A proposed South Texas oil refinery will be collocated with a geothermal power plant, a brine desalination plant and carbon capture and sequestration to create what the developer-owner is describing as the cleanest refinery in the world.

Renewable geothermal energy will power the refinery. Early cycles of geothermal power will be generated using high-temperature brackish water, while later cycles will rely on the refinery’s own carbon-dioxide emissions for power. Captured and pumped deep underground, those emissions will become supercritical from the pressure and heat and then will be drawn back up to drive the geothermal power plant’s turbines.

Owner Raven Petroleum LLC, The Woodlands, Texas, has signed memoranda of understanding with Thermal Energy Partners LLC, Austin, Texas, and Basic Equipment, Houston, to build the South Texas Energy Complex near Hebbronville. The refinery will process up to 55,000 barrels per day of Eagle Ford shale oil for Raven, producing gasoline and low-sulfur diesel. Thermal Energy will design and construct a geothermal power plant with a capacity up to 20 MW to power the refinery. Basic Equipment will perform engineering, procurement and construction for the refinery and construction management for the complex. The total cost, with the geothermal plant fully integrated, will be about $500 million, says Christopher Moore, Raven’s managing director.

“TEP’s role is to provide power and water to supply the plant,” says James Jackson, Thermal Energy’s chief business development officer. The company develops desalination and power plants for industrial companies. Texas has nearly 10% of the U.S. geothermal potential, Jackson says, but “South Texas’s resources are not flash-steam hot,” he adds. The complex’s geothermal plant will operate with Organic Rankine Cycle technology, which “is much more efficient and can also be utilized at lower temperatures” than flash steam, he says. A resource for flash steam would be 900-1,000°F, but “ORC technology can work right at boiling point, 250-300°,” he explains.

Basic Equipment’s scope of work will be EPC contracting for work inside battery limits, which includes all process units in the refinery and ancillary installations, and CM for the integrated project. Wink Engineering LLC, Baton Rouge, is engineering outside battery limits, such as the tank farm, rail car loading and unloading, and other support facilities, says Tommy Balke, Basic Equipment president and CEO.

Engineering design is “just shy of 80%” complete, says Moore. “We hope to be finalizing our engineering in the next 30-60 days.” Raven then will submit permit applications. With engineering finalized, dirt work will begin and begin the geothermal drilling. He expects permitting to take 90 days to nine months and buildout to be 16-18 months.