We have already documented for you, via a number of reports, the rather immense potentials that exist, and which are being further developed by various entities, including our own US Government, for utilizing Algae in controlled environments to recycle, and to convert into a number of crucial and needed materials, that boogeyman of the global warming scare mongers: Carbon Dioxide.
One example of our reportage on that topic would include:
USDOE Algae Recycle CO2 into Liquid Fuels | Research & Development; concerning the report: "Liquid Fuels from Microalgae; 1987; National Renewable Energy Laboratory (NREL), Golden, CO; USDOE; Abstract: The goal of the DOE/SERI Aquatic Species Program is to develop the technology to produce gasoline and diesel fuels from microalgae. The emphasis of the DOE-SERI Aquatic Species Program is to develop the technology base for large-scale production of lipid-yielding microalgae and conversion of the lipids into liquid fuels. This technology has the potential of producing between 150-400 barrels (of) oil (per) acre (per year). The algae can be grown in large outdoor ponds, using the resources of sunlight, saline water, nitrogen, phosphorus, and carbon dioxide. Analysis of fuel conversion options for microalgae biomass has demonstrated that the promise of microalgae for fuel production is best realized through using conversion processes based on cellular lipids. The two most promising fuel conversion options are transesterification to produce fuels similar to diesel fuels and catalytic conversion to produce gasoline. Although microalgae lipids represent the premium energy product, the energy trapped in the other biomass constituents can also be used; e.g., the cell residue after lipid extraction can be anaerobically digested for the production of methane and carbon dioxide."
And, we suggest you keep the last statement in the above excerpt in mind. We have previously made specific report on what can be done with "the cell residue after lipid extraction", that doesn't necessarily entail the co-production of some minor amount of CO2; but, as we will see in a report to eventually follow, the corporate sponsor and owner of the technology we call to your attention herein, Chevron, have their own thoughts on the matter, which might be of special interest to Coal miners everywhere.
First, as preface, we do need to clarify what the subject of our report herein is really all about, since the title of the invention, "Increased Yield in Gas-to-Liquids Processing via Conversion of Carbon Dioxide to Diesel via Microalgae", could lead to some doubts and ambiguity.
By the "Gas" in "Gas-to-Liquids", Chevron actually means hydrocarbon synthesis gas, a blend of Carbon Monoxide and Hydrogen, which can be catalytically and chemically condensed, as via the almost ancient, and now generic, Fischer-Tropsch synthesis, among others, into conventional liquid hydrocarbon fuels.
And, it doesn't matter to Chevron where that syngas, or just "Gas", comes from, as they make clear in advance excerpts taken from the "Definitions" segment of the "Detailed Description of the Invention", deep with the "Full Disclosure" of their invention, as follows:
"'Gas-to-liquids' ("GTL"), as defined herein, refers to processes that ... proceed through a syngas intermediate which is then converted to alkanes (paraffins) via a catalytic Fischer-Tropsch process.
'Synthesis gas' or 'syngas' is a gaseous mixture containing carbon monoxide and hydrogen and optionally other gases such as water and carbon dioxide. Syngas is typically produced by steam reforming of carbon- or hydrocarbon-containing precursors.
Steam reforming of coal yields syngas according to the following equation: C + H2O = H2 + CO.
In addition ... it is worth noting that CO from syngas can undergo a "water-gas shift (WGS)" reaction to produce CO2 and H2: CO + H2O = CO2 + H2.
'Transportation fuels', as defined herein, refer to hydrocarbon-based fuels suitable for consumption by vehicles. Such fuels include, but are not limited to, diesel, gasoline, jet fuel and the like."
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The above will be repeated, so that we don't lose sight of what this is really all about, in our more extended excerpts; but, the point is
Both the generation of the synthesis gas, and the subsequent catalytic condensation of the synthesis gas into liquid hydrocarbons, can generate small amounts of Carbon Dioxide as a byproduct.
Herein, Chevron explains how we can use Algae to convert any Carbon Dioxide which might be generated in a catalytic process for condensing synthesis gas, derived from Coal, or from Methane, or, even, we submit, as in:
More USDOE CO2 "Syntrolysis" | Research & Development; concerning: "Co-Electrolysis of Steam and Carbon Dioxide for Production of Syngas; 2007; Idaho National Laboratory, USDOE; and Ceramatec, Inc.;
Abstract: An experimental study has been completed to assess the performance of single-oxide electrolysis cells ... simultaneously electrolyzing steam and carbon dioxide for the direct production of syngas";
from Carbon Dioxide and Water, into, specifically, Diesel Fuel, through the intermediation of Algae, as seen in our above reference to our USDOE's: "Liquid Fuels from Microalgae":
"US Patent 7,838,272 - Increased Yield in GTL Processing via Conversion of CO2 to Diesel via Microalage
Date: November, 2010
Inventor: Stephen Miller, San Francisco
Assignee: Chevron USA, CA
Abstract: The present invention is generally directed to systems and methods for integrating gas-to-liquids (GTL) processing with biofuels production. In some embodiments of the present invention, carbon dioxide (CO2) generated by GTL processing is used to support grovel (via photosynthesis) of microalgae. In some such embodiments, the microalgae can be further processed to yield a diesel fuel that can be used either by itself, or mixed with fuel produced by the GTL processing.
