PROCESS TECHNOLOGY

Catalytic Turbine to Reduce Methane Emissions

Developed by CSIRO (Clayton South, Australia; www.csiro.au), a new technology called Ventilation Air Methane Catalytic Turbine (VAMCAT) is poised to take a sizable bite out of methane emissions resulting in a greenhouse effect equivalent to more than 237 million metric ton/yr of carbon dioxide. These emissions are released to the atmosphere every year from the world's underground coal mines through exhaust ventilation air.

CSIRO and the Australian Greenhouse Office, together with China's Shanghai Jiaotong University and Huainan Coal Mining Group, will construct the first pilot-scale demonstration unit at a coal mine in China. The low-heating-value gas turbine will be powered by about 1 % methane in ventilation air. It will generate 10-30 kW of green power, while also consuming the mine's fugitive methane, which is 23 times more potent than carbon dioxide as a greenhouse gas over a 100-yr time frame. The operational data and experience gained from this unit will then be used to design a second-generation turbine of at least 1 -MW output.

The leader of this project, Shi Su from CSIRO Exploration and Mining, notes that China is responsible for about 45% of total ventilation air methane emissions. "Although gas drainage efficiency in China has increased from 15% in 1998 to 26% in 2004, much of the captured gas is poor in quality," he continues. "It is estimated that more than 70-80% of the drainage gas has a methane concentration of less than 30%, which cannot be used by conventional technologies." While China is the largest source of mine methane emissions, it is also the largest potential market for technologies for mitigating those emissions.

"Once this technology is successfully demonstrated, it can also be applied to the mitigation and utilization of methane from landfills, livestock and combustibles in industrial offgas," says Su.

Catalyst Increases Reformate Yield

UOP (Des Plaines, IL; www.uop.com) has developed a new catalyst that has proven to increase gasoline production in its first commercial application. Dubbed the R-98 catalyst, it is used with the firm's Fixed-Bed Platforming technology, which is used in oil refineries to convert light hydrocarbons into high-octane gasoline. The R-98 catalyst contains a proprietary promoter to boost yields compared to other commercially available catalysts. It is fully regenerable under typical regeneration procedures provided by UOP, resulting in multiple cycles of similar cycle length.

The new catalyst is currently operating in its second cycle at a Hunt Refining Co. plant. "The R-98 catalyst has improved our reformate yield from hydrotreated coker naphtha by about 2% vol.," says Steve Jackson, Hunt Refining Co.'s vice president of refining and transportation.