WV Coal Member Meeting 2024 1240x200 1 1

Exxon Recycles Even More CO

United States Patent: 5985178

Very recently, and as now accessible on the West Virginia Coal Association's web site via the link:

New York City Reclaims and Recycles Carbon Dioxide | Research & Development;

we made report of the Carbon Dioxide reclamation technology now being commercialized by the New York City company, "Global Thermostat, LLC".

 

 

Though led by two highly-accomplished Columbia University scholars, Graciela Chichilnisky and Peter Eisenberger, we noted that Global Thermostat has a complete team of expert Carbon scientists on their advisory roster.

Among those team members is one Rocco Fiato, who, at least at one time, was employed by ExxonMobil, where, as we previously and separately documented through earlier reports concerning:

"United States Patent 5,140,049 - Method for Producing Olefins from H2 and CO2; 1992; Inventor: Rocco Fiato, et. al., NJ; Assignee: Exxon Research and Engineering Company; Abstract: This invention relates to a process for producing C2 -C20 olefins from a feed stream consisting of H2 and CO2 using an iron-carbide based catalyst"; and:

"Iron Catalyzed CO2 Hydrogenation to Liquid Hydrocarbons; Rocco A. Fiato, et. al.; Exxon Research and Engineering Company; Abstract: Many of the catalysts which are useful in Fischer-Tropsch synthesis are also capable of catalyzing the hydrogenation of CO2 to hydrocarbons";

he had, with Exxon colleagues, begun to establish an impressive body of CO2 utilization science.

Herein, via the initial link in this dispatch, we document even more of Rocco Fiato's, and his Exxon colleagues', Carbon Dioxide recycling achievements.

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

"United States Patent 5,985,178 - Low Hydrogen Syngas Using CO2 and a Nickel Catalyst

Date: November, 1999

Inventors: David Long, LA, and Rocco Fiato, NJ

Assignee: Exxon Research and Engineering Company, NJ

Abstract: A process for making a synthesis gas comprising H2 and CO in the presence of a reforming catalyst comprising a supported non-noble Group VIII metal catalytic component from a feed including a low molecular weight alkane, and preferably methane as in natural gas, O2, H2O and CO2.

Synthesis gas having H2 to CO mole ratios less than 2:1 and even less than 1.5:1 are easily achieved with net CO2 consumption, which also makes the process environmentally beneficial.

(To rephrase, for emphasis: "net CO2 consumption" is "easily achieved".)

Claims: A process for producing a synthesis gas comprising a mixture of H2 and CO wherein the H2 to CO mole ratio is less than 2 to 1, which comprises partially oxidizing and steam reforming a feed comprising a hydrocarbon, CO2, O2 and H2O, wherein said partial oxidation and reforming both occur in the presence of a Group VIII non-noble metal steam reforming catalyst resulting in net CO2 conversion.

A process ... wherein said catalyst comprises a supported nickel catalytic component (and) wherein said catalyst exhibits a deactivation rate of less than 1 mole % of hydrocarbon conversion per day.

(The catalyst, in other words, is both inexpensive and durable.)

A process ... wherein said feed hydrocarbon comprises mostly methane.

(We are compelled to interrupt at some length here. Since Methane is required in this Carbon Dioxide recycling process, note that, as seen, for just a very few examples, in:

Exxon Methane and Hydrogen from H2S and Carbon Monoxide | Research & Development; concerning: "United States Patent 4,517,171 - Synthesis of H2 and CH4 from H2S and CO; 1985; Assignee: Exxon Research and Engineering Company; Abstract: Hydrogen and methane are synthesized from a gaseous feed comprising a mixture of Hydrogen Sulfide and Carbon Monoxide"; and:

Texaco Clean Methane from High-Sulfur Coal | Research & Development; which details: "United States Patent 3,928,000 - Clean Methane ... from High-Sulfur Containing Hydrocarbonaceous Materials; 1975; Assignee: Texaco Incorporated; Abstract: This is an improved process for converting low-cost high-sulfur containing hydrocarbonaceous materials into a clean methane-rich gas stream"; and:

Penn State Solar CO2 + H2O = Methane | Research & Development; concerning: "High-Rate Solar Photocatalytic Conversion of CO2 and Water Vapor to Hydrocarbon Fuels; The Pennsylvania State University; 2009; Efficient solar conversion of carbon dioxide and water vapor to methane and other hydrocarbons is achieved";

we have what should be seen as some very intriguing options for obtaining that Methane.)

Background and Field: The invention relates to producing a syngas having a hydrogen to carbon monoxide ratio less than two by partial oxidation and reforming using carbon dioxide.

More particularly, the invention relates to producing a syngas mixture having an H2 to CO mole ratio of less than two from a feed comprising a hydrocarbon, oxygen, CO2 and steam by a combination of partial oxidation and catalytic reforming in a fluid bed containing a Group VIII catalyst, such as nickel, without coking the catalyst.

(Again, the "hydrocarbon" is Methane, and the inclusion of "steam", as we've documented in many of our previous reports concerning similar Carbon Dioxide "tri-reforming" technology, as, for instance, in:

More Swiss-Israeli CO2 Recycling | Research & Development; concerning:  "Flue-Gas Treatment by Methane Tri-Reforming; 2009; Weitzmann Institute of Science, Israel; and Swiss Institute of Technology, Switzerland; concerning the "simultaneous catalytic reforming of CH4 (Methane) with steam and with CO2, which are both strongly endothermic reactions, ... and also with oxygen by an exothermic reaction ... an overall thermo-neutral (autothermal) process of tri-reforming was achieved (and) the flue gas of just one 500MWe coal-fired power plant (through conversion to) methanol ... would supply 7.6% of the 2008 world production capacity of methanol";

serves both to supply more Hydrogen, and, to prevent Carbon deposition, "coking", on the catalyst.)

