July 19, 2022

Want to Spread Sustainable Manufacturing Across China While Balancing Environmental Protection and Business Growth

- Improving Plating Sludge Treatment Equipment to Reduce Up to 225 Tons of Industrial Waste Annually -

While industrial development has enriched our lives, the resultant waste is steadily accumulating. Some observers estimate that global industrial waste will reach as much as 27 billion tons by 2050 from approximately 12.7 billion tons in 2000*1, making the reduction of industrial waste a pressing and universal issue. Meanwhile, OMRON kicked off its long-term vision, Shaping the Future 2030 (SF2030), in April 2022 to "achieve decarbonization and reduce environmental impact" through business with the aim of "realizing a carbon neutral society." Our feature story this time is about an inspiring initiative by OMRON Electronic Components (Shenzhen) Ltd.'s plant(OMZ)in China to minimize the environmental impact of their production.

*1 Estimates and Forecasts of Global Waste Generation, 2020 Revised Edition, Research Institute of Solid Waste Management Engineering


Tackling Reduction in Industrial Waste that Increases as Business Expands in the Quest for Greater Competitiveness

Responsible for the production of relays, switches, sensors, and other devices, OMZ is located in Pingshan District, in the eastern part of Shenzhen, China. As this emerging industrial district develops, numerous plants there are faced with one major hurdle: an increase in the industrial waste they produce. In the spring of 2019, members from the OMZ Safety and Environment Department took the initiative of addressing this shared problem. They began by analyzing all sorts of industrial waste produced as a result of their production to find that plating sludge accounted for 20% of all such waste, thus kicking off the project to improve sludge treatment facilities.
"We were aiming to solve social issues through business and at the same time seek business growth through an enhanced competitive edge. To take the initiative, we concluded that we should take the lead," said Zhong Cheng-Xiao of the Safety and Environment Department as he reflected on the situation.


Undertaking 100 Attempts Before the Technique That Minimizes the Amount of Water Contained in Plating Sludge Was Devised

At OMZ, they do plating, a process which involves coating the surface of metallic materials with a thin metal film by dipping them in liquids to prevent electronic components from becoming rusty or deteriorating. After the plating process, plant effluent contains nickel, copper, cyanide, and other hazardous substances. Plating sludge is produced when such effluent is treated in order to reduce its toxicity to a low enough level that it can be discharged into rivers. In the past, OMZ used a tool called a filter press*2 which separated solids and liquids in order to lower the water content of plating sludge from 95% to 70% (a lower limit) and disposed them as industrial waste.
"Can we reduce the volume of plating sludge even more if we reduce the water content?" This was an idea suggested by Tan Tong-Gui of the Switch & Connector Department and other operators involved in the plating process. Tan and his team conducted a thorough analysis of the filter press structure and the separation process of each mechanism to see how they could improve the tool to enhance the dehydration effect.

"We came up with a solution of drying sludge in one go, as a dryer does, and we decided to add a process that would deliver compressed air," said Tan. After much trial and error, by making air holes at different locations, they were able to add the drying mechanism and valves and fine-tune a technique that would maximize the drying effect. Also, to avoid discharge drains from clogging with sludge, they added two more drains (bringing the total to three), and successfully reduced the water content of plating sludge to 30%.

"As we continued with our analysis, we realized that the water content was still high at some places. Based on one of Our Values, which encourages us to "Challenging Ourselves," members of our team began moving toward a higher goal." (Tan)

This time, they came up with an idea to add a pipe to feed compressed air after the filtration process, as a way of delivering air from behind. This increased the drying effect tremendously. Just by adding a small upgrade to the existing plating sludge treatment equipment, they made an efficient sludge treatment system that achieved a water content of 15%, completely upending industry norms. As a result, the annual plating sludge production at OMZ was reduced from 19 tons in 2019 to 9 tons in 2020, slashing as much as approximately 10 tons of plating sludge in a single year. (50% less than previous year) They are quite leading in the plating industry in China to come up with the plating sludge treatment technology for improving the flow of sludge by adding drains and drying sludge by blowing hot, compressed air, for which they obtained a patent in China in 2022.*³

567_2.jpgThe Patented Technique Invented by the Members of OMZ

*2 An array of filter bags separated by filter plates. Plating sludge is pressed into the filter bags, where it is dehydrated by the pressure of the compressed air.
*3 Patent: Drying of sludge by adding water drains to plating sludge treatment equipment and feeding compressed air


Sharing the Technique with Other Plants in the Pingshan District to Slash 225 Tons of Sludge Annually

"Reducing waste at OMRON plants only solves a part of the environmental problem," said a member of OMZ. "We want to expand the sustainability technique we have developed here at our company throughout the Pingshan District, Guangdong Province, and all across China and solve the problems of whole society." The project members at the Shenzhen Plant took on another, new challenge by presenting their sludge treatment system to the local Ecology Environment Bureau in the Pingshan District. They went on to visit plating plants and enterprises within the district and demonstrated their technology and its plating sludge reduction effect.

567_3.jpgOMZ members Sharing Their Technique/Technology at the Ecology Environment Bureau in the Pingshan District

For OMRON and other manufacturers, the chief obstacle of making improvements and installing the equipment needed to reduce plating sludge was the costs involved. The technique that OMRON gave birth to was quite simple because all that is required is a small improvement to existing filter presses. There is no need to introduce new equipment and the technique guarantees a huge reduction with a minimum investment. In fact, the technique has been so successful that all eight companies in the District who, like OMRON, treat sludge using a filter press, have decided to adopt it, reducing sludge in the Pingshan District by as much as 225 tons annually. (40% less than previous year in 2021)

"In hindsight, other plating plants and enterprises had the same challenge we did, that is, how they should go about mitigating their environmental impact and making the manufacturing business sustainable. Because we were able to convince them that using our technique and technology would not only help them to reduce their waste but also minimize environmental impact for society as a whole, they agreed to adopt it," recalled Huang Ying of the Safety and Environment Department.
OMZ's environmental initiatives received such great recognition that they were commended as a company excelling in clean product production by the Shenzhen municipal government on February 4, 2021. Then, in April 2021, the project members gave a presentation about this system to the Shenzhen City Plating Business Association in a bid to spread their initiative throughout Guangdong Province. They will be expanding this initiative across the country.
OMRON will remain committed to contributing to the creation of a sustainable society by addressing social issues through business and will be sharing know-how and technologies that we have painstakingly cultivated with people in China and the wider world.

567_4.jpgProject Members in OMZ
(From left to right: Zhong Cheng-Xiao, Huang Ying, Tan Tong-Gui)