We've cited Brookhaven National Laboratory researchers Creutz and Fujita, on the subject of Carbon Dioxide utilization previously.
Herein, via the enclosed link and attached file, they present a much fuller outline of the potentials for actually using Carbon Dioxide, in needed productive and profitable ways, as opposed to the costly, perhaps ineffective, disposal and storage of it.
The excerpt from the enclosed link and attached file, with comment interspersed and following:
"Carbon Dioxide as a Feedstock
Carol Creutz and Etsuko Fujita
Chemistry Department; Brookhaven National Laboratory; Upton NY 11973-5000
Carol Creutz and Etsuko Fujita
Chemistry Department; Brookhaven National Laboratory; Upton NY 11973-5000
This report is an overview on the subject of carbon dioxide as a starting material for organic syntheses of potential commercial interest and the utilization of carbon dioxide as a substrate for fuel production. It draws extensively on literature sources, particularly on the report of a 1999 Workshop on the subject of catalysis in carbon dioxide utilization, but with emphasis on systems of most interest to us.
Atmospheric carbon dioxide is an abundant (750 billion tons in atmosphere), but dilute source of carbon (only 0.036 % by volume), so technologies for utilization at the production source are crucial for both sequestration and utilization. Sequestration-such as pumping CO2 into sea or the earth-- is beyond the scope of this report, except where it overlaps utilization, for example in converting CO2 to polymers. But sequestration dominates current thinking on short term solutions to global warming, as should be clear from reports from this and other workshops."
(As we've seen, geologic "sequestration", in depleted oil reservoirs. for instance, "dominates current thinking on short term solutions to global warming". Wouldn't long term, and sustainable, solutions be far more preferable, what we should really be looking for? - JtM)
The 3500 million tons estimated to be added to the atmosphere annually at present can be compared to the 110 million tons used to produce chemicals, chiefly urea (75 million tons), salicylic acid, cyclic carbonates and polycarbonates. Increased utilization of CO2 as a starting material is, however, highly desirable, because it is an inexpensive, non-toxic starting material. There are ongoing efforts to replace phosgene as a starting material. Creation of new materials and markets for them will increase this utilization, producing an increasingly positive, albeit small impact on global CO2 levels. The other uses of interest are utilization as a solvent and for fuel production and these will be discussed in turn.
(So, "increased utilization of CO2 as a starting material is ... highly desirable". And, another CO2 use "of interest" is "for fuel production". - JtM)
"Principal current uses of carbon dioxide.
Urea synthesis is currently the largest use of carbon dioxide in organic synthesis. Urea, C(O)(NH), is the most important nitrogen fertilizer in the world. It is also an intermediate in organic syntheses such as production of melamine and urea resins, used as adhesives and bonding agents. Salicylic acid is used in pharmaceuticals.
Cyclic organic carbonates, high melting, but extremely high boiling, serve as solvents for natural and synthetic polymers such as lignin, cellulose, nylon, polyvinyl chloride. They are extensively used in the production of polyacrylic fibers and paints. Ethylene and propylene carbonates have many uses in chemical synthesis; also they react with ammonia and amines to form carbarnates; from reaction with diamines they yield di(hydroxyethyl)carbamates which can further react with urea to form polyurethanes.
Novel insertions are under active investigation: incorporation of CO, into polymers-polycarbonates, polypyrones, lactone intermediates, and polyurethanes Of particular interest is the incorporation of carbon dioxide into polymers, an active area of research and very promising for future applications. However, the impact of new materials and processes in this area will ultimately depend on market forces, a factor than
can be frustrating to the researchers.
can be frustrating to the researchers.
Carbon Dioxide as Solvent. Supercritical carbon dioxide is a hydrophobic solvent which can replace organic solvents in a number of applications. Its critical temperature is 31°C and it is of very low viscosity. When carbon dioxide is substituted for an organic solvent, solvent costs may be reduced and emission of toxic organics can be reduced.
(So, using Carbon Dioxide in a solvent application could enable the "emission of toxic organics" to "be reduced". Sounds rather environmentally friendly, to us. - JtM)
Thermodynamic Barriers to CO2 Utilization. Carbon dioxide is a very stable molecule and accordingly energy must generally be supplied to drive the desired transformation. Thus high temperatures, extremely reactive reagents, electricity, or the energy from photons may be exploited to carry out carbon dioxide reactions:
The reaction, CH, + CO2, = 2 CO -I- 2 Hz, is called the carbon dioxide reforming of methane. (It) could significantly mitigate CO, produced in cement, lime and metal (iron, aluminum) production ... .
