Geothermic fuel cells heat underground formations by solid-to-solid conduction more efficiently than non-conductive applications. GFCs produce heat at a uniform rate along its length and therefore heat the formation uniformly from top to bottom, leading to far greater yields and simplified production cycles

Unlike other conductive approaches employed to date, geothermic fuel cells do not consume vast quantities of energy — rather, after a start-up period, they become self-fueling. Further, instead of consuming hundreds of kilowatt hours of electricity per barrel of oil produced, geothermic fuel cells would yield approximately 174 kilowatt hours of electrical energy for every barrel of oil recovered. Consequently the operating costs of a GFC system in unconventional oil recovery are expected to be significantly lower than other geothermic approaches. Capital and operating costs of the GFC technology are estimated at $30 per barrel, decreasing to approximately $14 per barrel when offset by revenues associated with the sale of surplus gases and electricity produced.

By virtue of being an in-situ, closed-loop system, the environmental benefits of GFC technology are expected to be as follows:

	GFCs produce minimal air emissions. Since there is no combustion process in the GFC – fuel cells produce electricity through an electrochemical reaction – as a result, there is negligible production of NOx, SO2, particulate or toxic emissions, which are contributors to acid rain, ozone, haze, and health issues.
	GFCs require virtually no water. GFCs are essentially self-sufficient in process water. Fuel cells produce steam as an exhaust which is re-circulated through fuel pre-reformers, thus obviating most if not all needs for outside process water.
	?GFCs produce minimal surface impact. In contrast, significant environmental problems associated with mining and retorting-based operations include the need to dispose of massive quantities of waste “tailings” and dust. Since GFCs utilize a true “in-situ” approach, meaning that the ore body is not mined but is left in place relatively undisturbed, waste disposal problems are eliminated.

Description of Geothermic Fuel Cells

A solid oxide fuel cell (SOFC), as its name implies, utilizes a solid ceramic electrolyte instead of a polymer membrane or a liquid electrolyte as in other types of fuel cells. Because they are a solid-state technology, SOFCs have many advantages. They are simple, low cost, robust, and reliable.

SOFCs have no moving parts or liquid components. SOFCs of the planar variety are composed of stacks of solid ceramics interleaved between metal plates. This simple, solid-state, construction eliminates most potential failure modes.

SOFCs require no expensive noble metal catalysts for their operation. Other fuel cell types require varying amounts of platinum, for example, to operate. SOFCs dispense with expensive catalysts by operating at high temperatures, 700 – 1,000 degrees Celsius (C). In ordinary applications this is a serious drawback. For geothermic fuel cells it is an advantage.

Compared to fuel cells which use liquid electrolytes, phosphoric acid for example, SOFCs are easy to store, transport and handle. When not operating, SOFCs are essentially inert.

Geothermic fuel cells utilize SOFCs that have been specifically adapted to their down-hole application. Compared to most fuel cells the metal-interconnect plates composing the GFC stacks are quite thick and hence durable and resistant to shock.

Geothermic Fuel Cell

stack__25 cells

GFCs are held together under considerable pressure applied by compression rods that bind the stack together. Once the stack is assembled and the tie rods have been tightened, the assembly creates a compact metal bundle that is difficult to damage.

Geothermic Fuel Cell Stack Module

Compression plate assembly

Finally, the assembled stack of fuel cells is installed in a tough metal casing. The casing seals the outside surface of the stack and protects the plates from shock and the outside environment.

Inside the casing, the SOFCs are in a protected and controlled environment. Fuel and air are fed to the cells from treatment facilities on the surface, but all gases, dust, liquids or other contaminants in the bore hole are sealed out.

Geothermic Fuel Cell Stack Module

mating assembly, female end

The GFC modules will be factory assembled under controlled conditions. The modules will be sealed, packaged in crates or other protective shipping containers, and transported to the field. There, the modules will be unpacked, unsealed, and assembled into strings which will be lowered into boreholes drilled in the formation. Once in place, the strings will be secured in the borehole, either cemented in with a heat conductive grout, or packed in with sand or gravel.

Geothermic Fuel Cell Stack Module

Unlike other fuel cells which can only operate on pure hydrogen, SOFCs can operate on a variety of fuels. This works because the hot cathode forms an “auto-reformer” where hydrocarbons spontaneously disassociate into hydrogen and carbon. Consequently, SOFCs can operate on natural gas, propane, landfill methane, coal gas, and the non-condensable gases produced from in-situ heating of petroleum, coal, tar sands and oil shale.