Energy Citations Database (ECD) - - Document #7854
As we've documented, and tried to explain, in many of our previous reports, the key to converting Coal and Carbon Dioxide into - more versatile and more desired - Hydrocarbons lies in combining the Carbon content of CO2 and Coal in some way with Hydrogen.
Hydrogen is a common element, of course, as the chemical formula for plain old Water, i.e., "H2O", attests.
The trick lies in freeing Hydrogen from the other elements with which it might be combined, and in which compounds it is usually tightly bound, so as to make it available for recombination with the Carbon in either Carbon Dioxide or Coal.
Technologies wherein Coal, or any Carbon, is gasified in the presence of Steam, as seen, for just one example, in:
Exxon Gasifies Coal, and Steam-Gasifies the Char | Research & Development; concerning: United States Patent 5,055,181 - Hydropyrolysis-Gasification of Carbonaceous Material; 1991; Exxon Research and Engineering Company; Disclosed is a process for obtaining liquids and gases from carbonaceous material, such as coal. The carbonaceous material is first treated with a gasification catalyst, and optionally a hydrogenation catalyst, and hydropyrolyzed ... to make liquid products. The resulting char is gasified in the presence of steam at a temperature from about 500C to about 900C";
and wherein Carbon is heated to the point where it is reactive enough to break apart the H2O molecule, are actually rather numerous, and descriptions of them relatively easy to find.
The one problem inherent in such processes is that a significant amount of energy is needed to generate the Steam, for the "hydropyrolysis", as it is sometimes called, of Coal; and, that, the molecular structure of Carbon Dioxide is so strong that it can't really be made to react with Steam unless it has first been chemically "reduced", perhaps, as specified by many of the technologies we've documented for you, by being passed through red-hot Coal, the making of which demands even more energy, and, through reactions with the hot Coal, being converted into the more reactive Carbon Monoxide.
Those technologies do work, but the drawback to them lies, as indicated, in the expenditure, and loss, of the energy required to either generate the Steam, and/or to heat the Coal, and/or to reduce the Carbon Dioxide into Carbon Monoxide.
Some innovative technologies wherein environmental energy can be used to effect those needed processes have been developed, as seen, for a few examples, in:
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,
USDOE Hydrogasifies Coal with Solar Power | Research & Development; which details: "United States Patent 4,415,339 - Solar Coal Gasification Reactor; 1983; Assignee: The USA, as represented by the Department of Energy; Solar energy supplies the energy for the endothermic steam-char reaction".
However, concentrated sunlight, in amounts sufficient to drive chemical reactions through the brute force supply of heat energy, is often in short supply in US Coal Country, as her pale residents know all too well.
And, Carbon Dioxide hydrogenation reactions with H2O require the input of relatively even greater expenditures of energy; or, since CO2 brings its own burden of Oxygen into such reactions, sophisticated catalyst technology, as in the Penn State "Photocatalytic Conversion" cited above, to make them "work".
In any case, Coal and Carbon Dioxide hydrogenation reactions wherein the Oxygen content of Steam can be excluded are more efficient, and result in the production of more true Hydrocarbons, as opposed to, as are produced most often by the described Steam-hydrogenation processes, "oxygenated" Hydrocarbons; that is, Alcohols such as Methanol and Ethanol, which, extraordinarily valuable as they are, cannot serve, as is, as full, direct replacements for the Hydrocarbon fuels we currently use in our established fuel supply infrastructure and vehicle fleet.
The use of elemental, molecular Hydrogen for the more direct hydrogenation of Carbon Dioxide and Coal could this be seen as more economically desirable, and examples of technology based on such direct hydrogenation would include those described in:
USDOE Converts 100% of Power Plant CO2 to Methanol | Research & Development; concerning: "Brookhaven National Laboratory Report Number 63316; The Carnol Process System for CO2 Mitigation and Methanol Production; The Carnol system ... (reacts) CO2 with H2 ... to (form) methanol"; and:
Exxon 1982 CoalTL Uses WVU CoalTL Hydrogen Donor Solvent | Research & Development; which reports: "United States Patent 4,345,989 - Catalytic Hydrogen-donor Liquefaction Process; 1982; Exxon Research and Engineering Company; Coal or a similar solid carbonaceous feed material is converted into lower molecular weight liquid hydrocarbons by contacting the feed material with a hydrogen-donor solvent containing above about 0.6 weight percent donatable hydrogen and molecular hydrogen ... . A catalytic hydrogen-donor liquefaction process for converting a solid carbonaceous feed material into lower molecular weight liquid hydrocarbons which comprises contacting said feed material with a hydrogen-donor solvent ... and a hydrogen-containing gas".
So, given that Hydrogen would be a good thing to have a little of, our US Department of Energy herein tells us how, in an environmentally-sensible way, a way that ties in with USDOE Carbon Dioxide-recycling technology we recently reported for you, we could make some of it.
