This mine-mouth gasification project, to be known as Kentucky NewGas, would use ConocoPhillips’ proprietary E-Gas technology to produce synthesis gas that is then transformed into pipeline quality methane (natural gas). The main reaction is to convert the syngas produced from coal gasification to methane in a methanation reactor. The product gas is then adjusted to meet natural gas pipeline specifications.

The reaction is typically catalyzed by nickel catalysts and it is best performed at high temperatures (1,300-1,800° F) where additional heat is liberated, which can be used in the gasification process.

A 2007 feasibility study by the University of Kentucky (UK) on producing fuels, chemicals and SNG from the gasification of coal examined three SNG cases—two without carbon capture, and one with—all at a projected SNG output of 74 MMscfd. Without carbon capture, more than 8,200 tons per day of CO₂ are released to the atmosphere; with carbon capture, about 165 tons per day of CO₂ are released to the atmosphere while 8,200 tons per day are captured and sequestered.

When carbon capture is required there is a small efficiency penalty of about 2 percent and a cost of product penalty of about 4 percent. The efficiency penalty is small because even in the cases where carbon capture is not required, the carbon dioxide still has to be removed. The only difference is that the carbon dioxide has to be compressed to 2,000 psi when capturing is necessary. This additional cost does not include the actual cost of sequestering this compressed carbon dioxide. Ideally this carbon dioxide could be used for enhanced oil recovery if there are suitable opportunities within a feasible distance from the plant.

—UK report 2007

Kentucky NewGas would be carbon storage ready. Kentucky NewGas will meet regulatory standards to protect the environment, including adoption of low emissions design criteria, anticipated to be less than 5% of the emissions of a comparably sized traditional coal plant.

The companies said they are working with a diverse group of industry, academic, governmental and non-governmental organizations to advance development of a regulatory and legal framework that would make carbon storage viable and enable competitive project economics. ConocoPhillips and Peabody also are funding research on carbon storage in Western Kentucky through a test well project directed by the Kentucky Geological Survey.

Resources

• Technologies for Producing Transportation Fuels, Chemicals, Synthetic Natural Gas and Electricity from the Gasification of Kentucky Coal (UK, 2007)