Two- and Three-Phase Equilibrium Calculations for Coal Gasification and Related Processes

Abstract

The gasificiation of coal, shale-oil, or other lower grade hydrocarbon base stocks inevitably leads to the production of process streams which contain a very wide range of paraffinie, naphthenic, aromatic and olefinic hydrocarbons in the presence of associated non-hydrocarbons such as hydrogen, nitrogen, carbon dioxide, hydrogen sulfide and ammonia. These streams are often contacted with water at process conditions which normally lead to either gas -water -rich liquid equilibrium or gaswater -rich liquid -hydrocarbon rich liquid equilibrium. The processing conditions and stream compositions which may lead to the formation of these different phases and the distribution of the components between phases are of great importance to the design engineer. For this reason the establishment of reliable procedures for predicting the behavior of these mixtures in the one-, two-, and three-phase regions is a matter of considerable importance.In an earlier paper (1), the authors presented an efficient procedure for predicting the phase behavior of systems exhibiting a water -rich liquid phase, a hydrocarbon -rich liquid phase, and a vapor phase.The Peng-Robinson equation of state (2) was used to represent the behavior of all three phases.It has the following form: v v-b " v(v+bj + b(v-b) where a(T) = a α = KL . a(T) (1) ac = 0.45724 -j ± = 1 + K(1-TR^2)

Simulation of Trapping Processes for CO2 Storage in Saline Aquifers

“…Gas solubility increases with increasing pressure and decreases with increasing temperature and salinity. In the SWPR EOS, Søreide and Whitson use different interaction coefficients for the gas and aqueous phase (Peng and Robinson, 1980). In addition, they give correlations for interaction coefficients of gaseous components in the water phase that are functions of temperature and salinity.…”

Prediction of Phase Behavior for the System Methane-Carbon Dioxide- Hydrogen Sulfide-Water with the PR and PC-SAFT Equations of State

“…This table shows that, as expected, the solubility of water in the vapor-and hydrogen sulfide-rich liquid phase is over predicted by several orders of magnitude, especially in the hydrogen sulfide-rich liquid phase, while methane is under predicted in both liquid phases at the two temperature and pressure conditions. Of course, these results can be improved if different interaction parameters were used in the calculations such that proposed by Peng and Robinson [34] for modeling more accurately the phase compositions for binary systems of alkanes and water. Table 3 indicates that the PR EoS could be able to represent the entire three phase region in the P-T diagram but it shows differences once the comparison against the experimental compositions are made.…”

The solubility of CO2+H2S mixtures in water and 2M NaCl at 120°C and pressures up to 35MPa

“…It is based on a conventional cubic equation of state (EOS) including the effect of dissolved salts. The formalism is taken from Peng and Robinson (1976) (PR), but includes some later modifications (Peng and Robinson, 1980). Søreide and Whitson (1992) provided two main modifications of the PR EOS, i.e.…”