Controlling sulphur in China's power sector

China Guodian Corporation, one of the country's largest power generators, has taken a positive step to enhance its environmental performance and cut costs by adopting the Cansolv SO₂ (sulphur dioxide) Scrubbing System.

China Guodian is constructing a new 1.2-GW coal-fired power plant at Duyun in Guizhou Province to meet the region's rapidly rising energy demand. However, as in many parts of the world, local air quality standards are tightening and there are stricter limits on SO₂ emissions on the horizon. The company was therefore keen to find a robust solution to the SO₂ that would be produced by the plant's combustion processes.

There are two main types of flue gas desulphurisation technologies: non-regenerable and regenerable. Flue gas desulphurisation systems have historically been of the non-regenerable type; these feature a single-use absorbent and therefore generate effluent streams.

Cansolv Technologies Inc.¹, however, has developed a regenerable desulphurisation technology, the Cansolv Technologies Inc. SO₂ Scrubbing System. This reuses the absorbent and recycles it through the system for repeated use. This system captures more than 99.9% of SO₂ emissions, results in less waste and cuts solvent costs, as restocking is minimal.

The Cansolv Technologies Inc. SO₂ Scrubbing System licence was sold to China Guodian subsidiary Beijing Guodian Longyuan Environmental Engineering Co. Ltd (GDLY), which specialises in the prevention of environmental pollution through flue gas desulphurisation and is supporting China Guodian to ensure that the project meets its environmental mandate.

Capturing value from by-products

According to Stéphane Charest, Business Development Manager, Cansolv Technologies Inc., "The technology avoids the waste being generated that would be sent to landfill with a traditional flue gas desulphurisation technology. In fact, more than one million tonnes a year of landfill is being avoided compared with a conventional, non-regenerable system."

Charest goes on to explain that the technology has a wide range of applications. "Refiners worldwide are using it to control emissions and capture additional by-product value from the SO₂ emitted in various refinery flue gas streams, such as those generated by fluidised catalytic cracking units, process heaters and boilers, sulphur plants and spent acid regeneration units," he says.

"The SO₂ can be recycled to the sulphur recovery unit to produce marketable sulphur or it can be sent to a sulphuric acid production plant. The resultant sulphuric acid can be sold to local fertiliser manufacturers, a booming Chinese industry, as the country strives to feed its growing population."

Liu Hanqiang, Vice General Manager of GDLY, says, "GDLY, as the major force on behalf of China Guodian in the flue gas desulphurisation market, is committed to integrating regenerable desulphurisation technology into the Chinese power sector. Our selection of a Cansolv system for capturing SO₂ at Duyun power plant is a highly significant moment for both GDLY and Cansolv."

China Guodian will be the first power company in China to adopt a regenerable flue gas desulphurisation technology and Hanqiang believes that this is very important. "It shows that desulphurisation technology in China is entering a new era," he adds.

For more information contact Stéphane Charest.

^{1. Cansolv Technologies Inc. is wholly owned by Shell Global Solutions International BV. CANSOLV is a Cansolv Technologies Inc. trademark.}