United States Patent Application: 0100022666
As seen, for one instance, in our recent report of:
Eastman Coal to Methanol and Electric Power | Research & Development | News; wherein is disclosed:
"US Patent Application 20060096298 - Method for Satisfying Variable Power Demand; 2006; Eastman Chemical Company; Abstract: A process for satisfying variable power demand and a method for maximizing the monetary value of a synthesis gas stream are disclosed. ... A process for intermittently producing electrical power and chemicals (from) a carbonaceous material. ... This invention relates to a process for the production of regularly varying amounts of electric power and chemicals from synthesis gas";
it is feasible to, in one integrated facility, depending on variable demand and circumstances, produce both electrical power and hydrocarbons, as specified by Eastman to include "Fischer-Tropsch products", "methanol", and, the substitute Diesel fuel "dimethyl ether"; via synthesis gas, from Coal.
Herein, we see that the accomplished Coal liquefaction experts in South Africa, Sasol, "South Africa Synthetic Oil Limited", have recently developed a very similar technology, wherein the return on Coal-use industry investment is maximized through the co-production, from Coal, of both electric power and hydrocarbon chemicals.
Comment follows excerpts from the initial link in this dispatch to:
"US Patent Application 20100022666 - Co-Production of Power and Hydrocarbons
Date: January, 2010
Inventor: Jan Boshoff, et. al., Vaalpark and Johannesburg
Assignee: Sasol Technology Limited, South Africa
Abstract: A process for co-producing power and hydrocarbons includes in a wet gasification stage, gasifying coal to produce a combustion gas at elevated pressure comprising at least H2 and CO; enriching a first portion of the combustion gas with H2 to produce an H2-enriched gas; and generating power from a second portion of the combustion gas. In a dry gasification stage, coal is gasified to produce a synthesis gas precursor at elevated pressure comprising at least H2 and CO. At least a portion of the H2-enriched gas is mixed with the synthesis gas precursor to provide a synthesis gas for hydrocarbon synthesis, with hydrocarbons being synthesized from the synthesis gas.
Claims: A process for co-producing power and hydrocarbons, the process including in a wet gasification stage, gasifying coal to produce a combustion gas at elevated pressure comprising at least H2 and CO; enriching a first portion of the combustion gas with H2 to produce an H2-enriched gas; generating power from a second portion of the combustion gas; in a dry gasification stage, gasifying coal to produce a synthesis gas precursor at elevated pressure comprising at least H2 and CO; mixing at least a portion of the H2 enriched gas with the synthesis gas precursor to provide a synthesis gas for hydrocarbon synthesis; and synthesising hydrocarbons from the synthesis gas.
(Note that the needed "H2-enriched gas" is generated as an integral function of the overall process. It doesn't, apparently, have to be "pumped in" from an external source.)
The process ... in which the H2-enriched gas is at elevated pressure and in which mixing at least a portion of the H2-enriched gas with the synthesis gas precursor includes passing the H2-enriched gas through an expansion turbine to generate power.
The process ... in which generating power from a second portion of the combustion gas includes combusting the combustion gas at elevated pressure in the presence of oxygen to produce hot combusted gas and expanding the hot combusted gas through a gas turbine expander to generate power and to produce hot exhaust gas, and recovering heat from the hot exhaust gas in a waste heat recovery stage which includes a waste heat boiler generating steam.
(Which "waste heat", through "generating steam", is recycled back into the Hydrogen and Synthesis Gas production systems.)
Description: This invention relates to the co-production of power and hydrocarbons.
Coal is used as a feedstock for production of power and for production of hydrocarbons. It is generally accepted that Integrated Gasification Combined Cycle (IGCC) processes have environmental advantages over conventional coal-fired power plants. In IGCC processes coal is first gasified to produce synthesis gas and the synthesis gas then serves as fuel source to a combined cycle power production stage.
One route for production of hydrocarbons from coal is to gasify coal to produce synthesis gas and then to convert the synthesis gas to hydrocarbons.
It would be an advantage to provide an IGCC process integrated with a hydrocarbon production process which shows economic (i.e. capital and operating cost) benefits and environmental benefits.
According to the invention, there is provided a process for co-producing power and hydrocarbons, the process including: in a wet gasification stage, gasifying coal to produce a combustion gas at elevated pressure comprising at least H2 and CO; enriching a first portion of the combustion gas with H2 to produce an H2-enriched gas; generating power from a second portion of the combustion gas; in a dry gasification stage, gasifying coal to produce a synthesis gas precursor at elevated pressure comprising at least H2 and CO; mixing at least a portion of the H2-enriched gas with the synthesis gas precursor to provide a synthesis gas for hydrocarbon synthesis; and synthesizing hydrocarbons from the synthesis gas."
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Other, somewhat similar in general concept, but perhaps even more efficient, technologies have been under development, as well, by our United States Department of Energy, as we have once or twice documented. In that USDOE concept, a technology centered on the mouthful of a process called "magnetohydrodynamics" can electro-magnetically extract electrical energy from hot, moving synthesis gas, generated from Coal, as it flows from the synthesis gas generator to it's point of use, i.e., where it's burned in a combustion chamber to generate even more power, or, where it's catalytically condensed into liquid hydrocarbons.
In any case, we have herein, from a long-established commercial practitioner of the art of converting abundant Coal into needed liquid hydrocarbons, confirmation of the fact, that:
Not only can we convert Coal into anything we now obtain from increasingly-dear natural petroleum; we can, at the same time, as a by-product of such a Coal conversion process, generate useful amounts of electrical power while we synthesize those Coal-derived petroleum substitutes.
And, we must consider, and take into our calculations, the beneficial effect such co-generation of commercial amounts of electrical power would have on the real economics, the true costs and profits, of synthesizing liquid hydrocarbons from our abundant Coal.