Modeling and Simulation
P. Sharafi; E. Salehi; H.R Sanaeepur; A. Ebadi Amooghin
Abstract
In this work, the separation of carbon monoxide (CO) from a synthesis gas (syngas) mixture was modeled. It was considered a copper-based adsorbent consisting of cuprous chloride (CuCl) on an activated carbon (AC) support (CuCl/AC) in a pressure swing adsorption (PSA) process. First, the adsorption of ...
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In this work, the separation of carbon monoxide (CO) from a synthesis gas (syngas) mixture was modeled. It was considered a copper-based adsorbent consisting of cuprous chloride (CuCl) on an activated carbon (AC) support (CuCl/AC) in a pressure swing adsorption (PSA) process. First, the adsorption of syngas components on the CuCl/AC adsorbent at 303.15 K was simulated to determine the required data. Next, the PSA process to separate CO from syngas using CuCl/AC absorbent at ambient temperature and pressure of 1000 kPa was evaluated by computational fluid dynamics simulation. The simulation results showed that with an adsorption bed of 2 m in height and 1 m in diameter, CO with appropriate purity (~ 99.5%) is separated from syngas by CuCl/AC. In addition, reducing the inlet feed pressure, or in other words, its velocity or flow can increase the efficiency of the operation (e.g, with a shorter bed height of 0.5 m, a CO purity of more than 99.8% can be achieved at 700 kPa, but with a significant increase in operating cost).
Modeling and Simulation
H. Salimi; Sh. shahhosseini
Volume 15, Issue 1 , February 2018, , Pages 1-17
Abstract
Abstract Gas to liquid (GTL) process involves heterogeneous catalytic chemical reactions that convert synthesis gas to hydrocarbons and water vapor. A three phase reactor, called Low temperature Fischer-Tropsch (LTFT) is commonly applied for GTL process. In this reactor the gaseous phase includes the ...
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Abstract Gas to liquid (GTL) process involves heterogeneous catalytic chemical reactions that convert synthesis gas to hydrocarbons and water vapor. A three phase reactor, called Low temperature Fischer-Tropsch (LTFT) is commonly applied for GTL process. In this reactor the gaseous phase includes the synthesis gas, light hydrocarbons and water vapor, the liquid phase is a mixture of the heavy hydrocarbons, and the solid phase is composed of the catalyst and the waxy products. The presence of the liquid phase in LTFT reactor causes mass transfer restriction, affecting the reaction conversion. In this work a numerical simulation of the LTFT fixed bed reactor in trickle flow regime has been accomplished to understand the impact of the liquid phase on the reactor performance. For this purpose, we have developed an axisymmetric two-dimensional multiphase heterogeneous model, where contain carbon monoxide and hydrogen, are transferred into the liquid phase. The reactor consisted of a shell and a tube that was filled with the spherical cobalt catalyst. The reaction conditions were as follows: the wall temperature was 473 K, pressure was 20 bars and a gas hour space velocity (GHSV) was 111 Nml.g_cat^(-1).h^(-1). The numerical simulation results proved the negative impact of the liquid phase on the reaction conversion. The model predictions were evaluated against the reported experimental data and also compared with the result of a numerical pseudo-homogeneous model. It was found that applying the heterogeneous model instead of the pseudo-homogeneous model clearly decreases the deviation of the numerical results.