Iranian Journal of Chemical Engineering (IJChE)

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 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).

Abstract It is crucial to design and develop new polymers with desirable characteristics. Aromatic polyimides have been attracted more attention in comparison with other polymeric materials, because of their excellent properties, such as the high thermal stability, mechanical strength, and chemical resistance. In this work, two semi-aromatic polyimides (BCDA-mPDA and BCDA-Durene) were successfully synthesized from bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarbocylic dianhydride (BCDA), 1,3-phenylenediamine (mPDA), and 2,3,5,6-tetramethyl-1,4-phenylenediamine (Durene) to investigate the effect of methyl functional groups on the physicochemical and structural properties of the synthesized polyimides. The synthesized polyimides were characterized by the proton nuclear magnetic resonance (¹H-NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, inherent viscosity measurement, and solubility test. FTIR and ¹H-NMR results confirmed the chemical structure of the synthesized polyimides. XRD results showed that the presence of bulky methyl groups has led to increasing amorphous regions in the polymer structure. In addition, these new polymers were soluble in various organic solvents such as dimethylformamide (DMF), dimethylsulfoxide (DMSO), and N-methyl-2-pyrrolidone (NMP). The inherent viscosity of the synthesized polyimides was 0.65 dl/g for BCDA-Durene and 0.96 dl/g for BCDA-mPDA, which indicates the moderate molecular weight of the polymers.

Abstract A new method is developed to enhance the gas separation properties of mixed matrix membranes (MMMs) by interior modification of an inorganic nano-porous particle. Ship-in-a-bottle (SIB), as a novel synthesis strategy, is considered to encapsulate a polyaza macrocyclic Ag-ligand complex into the zeolite Y, which is resulted in a new host-guest nano-composite. It is consequently incorporated into a glassy polymer matrix to fabricate a novel MMM for CO2 separation. Accordingly, cellulose acetate (CA) with relatively low gas permeability is selected as the membrane polymeric matrix to provide an appropriate opportunity for better tracking the effect of incorporating the new synthesized nano-porous hybrids. The results showed a promising increase in both the CO2 permeability (45.71%) and CO2/N2 selectivity (40.28%) of the prepared MMM over its pristine CA membrane. It can be concluded that the proposed method makes it possible to fabricate novel MMMs with significant intensification in performance of the current MMMs.