Carbon dioxide pressure increase

Increased partial carbon dioxide pressure increases... 

The oxidation rates in carbon monoxide (Fig. 5.12) are less than those for carbon dioxide. They increase steadily with temperature up to 800°C but then decrease markedly by a factor of 100 up to 1 000°C. The decrease in rate can be attributed to the beneficial factors operating at the higher temperatures with carbon dioxide and to the unfavourable thermodynamics for reaction 5.2 resulting in low equilibrium partial pressures of carbon dioxide. 

The hazard of well blowout is greatest if hydrochloric acid wastes exceeding certain temperature and concentration limits are injected into a carbonate formation. When carbonate dissolves in acid, carbon dioxide is formed. Normally, this gas remains dissolved in the formation waters at deep-well temperatures and pressures, but if the temperature exceeds 88°F or acid concentration exceeds 6% HC1, carbon dioxide will separate from the formation waters as a gas. The resulting gas accumulation can increase pressures to a point where, if injection stops or drops below the subsurface carbon dioxide pressure, a blowout can occur. 

The melting point of carbon dioxide increases with increasing pressure, since the solid-liquid equilibrium line on its phase diagram slopes up and to the right. If the pressure on a sample of liquid carbon dioxide is increased at constant temperature, causing the molecules to get closer together, the liquid will solidify. This indicates that solid carbon dioxide has a higher density than the liquid phase. This is true for most substances. The notable exception is water. 

In order to remove the undesirable Texanol, ve extracted the pigment with supercritical carbon dioxide which was held at a low pressure (100 atm) for five minutes. The extract was found to contain Texanol. We increased the carbon dioxide pressure to 400 atm for five minutes to extract the pigment additive. The pressure control in SFE allows us to control the solubilizing power of the carbon dioxide, therefore, perform selective extractions. 

The observed decrease of the p values for the time-lag of carbon dioxide with increasing pressure is consistent with published data that have been interpreted using a partial immobilization model (11,12). It is somewhat surprising that we do not observe a concomitant decrease in the permeance perhaps the pressures used are too low or the pressure range is not broad enough. 

The fugacity ratio of carbon dioxide, Yco, increases tens or hundreds or times as pressure increases (Fig. 68). Correspondingly / exceeds P, and the increase in pressure with a rise in temperature leads to a nonlinear increase in fugacity. 

Carbon dioxide is readily absorbed by molten melts containing sulfide. The amount of carbon dioxide absorbed increases as the temperature decreases and as the carbon dioxide partial pressure increases. Although thiocarbonate intermediates (M2CO2S, M2COS2 and M2CS3) have not... 

For the hydrodimerization of butadiene with water, attempts have been made to increase the reactivity by adding acidic solids [4], salts such as sodium phosphate [5], emulsifiers [6], carbon dioxide [7], or the like, with no satisfactory results. In particular, the reaction rate increases under a carbon dioxide pressure, but carbonate ions, not carbon dioxide itself, are considered to play an important role in this effect. It is known that the carbonate ion concentration in water is very low even under a carbon dioxide pressure. If the carbonate ion is the true reactant, the reaction rate should increase with the carbonate ion concentration. Since inorganic carbonates show almost no effect, the addition of various tertiary amines having no active hydrogen, under a carbon dioxide pressure was tested [8]. Diamines and bifunctional amines inhibited the reaction. The reaction rate increased only in the presence of a monoamine having a p/f of at least 7, almost linearly with its concentration (Figure 3). 

Carbon dioxide pressures from 1 to 75 atmospheres and temperatures from 0° to 80°C were assessed. Since the liquid phase is in contact with the coal and is responsible for mineral matter dissolution, its composition would be expected to have a bearing on ash reduction in the coal. The solubility of CO2 in the liquid phase increases as the CO2 pressure increases and may be related to swelling of coal structure (although not linearly). Table I summarizes a set of experiments directed toward determining the effect of aqueous phase concentration of CO2 on the treated product ash content for Pittsburgh Seam coal. At low CO2 concentrations,... 

Figure 2 shows that the percentage conversions to glycolic acid increase with the pressure. The conversions to carbon dioxide also increase with... 

All these projections must be treated with caution since the science involved in the uptake of gases by coal is imperfectly understood and complications may arise. As the concentration and prevailing pressure of carbon dioxide increase, adsorption on the coal surface is replaced by absorption (or dissolution) into the structure of the coal. The coal loses its brittle nature and becomes rubbery the latter, in turn, leads to plastic flow. The extent to which this change in state occurs is dependent upon the carbon dioxide pressure, the temperature and the nature of the coal. A probable consequence of plastic flow would be the sealing of capillary channels in the coal and thereby a reduction in its capacity to absorb more gas. Another pertinent factor is that coal swells as carbon dioxide is absorbed and this, too, would cause a major decrease of permeability and consequent gas uptake. For both of these reasons, present estimates of the capability of coal seams to absorb carbon dioxide should be treated as tentative. 

Respiratory depression Opioid actions in the medulla lead to inhibition of the respiratory center, with decreased response to carbon dioxide challenge. Increased Pco may cause cerebrovascular dilation, resulting in increased blood flow and increased intracranial pressure. 

The shape and the size of the formed particles can be manipulated by the temperature of the melt and by the CO2 concentration. The bulk densities of the formed powder decrease with increasing amount of dissolved carbon dioxide and increase with increasing melt temperature. There is no significant effect of atomization pressure and nozzle temperature on the bulk density. 

The specific heaf Cp is assumed fo be consfanf and equal for bofh compression and expansion. In practice these assumptions are not valid because the specific heaf Cp is a function of femperafure. The average femperafure in the turbine is about twice that in the compressor. Also the products of combustion i.e. water vapour and carbon dioxide, slightly increase the specific heaf of air-gas mixture in the turbine. Figures 2.8 and 2.9 show the spread of values for the pressure ratio and exhaust temperature for a range of gas turbines from 1 MW to approximately 75 MW. 

According to Henry s law, the solubility of a gas in a liquid increases as the pressure increases (c = kP). The soft drink tastes flat at the bottom of the mine because the carbon dioxide pressure is greater and the dissolved gas is not released from the solution. As the miner goes up in the elevator, the atmospheric carbon dioxide pressure decreases and dissolved gas is released from his stomach. 

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