A total of more than 300,000 tons of wastewater emissions have been reduced throughout the year. This pilot project in Nanjing has passed the national assessment.
The General Office of the Ministry of Ecology and Environment and the General Office of the National Development and Reform Commission recently jointly announced the list of the first batch of cleaner production audit innovation pilot projects that passed the evaluation. 44 projects across the country passed the evaluation."Nanjing City Automobile and Parts Manufacturing (Coating) Industry Cleaner Production Audit Innovation Pilot Project" is on the list, becoming the first batch of cleaner production audit innovation pilot projects in the country to pass the evaluation.
Cleaner production audit refers to the investigation and diagnosis of the production and service process in accordance with certain procedures, find out the reasons for high energy consumption, high material consumption, and heavy pollution, and propose to reduce the use and production of toxic and harmful materials, reduce energy consumption, material consumption, and reduce waste generation plans, and then select a technically, economically and environmentally feasible cleaner production plan. Why was Nanjing selected for this national-level pilot? What results have been achieved in the process of innovation exploration and implementation?
Why pilot? Common problems such as VOCs pollution in the automobile industry are prominent
Walking into the final assembly workshop of SAIC Chase Nanjing Branch in Jiangning District, there are highly flexible production lines using advanced technologies such as lifting skateboards, EMS cradles, AGV trolleys, and SPS bicycle ingredients. A variety of traditional and new energy models of SAIC Chase are produced online at the same time. After raw materials such as steel and various accessories pass through various workshops and production lines in turn, a brand new car is successfully rolled off the production line.
"We focus on user needs and drive the intelligent upgrade of the entire manufacturing system and change the production model of automobiles." Wang Ying, executive director of SAIC Chase's Manufacturing Center, said that SAIC Chase took the lead in introducing the C2B large-scale personalized intelligent customization model into the automotive industry and is the first car company in the world to implement the C2B personalized customization strategic deployment. In the first seven months of this year, the company achieved an output value of 4.012 billion yuan, a year-on-year increase of 27.52%.
The automobile manufacturing industry is one of Nanjing's characteristic pillar industries. According to statistics, in 2023, Nanjing City's complete vehicle output will exceed 600,000 units, of which new energy vehicle output will account for about one-third, a year-on-year increase of more than 25%. Vehicle equipment and technical capabilities are generally at the leading level in China. However, when the automobile and parts manufacturing industry carries out machining, injection molding, coating and other processes, it is easy to produce volatile organic compounds (VOCs) and other toxic chemical substances. Its clean production level is directly related to Nanjing's atmospheric environment quality protection and the realization of the "double carbon" goal.
In December 2022, taking advantage of the opportunity that the clean production audit innovation pilot project of the complete automobile and parts manufacturing (coating) industry in Nanjing City was selected as a national pilot, the Municipal Ecological Environment Bureau selected 7 complete automobile manufacturing enterprises and 30 key automobile parts manufacturing enterprises involved in coating conducted a comprehensive survey and found that the city's complete automobile and parts manufacturing enterprises have common and prominent problems such as clean raw and auxiliary material substitution, VOCs emission reduction, and solid waste reduction. In addition, the traditional cleaner production audit model has cumbersome audit methods and long audit times. It is urgent to explore innovative cleaner production audit methods suitable for the automobile manufacturing industry and formulate corresponding specifications and guidelines.
How to pilot? "Group" based on industry to accept cleaner production audits
It is reported that during the pilot process, Nanjing City focused on key key links and common problems and proposed solution paths, and explored the formation of "unified government deployment + enterprise filing and implementation","targeted at key links, taking into account the entire process" and "government departments + industry associations" coordinated the overall audit model of clean production in the industry.
"In the past, the review of individual enterprises was to carry out cleaner production transformation based on the problems existing in the enterprise. The enterprise required the enterprise to submit an application. The competent department organized experts to hold two evaluation and acceptance meetings, which was time-consuming and laborious." Zhang Zhimin, director of the Pollution Prevention Division of the Municipal Ecological Environment Bureau, introduced that after the pilot was launched, Nanjing City further simplified the review process. Pilot enterprises do not need to "physical examinations" at their own expense. Instead, they use the industry as a unit to "organize" centralized cleaner production audits, and only need to implement two-level filing procedures during the plan selection and acceptance summary stages, which saves enterprise expenses and also improves review efficiency.
