CFB technology turns waste into energy

When Shanying International Holdings Co., Ltd. wanted to minimize waste and turn it into a resource, they chose Valmet’s circulating fluidized bed (CFB) boiler technology to achieve their aims. The result is a highly efficient waste-to-energy plant that reaps economic benefits from waste sources like the scum generated in pulping waste paper. The plant can also create value from industrial solid waste generated in the non-pulping papermaking industry.

A view of the project at the Shanying International Holdings Co., Ltd. waste-to-power plant.

Closing the loop to reduce waste

“Our vision is a long-running enterprise and an eco-friendly Shanying. The project’s original aim was to treat the industrial solid waste generated in pulping and papermaking, such as scum and sludge, in a closed loop by using them as resources, making them harmless and reducing their quantity. Having assessed its economic and technical reliability, we chose a Valmet CFB Boiler for the incineration of industrial solid waste for power generation,” says Zhu Guoliang, Deputy General Manager of the Asia-Pacific papermaking department at Shanying International Holdings Co., Ltd.

Zhu Guoliang, Deputy General Manager of the Asia-Pacific papermaking department at Shanying International Holdings Co., Ltd.

Ideal technology for industrial solid waste

“When we considered using a CFB boiler for the incineration of industrial solid waste, our first concern was whether the material could be evenly fed into the combustion chamber. After discussions and thorough communications with Valmet’s technical team, we designed five operational modes for the materials. Not only can our CFB boiler adapt well to changes in feed materials, its various environmental protection and economic indicators are also good,” says Ma Zhongxiang, Deputy Manager of the thermal power department of Shanying International Holdings Co., Ltd.

This is one of the first solid waste-to-energy projects in China to implement the ultra-low emission standard.

Special ash removal system

“One feature of the ash removal system in Valmet’s CFB boiler is that there is a screening system which removes the ash after the water-cooled screw. This screens the material from our boiler and then feeds it back into the combustion chamber, while larger particles like iron are removed. This has two obvious benefits. First, it compensates for the loss of material in the bed material system, and second, it ensures the stable operation of the CFB. The emissions from the CFB boiler during operation are also stable, so its environmental protection indicators are also good,” Ma Zhongxiang continues.

Ma Zhongxiang, Deputy Manager of the thermal power department at Shanying International Holdings Co., Ltd.

Unique design prevents corrosion

“In the light of the previous experience we’ve had with the incineration of industrial solid waste in a coal-fired CFB boiler, our other concern was corrosion. Valmet’s three-stage superheater has a double-pipe design. This means the flue gas burns fully at a high temperature, avoiding the corrosion of the outer layer, while the inner pipe cannot come into contact with the flue gas. That’s why this design prevents corrosion,” Ma Zhongxiang explains.

Designed for ultra-low emissions

“This project was designed, planned, constructed and handed over in accordance with the ultra-low emission standard. By designing it to handle five kinds of fuel, including pulp dregs and sludge with a low calorific value and scum with a high calorific value, we’ve not only solved our own industrial solid waste issues but can also treat solid waste from around Ma’anshan, thus realizing both economic and social benefits,” Su Chuanchun, Deputy General Manager of Shanying International Holdings Co., Ltd., says proudly.

Su Chuanchun, Deputy General Manager at Shanying International Holdings Co., Ltd.

Good support leads to success

“As the project is one of the first to involve the incineration of solid waste for power generation in China, which implements the ultra-low emission standard, Valmet has provided us with a lot of support in both the technologies and the project management during the construction of the project and operation of the equipment. This means our project has been very successful, and our environmental protection and economic indicators have been reached quickly,” says Ma Zhongxiang, thanking both parties’ teams for their efforts. 

The control center of the thermal power department of Shanying International Holdings Co., Ltd.