Ethanol industry ideal carbon source for advanced oil recovery

By Lisa Gibson | September 28, 2017

Occidental Petroleum Corp. injects about 1 billion cubic feet per day of carbon dioxide into oil reservoirs for enhanced oil recovery (EOR), said Daniel Keiser, the company’s manager of commercial development. That CO2 comes mostly from natural sources, which means they decline over time.

Keiser told the audience at Christianson’s Biofuels Financial Conference in Minneapolis Sept. 28 that other sources like ethanol plants would provide a stable source of CO2. “We wouldn’t have to continually invest to maintain the same level of CO2.”  

Occidental is the world leader in EOR. It has 34 projects that use CO2, mostly in the Permian Basin in Texas, Keiser said. The company has a dense CO2 pipeline network in place to distribute to all the projects there. “Once the CO2 gets there, there’s always a need for it,” he said.  

When the CO2 is delivered to the field, it’s injected into a well. It sweeps across the reservoir and picks up hydrocarbon in the rock, delivering it to the production wells. Some CO2 stays in the well, some comes out, he said. The portion that comes out is separated from the gas and is reinjected into the reservoir. “The amount of CO2 that’s delivered to the field to begin with is equal to the amount that gets stored underground,” Keiser said.  

The fermentation process in ethanol plants has a high CO2 concentration. “That’s a huge advantage for ethanol.” One drawback, however, is that one ethanol plant does not produce enough concentrated CO2—at about 10 to 15 million cubic feet per day—to make a project worthwhile, he said. That would require about 300 to 500 million cubic feet per day. “You really need a bunch of plants to participate to get the amount we need.”

Occidental supports incentives for ethanol plants to provide CO2 for enhanced oil recovery, Keiser said. “I think ethanol is a fantastic source. We just need to figure out which plants are able to participate.”