MEGTEC Systems’ China subsidiary has been contracted to build the largest plant in the world to capture and eliminate ventilation air methane (VAM) from the Datong coal mine in China’s Chongqing municipality. The agreement was formally signed between MEGTEC and a three-way joint venture partnership, consisting of AES Climate Solutions, Shenzhen Dongjiang Environmental Renewable Power, and Songzao Coal and Chongqing Electricity.

Negotiations for constructing the Datong VAM system began in November 2009, and it is planned to be operational late 2010. It will use MEGTEC’s proven VOCSIDIZER® technology to eliminate about 97% of the methane in the exhaust stream before it enters the atmosphere, which is expected to reduce greenhouse gas emissions by up to 200,000 t of CO2 equivalent every year. In addition, energy released in the process will be used to heat water for nearby buildings. Mohit Uberoi, President & CEO: “It is by far the largest VAM emission control system anywhere in the world, with six of our VOCSIDIZER units and a capacity of 375,000 Nm3/h of ventilation air”.

This greenhouse gas reduction project also has the potential to generate carbon offset (CER) credits. Emissions reduction projects that involve the transfer of technology to an emerging market (China) and are developed under the Clean Development Mechanism (CDM) of the United Nations Framework Convention on Climate Change (UNFCCC) can be considered for CER credits. “So far the UNFCCC has formally approved CERs from only one VAM abatement project in the world,” Uberoi pointed out. “This is also a MEGTEC system, commissioned in 2008 at the ZhengZhou Mining Group in China’s Henan province”. That system, a single-unit installation, processes around 60,000 Nm3/h of ventilation air, and also generates hot water for local use. MEGTEC units are modular, so smaller scale projects can be expanded as needed.

MEGTEC’s technology is used at the world’s second largest VAM installation, WestVAMP at West Cliff coal mine for BHP Billiton, Australia. For three years, four VOCSIDIZER units have been converting the energy from the mine’s VAM stream into superheated steam that operates a 6 MW turbine, generating electricity that is fed into the local power grid.

The patented VAM technology also earned MEGTEC an EPA Climate Protection Award from the US Environmental Protection Agency in 2008, in recognition of its systems’ ability to turn greenhouse gas into green energy. However, generating electricity requires more complex systems and a much longer lead time than the large-scale Datong project, according to Ake Kallstrand, Technical Director: “The gas composition and mine safety considerations also pose unique challenges in implementing VOCSIDIZER technology or, for that matter, other abatement systems”. China is the largest VAM emitter in the world, and nearly 80% of its electricity stems from coal.