Research can help fight pollution, but firms need clear standards, reports Du Juan.

With major cities on the Chinese mainland often shrouded in smog, the government and many companies are striving to cut the use of coal - the major fuel source for the nation's power supply - and make it cleaner. But those efforts face a number of difficulties, including unclear standards, high costs and reluctance by coal producers to assume the expense of compliance.

"China has world-class clean coal technology, but the absence of clear standards and the weak level of supervision are hampering the industry's growth," said Bian Cheng, president of Keda Clean Energy Co Ltd.