Texaco CO2 + Coal = Hydrocarbon Synthesis Gas

United States Patent: 3976442

 

As now available via: More Oklahoma CO2 + Coal = Hydrocarbon Syngas | Research & Development | News; we earlier sent you information concerning: "US Patent 4.040,976 - Process of Treating Carbonaceous Material with Carbon Dioxide; August, 1977", wherein Oklahoma's Cities Service Company, aka "Citgo", disclosed their technology for reacting a "mixture of carbon dioxide and ... coal" in order to generate "a gaseous effluent comprising carbon monoxide"; which, as the Disclosure specifies, is to be combined with Hydrogen to produce, in essence, a synthesis gas mixture suitable for catalytic condensation into liquid hydrocarbons.

Herein, we see that the venerable Texaco, subsequently absorbed into the Chevron conglomerate, had, one year earlier, received their own United States Patent for very similar technology, wherein Carbon Dioxide, if combined with hot Coal, can be utilized as a valuable raw material resource, the basis for producing a Hydrogen and Carbon Monoxide gas mixture suited for, as noted above concerning the product gas of USP 4.040,976, the synthesis of more versatile, and more valuable, hydrocarbon fuels.

Moreover, although the system does produce some of it's own Carbon Dioxide, which is directed to be recycled back into the hot Coal reaction zone, there is clearly evidence herein of great potential for recycling Carbon Dioxide recovered from other sources; since, as revealed in the Claims section, the weight amount of Carbon Dioxide utilized, depending on desired product gas composition, can be up to twice the weight amount of Coal.

 

Comment follows excerpts from the initial link in this dispatch to:

 

"United States Patent 3,976,442 - Synthesis Gas from Gaseous CO2-Solid Carbonaceous Fuel Feeds

 

Date: August, 1976

 

Inventors: Peter Paull, CT, and Warren Schlinger, CA

 

Assignee: Texaco, Incorporated, NY

 

Abstract: This is an improved continuous partial oxidation process for producing synthesis gas or fuel gas from gaseous CO2 (and) solid carbonaceous fuel feeds. A solid carbonaceous fuel such as finely ground coal from a pressurized lock hopper is passed directly into a high pressure high velocity CO2 -rich gas stream which carries the particles of coal into a free-flow non-catalytic gas generator where by the partial oxidation reaction with a free-oxygen containing gas, preferably in the absence of supplemental H2O other than that normally present in the reactants, gaseous mixtures principally comprising H2, CO, CO2, and H2O are produced. A CO2 -rich gas stream is recovered downstream in the process and recycled to the pressurized feed system.

Claims: A continuous process for producing a gas stream principally comprising gases selected from the group consisting of CO, H2, CO2, H2O, CH4 ... comprising: 

Dispersing ground solid particles of carbonaceous fuel in a high pressure high velocity stream of CO2 -rich gas (and) introducing the gas-solid fuel dispersion from  (and) a stream of free-oxygen containing gas ... into  the reaction zone of a free-flow non-catalytic gas generator in the absence of supplemental H2O other than that normally found in said gas-solid fuel dispersion and free-oxygen containing gas; 

(And) reacting said carbonaceous fuel and free-oxygen by partial oxidation and reacting CO2 in said reaction zone ... wherein the weight ratio of CO2 to carbonaceous fuel ... is in the range of about 0.5 to 2.0.

(And) wherein H2O at (specified conditions) is introduced into the reaction zone ... . 

(And) wherein said solid carbonaceous fuel is selected from the group consisting of coal, coke from coal, char from coal, ... lignite, rubber, rubber tires, and mixtures thereof.

Background and Summary: This invention relates to a continuous process for the production of a CO-rich gas stream by the partial oxidation of a solid carbonaceous fuel. More specifically, the present invention relates to the production of synthesis gas by ... starting with gaseous CO2 -solid carbonaceous fuel e.g. ground coal ... .

Oil embargoes coupled with already developing petroleum shortages have led to an energy crisis in this country. To help meet the accelerating demand for energy ... long-term solutions demand that alternate energy resources be developed and utilized to the maximum degree. Coal is the most promising raw material in the USA for the production of synthetic natural gas (SNG) and synthesis gas ... .

A principal limitation to the use of large reserves of sulfur-containing coal possessed by the United States in particular as well as some other countries is concern for environmental pollution. The subject gasification process appears to be a most feasible way of utilizing sulfur-containing coal for a wide variety of purposes, including the production of synthesis gas, fuel gas and the generation of power, with minimal or negligible deleterious effect upon the environment.

Further, when production of synthesis gas i.e. H2 +CO and the processing of the synthesis gas by catalytic synthesis into oxygen containing hydrocarbons e.g. alcohols, aldehydes and into gasoline and diesel fuels, are both done at the mine, then cross-country rail transport of bulk coal may be eliminated at substantial savings. Advantageously, this may be done by the subject invention."