Comment, and additional links and excerpts, follows excerpts from the initial link in this dispatch to:
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"Photosynthetic Hydrogen and Oxygen Production by Green Algae
E. Greenbaum and J. W. Lee; Oak Ridge National Laboratory; Tennessee
Symposium on Hydrogen Production, Storage and Utilization; American Chemical Society; 1999
Report Number ORNL/CP-103431; USDOE Contract Number: AC05-96OR22464
Abstract: Photosynthesis research at Oak Ridge National Laboratory is focused on hydrogen and oxygen production by green algae in the context of its potential as a renewable fuel and chemical feed stock. Beginning with its discovery by Gaffron and Rubin in 1942, motivated by curiosity-driven laboratory research, studies were initiated in the early 1970s that focused on photosynthetic hydrogen production from an applied perspective. From a scientific and technical point of view, current research is focused on optimizing net thermodynamic conversion efficiencies represented by the Gibbs Free Energy of molecular hydrogen. The key research questions of maximizing hydrogen and oxygen production by light-activated water splitting in green algae are: (1) removing the oxygen sensitivity of algal hydrogenases; (2) linearizing the light saturation curves of photosynthesis throughout the entire range of terrestrial solar irradiance-including the role of bicarbonate and carbon dioxide in optimization of photosynthetic electron transport and (3) constructing real-world bioreactors, including the generation of hydrogen and oxygen against workable back pressures of the photo-produced gases.
(We urge you to make note of the phrase: "the role of bicarbonate and carbon dioxide in optimization of photosynthetic electron transport". That has significance related to another of our recent reports concerning CO2 recycling, as we indicated in our introductory notes, which we will explain in closing comments.)
Introduction: Photosynthetic hydrogen production by green algae was discovered in ... 1942.
Research on photosynthetic hydrogen production as a renewable energy source began in the 1970's."
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The bulk of the report is so technical as to be unintelligible to us mere Coal-mining mortals; and, likely to most of our journalistic demigods out there, as well.
The point is, there are strains of Algae that, while they photo-synthetically recycle Carbon Dioxide, also split Water into Oxygen and Hydrogen.
And, actually, the above developments, published in 1999, were founded on earlier Algae-based Hydrogen production work by one of the report's authors; work that was already so successful it had, a decade and a half earlier, been awarded a United States Patent; as witnessed by:
"United States Patent: 4442211 - Method for Producing Hydrogen and Oxygen by Use of Algae
Date: April, 1984
Inventor: Elias Greenbaum, Oak Ridge, TN
Assignee: The United States of America
Abstract: Efficiency of process for producing H2 by subjecting algae in an aqueous phase to light irradiation is increased by culturing algae which has been bleached during a first period of irradiation in a culture medium in an aerobic atmosphere until it has regained color and then subjecting this algae to a second period of irradiation wherein hydrogen is produced at an enhanced rate.
Claims:A method of producing H2 and O2 by use of algae and light comprising the following steps in the sequence set forth:
(1) subjecting algae in an aqueous phase to light in an environment substantially free of CO2 and atmospheric O2 to produce H2 and O2 by the action of the light-stimulated algae in splitting water molecules during a first period of time of sufficient duration to produce a physiological stress on said algae;
(2) culturing said algae in culture medium in an aerobic atmosphere during a second period of time sufficient to remove said physiological stress; and
(3) subjecting said algae in an aqueous phase to light in an environment substantially free of CO2 and atmospheric O2 during a third period of time at an enhanced rate of production of H2 and O2 compared to that occurring during said first time period of step (1).
The method ... wherein steps (2) and (3) thereof are repeated.
The method ... wherein irradiation of said algae in step (1) thereof is terminated when a predetermined loss of chlorophyll occurs in said algae.
4. The method ... wherein irradiation of said algae in step (1) thereof is terminated when a predetermined diminution in the production of H2 and O2 occurs.
(The algae are "cycled" in other words, through periods when they're being "fed" Carbon Dioxide, and, when they are not. Which cycling has some interesting implications, again as we discuss in closing.)
Background and Summary: This invention, which resulted from a contract with the United State Department of Energy, relates to a process for producing hydrogen and oxygen by exposing algae in an aqueous phase to light under anaerobic conditions.
It has been demonstrated that certain algae, when placed in an aqueous phase and exposed to light in the absence of carbon dioxide and oxygen, split water into molecular hydrogen and oxygen. However, the proposed use of algae and solar energy to produce hydrogen for fuel has not yet become economically feasible because the algae used heretofore provide low hydrogen yields and also lose their color (or chlorophyll) after a relatively short exposure to light and thus become ineffective.
It is therefore an object of this invention to increase the efficiency of the process of producing hydrogen by irradiating algae with light.
Another object of the invention is to provide a process which extends the time during which algae can effectively produce hydrogen under light stimulation.
