and integrated wastewater intelligent purification system are solving problems. "During the comprehensive utilization of solid waste, the difficult-to-regenerate polymer solid waste generated has been made into rubber and plastic runways." Luo Yongjin introduced that in addition, there are waste gas and wastewater pollutants such as volatile organic compounds, dust, oil smoke, and suspended solids. In view of the complexity and particularity of their components, the scientific research team cooperated with Zhongke Sanjing to develop efficient and economic chemical-physical-biological coupling purification technology and complete sets of equipment, which can achieve "near-zero" emissions of the three wastes for solid waste recycling.

Vision: Towards a greener future

After four years of exploration, a green value chain based on high-value utilization of industrial coupling has taken shape in Quanzhou. Schools and local governments, schools and enterprises work together to break through, carry out green innovative technology research and development, establish green technology integration solutions, promote policy and standard formulation, and build a sustainable business model. They contribute wisdom to a new round of emission reduction and carbon reduction in traditional industries and the construction of a circular industrial chain with good economic benefits, and jointly run towards a greener future.

"At present, in the new version of the Solid Waste Law, general industrial solid waste has been included in legal supervision. In addition to the terminal disposal of harmless, energy and resource, the requirements of model innovation and management innovation cannot be ignored." Luo Yongjin said that it is not only about technological innovation, nor is it simply to demonstrate the application of laboratory results. It is also necessary to explore and build a stable business model so that new technologies can gain more recognition and be more widely used.

"The continuous improvement of the level of industrialization can promote the construction of national ecological civilization pilot zones, accelerate the pace of building "zero-waste cities", and bring better employment and tax opportunities to the local area." He said that solid waste in different industries has different business models due to different values.

For example, textile and clothing ecological products with high-quality utilization in stages can adopt a profitable business model of high-quality recycled products in stages, which is mainly based on encouraging social capital investment and market competition, supplemented by financial and fiscal support, to achieve the greatest value.

For leather and shoe products such as pre-tanned cow hair and leather waste, driven by innovative technologies, the Ministry of Ecology and Environment will include chromium-containing leather waste in the "Hazardous Waste Exemption Management List" in 2021. This product has good environmental benefits, but poor economic benefits. A closed-loop recycling business model should be adopted to reduce the cost of hazardous waste disposal by investing in waste-producing enterprises and reducing the cost of hazardous waste disposal, so as to achieve harmless disposal as much as possible.

The utilization of stone waste is relatively low-value. On the basis of the original association's unified recycling and disposal and the government's supporting tiered subsidy policy, by breaking down technical barriers, the solid waste of the stone processing industry and light textile products have achieved coupled high-value utilization, which has good environmental benefits.

¡°China has a complete range of industries, and the complexity and universality of industrial solid waste problems are rare in the world. Quanzhou's light industrial building materials industry cluster is very distinctive. It is the responsibility and significance of our research team to blaze a new trail for the high-quality development of the solid waste resource utilization industry.¡± As the chief expert of the project, Chen Qinghua said, ¡°In addition to making up for the shortcomings in scientific research, we are also promoting the formulation of relevant standards and policies to truly form a standardized operating model, which will strongly support the construction of Fujian Province¡¯s ¡°National Ecological Civilization Pilot Zone.¡±

Based on the solid waste recycling economic chain, Quanzhou has researched and issued relevant policies covering education, industrial guidance, economic responsibility, administrative penalties, mass supervision, black lists, red lists, subsidies, tax cuts or exemptions, etc. A relevant person in charge of the Quanzhou Municipal Science and Technology Bureau said: "How to make good use of policy incentive tools to provide a strong external driving force for the symbiosis of enterprises in the light industry and building materials industry is a long-term proposition for the development of the circular economy."

In addition, Fujian Normal University also took the lead in formulating relevant local standards-"Technical Guidelines for Recycling and Resource Utilization of Waste Polymer Materials in Industrial Parks", participated in the formulation of a series of industry standards such as "Management Specifications for Renewable Resource Processing Bases" and "Management Specifications for Waste Polymer Materials Processing Bases", and stepped up the drafting of the local standard "Guidelines for the Creation and Evaluation of Low-Zero Carbon Circular Industrial Parks in Fujian Province".

On this basis, Chen Qinghua set his sights on the full-chain control of Quanzhou's characteristic industries. He believes that during the "14th Five-Year Plan" period, under the background of the country's "dual carbon" goals and green and high-quality development, Quanzhou's light industry and other characteristic industries should expand from "end governance" to "source reduction", and shift from focusing on "single links" to "focusing on the entire industrial chain" to achieve quality improvement and efficiency increase of the entire industrial chain.

In December 2023, the project "Integrated Technology and Demonstration for Improving Quality and Efficiency of Circular Economy in Southeast Characteristic Rubber and Plastic Industry" chaired by Chen Qinghua, a special project of the "Key Technologies and Equipment for Circular Economy" in the "14th Five-Year Plan" National Key R&D Program, was officially approved by the Ministry of Science and Technology. Fujian Normal University, together with Tsinghua University, Beijing University of Technology, China Leather and Footwear Industry Research Institute (Jinjiang) Co., Ltd., Peak (China) and other universities, research institutes, industry associations, and leading enterprises, formed a joint research team of government, industry, academia, and research to carry out technical research.

"The project starts with ecological design, and will break through the core technology of the entire industry chain of "integrated design-green disassembly-high-quality regeneration-closed-loop reuse" of footwear and clothing products, and solve the problem of high carbon emissions throughout its life cycle." Chen Qinghua said. (Reporter Chen Min Zhang Yingwen/Picture)

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