This is just a quick junk diary, hopefully non-controversial, that I throw out there for the hell of it.
My view increasingly is that it is not enough to merely stop dumping carbon dioxide into the atmosphere, but that, given the inertia present in dangerous fossil fuel use, we will need to find ways to remove from air near the concentrations at which it is already present. In the spirit of our President, let me say that this will hardly be a simple task. On the contrary, for thermodynamic reasons it will be difficult.
I am the wrong person to speak on the subject of motor fuels, since I am an intractable opponent of the car CULTure, but I fully concede that it is inevitable that at least some people will continue to use self propelled vehicles for as long as humanity as we know it survives. I have written here before extensively on the ideal motor fuel, DME, but there is a sister compound, DMC, dimethyl carbonate, also useful as a diesel fuel. This is a diary about DMC.
Recently James Lovelock - in a bit of obliviousness to the question of air pollution - suggested that humanity set forth on a quest to produce as much charcoal as possible from biomass on an emergency basis, because, although he supports nuclear power, he doesn't believe it "can be fast enough."
Whatever.
In a large sense, such an effort - which, um, will require a source of energy is simply the reversal of coal burning.
I favor the phase out of all dangerous fossil fuels, but even though this is not in the same order of external impact, I would phase out dangerous fossil fuels in the following order: Dangerous Oil first (the easiest), dangerous coal second, relatively easy in a rational world, and dangerous natural gas last. This is simply an order of fast technological feasibility.
Dangerous coal's most dangerous waste is, of course, carbon dioxide, but interestingly this dangerous waste can be, under the right circumstances - and already is - a useful starting material for many processes.
One of the easiest chemicals to make from the charcoal (and, dare I say it, coal) is ethylene, a gas with the formula H2C=CH2, which is itself accessible from acetylene and hydrogen. Acetylene, in turn is accessible from water and certain metal carbides which are obtained by heating the metals in the presence of carbon, charcoal or coal. (I am unaware of the extent to which this is an industrial process, but it is an ancient lab process.)
I have a paper before me now, J. Phys. Chem. B, 1999, 103 (30), 6277-6282, from Robert Davis and coworkers at the University of Virginia which discusses the chemistry of using acetylene to make dimethyl carbonate.
The abstract is here.
(Note, that as a compound having a carbon-carbon bond, the direct burning of ethylene carbonate is undesirable in diesel engines, because unlike DME and DMC, it is possible to form soot.)
Ethylene carbonate, when reacted with methanol, gives dimethyl carbonate, the potential fuel.
Zeolites that have been modified by ion exchange of alkali metal cations or by decomposition of an occluded alkali-metal salt have emerged as interesting solid bases. They are known to catalyze many reactions, including double-bond isomerization of olefins, side-chain alkylation of aromatics, dehydrogenation of alcohols, and Knoevenagel condensation of aldehydes.1-5 The base strength of alkali-metal ion-exchanged zeolites increases with increasing electropositivity of the exchange cation, and occlusion of alkali-metal oxide clusters in zeolite cages via decomposition of impregnated alkali-metal salts results in a
further increase in the basicity of these materials.1,3,6-
My interest in this paper was piqued by my continual interest in cesium chemistry, which in turn derives from my interest in fission product chemistry. This is cesium chemistry.
In this paper, we extend the application of iodine as a visible probe for the determination of the basic strength for zeolites to include cesium-exchanged samples as well as various metal oxides. A limitation of this technique for use with strong bases will also be presented. To correlate the characterization results with the catalytic function, the activity of alkali-metal-modified zeolites was examined for the reaction of ethylene oxide and carbon dioxide to produce ethylene carbonate, an important intermediate in the manufacture of rubber chemicals and textile agents, as well as a precursor in the production of high-purity ethylene glycol.47-51
Ethylene carbonate's use as a medium in lithium batteries, the purpose for which probably most people actually own some ethylene carbonate is missed.
Anyway.
Conclusions.
The adsorption of iodine as a probe for surface basicity has been shown to be effective in determining the relative basicity for alkali-metal-exchanged zeolites. Blue shifts in the visible absorption spectra of iodine correlated well with the basic strength of alkali-metal-exchanged zeolites...
...Alkali-metal ion-exchanged zeolites were active for the reaction of ethylene oxide with carbon dioxide to make ethylene carbonate, and the activity increased with the electropositivity of the exchange cation. Incorporation of the occluded cesium oxide species in the ion-exchanged zeolites via decomposition of impregnated cesium acetate further promoted their catalytic activity. Water adsorbed in zeolite pores played a critical role in ethylene carbonate formation.
Voila, wunderbar and all that stuff.