|USDOE Hydrogen from Sunlight and Water|
|Friday - February 10, 2012|
Since we've more recently been documenting the fact, as in, for just two examples:
California Rocket Scientists Liquefy Coal | Research & Development; concerning, in part:
"United States Patent 4,243,509 - Coal Hydrogenation; 1981; Rockwell International Corporation, CA; Disclosure is made of a method and apparatus for reacting carbonaceous material such as pulverized coal with heated hydrogen to form hydrocarbon gases and liquids suitable for conversion to fuels"; and:
"United States Patent 8,017,658 - Synthesis of Hydrocarbons via Catalytic Reduction of CO2; 2011; The United States of America as represented by the Secretary of the Navy; A method of: introducing hydrogen and a feed gas containing at least 50 % carbon dioxide into a reactor containing a Fischer-Tropsch catalyst; and heating the hydrogen and carbon dioxide to a temperature of at least about 190 C. to produce hydrocarbons in the reactor. An apparatus having: a reaction vessel for containing a Fischer-Tropsch catalyst, capable of heating gases to at least about 190 C.; a hydrogen delivery system feeding into the reaction vessel; a carbon dioxide delivery system for delivering a feed gas containing at least 50 % carbon dioxide feeding into the reaction vessel; and a trap for collecting hydrocarbons generated";
that both Coal and Carbon Dioxide can be converted, at high rates and in high volumes, as a study of the full disclosures of the two above references will reveal, into liquid and gaseous hydrocarbon fuels, through direct reactions with elemental Hydrogen, we herein document that the making of such needed elemental Hydrogen shouldn't be seen as too much of an economic barrier to the implementation of such Coal conversion and Carbon Dioxide recycling processes.
Our United States Department of Energy had, very nearly three decades ago, solved the issue of efficient Hydrogen production, as we documented in:
"United States Patent 4,442,211- Method for Producing Hydrogen and Oxygen by Use of Algae; 1984; Inventor: Elias Greenbaum, Oak Ridge, TN; Assignee: The United States of America; A method of producing H2 and O2 by use of algae and light";
via a process whereby certain strains of Green Algae, in the course of their daily routine of sucking Carbon Dioxide out of their environment and converting it into various useful things, could be made, as well, to excrete elemental, molecular Hydrogen in useful quantities as a byproduct.
Herein, we learn that our USDOE, and their gifted Hydrogen scientist, Elias Greenbaum, had, at the same time, been developing efficient Hydrogen production processes that could utilize environmental energy to drive the needed Hydrogen production reactions, but which processes didn't require the biological intermediation of living Green Algae.
Comment follows excerpts from the initial link in this dispatch to:
"United States Patent 4,476,105 - Process for Photosynthetically Splitting Water
Date: October, 1984
Inventor: Elias Greenbaum, Oak Ridge, TN
Assignee: The United States of America
Abstract: The invention is an improved process for producing gaseous hydrogen and oxygen from water. The process is conducted in a photolytic reactor which contains a water-suspension of a photoactive material containing a hydrogen-liberating catalyst. The reactor also includes a volume for receiving gaseous hydrogen and oxygen evolved from the liquid phase. To avoid oxygen-inactivation of the catalyst, the reactor is evacuated continuously by an external pump which circulates the evolved gases through means for selectively recovering hydrogen therefrom. The pump also cools the reactor by evaporating water from the liquid phase. Preferably, product recovery is effected by selectively diffusing the hydrogen through a heated semipermeable membrane, while maintaining across the membrane a magnetic field gradient which biases the oxygen away from the heated membrane. This promotes separation, minimizes the back-reaction of hydrogen and oxygen, and protects the membrane.
(And, yes, such "membrane"s, or filters, capable of separating Hydrogen and Oxygen evolved by the process do exist. We've previously cited one manufacturer of them, in our report of:
Utah 2011 CO2 + H2O = Hydrocarbon Syngas | Research & Development; concerning: "United States Patent 8,075,746 - Electrochemical Cell for Production of Synthesis Gas Using Atmospheric Air and Water;
2011; Assignee: Ceramatec, Inc., Salt Lake City; Abstract: A method is provided for synthesizing synthesis gas from carbon dioxide obtained from atmospheric air or other available carbon dioxide source and water using a sodium-conducting electrochemical cell. Synthesis gas is also produced by the coelectrolysis of carbon dioxide and steam in a solid oxide fuel cell or solid oxide electrolytic cell. The synthesis gas produced may then be further processed and eventually converted into a liquid fuel suitable for transportation or other applications".)
Claims: A process for producing gaseous hydrogen, comprising:
(There is a bit more to the Claims section, but, note that there are actually two Hydrogen-producing intermediaries being described, of which either would serve to effect the splitting of H2O into Hydrogen and Oxygen upon exposure to light.
One is the "hydrogenase" enzyme; and, don't be put off by that. We can, as seen in:
"United States Patent Application: 0100041121 - Metabolically Engineered Organisms for the Production of Hydrogen and Hydrogenase; 2010; Guangyi Wang, Hawaii; University of Hawaii; Abstract: The present application relates to the use of metabolically-engineered microbial cells for the production of hydrogen and hydrogenase enzymes. The microbial cells are strains of E. coli which are genetically engineered to optimize the cell for production of hydrogen or active hydrogenase. The strains of E. coli are transformed with at least one expression vector directed towards the biosynthesis of a hydrogenase enzyme";
bio-engineer some darned-common bugs to make plenty of it for us, which can be extracted and utilized in the process of our subject herein. Another is more-generically-labeled as just "biophotolytic material", which might incorporate a hydrogenase enzyme; and, as we will document in a future report, Elias Greenbaum and the USDOE have that base covered, as well. The point is that the functional units described herein by Greenbaum, though indecipherable to most of us, are well-known in certain scientific circles; and, the methods for producing them in quantity have been established.)