(Don't be distracted by esoteric terminology. The word "grovel", as above, when applied to algae, and, according to an aquarium specialist at our local Pet Smart(r), perhaps other aquatic plants and organisms as well, can mean, in essence, just "growth". So, byproduct Carbon Dioxide, generated by a process for converting synthesis gas into liquid hydrocarbons, can be used to support the growth of Algae.
And, while we're at it, let's take a look at another process for generating that synthesis gas, developed by Chevron themselves, as seen our report of:
West Virginia Coal Association | Chevron CO2 Converts Carbon-Recycling Wastes to Syngas | Research & Development; concerning: "United States Patent 3,850,588 - Production of Synthesis Gas Rich in Carbon Monoxide; 1974; Assignee: Chevron Research Company; A carbon-monoxide-rich synthesis gas is produced by feeding a mixture of carbon dioxide and an organic material to a reaction zone ... . The present invention relates to the production of synthesis gas. More particularly, it relates to the production of synthesis gas rich in carbon monoxide by the reaction of carbonaceous material with carbon dioxide."
Carbon Dioxide, it seems, could become a material in great demand.)
Claims: A method comprising the steps of; a) generating CO2 in a gas-to-liquids plant; b) using at least some of the CO2 generated in the gas-to-liquids plant to grow microalgae by supporting photosynthesis in their growth cycle, wherein such growth yields harvestable microalgae; c) harvesting the microalgae and processing the harvested microalgae to yield a triglyceride-based biofuel precursor comprising triglycerides; d) hydroprocessing the triglyceride-based biofuel precursor to deoxygenate triglycerides contained therein and yield a paraffinic product; and e) isomerizing the paraffinic product to yield a transportation fuel.
The method ... wherein at least one of the hydroprocessing and isomerizing steps are integrated with processes carried out in the gas-to-liquids plant.
The method ... wherein the triglyceride-based precursor is hydroprocessed together with gas-to-liquid-derived hydrocarbons.
The method ... wherein the paraffinic product is isomerized together with gas-to-liquid-derived paraffins.
(The point of the above several claims being, as the full Disclosure makes more or less clear, that the Algae oils can be synergistically blended with the liquid effluent of the Fischer-Tropsch syngas-to-liquids processor for further refining steps to make the final Diesel fuel product.)
The method ... wherein the gas-to-liquids plant is operable for producing transportation fuels.
The method ... using at least some of the CO2 generated in the gas-to-liquids plant to grow microalgae involves dissolving said CO2 in an aqueous solution.
The method ... wherein using at least some of the CO2 generated in the gas-to-liquids plant to grow microalgae involves sequestering said CO2 through the use of gas separation membranes and subsequently delivering the sequestered CO2 to the microalgae.
(The immediately above is an unfortunate misspeak, or miswrite. They really don't mean "sequestering" the "CO2 through the use of gas separation membranes", but, actually, "separating" it. Further, we've documented several technologies for the separation of Carbon Dioxide from gas streams, but, not, yet, we believe, "gas separation membranes". We do intend to make report of such technology in the future, especially since the Utah company, Ceramatec, as seen, for one instance, in our report of:
West Virginia Coal Association | 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";
has developed some membrane technologies for the collection of Carbon Dioxide that seem especially effective.)
The method ... wherein the step of harvesting comprises removal of at least some of the microalgae for subsequent processing (as described, which) serves to extract triglycerides from the microalgae.
The method ... wherein the triglyceride-based biofuel precursor comprises at least 75 weight percent triglycerides (and) wherein the step of hydroprocessing comprising processing the triglyceride-based biofuel precursor in a hydrogen-containing environment in the presence of a catalyst.
The method ... wherein the paraffinic product comprises at least 75 weight percent paraffinic species.
The method ... further comprising a step of blending the transportation fuel with other transportation fuels (and) wherein the transportation fuel is a low pour-point diesel.
A system comprising: a) a conventional gas-to-liquids plant that produces a CO2 by-product; b) a repeatedly-harvestable population of microalgae; c) a means for directing the CO2 to the microalgae to support growth thereof; d) a means for harvesting the microalgae and extracting from it a triglyceride-based product comprising triglycerides; e) a means for hydroprocessing at least a portion of the triglyceride-based product to deoxygenate triglycerides contained therein and yield a paraffin-based product; and f) a means for isomerizing at least a portion of the paraffin-based product to yield a transportation fuel.
The system ... wherein at least one of the means for hydroprocessing and the means for isomerizing are integral with the gas-to-liquids plant (and) wherein the conventional gas-to-liquids plant is operable for producing transportation fuels.
