CO2 concentration

If coke is not present in sufficient quantity, more silicates are formed, presumably because of increased CO2 concentration which leads to greater amounts of BaCO being formed (1). 

Fig. 2-4. Average CO2 concentration North Atlantic Region O, Pacific Region A. (The dashed line is the nineteenth-century base value 290 ppm.) Source Combination of data from Callender, G. C., Tellus, 10, 243 (1958), and Council on Environmental Quality, "Global Energy Futures and the Carbon Ehoxide Problem." Superintendent of Documents, Lf.S. Government Printing Office, Washington, DC, 1981. (See also Fig. 11-1.)...

The Stretford Process sweetens and also produces sulfur. It is good for low feed gas concentrations of H2S. Economically, the Stretford Process is comparable to an amine plant plus a Claus sulfur recovery plant. Usually, the amine/Claus combination is favored over Stretford for large plants. Stretford can selectively remove H2S in the presence of high CO2 concentrations. This is the process used in the coal gasification example in the Introduction. 

Test a hypothesis about the source of the problem, such as checking emissions from a piece of equipment. Testing for "indicator" compounds associated with particular types of building conditions Peak carbon dioxide CO2) concentrations over 1000 ppm (parts per million) are an indicator of underventilation. Carbon monoxide (CO) over several ppm indicates inappropriate presence of combustion by-products (which may also account for high CO2 readings). Compare any measured concentrations to guidelines or standards. 

The necessary data required to properly design a CO2 scrubber are separated into three sections, depending upon the CO2 concentration in the feed gas. Corrections... 

With increased CO2 concentrations, by the injection of CO2 gas into ponds, outputs of 3 x 104 kg dry protein per hectare per year are possible. This compares very favourable with conventional sources of protein (Table 4.3), note the low yields of meat and milk. 

Figure 2b. Since the end of last glaciation, atmospheric CO2 concentration has remained around 280 until it began rising in the 18th century.

The formation and dissolution of CaCOa in the ocean plays a significant role in all of these effects (34)- CaCOa is produced by marine organisms at a rate several times the supply rate of CaCOa to the sea from rivers. Thus, for the loss of CaCOa to sediments to match the supply from rivers, most of the CaCOa formed must be redissolved. The balance is maintained through changes in the [COa] content of the deep sea. A lowering of the CO2 concentration of the atmosphere and ocean, for example by increased new production, raises the [COa] ion content of sea water. This in turn creates a mismatch between CaCOa burial and CaCOa supply. CaCOa accumulates faster than it is supplied to the sea. This burial of excess CaCOa in marine sediments draws down the [COa] - concentration of sea water toward the value required for balance between CaCOa loss and gain. In this way, the ocean compensates for organic removal. As a consequence of this compensation process, the CO2 content of the atmosphere would rise back toward its initial value. 

Periodic climatic events such as the El Nino/Southern Oscillation events produce detectable changes in both vegetation dynamics and in atmospheric CO2 concentration 37, 88). Evidence from ratios in atmospheric CO2... 

Keeling, C. D. Atmospheric CO2 Concentrations—Mauna Loa, Hawaii, 1958-1987 NDP-OOl/Rl Carbon Dioxide Information and Analysis Center, Oak Ridge National Laboratory Oak Ridge, TN, 1988. 

Fluxes are linear functions of reservoir contents. Reservoir size and the residence time of the carbon in the reservoir are the parameters used in the functions. Between the ocean and the atmosphere and within the ocean, fluxes rates are calculated theoretically using size of the reservoir, surface area of contact between reservoirs, concentration of CO2, partial pressures of CO2, temperature, and solubility as factors. The flux of carbon into the vegetation reservoir is a function of the size of the carbon pool and a fertilization effect of increased CO2 concentration in the atmosphere. Flux from vegetation into the atmosphere is a function of respiration rates estimated by Whittaker and Likens (79) and the decomposition of short-lived organic matter which was assumed to be half of the gross assimilation or equal to the amount transferred to dead organic matter. Carbon in organic matter that decomposes slowly is transferred... 

The atmospheric CO2 concentration has been increasing since the beginning of the indus-... 

Fig. 11-3 Direct atmospheric measurements of the CO2 concentration (left-hand scale) at Mauna Loa (Hawaii) and the South Pole station (Keeling et al., 1995) together with the concurrently observed decrease in atmospheric oxygen content (right-hand scale) at La Jolla, CA after 1989. (Taken from Heimann (1997) with permission from the Royal Swedish Academy of Sciences.)...

Figure 11-4 Globally and annually averaged oxygen versus CO2 concentration from 1991 to 1994. The oxygen concentration is displayed as the measured O2/N2 ratio and expressed in per meq" which denote the pm deviation from a standard ratio. The inset shows the directions of the state vector expected for terrestrial and oceanic uptake. The long arrow shows the expected atmospheric trend from fossil fuel burning if there were no oceanic and terrestrial exchanges. (Used with permission from Keeling et al. (1996). Nature 381 218-221, Macmillan Magazines.)...

Measurements of CO2 concentrations in air bubbles trapped in glacial ice (Berner et ah, 1980 Delmas et ah, 1980 Jouzel et ah, 1993 Raynaud et ah, 1993) show that atmospheric Pqo was about 200 ppmv toward the end of the last glaciation 20000 years ago (Fig. 11-19). 

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