Fossil carbon

Assuming that the carbon cycle of Fig. 4-12 will remain a closed system over several thousands of years, we can ask how the equilibrium distribution within the system would change after the introduction of a certain amount of fossil carbon. Table 4-2 contains the answer for two different assumptions about the total input. The first 1000 Pg corresponds to the total input from fossil fuel up to about the year 2000 the second (6000 Pg) is roughly equal to the now... 

The content of the material in a carbon reservoir is a measure of that reservoir s direct or indirect exchange rate with the atmosphere, although variations in solar also create variations in atmospheric content activity (Stuiver and Quay, 1980, 1981). Geologically important reservoirs (i.e., carbonate rocks and fossil carbon) contain no radiocarbon because the turnover times of these reservoirs are much longer than the isotope s half-life. The distribution of is used in studies of ocean circulation, soil sciences, and studies of the terrestrial biosphere. 

Figures 19-3d-f depict both the recent data from ice cores and the contemporary records of N2O, CH4, and CO2 during the most recent 250 years. These illustrate the profound changes that have occurred since the industrial revolution. Although the exact causes of the increases of N2O and CH4 are not yet fully agreed upon, there is no debate regarding the relationship of the increase of CO2 to the burning of fossil carbon and deforestation. In the case of CH4 and CO2, there is also excellent agreement between the ice-core records and the records from direct sampling of the atmosphere, which began in 1957 for CO2 and in ca. 1973 for CH4.

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. 

Use of renewable feedstocks is most likely where they can compete economically with petrochemically derived materials. This already happens in many areas, and it is sometimes forgotten that even in a world that seems to be dominated by chemicals and materials from fossil carbon and other non-renewable sources, industry already uses annually 19.8 MT of vegetable oils, 22.5 MT starch, 28.4 MT of plant fibres and 42.5 MT of wood pulp. These all compete on price and performance with synthetic alternatives. 

Energy production and consumption pose nature into pressure and make the energy sector becomes the largest contributor of greenhouse gas (GHG) emission in Vietnam since 2010, accounting for 67%. Several emission sources of GHG could be found in a waste treatment facilities it came from (1) emission of methane (CH4, GWP 25) at landfill of mixed waste, (2) from emission of fossil carbon dioxide through the combustion of plastics and composites or supported fuels (auxiliary), and (3) from emission of nitrous oxide (NOx) during incineration/ pretreatment process, etc. 

Almost carbon (C) in waste is oxidized into C02 through combustion process. A small amount is converted into carbon monoxide (CO), but this is often ignored. According to IPCC 2006, only fossil C02 is accounted as GHG emission source, while C02 which is formed from C bio is considered neutral and not added to total GHGs emission. However, amount of C02 bio was still calculated for reference purpose. C02 emission in RDF utilization process (burning process) is calculated based on fossil carbon content of waste fractions by the following formula ... 

Lackner, K.S., Carbonate chemistry for sequestering fossil carbon, Ann. Rev. Energy Environ., 27(1), 193, 2002. 

Fossil fuel source terms appear not only in equation 1 for atmospheric carbon dioxide fuel/matmco2 but also in equations 6 and 9 for carbon isotopes in the atmosphere fuel/matmco2 defuel or drfuel. The 13C delta value for the fossil fuel source is defuel = — 25, and the radiocarbon value is drfuel = —1000, because fossil carbon is devoid of radiocarbon, rfs = 0, and del = — 1 1000. 

Comparing rural with "typical" urban samples (2nd entry, Table 5), we find that fossil carbon predominates in the urban particulate matter, and the converse. A significant amount of biogenic carbon is found in the urban samples (even in the absence of wood burning), however and this may be related to vegetative emissions. For example, besides fossil fuel indicators such as... 

Another source of non-fossil carbon that can be used to produce SNG is organic wastes. The growing environmental and... 

Carbon is a true pharmakom a poison and a gift, powering the modern world. Carbon released into the atmosphere mere years or decades ago is now being taken up by plants. But fossil carbon taken from the earth accumulated over millions of years. Carbon, then, is a temporal problem, and thus it is intimately linked with the nexus of alchemy and mining. 

Wahlen, M., N. Tanaka, R. Henry, B. Deck, J. Zeglen, J. S. Vogel, J. Southon, A. Shemesh, R. Fairbanks, and W. Broecker, Carbon-14 in Methane Sources and in Atmospheric Methane The Contribution from Fossil Carbon, Science, 245, 286-290 (1989). 

Lackner, K. S. 2002. Carbonate chemistry for sequestering fossil carbon. Annual Review of Energy and the Environment, 27, 193-232. 

As noted above, an aquatic biomass contains a much wider variety of molecules when compared to fossil carbon or oil. Hence, the exploitation of their full... 

The biorefinery approach is the most sound in terms of truly exploiting the potential of an aquatic biomass, and this concept is now becoming accepted on a worldwide basis. In the biorefinery approach, the economic and energetic value of the biomass is maximized, although it must be emphasized that fluctuations in the prices of fossil carbon (coal, oil, gas) raises uncertainty regarding the opportunity to produce biodiesel from aquatic biomass. For example, when the oil price is below US 120 per barrel it is uneconomic to produce biodiesel in this way. On the other hand, an aquatic biomass demonstrates an excellent potential for use as a source of specialty chemicals, with some components also having added value as animal feeds or fertilizers. 

Carbon dioxide is considered to be an inert molecule since, with water, it is the end product of any combustion process, including biological cellular oxidation reactions. Although it is produced by all living organisms, whether animal or vegetable (for example, an adult man emits about 0.9kg C02 per day), by far the main source of C02 is the combustion of fossil carbon (coal, oil, gas) used for the production of energy. 

The present resources of drinking water and fossil carbon components are already seen as limited. Careful use and development of alternatives is now being pursued. Process intensification has the potential of requiring less energy and thereby requiring less fossil carbon as fuel. 

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