The system ... wherein the CO2 is (delivered into) an aqueous solution (and) wherein the aqueous solution comprises the repeatedly-harvestable population of microalgae (or) wherein the aqueous solution is delivered to the repeatedly-harvestable population of microalgae.
The system ... further comprising a means for blending the transportation fuel with other species to impart to it desirable properties.
Description: This invention relates generally to an integration of gas-to-liquids (GTL) processing with biofuels production, and specifically to methods and systems for utilizing carbon dioxide (CO2) produced during GTL processing to support photosynthesis in microalgae--a biofuels precursor.
In some embodiments, the present invention is directed to a system comprising: (1) a conventional gas-to-liquids plant that produces a CO2 by-product; (2) a repeatedly-harvestable population of microalgae; (3) a means for directing the CO2 to the microalgae to support growth thereof; (4) a means for harvesting the microalgae and extracting from it a triglyceride-based product; (5) a means for hydroprocessing at least a portion of the triglyceride-based product to yield a paraffin-based product; and (6) an optional means for isomerizing at least a portion of the paraffin-based product to yield a transportation fuel.
(The) present invention is generally directed to systems and methods for integrating gas-to-liquids (GTL) processing with biofuels production. In an effort to reduce carbon dioxide (CO2) emissions and to utilize biofuel precursors that do not compete with food, in some embodiments of the present invention, CO2 generated by GTL processing is used to support growth (via photosynthesis) of microalgae. In some such embodiments, the microalgae can be further processed to yield a transportation fuel (e.g., diesel) that can be used either by itself, or mixed with fuel produced by the GTL or other processing. In some embodiments, processing of the microalgae (or products derived therefrom) can be at least partly integrated with the GTL processing.
Certain terms and phrases are defined throughout this description as they are first used, while certain other terms used in this description are defined below:
'Gas-to-liquids' ("GTL"), as defined herein, refers to processes that ... proceed through a syngas ... which is then converted to alkanes (paraffins) via a catalytic Fischer-Tropsch process.
'Synthesis gas' or 'syngas' is a gaseous mixture containing carbon monoxide and hydrogen and optionally other gases such as water and carbon dioxide. Syngas is typically produced by steam reforming of carbon- or hydrocarbon-containing precursors.
Steam reforming of coal yields syngas according to the following equation: C + H2O = H2 + CO."
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In other words, and in sum:
Any Carbon Dioxide generated anywhere in a process that produces liquid hydrocarbon fuels "via a catalytic Fischer-Tropsch process" from a "synthesis gas" made by the "steam reforming of coal", or other methods, such as that described by the USDOE in our above-cited report concerning "Co-Electrolysis of Steam and Carbon Dioxide for Production of Syngas", can be collected and fed to certain strains of Algae, which Algae then, as in our report of:
Illinois Algae Convert Flue Gas CO2 into $60 Oil for USDOE | Research & Development; concerning: "Removal of Carbon Dioxide from Flue Gases by Algae; 1993; Institute of Gas Technology, Chicago, (and) Illinois Dept. of Energy and Natural Resources (and) USDOE, Washington, DC; The objective of this research program is to determine the feasibility of the alga Botryococcus braunii as a biocatalyst for the photosynthetic conversion of flue gas CO2 to hydrocarbons. The feasibility and economic evaluation estimated the cost of oil produced from flue gas CO2 by algae to range between $45 and $75 per barrel";
can convert that Carbon Dioxide into some pretty reasonably-priced "oil".
Which "oil", according herein to Chevron can be harvested and added to the liquid hydrocarbon effluent of the combined Coal Gasification and Fischer-Tropsch synthesis for further refining, thus the "Increased Yield" of liquid fuels from a synthesis gas processor of the Fischer-Tropsch type, heralded by Chevron in the title of their "United States Patent 7,838,272" herein.
As in other of our reports documenting similar Algae-based Carbon Dioxide recycling technologies, with more to follow, there remains, in Chevron's process of "United States Patent 7,838,272", a certain amount of Algal cellular debris after the "processing (which) serves to extract" the Algal lipids for further processing with the liquid product of the Fischer-Tropsch synthesis.
That cellular debris also contains compounds derived from the Carbon Dioxide which was fed to the Algae; and, as in other of our reports documenting the fact, that debris, or residue, can as well be further processed to yield more hydrocarbon values.
Chevron themselves have addressed that issue in a fruitful way, as we will document in a separate report to follow in coming days.
However, it is again demonstrated herein that Carbon Dioxide, no matter, really, where we get it, is a valuable raw material resource.
According to Chevron, and as confirmed by our own US Government technical experts, we can feed Carbon Dioxide to certain strains of Algae; and, those Algae will then convert that CO2 into "triglycerides", and other metabolic products, which can be processed to "yield a paraffin-based product" that can then, utilizing standard petroleum refining technology, be further processed and made "to yield a transportation fuel".