For electrochemical reduction of CO2 to methane, energy may be derived from a solar cell or nuclear power. Reduction may also be accomplished photochemically by utilizing a dye to absorb visible light, since carbon
dioxide itself does not absorb visible light. Interestingly, with vacuum ultraviolet irradiation of carbon dioxide yields oxygen and carbon monoxide.
Conversion of Carbon Dioxide to Fuels: Direct Hydrogenation
With abundant renewable energy sources carbon dioxide can be converted to fuels by reduction to methanol or methane. The value of a fuel is based on its energy content and its ease of transport and storage. ... The high energy density of carbon-based fuels and their availability as either gases, liquids, or solids are important reasons for the dominant position of fossil fuels in the current market place. Today carbon
dioxide is a by-product of fuel use, not a feedstock for fuel production. Utilization of CO2 converted to fuels using renewable or nuclear power produces no net emission of CO2 (when carbon dioxide produced by energy consumption in the reduction process is excluded) and it would complement the renewable production of fuels from biomass which is likely to be insufficient to meet future world demands. Catalysis can play an important role in this area. The objective is to develop strategies for reduction of CO2
that can be adapted to utilization at different sources and to attain fuel products widely utilizable with current and future technologies.
Hydrogenation of carbon dioxide to methanol is slightly exergonic, and to methane to a greater extent ... because of the favorable thermodynamics of water formation.
Catalysis of hydrogenations leading ... to hydrocarbons is being successfully addressed. Reduction to carbon monoxide is also useful when the carbon monoxide-hydrogen mixtures can be used to augment feeds in industrial processes such as ethylene and methanol production. Methanol, lower hydrocarbons (methane, ethane, ethylene, etc), CO, and HCOOH have been prepared .
(So, reactions of CO2 "leading ... to hydrocarbons is being successfully addressed", as we have documented from Penn State University. - JtM)
Copper on ZnO seems to be the most active catalyst for methanol production. Selectivity for methanol
production was found to be very high and direct methanol production from CO2 may be commercially feasible with an inexpensive source of H2.
production was found to be very high and direct methanol production from CO2 may be commercially feasible with an inexpensive source of H2.
(The "inexpensive source of H2" is needed in direct hydrogenation reactions. There are alternatives. - JtM)
Conversion of Carbon Dioxide to Fuels: Indirect Hydrogenation
Hydrogen (H2) may be replaced by electrons and protons, available, for example, in electrochemical reduction in aqueous media.
(In other words, as other researchers have noted, the Hydrogen needed for CO2 hydrogenation can be obtained through "electrochemical reduction". - JtM)
Electrochemical reduction.
As noted earlier, direct electroreduction is achieved at high overvoltage. An unreactive metal or carbon electrode produces carbon dioxide radical anion ... . (Other) metals ... can direct CO2 reduction to hydrogenated products and at much smaller applied voltage ... . Particularly noteworthy is the work of Hori which showed that copper produces high yields of methane from aqueous bicarbonate at 0 C-and high yields of ethylene at 45 C.
Photochemical systems.
Photochemical reduction systems require efficient light harvesting, usually by a so-called dye or sensitizer, and efficient charge separation and energy utilization. Transition metal complexes ... serve as sensitizers.
Electrocatalysis Photocatalytic Reduction.
At present, electrochemical reduction of CO2 yields carbon monoxide, formate, methane, etc. with good current efficiencies and, in photochemical systems, quantum yields for carbon monoxide (and/or formate) are up to 40%.
There are many areas in which ongoing and future research can lead to new modes of carbon dioxide utilization.
This research was carried out at Brookhaven National Laboratory under contract DE-AC02-98CH10886
with the U.S. Department of Energy and was supported by its Division of Chemical Sciences, Office of Basic Energy Sciences."
with the U.S. Department of Energy and was supported by its Division of Chemical Sciences, Office of Basic Energy Sciences."
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So, there are almost half a dozen known processing routes for Carbon Dioxide that would yield liquid and gaseous fuels, fertilizer, and plastics manufacturing raw materials; and, at the same time, reduce the need for some hazardous raw materials, such as "phosgene", and, subsequently "emission of toxic organics can be reduced".
Naw. Let's just waste a lot of money, instead, to stuff it all down leaky geologic storage rat holes.
And, note: This research was conducted by a US Government Lab, and it was paid for with our tax dollars under USDOE contract DE-AC02-98CH10886. Why haven't we US taxpayers, especially those of us resident in US Coal Country, been told about any of it? Why haven't these opportunities been published and promoted? Why is it that all we hear about is Cap & Trade and Sequestration?