The Colorado School of Mines has announced receipt of the world’s first geothermic fuel cell to test for extraction of oil from oil shale in an economic and environmentally responsible manner. If the technology works, it could make available an estimated worldwide resource of 4.8 trillion barrels of oil, much of which, 2.6 trillion barrels, is in the United States.
Before proceeding, let’s clear up some terminology, the difference between oil shale and shale oil.
The term “shale oil” (and “shale gas”) refers to liquid crude oil and gas trapped in pores and fractures in rock. This resource can be directly pumped from wells. The recent revolution in “fracking” is all about shale oil.
As described by the Department of the Interior:
The term “oil shale” generally refers to any sedimentary rock that contains solid bituminous materials (called kerogen) that are released as petroleum-like liquids when the rock is heated in the chemical process of pyrolysis. Oil shale was formed millions of years ago by deposition of silt and organic debris on lake beds and sea bottoms. Over long periods of time, heat and pressure transformed the materials into oil shale in a process similar to the process that forms oil; however, the heat and pressure were not as great. Oil shale generally contains enough oil that it will burn without any additional processing, and it is known as “the rock that burns”.
Oil shale can be mined and processed to generate oil similar to oil pumped from conventional oil wells; however, extracting oil from oil shale is more complex than conventional oil recovery and currently is more expensive. The oil substances in oil shale are solid and cannot be pumped directly out of the ground. The oil shale must first be mined and then heated to a high temperature (a process called retorting); the resultant liquid must then be separated and collected. An alternative but currently experimental process referred to as in situ retorting involves heating the oil shale while it is still underground, and then pumping the resulting liquid to the surface.
That’s were the geothermic fuel cell comes in. The unit being tested at the Colorado School of Mines was built by Delphi, headquartered in Rochester, NY, for IEP Technology, of Parker, Colorado. The unit is described in detail by IEP here.
The idea is to place these fuel cells in wells where they will produce crude oil and natural gas to be collected by surrounding recovery wells. A portion of the oil and gas produced is returned to power the fuel cell.
“After an initial warm up period in which the cells are fueled with an external source of fuel, the GFC self-fuels from gases created by its own waste heat. This self-fueling system, in steady-state operation, produces oil, electricity and surplus natural gases. The result is a geothermic heater that is designed to produce a Net Energy Ratio (NER) of approximately 7.0 (i.e., 7 units of energy produced for every unit used). The net energy ratio of GFCs will increase to approximately 18.0 when primary recovery is combined with residual char gasification and resulting synthesis gas.”
The map below shows the location of the main oil shale resources of the United States.