【Ten Years of Great Progress in Chemical Technology】157-2023: SHANGU achieved success in the centralized recovery of high-concentration DMF wastewater

Thread Content

Ten years of rapid development in chemical technology – praise for China’s prosperity and strength. This is just a starting point; more participation will make things even more lively. HaiChuan becomes even better with your involvement; we welcome everyone to join in the forum discussions. Be careful with fire risks as the heat increases in July. ---------------------------------------------On October 11, 2018, the project for the centralized treatment of high-concentration wastewater containing dimethylformamide (DMF) from synthetic leather production in the Lishui Economic and Technological Development Zone in Zhejiang Province was completed successfully. This project made use of the latest low-temperature heat pump distillation technology, as well as energy-saving and environmentally friendly equipment such as the MVR steam compressor developed by Shaanxi Blower (Group) Co., Ltd. The pilot phase of this project was successful, producing DMF with a purity of 99.59%. Meanwhile, the levels of ammonia nitrogen, total nitrogen, COD, and other pollutants in the wastewater discharged were well below the specified emission standards. The successful development of this process technology and equipment tuning holds the promise of completely resolving the long-standing problems and challenges associated with the treatment of DMF-containing wastewater, which have hindered the development of the synthetic leather industry. 　　The synthetic leather industry in the Economic and Technological Development Zone of Lishui City, Zhejiang Province, is a sector characterized by high pollution and high energy consumption. Our country is a major producer and consumer of synthetic leather in the world, with domestic production capacity accounting for about 80% of the global total, and an annual output value of around 100 billion yuan. The Lishui Economic Development Zone in Zhejiang Province is the second-largest synthetic leather industry hub in the country, with over 20 synthetic leather manufacturers and more than 140 production lines. The synthetic leather industry is the key driving force behind the economic development of Lishui, Zhejiang. Leather synthetic material manufacturers are concentrated in the development zone, resulting in serious environmental problems; at one point, there was even a debate within the zone as to whether environmental protection or industrial development should take priority. The treatment of waste materials in the synthetic leather industry, particularly the comprehensive treatment of high-concentration wastewater containing DMF, has long been a major challenge that hinders the survival and development of enterprises. At the same time, toxic and harmful organic solvents such as DMF and toluene are used in the production of synthetic leather. DMF is miscible with water and has a high boiling point, which can lead to residual solvents remaining after processing, thereby increasing the environmental challenges associated with production. Removing DMF, the main pollutant in the wastewater discharged by the synthetic leather industry, has been listed as a key project for improvement in the Lishui Economic Development Zone. 　　Zhejiang Shanggu Energy Development Co., Ltd. is a wholly-owned subsidiary of Shanggu Group. Yang Hongfei, general manager of the company’s project for the centralized treatment of high-concentration DMF wastewater from synthetic leather production, told reporters that in December 2016, Shaanxi Gear Group signed an EPC contract with Lishui Economic and Technological Development Zone to undertake the project for the centralized treatment of high-concentration DFM wastewater from synthetic leather production in that zone. 　　Based on the development of a green circular economy in the Lishui Economic Development Zone, as well as the new demands from synthetic leather manufacturers in the region for energy-saving and environmental protection upgrades, Shaanxi Gear Group developed a new domestic treatment process for high-concentration DFM-containing wastewater from synthetic leather production. Using a low-temperature heat pump distillation technology package as its core, the company designed a distributed energy system solution that combines integrated systems with industrial funds, tailored specifically for the manufacturers in the Shuige Industrial Park in Lishui. This solution focuses on overall energy efficiency and proper planning within the park, thereby enabling effective treatment of DFM-containing wastewater from synthetic leather production there.