December 14, 07
New Synthetic Gas Plant Captures 100% of CO2 Emissions

Hunton Energy and the Dow Chemical Company have signed a Memorandum of Understanding (MOU) that will result in Hunton Energy building and operating a Synthetic Natural Gas (SNG) plant at Dow’s Oyster Creek Facility on the Texas Gulf Coast.

Under the proposed 15-year agreement with Dow, the Hunton Energy facility is slated to produce SNG and will use steam turbines to produce additional power from its byproduct steam. Processes in Hunton’s gasification system will capture 100% of the CO2 emissions from the facility for use in enhanced oil recovery, according to Hunton.

Hunton will feed petroleum coke slurry and biomass (wood chips, rice hulls, etc.) along with compressed oxygen into a gasifier. The feed is converted into a high-temperature, high-pressure, medium-BTU syngas (about 270 BTU/standard cubic foot) consisting of CO, H2, H2S, and CO2.

The syngas then passes through an acid gas removal process where CO2 and H2S are separated and captured. The H2S is converted to elemental sulfur and sold as a byproduct from the facility. The CO2 is compressed and fed into oil wells in the region for enhanced oil recovery (EOR).

The syngas then passes through a methanation block where it is converted into a synthetic natural gas (SNG) of pipeline quality. Any inorganic materials, such as metals that naturally occur in the feed, are melted by the heat of the reactor.

The hot gas and the molten minerals travel from the reactor into a radiant cooler. The radiant cooler uses the high-temperature heat of the reactants to generate high-pressure steam. The steam will be sold to Dow Chemical Company located next to the gasification facility. Dow will use this steam in their chemical processes instead of burning natural gas to generate the steam. Utilizing the process heat increases the efficiency of the gasification facility and reduces emissions from the Dow plant.

Vaporized water in the gas is condensed, and the molten minerals solidify into slag as the gas cools. The byproduct slag will be sold into the concrete/aggregate market. Water recovered from the process is used to make the feed slurry. The water contains unconverted carbon from the process.

Hunton Energy estimates a fourth quarter 2008 groundbreaking for the project.