Carbon dioxide emissions, chemical

For my part, although I may be somewhat of a visionary, I see a solution to the problem by chemical recycling of excess carbon dioxide emissions into methyl alcohol and derived hydrocarbon products. 

The effect of the type of catalyst is illustrated in Figure 4. The carbon dioxide emission curves using DABCO as a catalyst show an "autocatalytlc" effect. So far this phenomenon has remained unexplained it may be due to physical (diffusion hindrance) or chemical effects. 

The use of the lignin fraction is much more cumbersome currently the best-known chemical of a real commercial importance is vanillin, which is obtained by oxidation of the black liquor. Another example is a product called spray-dried lignosulfonate (as sodium salt) obtained from the older, acidic sulfite pulping process. It is sold as a commercial product primarily as a concrete additive for enhanced strength. Since the cement industry is one of the big contributors of carbon dioxide emissions (due to the production of calcium oxide from calcium carbonate), the use of this renewable, wood-derived product not only is fossil-carbon neutral in itself but also reduces carbon dioxide emission due to the diminished need for cement in large infrastructures made of concrete. 

Also, by the very nature of chemical transformations, there are almost always unused chemicals remaining. These chemical leftovers include contaminants in the raw materials, incompletely converted raw materials, unavoidable coproducts, unselective reaction by-products, spent catalysts, and solvents. There have long been efforts to minimize the production of such waste products, and to recover and reuse those that cannot be eliminated. For those that cannot be reused, some different use has been sought, and as a last resort, efforts have been made to safely dispose of whatever remains. The same efforts apply to any leftovers from the production of the energy from the fuels produced or consumed by the processing industries. Of particular immediate and increasing concern are the potential detrimental effects of carbon dioxide emissions to the atmosphere from fossil fuel combustion, as discussed further in Chapters 9 and 10. 

One of the main drivers for the use of bioenergy and bioproducts is their potential environmental benefits (e.g. carbon dioxide emission reduction, biodegradability). It is thus essential that we assess the environmental impact of all the energy and chemical products we manufacture (across their life cycle) to make sure that they... 

Fossil fuels will remain an abundant and affordable energy resource well into the 21st century. Since potential limitations on carbon dioxide emissions may restrict their utilization in the long term, it is imperative that chemical sciences research and engineering focus on making significant... 

The OECD transport sector produced nearly three times as much carbon dioxide in 1990 as it did in 1960 (lEA, 1993). There is a growing concern that these increasing carbon dioxide emissions will create a greenhouse effect on our planet (Boer et al., 1990). One way of reducing the emissions of CO2 would be to introduce renewable fuels, such as alcohol fuels or biogas. Carbon dioxide, which is produced by combustion of biomass-derived fuels, is naturally recycled and consumed in the photosynthesis. This means that there will be no net increase of COj in the atmosphere when using, for example, ethanol produced from biomass. This is valid if biomass-derived fuels or chemicals are used in all parts of the production chain. 

When Wilhelm Ostwald, toward the end of the nineteenth century, formulated his idea of using an electrochemical mechanism for the direct conversion of natural fuels chemical energy to electrical energy, coal was the chief kind of fuel in the hands of mankind. Even today, notwithstanding the widespread use of petroleum products and the development of nuclear power, coal remains a very important component of world energy supply. Its share of all known natural fuel reserves worldwide is about 60%. In China today, about 80% of the electrical energy is produced by coal-fired power stations, these being responsible for 70% of the carbon dioxide emissions and 90% of the sulfur dioxide emissions in this country (Cao et al 2007). 

The demand to reduce carbon dioxide emissions has led to the rapid development of renewable biomass for the production of fuels and chemicals. Lignocellulose is the most abundant biomass resource, which consists of cellulose (40-50%),... 

Biasing, T.J., Broniak, C.T., and Marland, G. 2005. The annual cycle of fossil-fuel carbon dioxide emissions in the United States. Tellus, Chemical Physical Meteorology, 57B 107-115. 

Methanol (CH3OH, MeOH) is now attracting worldwide attention because it is not only an important industrial raw material for chemicals such as formaldehyde, but is also a clean fuel which bums without emission of NOx and SOx. Previously, Feasibility studies of MeOH production from blast furnace offgas (BFG) have been carried out theoretically and experimentally for energy saving and environmental protection due to reduction of carbon dioxide emission. Since composition of BFG is quite different in comparison to industrial... 

Direct fixation of carbon dioxide into the target compound represents an important strategy for the rninimization of carbon dioxide emission [599]. Despite the fact that the activation and use of carbon dioxide in chemical reactions is not an easy process, several important applications have been developed, such as the production of carbamates these are utilized per se and as intermediates for fine chemicals, including unsymmetrical ureas. 

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