Description and Background: This invention relates generally to processes for the production of gaseous hydrogen and/or oxygen by photosynthesis. More particularly, it relates to improvements in a water-splitting process wherein splitting is effected by directing visible light onto water which contains a photolytic material incorporating a catalyst as a hydrogen-liberator. In biological systems, the catalyst is the enzyme hydrogenase. As used herein, the term photosynthesis is defined as the light-induced cleavage of water into molecular hydrogen and oxygen wherein the photocatalysts that participate in the reaction may be of biological or non-biological origin.
At this time, there are four experimentally verified photosynthetic systems for splitting water to produce molecular hydrogen and oxygen simultaneously. Two of the systems utilize living algae (e.g., green or blue-green algae) as the hydrogen source. A third so-called chloroplast system utilizes non-living components extracted from plants and bacteria as the hydrogen source. The fourth is a purely photochemical system containing no biological components; this system is composed of pigments and precious-metal catalysts with associated electron carriers. The three biological systems employ hydrogenase enzyme as a hydrogen-liberator. Because the hydrogenase cannot function or be synthesized when exposed to oxygen at partial pressures above a certain level, it is essential that the water-splitting be initiated anaerobically and conducted under conditions limiting the buildup of photosynthetically produced gaseous oxygen. Hitherto, oxygen buildup has been limited to acceptable concentrations by either chemically trapping the evolved gaseous oxygen while it is within the liquid medium or by continuously purging the region above the liquid medium with a non-reactive sweep gas, such as helium. Neither of these techniques for preventing oxygen-inactivation of the hydrogenase is suitable for the production of hydrogen on a practical scale because chemical trapping entails excessive energy losses and because sweep gases introduce gaseous diluents which seriously interfere with subsequent recovery of the hydrogen.
It is an object of this invention to provide a novel process for photosynthetically splitting water to produce gaseous hydrogen.
In one form of the invention, hydrogen is produced by providing a reactor containing a body of water. The water contains photolytic material i.e., photoactive material containing a hydrogen-catalyst. The interior of the reactor is isolated from atmosphere and includes a volume for receiving gases evolved from the body of water. The photolytic material is exposed to light to effect photosynthetic splitting of the water into gaseous hydrogen and oxygen. The gas-receiving volume is continuously evacuated by pumping to promote evolution of gaseous hydrogen and oxygen into that volume and to withdraw them therefrom. In another form of the invention, separation of the hydrogen and oxygen is effected by selectively diffusing the hydrogen through a heated semipermeable membrane in a separation zone while maintaining across the zone a magnetic field gradient biasing the oxygen away from the membrane. In a third form of the invention, the withdrawn gas is contacted with a membrane blocking flow of water vapor to the region for effecting recovery of the hydrogen. In a fourth embodiment, the invention comprises a process for selectively recovering hydrogen from a gas mixture comprising hydrogen and oxygen. The process is conducted in a separation zone and comprises contacting the mixture with a semipermeable membrane effecting selective diffusion of hydrogen while maintaining across the zone a magnetic field gradient effecting movement of oxygen in a direction away from the membrane."
Again, there isn't anything specified by the USDOE herein involving technology that hasn't already been reduced to one form of practice or another by other parties; and, that includes the bio-engineering of microorganisms to produce the needed "hydrogenase" enzymes and "photolytic material"; and, as in our citation of "United States Patent 8,075,746 - Electrochemical Cell for Production of Synthesis Gas Using Atmospheric Air and Water", a process developed by a company, Ceramatec, one of whose specialties is the manufacture ceramic filters which could serve as the "semipermeable membrane"s specified by the process of our subject, "United States Patent 4,476,105 - Process for Photosynthetically Splitting Water", to separate the product Oxygen and Hydrogen gases.
As we will document in at least one report to follow, our USDOE has taken the technology disclosed herein a step or two further, thus making the production of Hydrogen from plain old Water even more efficient and even more amenable to large-scale practice.
And, to emphasize the point, once we have the elemental Hydrogen, so efficiently produced herein from nothing but Water, in a process driven by sunlight, we can use that Hydrogen in a process such as that disclosed in our report of:
"United States Patent 7,989,507 - Production of Fuel ... Utilizing Waste Carbon Dioxide; 2011; Assignee: Siemens Aktiengesellschaft (AG), Munich, Germany; The present invention is directed to a method for utilizing CO2 waste comprising recovering carbon dioxide from an industrial process that produces a waste stream comprising carbon dioxide in an amount greater than an amount of carbon dioxide present in starting materials for the industrial process. The method further includes producing hydrogen using a renewable energy resource and producing a hydrocarbon material utilizing the produced hydrogen and the recovered carbon dioxide";
to convert Carbon Dioxide, recovered from whatever source, into "hydrocarbon material" i.e., "Fuel"; and/or, as seen in our report of:
"United States Patent 4,045,328 - Production of Hydrogenated Coal Liquids; 1977; Assignee: Exxon Research and Engineering Company; A process for the production of liquid hydrocarbons from coal or similar liquefiable carbonaceous solids which comprises contacting said carbonaceous solids with a hydrogen-donor solvent and molecular hydrogen";
to efficiently convert some of our abundant Coal into "liquid hydrocarbons"