In accordance with the invention, these objects are achieved by (1) subjecting algae in an aqueous phase to light in an environment substantially free of CO2 and atmospheric O2 to produce H2 and O2 by splitting water molecules during a first period of time of sufficient duration to produce a physiological stress on said algae, (2) culturing said algae in culture medium in an aerobic atmosphere during a second period of time, and (3) subjecting said algae in an aqueous phase to light in an environment substantially free of CO2 and atmospheric O2 to produce H2 and O2 during a third period of time at an enhanced rate of production."
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In sum, the production of Hydrogen by the USDOE's algae is not continuous, since the "bugs" only perform that little trick when their metabolism is "stressed" by being denied their usual regime of nutrients, which would include Oxygen and Carbon Dioxide.
And, since the Algae must, during periods in the cycle, be fed Carbon Dioxide, we submit it to be possible that the strains of Algae specified by the USDOE in "US Patent 4,442,211", which specifications we haven't included in our excerpts, might well be among those which could be used in the processes described in several of our recent reports, as in:
USDOE Finances Ohio CO2 Recycling | Research & Development; concerning: "US Patent Application 20020072109 - Enhanced Practical Photosynthetic CO2 Mitigation; 2002; David Bayless, et. al., (of) Ohio University; Abstract: An on-site biological sequestration system directly decreases the concentration of carbon-containing compounds in the emissions of fossil generation units. In this process, photosynthetic microbes are attached to a growth surface arranged in a containment chamber that is lit by solar photons. A harvesting system ensures maximum organism growth and rate of CO2 uptake. Soluble carbon and nitrogen concentrations delivered to the cyanobacteria are enhanced, further increasing growth rate and carbon utilization. The U.S. Government has a paid up license in this invention ..."; and:
Ohio Improves CO2 Bio-Recycling | Research & Development; concerning: "Carbon Dioxide Mitigation Through Controlled Photosynthesis; David Bayless, et. al.; USDOE Contract Number: FG26-99FT40592; (The) Ohio Coal Research Center at Ohio University developed a novel technique to control the emissions of CO2 from fossil-fired power plants by growing organisms capable of converting CO2 to complex sugars through the process of photosynthesis. Biomass developed from photosynthesis has numerous beneficial uses, the most attractive being a replacement fuel"; and:
USDOE Enables CO2-Recycling Processes | Research & Development; concerning: "United States Patent 6,603,069 - Adaptive Full-Spectrum Solar Energy System; 2003; Assignee: UT-Battelle (then manager of the Oak Ridge, Tennessee, National Laboratory for the USDOE); An adaptive full spectrum solar energy system having at least one hybrid solar concentrator ... at least one hybrid photobioreactor, and a light distribution system. The solar system uses a hybrid solar concentrator ... that efficiently collects, separates, and distributes the visible portion of sunlight while simultaneously generating electricity from the infrared portion of the spectrum (and is designed to) deliver large quantities of visible sunlight (to) photobioreactors. This invention uses: advanced materials ... and ... biomass resource development through innovative approaches to improve sunlight utilization in photobioreactors used in carbon sequestration and the production of fuels".
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We, thus, submit it to be conceivable that the same Algae, which, in "United States Patent 6,603,069", serve in effecting such "carbon sequestration and the production of fuels" while they're being generously fed with "carbon-containing compounds in the emissions of fossil generation units", could be the same ones, or could be bio-engineered to be like those, that, in "United States Patent 4,442,211 - Method for Producing Hydrogen and Oxygen by Use of Algae", switch their metabolisms to produce Hydrogen during intermittent, though regular, periods of time when they're denied "carbon dioxide and oxygen", and, instead, in order to generate the metabolic energy they need, "split water into molecular hydrogen and oxygen".
And, again, "molecular hydrogen" could be of immense value in technologies such as those disclosed in:
Conoco Hydrogenates More Carbon Monoxide | Research & Development; concerning: "United States Patent 6,730, 708 - Fischer-Tropsch Processes and Catalysts"; 2004; ConocoPhillips Company, TX; Abstract: A process ... for the hydrogenation of carbon monoxide (which) involves contacting a feed stream comprising hydrogen and carbon monoxide with a catalyst ... to produce ... hydrocarbons";
and, that, especially, if the Carbon Monoxide were produced, in a way like that revealed in:
1915 CO2 Recycling | Research & Development; "United States Patent 1,163,922 - Producing Carbon Monoxid from Carbon Dioxid; 1915; This invention relates to the production of carbon monoxid (CO) gas and the controlling method embraces mixing powdered carbon and carbon dioxid (CO2) gas under sufficiently high temperature to cause a carbon molecule to combine with one of the oxygen elements of the CO2, resulting in 2CO";
by simply blowing Carbon Dioxide, recovered from whatever handy source, through red-hot Coal.