While forming a systematic cleaner production system, Nanjing City has not ignored the "personality" issue of enterprises. By issuing a series of documents such as overall cleaner production audit guidelines and technical guidance catalogs suitable for the automobile manufacturing (coating) industry, enterprises have been allowed to choose recommended technologies or self-selected plans "according to their own conditions" and carry out cleaner production audits in an orderly manner.
SAIC Chase Nanjing Branch has been looking for alternative materials for axle paint since 2015. "The original axle paint has a strong odor and is also prone to producing toxic and harmful gases. Due to a lack of professional guidance, we have not found a solution for many years. Later, under the service and guidance of Nanjing City Ecological Environment Bureau, we reached cooperation with Changzhou Paint Chemical Research Institute and other units." The person in charge of the company said that the Municipal Ecological Environment Bureau has also invited experts from the automobile industry and cleaner production industry to come into the company many times to gain an in-depth understanding of the company's process flow, pollution production links and cleaner production work foundation, and point out the direction for the cleaner production review work."After more than 100 formula adjustments, we have finally successfully implemented the water-based paint replacement project in 2023, and the company's VOCs emission reduction ratio reaches 84%."
How effective was it? Accumulatively reduce various air pollutants by about 4000 tons/year
During this period, Tao Ming, the person in charge of environmental protection at Changan Mazda Automobile Co., Ltd., was in a very good mood."We invited professional organizations to evaluate the company's cleaner production level, and finally scored 91 points, reaching the advanced level of cleaner production in China."
Recently, the reporter walked into the assembly workshop of the company and saw automated material carts shuttling back and forth on the ground. The giant mechanical arm danced flexibly to glue the car glass. The entire workshop was clean and orderly without any pungent smell. "Clean production is reflected in all aspects. For example, we have reduced the cost of bicycle glass glue from 21.92 yuan to 18.63 yuan through dosage optimization. We have reduced VOCs emissions from the source through substitution of low-VOCs coatings and water-based cleaning solvents. VOCs emissions from the whole plant are expected to be reduced. 2 tons/year." Tao Ming said.
In terms of the treatment of wastewater and exhaust gas, Changan Mazda's approach is equally remarkable. "We have added two stages of reverse osmosis and fluorine and nickel removal facilities to allow wastewater containing heavy metals to be recycled in the factory. At present, the treatment efficiency of nickel-containing wastewater in the factory reaches 200 tons/day, and the average daily recovery of wastewater is 140 tons." Jin Hao, the company's environmental engineer, told reporters that this year the company has also upgraded its exhaust gas treatment system, effectively reducing carbon emissions by about 30%.
Changan Mazda's practice is the epitome of the full burst of clean production innovation vitality in Nanjing City's automobile industry. Nanjing Chang 'an Automobile Co., Ltd. has installed a 9MW solar photovoltaic power generation device, which can reduce carbon dioxide emissions by 4,350.6 tons a year; SAIC Chase Automobile Co., Ltd. adopts zirconization pretreatment process in the coating process, saving water washing and surface conditioning processes, and reducing emissions of pollutants such as cadmium and nickel... According to statistics, since the implementation of the pilot, Nanjing City has reduced wastewater emissions by more than 300,000 tons per year, reducing various air pollutants by about 4000 tons per year, and reducing solid waste by about 600 tons per year. At present, there are 30 advanced cleaner production enterprises among the city's pilot enterprises, accounting for 81% of the total number of audits. The green transformation of the city's automobile manufacturing industry has achieved remarkable results.
The relevant person in charge of the Nanjing City Ecological Environment Bureau said that the next step will be to scientifically refine existing advanced experiences and practices in accordance with the principle of "piloting, summarizing, promoting, and improving", and carry out a new round of pilots in a targeted and innovative manner to form a good atmosphere for the government, industry associations, enterprises and other parties to work together to promote cleaner production, and promote the continuous improvement of the overall greening level of the industry.
