Journal of Gas Technology
Volume:5 Issue: 1, Summer 2019

Mixed fluid cascade natural gas liquefaction process control system is designed and analyzed in this study. The specific energy consumption (SEC) of this process is 0.2647 kWh/kg LNG. After steady state simulation and sizing the process components, a control structure is designed to control the whole process. In addition, dynamic simulation is carried out and performance of the controllers is investigated. By dynamic simulation, specific energy consumption is reduced to 0.2574 kWh/kg LNG, which means the designed control structure can stably and accurately control the process. To validate the performance and stability of the control structure, changes in the flow rate and temperature of the feed gas are inflicted as a disturbance to the process.

Estimating reservoir permeability in un-cored intervals-wells are a generic problem common for all reservoir engineers. In this paper, routine core analysis and well log data of an actual existing gas reservoir, from southwest west of IRAN, were used to develop a model of matrix permeability in uncored well by using Hydraulic Flow Unit Approach (HFU). The Graphical Clustering Methods such as histogram analysis and probability plot are used to identify the number of hydraulic flow units. Also, the sum of square errors (SSE) method was used as criterion for confirming the optimal number of HFU’s. Permeability data can be obtained from well tests, cores or logs. Normally, using well log data to derive estimates of permeability is the lowest cost method. Formation permeability controls the strategies involving well completion, stimulation, and reservoir management. Results showed that six HFUs were identified from core data and each unit has its own mean Flow Zone Indicator (FZI). In addition, a correlation between FZI calculated from core data and that obtained from well log data was developed for estimating permeability in un-cored intervals-wells with R-Squared Value of 0.60. Also, Lorenz plot shows that the flow units 3 and 6 have a good porosity and high permeability.

Cryogenic air separation unit is integral part of many industrial manufacturing plants like steelmaking, glass, chemical and petrochemicals industries where high purity argon, oxygen and nitrogen are required. Argon, nitrogen and oxygen quality, its production cost and its energy consumption are important parameters in any cryogenic air separation plant design. In this paper, the importance of parameters which used in designing the cryogenic air separation plant are evaluated. Here, in this paper, ESCO, referred to Esfahan steel company in designing cryogenic air separation unit. Products purity is the main issue in every cryogenic air separation plant design. Pressure and temperature variation must be well controlled within cryogenic air separation unit. The annual steel production of ESCO is about 2.5 Mt pre year and it is planned to increase its production to 3.2 Mt by end of 2016. ESCO requires about 300×106 Nm3 /y (34300 Nm3 /h) of oxygen for its present steel production. ESCO needs an additional 84×106 Nm3 (9600 Nm3 /h) oxygen for its proposed 0.7 Mt crude steel production increase.

An experimental and computational fluid dynamic (CFD) investigation was carried out to intensify the production of gasoline in a bench-scale Fischer-Tropsch Synthesis (FTS) process. A cylindrical reactor with one preheating and one reaction zone was employed. The reactor temperature was controlled using a heat jacket around the reactor’s wall and dilution of the catalyst in the entrance of the reaction zone. An axi-symmetric CFD model was developed and the non-ideality of the gas mixture was considered using Peng-Robinson equation of state. A kinetic model based on 25 chemical species and 23 reactions was utilized. The model validated against experimental measurements and the validated model employed to investigate the effects of operating conditions on the performance of the reactor. The optimum values of operating conditions including pressure, reactor temperature, GHSV and H2 /CO ratio were determined for maximum reactor performance.

Nano composites of graphene oxide and modified nanoclay (Cloisite 15A) were produced based on 80 phr chlorobutyl and 20 phr natural rubber according to inner liner recipe. The results show modified nano fillers have remarkable change in dispersion in the matrix. Subsequently Improved cured products properties. Exfoliation of graphen oxide and Cloisite 15A was confirmed by XRD and TEM. In the case of graphite intercalation has happened. Also physical and mechanical properties of this composite was studied.

Multiphase separation in gravity separators is one of the important processes in different industries. This study presents a computational fluid dynamics (CFD) simulation of an industrial three-phase boot separator applying a coupled volume of fluid (VOF)- dispersed phase model (DPM) method for hydrodynamic analysis and troubleshooting of the separation process. Noted that despite the wide application of the boot separator in different industries, no research has been performed on this type of separator to investigate the macroscopic and microscopic behavior of the separation process. The results of numerical calculations based on three-phase flow profile, secondary phase behavior, separator performance, and size distribution of the droplets were investigated in this research. Results showed that the CFD model is well capable of estimating the separation behavior in a threephase boot separator. Troubleshooting of the studied separator was also investigated to detect the parameters that might decrease the separation performance. Based on the results, it is concluded that the separator suffers from the type of the inlet diverter, lack of an efficient mist extractor at the gas outlet and also lack of an appropriate vortex breaker at the oil outlet. The effect of increasing the inlet water flow rate on the separator performance was another parameter that was studied in this research. Results demonstrated that increasing the inlet water flow rate from 11823-47295 kg/hr caused an increase in the mass of droplets at the gas outlet from 0.09 to 1.6 kg/hr, but this increase did not lead to a significant decrease in the separation efficiency.