Fuel: Mixed Fuel Biomass

Anhui Dangshan, China

Advanced Straw Fired Power Plant (cotton straw & forestry waste)



Dangshan Biomass power plant is the 1st project for the Everbright International Co., Ltd. (a HK listed company), and is located in Dangshan Economic Development zone, Anhui province. The plant was owned by China Everbright International, and it is the first project delivered by DPCT to the company. It covers an area of 20 hectares with a total investment of about 581M RMB. It was put into operation in 2011.

The plant has been instrumental in promoting the local rural economy by making good use of agricultural residues. It has helped the local government improve energy structure, protect the environment, and has greatly increased local farmers’ income whilst making significant contributions to a low carbon economy.


Plant performance 

The 30 MWe plant at Dangshan is one of the most advanced biomass plants in China; it consumes 200,000 ton of agricultural & forestry residue and generates 2*108 kWh of clean electricity every year. The plant consists of High Pressure High Temperature vibrating grate boiler and condensed steam turbine, which enables very high overall plant efficiency (33%). In addition, the superior design equipment ensures high reliability, and corrosion& fouling resistance.


Core components 

Fuel feeding system is one of DP CleanTech core technologies. The technology is based on DPCT’s experience with European projects; DPCT was the first to introduce this most advanced biomass fuel feeding system to China. For the Dangshan project, the spreader feeding system was selected, as it is specialized for hard straw and tailored to handle 20% soft straw. The automatic control system is easy to operate and highly stable and includes specific safety systems to protect from fuel firing-burning and jamming, together with a water supply to extinguish fires.

The grate system is another feature unique to DP CleanTech. We use the well-developed vibrating water cooled grate system. Originally from Denmark, this system was designed for the combustion of biomass fuels. The grate vibrates periodically during biomass combustion, thus ensuring full burnout and controlling fuel combustion time in order to prevent slagging on the grate segments.


High efficiency and reliability are the main features of DP CleanTech’s products. This boiler is supported from the bottom, and the placement of the expansion centre and guiding devices ensure the expansion in all directions, as well as supporting the boiler itself. In addition, the boiler is designed to resist earthquakes.

External Air Preheater (to reduce flue gas temperature and prevent low temperature corrosion) 

Biomass fuels are different from coal in that they may have a higher content of chlorine and alkali metal content and a lower sulfur content. An external air preheater can preheat the cold air to ~180℃ by feed water. At the same time, the feed water temperature is  reduced from  ~210℃ to ~90℃ after  air preheater. Then 90℃ feed water goes into the flue gas cooler and is reheated to ~210℃, which also cools down the flue gas temperature to 130℃.  At the same time, low temperature corrosion has been reduced as cold end average temperature【(130+90)/2=110℃】 is higher than dew temperature. This patented technology reduces flue gas temperature to improve the efficiency of boiler.

3#, 4# Superheater 

As biomass combustion product exhibits a strong tendency for high temperature corrosion and coking, a special type of structure (vertical tube panels structure, coarse pitch) and high grade materials (ASME material SA-213TP347H, stainless steel, high margin of pipe thickness) are used for high temperature 3#, 4# Superheaters. This efficiently avoids high temperature oxidation on steam side, and greatly reduces coking and high temperature corrosion on the flue gas side.