Simulation and Optimization of a Condensate Stabilization Process

yesA simulation was conducted using Aspen HYSYS® software for an industrial scale condensate stabilization unit and the results of the product composition from the simulation were compared with the plant data. The results were also compared to the results obtained using PRO/II software. It was found that the simulation is closely matched with the plant data and in particular for medium range hydrocarbons. The effects of four process conditions, i.e. feed flow rate, temperature, pressure and reboiler temperature on the product Reid Vapour Pressure (RVP) and sulphur content were also studied. The operating conditions which gave rise to the production of off-specification condensate were found. It was found that at a column pressure of 8.5 barg and reboiler temperature of 180°C, the condensate is successfully stabilised to a RVP of 60.6 kPa (8.78 psia). It is also found that as compared to the other parameters the reboiler temperature is the most influential parameter control the product properties. Among the all sulphur contents in the feed, nP-Mercaptan played a dominant role for the finishing product in terms of sulphur contents.The full text will be available at the end of the publisher's embargo, 12 months after publication

Comparing different methods for prediction of liquefied natural gas Densities

The densities of several liquefied natural gas (LNG) mixtures and pure methane using different equations of state and correlations have been predicted and compared with the experimental values. The equations of state were Peng-Robinson (PR), Soave-Redlich-Kwong (SRK), Usdin-McAuliffe (UM), Volume Translated SRK (VT SRK), Nasrifar-Moshfeghian (NM) and modified Nasrifar-Moshfeghian (MNM). The correlations were Racket-Spencer-Danner (RSD), Hankinson-Thompson (HT), Nasrifar-Moshfeghian (NML), and simplified Nasrifar-Moshfeghian (S-NML). It has been attempted to choose the most popular EoSs and correlations with the highest accuracy for predicting the density of LNG mixtures. For the systems under study, the NM EoS had the least average absolute deviation of liquid density among the equations of state evaluated, and the NML correlation predicted the LNG liquid density more accurately than the other liquid density correlations. The accuracy of this method for prediction of methane liquid density is also as good as that of RSD's and HT's. Moreover, using the NM EoS, density as a function of temperature and pressure for the whole phase envelope has been plotted. Results, especially near the critical point, show good compatibility between the bubble and dew point densities. The predicted values of methane vapor and liquid density/specific volume up to near the critical point based on these equations of state are also given. No fitting or adjustable parameters were used for any of the EoSs or correlations

Predict The Properties Of Aqueous Mixed Electrolyte Solutions From Properties Of The Individual Electrolyte Solution

For calculating the thermodynamic properties of mixed electrolyte solutions, a thermodynamic framework is developed. The vapor pressure, density and osmotic coefficient of several mixed electrolyte solutions are predicted and compared with the experimental data and the prediction of other models. The agreement is quite good. The average of absolute error is 0.1 % for predicting the vapor pressure and density of electrolyte solutions and 1.3 % for predicting the osmotic coefficient

Correlation Of Vapor-Liquid Equilibrium Data For Binary Mixtures Containing One Polar Component By The Parameters From Group Contributions Equation Of State

Use of a quadratic mixing rule in the Parameters from Group Contributions Equation of State increases the range of compounds for which vapor-liquid equilibrium behavior can be satisfactorily correlated. This is demonstrated by correlation of vapor-liquid equilibrium for several binary mixtures containing at least one polar component

A simplified method for calculating saturated liquid densities

A simplification for the Nasrifar–Moshfeghian (NM) liquid density correlation has been developed. A replacement for the Mathias and Copeman temperature-dependent term with the original Soave–Redlich–Kwong equation of state (SRK EOS) temperature-dependent term has been done. This replacement has overcome the limitations in use for the original model due to the Mathias and Copeman vapor pressure-dependent parameters. The new correlation uses one characteristic parameter for each compound and suggests a value of zero for generalization purpose. The revised model has been tested for pure compounds liquid density prediction of different types including paraffins, cyclo-paraffins, olefins, diolefins, cyclic olefins, aromatics, ethers, liquefied inorganic gases and alcohols. The average absolute percent deviation for 76 compounds consisting of 2379 experimental data points was found to be 0.58%. The simplified method was then used to predict the saturated liquid density of multi-component systems. The average absolute percent deviation for 58 multi-component systems consisting of 978 experimental points was found to be 0.67%. Generalizing the correlation, by setting a value of zero for the characteristic parameter, gave average absolute percent deviation of 2.01% for the same pure compounds and 1.57% for the 58 multi-component systems. The accuracy of the simplified model has been compared with other correlations and equations of states

Thermodynamic fluid characterization of an Iranian oil reservoir

To achieve the best simulation model, fluid thermodynamic modeling and reservoir fluid characterization are basic steps, in which laboratory data should be validated and matched with a proper model. A proper fluid model can avoid expensive PVT experiments. In this paper, a case study is presented using PVT properties of live fluid samples obtained from one of the southwest Iranian oil reservoirs which resulted in a more accurate understanding of the reservoir. The model was used to investigate the effect of different hydrocarbon and non-hydrocarbon gas injection streams into the reservoir. In this paper, PR (Peng-Robinson) equation of state was selected as the best equation to attain the good agreement matching. For splitting the heavy fraction of crude oil, different critical property correlations were studied and the Twu correlation was found to be the best one. Volume shift of C12-C32 and Omega A were more sensitive for matching the experimental data with model. Another sensitive parameter is hydrocarbon interaction coefficient. The average error of CCE tests is 0.013401 and the average error of DL tests is 0.034204 which results in error equal to 0.029003 totally. As a result of this study, an excellent agreement achieved between experimental data and tuned model