Synthesis gas (syngas) ... comprises a mixture of H2 and CO and is used for various purposes, including synthesis of hydrocarbons and oxygenates (i.e,, alcohols)

While syngas may be derived by the partial oxidation of ... coal ... it is convenient to form it from low molecular weight hydrocarbons, preferably alkanes and most preferably methane.

(And, just for kicks, have another look at:

NASA Recycles CO2 to Methane at Room Temp | Research & Development | News; which make report of:

"Electrocatalytic Reduction of Carbon Dioxide to Methane; Lyndon B. Johnson Space Center; 2008; Abstract: A room-temperature electrocatalytic process that effects the overall chemical reaction CO2 + 2H2O → CH4 + 2O2 has been investigated as a means of removing carbon dioxide";

wherein it's again documented that we can make the Methane, CH4, directly from Carbon Dioxide.)

In converting natural gas or other gaseous hydrocarbon feed liquid hydrocarbons, the gas is typically reacted with oxygen and steam to form the syngas which then serves as the feed for subsequent synthesis operations.

It is known that adding CO2 to the syngas feed will drive the shift reaction equilibrium towards the low hydrogen to CO ratios desired for chemicals synthesis ..., but this quickly deactivates and cokes a nickel reforming catalyst.

Since all natural gas has some CO2 in it, using CO2 as part of the syngas feed will reduce the amount of CO2 which must normally be removed from the gas before it is fed into a syngas generator and net CO2 consumption would be environmentally beneficial.

(Note, yet again, that "natural gas" always carries it's own, sometimes quiet high, inherent burden of  naturally-occurring Carbon Dioxide. But, since we can, as seen in:

Coal to Methane, Methanol & Power | Research & Development; concerning the three-decades old: "United States Patent 4,199,327 - Process ... to Maximize Coal Utilization and Minimize ... Waste; 1980; Assignee: Kaiser Engineers, Inc.; California; Abstract: Coarse, graded coal is fed to a pressurized relatively fixed bed, non-slagging gasifier from which crude gas is recovered. Fine coal is slurried in an aqueous mixture comprising the discharge from the relatively fixed bed gasifier, which discharge is composed of hydrocarbons, phenolic water and other liquids as major components and additional makeup water, if required, and the slurry is fed to a slagging, pressurized entrained flow gasifier from which additional crude gas is recovered. The two streams of gas are cleaned and then used to meet a variety of demands, including, but not limited to, gas turbine generation of electric power, manufacture of synthetic natural gas and manufacture of methanol";

co-produce Methane in a process that synthesizes liquid fuel and generates electricity from our abundant Coal, we shouldn't have to worry about ungainly well-drilling trucks careening around and off our country roads, or fracking chemicals seeping into our well water, just to get some "natural gas" Methane. - JtM)

It would be an improvement to the art if CO2 could be used as part of the syngas feed without the drawbacks of reduced syngas production associated with a low pressure reactor, catalyst coking, or the need for highly expensive noble metal catalysts.

Summary: The invention relates to a process for producing a synthesis gas (syngas) comprising a mixture of H2 and CO from a feed comprising CO2 and a hydrocarbon, with net CO2 consumption ... .

In the process of the invention, feed components comprising a hydrocarbon, CO2, H2O and O2 in which the mole ratio of H2O to the carbon in the hydrocarbon component of the feed to the syngas generator is less than 2, are passed into an FBSG (fixed-bed syngas generator) in which the hydrocarbon is partially oxidized and steam reformed in the presence of a reforming catalyst at conditions effective to convert the feed to the desired syngas."

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And, which "syngas", generated, as herein, via Exxon's process of "United States Patent 5,985,178", is so "desired" because, as Exxon specifies above, it is well-suited for the catalytic "synthesis of hydrocarbons".

Note that Exxon specifies that a little pure Oxygen, O2, is actually needed, which use of O2, as we have earlier documented, prevents the co-production of unwanted Nitrogen Oxides when plain air is used instead.

We submit that, to obtain the Oxygen which might be required, we could turn to a process such as that seen in our report of:

More NASA Hydrogen from Water and Sunlight | Research & Development; wherein is disclosed: "United States Patent 4,051,005 - Photolytic Production of Hydrogen; 1977; The invention described herein was made in the course of a contract with the National Aeronautics and Space Administration; Abstract: Hydrogen and oxygen are produced from water in a process involving the photo-dissociation of molecular bromine with radiant energy at wavelengths within the visible light region";

and, in addition to the required pure Oxygen, also co-generate Hydrogen, which could be used, where desired and needed, to increase the Hydrogen content of the "Low Hydrogen Syngas" produced, as herein, by Exxon, via the process of their "United States Patent 5,985,178", from "CO2".

And, again, since we can make the needed Methane via a process such as that seen in:

Chicago Recycles CO2 to Methane | Research & Development; wherein we make report of: "United States Patent 4,609,440 - Electrochemical Synthesis of Methane; 1986; Gas Research Institute, Chicago; Abstract: A method is described for electrochemically reducing carbon dioxide to form methane";

out of Carbon Dioxide itself, that should, as Exxon itself states herein, increase the "net CO2 consumption" and thereby make Exxon's process, of "US Patent 5,985,178", even more "environmentally beneficial".