Nine Institute Project Case | The Clever and Fast VOC Management Project of Sichuan FAW Toyota

As environmental regulations become increasingly stringent, various automobile manufacturers are facing the urgent need to address the exhaust gases from their old spray booths. The Ninth Institute provides customized VOC treatment technologies and solutions based on the specific conditions of the client's factory area, effectively solving the client's environmental protection pain points and working together with clients to protect clear waters and blue skies.

In August 2020, the VOC treatment project undertaken by the Ninth Institute for Sichuan FAW Toyota Motor Co., Ltd. passed formal acceptance. The project team accurately identified client needs and employed clever solutions to easily resolve dehumidification challenges, quickly completing the construction, debugging, and operation of the VOC treatment system without affecting normal production in the workshop. Below, we share the project practice experience of the VOC expert team from the Ninth Institute:

01 Ultra-high treatment efficiency, ultra-low energy waste

Like many industrial processes, a large amount of solvent-containing exhaust gas is generated during the automotive painting process. Both the interior and exterior of the car body have coatings, which include primer, color paint, and clear coat during spraying. The clear coat is a solvent-based paint, and most solvents contained in it are also discharged with the exhaust gas. Sichuan FAW Toyota Motor Co., Ltd. has multiple production lines. Given the characteristics of high air volume and low concentration in the spray painting line, this project uses zeolite wheels to concentrate exhaust gases and employs a regenerative thermal oxidizer (RTO) for combustion oxidation treatment of the concentrated exhaust gases. The concentration wheel achieves over 95% efficiency in exhaust gas treatment, while RTO achieves over 98% efficiency, with the gas concentration after treatment far below environmental protection standards. Additionally, this highly sustainable technology is particularly suitable for treating large amounts of solvent-containing or odorous exhaust gases, almost completely oxidizing organic pollutants. Furthermore, the heat released during the oxidation of concentrated VOC exhaust gases is stored in the RTO furnace to maintain the high temperatures required for cracking, and the energy contained in high-temperature exhaust gases can be used to preheat incoming exhaust gases. Therefore, the primary energy required by the RTO system is much less than that needed for other air pollution control methods. When VOC concentration reaches about 1.5 g/Nm³, the RTO system can operate in self-heating mode; in other words, it can run without consuming additional natural gas.

02 Clean fan cleverly repositioned to easily solve dehumidification challenges

The original factory used wet spray painting technology, resulting in extremely high humidity (over 95%) after washing the discharged gases. When humidity exceeds 80%, it greatly affects the efficiency of the wheel while also impacting its lifespan. Adding a dehumidification system before the wheel would increase investment costs and also raise system failure rates. After fully considering various factors, the VOC expert team from the Ninth Institute made a clever change to place clean fans before the wheel, eliminating the need for an additional dehumidification system. This not only solved dehumidification issues but also reduced investment costs and decreased system failure rates.

03 Customized services significantly reduce costs

This project is a renovation project with very tight space within the factory area and complex piping routes that vary greatly. After years of maintenance and renovation within the factory area, actual conditions have diverged significantly from old blueprints. If prefabrication were done in advance, there would be a high likelihood of unusable pipes or rework issues arising. To ensure smooth project progress and avoid issues like abandoned ductwork affecting timelines, the Ninth Institute provided customized services for Toyota. On-site construction personnel worked in two shifts: daytime for installation work and nighttime for customized duct fabrication based on actual conditions. This measure ensured both construction quality and project progress while significantly saving costs.

04 Tight project schedule completed three system debugging tasks in just seven days

This project had a tight schedule, with a critical milestone on October 8, 2019, requiring waste gas processing to be guaranteed. Additionally, external construction was delayed by 80 days due to rainy season impacts on civil works, severely compressing subsequent installation and debugging timelines. Originally planned for two weeks of joint debugging with workshops during August holidays and National Day holidays in October, delays from earlier phases meant that conditions for waste gas introduction were not met during August holidays; thus debugging could only occur during October 1 holiday period. The time left for joint debugging between the Ninth Institute and workshops was less than seven days. The project team overcame difficulties by utilizing temporary electrical adjustments, choosing multiple systems for simultaneous debugging, and implementing a dual-shift system to ensure that waste gas connection on October 8 was stable and that Toyota's normal production was safeguarded.

As of now, the Ninth Institute has successfully implemented nearly 20 VOC treatment projects including those for Tianjin FAW Toyota, Hongqi H Paints, Tesla's Shanghai factory painting line, and Chery Yibin Kaiyi painting line. The VOC technologies and solutions from the Ninth Institute have been tested across different application scenarios and continue to be enriched and upgraded. In the future, the Ninth Institute will continue to explore new technologies and applications based on customer needs and grow rapidly together with users.