Technology Overview

Western Hydrogen Limited is developing a new method for producing hydrogen using a bed of molten salts that can gasify any carbonaceous material. The process has been proven in the US Department of Energy's Idaho National Laboratory to generate hydrogen from heavy petroleum residue, petroleum coke, glycerol and methane. Depending on operating conditions, the system can either produce separate streams of hydrogen and carbon dioxide at pressures up to 2000 psig or synthesis gas (i.e. CO + H2) at similar pressures. A large advantage of the Molten Salt Catalyzed Gasification technology is that it does not require the injection of air or oxygen for the gasification process. The second significant advantage is that the system produces a relatively pure stream of carbon dioxide at pressure (~ 2000 psig) that is ready for sequestration. The molten salts catalyze the reactions and obtain the required oxygen from water – which is fed into the reactor along with the carbonaceous materials. The Molten Salt Catalyzed Gasification reaction is slightly endothermic with the energy needed to sustain the system being provided by the carbon input.

PROCESS CHEMISTRY

The Molten Salt Catalyzed Gasification process occurs in a single high-pressure reactor — where a carbon-based feedstock and water react with a molten salt bed. The Molten Salt Catalyzed Gasification process can produce either "hydrogen and carbon dioxide", "synthesis gas" (CO + H₂) or "methane" depending on the reactor operating conditions. All of these gases will be produced at high pressure (~2000 psig).

In "hydrogen" mode — the high-pressure hydrogen stream can be fed directly to an upgrading or refining process with little or no compression. A separate stream of high-pressure carbon dioxide is also produced which is ready for sequestration or enhanced oil recovery.

In "synthesis gas" mode a mixture of hydrogen and carbon monoxide can be fed to a Fischer Tropsch unit to produce synthetic liquid fuels. If required, the hydrogen to carbon monoxide ratio can be adjusted by conducting a water gas shift reaction prior to the Fischer Tropsch reactor. In the process of generating liquid fuels, the Fischer Tropsch process produces water that can, in turn, be recycled as feed water to the Molten Salt Catalyzed Gasification process. Any hydrocarbon contamination in this water will not impact the operation of the Molten Salt Catalyzed Gasification reactor. The advantages of integrating the Molten Salt Catalyzed Gasification process with the Fischer Tropsch process are: (a) heat integration (i.e. Molten Salt Catalyzed Gasification is slightly endothermic and Fischer Tropsch is exothermic), (b) the Molten Salt Catalyzed Gasification process supplies the synthesis gas at high pressure — which the Fischer Tropsch process requires and (c) the hydrocarbon contaminated water produced by the Fischer Tropsch reaction can be recycled back into the Molten Salt Catalyzed Gasification process.

PROCESS FEEDS

The feeds to the process will be water, a carbonaceous waste (e.g. coal, petroleum coke or pitch), sodium hydroxide, and sodium carbonate. The process will be initiated with the sodium compounds -- not with sodium. The amounts of sodium present in the process at any given time will be extremely small since the sodium is consumed by the process almost as fast as it is generated. There will be some small amounts of the sodium compounds that will be required for make-up to the process but laboratory results have shown that less than one percent of the compounds are consumed in the process.

The Molten Salt Catalyzed Gasification process uses a wide variety of low value carbon based feedstock. The carbon sources that have been evaluated to date include heavy petroleum residue, petroleum coke, glycerol and methane.

Hydrocarbon contamination of the feed water does not affect the Molten Salt Catalyzed Gasification process. Produced water associated with hydrocarbon recovery and water contaminated during refinery operations can be used and actually increases the hydrogen yield from the process. Glycerol (i.e. a waste product from bio-diesel production) can also be blended with water in the sodium water reaction. This increases the quantity of hydrogen produced in the water sodium reaction and provides carbon for the reconstitution of the sodium.