New CCS Technologies

Underground Coal Gasification (UCG)

UCG (also known as in-situ gasification) is a potential game changing climate technology. It could allow coal to be used with CCS at prices that rival new uncontrolled fossil plants.

UCG gasifies deep coal seams that are economically unrecoverable through conventional mining practices. Pairs of wells are drilled into the seam and a connection between the wells is established. As the figure below shows, an oxidant is introduced into the seam, the Earth’s crust acts as the gasification vessel, and a synthesis gas is removed to the surface for clean-up and power production. The syngas can be used as “feedstocks” for other products, including electric power, chemicals, liquid fuels, hydrogen, and synthetic natural gas.

UCG has significant enironmental and economic benefits.

UCG could increase usable coal in the U.S. by 300-400%.
Capital costs for UCG plants are substantially less than the equivalent plant using surface gasifiers.
UCG can substantially reduce the pollution output and reduce local water demands for the production of power or products.
It substantially reduces the cost of deployed carbon capture and sequestration because UCG plants are cheaper to build and operate.
UCG is a proven technology. Commercial-scale tests are underway in the U.S., Canada, Australia, New Zealand, India, China, and South Africa.

Carbon Energy, an operating UCG pilot project located in Queensland, Australia

As the figure below shows, CATF estimates the cost of UCG with 80% CCS to be about the cost of new uncontrolled natural gas power plant or a new uncontrolled coal plant. The cost figures in the chart below are a conservative estimate for a “first of a kind”, sub-optimal scale project and are likely to be substantially lower as this technology develops at some scale.

The cost savings result from several factors:

1) Transportation and mining costs are eliminated or reduced relative to conventional power plants;

2) Capital costs for plant are low because gasifiers and coal handling equipment are eliminated, and

3) The composition and pressure of the syngas reaching the surface allow for processing cost savings.

UCG technology may be important for building CCS support in India and China.

China’s 12^th five year plan identifies the establishment of a strong industrial UCG industry as a priority. This is a sign that UCG has political support within the Chinese central government. While the document seems to emphasize industrial applications such as UCG to chemicals rather than power, this is likely a key first step.
In India, the government has established purchasing procedures to access the nation’s coal through UCG. China’s high ash and relatively wet coal are ideal for UCG. Minimal surface disruption is also a key driver in India for UCG.

UCG/CCS poses special challenges within a company. It requires the geotechnical expertise normally housed in an oil or coal company, plus the power production expertise found in a utility. Combining these talents under one roof poses special difficulties not found in other CCS projects.

The Clean Air Task Force- Coal Transition Project is working to:

Reduce the climate impact of coal-based energy
Publicly advocate for the widespread use of CCS
Ensure that federal policy demands carbon reductions and advances rapid deployment of CCS
Promote collaboration of CCS projects between the US and China
Support projects in the US that utilize advanced CCS technologies
Communicate the importance of CCS to the public
Proving out in a commercial scale CCS technologies such as UCG and EOR
Identify RD&D needs and opportunities for the CCS industry