Partial oxidation of butane to syngas using nano-structure Ni/zeolite catalysts

Amir Mosayebi,Reza Abedini 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

In this study, performance of nano-structure Ni over different zeolite supports in partial oxidation of butane was investigated. First, partial oxidation process was performed without catalyst to evaluation of optimal conditions. For in situ reduction of catalysts, H2 produced from homogenous reaction was used. Catalytic partial oxidation was carried out using nano-structure nickel catalysts supported by ZSM5, mordenite and Y. Each catalyst was synthesized through reverse microemulsion method. The catalysts were characterized by BET surface area, XRD, SEM and TGA. Highest butane conversion ( 89%) observed in the presence of Ni/Y catalyst. Also Ni/Y shows the highest overall selectivity to CO and H2 as the most desired partial oxidation products. Results from TGA showed that the minimum quantity of formatted coke was related to Ni/Y, which confirmed the stability of butane conversion versus time for this catalyst.

A preferential CO2 separation using binary phases membrane consisting of Pebax®1657 and [Omim][PF6] ionic liquid

Kamran Shahrezaei,Reza Abedini,Mostafa Lashkarbolooki,Ahmad Rahimpour 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.12

Pebax ® 1657 and [Omim][PF6] ionic liquid (IL) were used to fabricate a blend membrane and applied for CO2 separation. The changes upon adding ionic liquid into the polymer matrix as well as the membrane characteristics were studied through SEM, FTIR, DSC and TGA analysis. The obtained gas permeation results indicated that the CO2 permeability in all membranes was much higher than the other studied gases. CO2 permeability of Pebax containing 8wt% IL increased from 82.3 Barrer up to 125.6 Barrer at a pressure of 2bar, which showed a 53% increment compared to the neat Pebax membrane. Furthermore, as the [Omim][PF6] loading within the polymer matrix was increased, the CO2/CH4 and CO2/N2 selectivities improved. In addition, the permeability and selectivity of gases was enhanced as the feed pressure increased. Upon increasing feed pressure to 10bar, the CO2 permeability of Pebax containing 8wt% IL reached 185.3 Barrer, which was approximately 48% higher than the permeability at a pressure of 2bar. Moreover, the selectivity of CO2/CH4 and CO2/N2 for the Pebax/8wt% IL membrane at pressure of 2bar was 15.3 and 46.5, respectively, which improved to 19.7 and 59.8 as the pressure increased to 10bar.

The influence of nanoparticles on gas transport properties of mixed matrix membranes: An experimental investigation and modeling

Mona Jamshidi,Vahid Pirouzfar,Reza Abedini,Mona Zamani Pedram 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.3

Mixed matrix membranes were made of polysulfone and Matrimid® polymers, and SiO2 and TiO2 nanoparticles in order to improve the efficiency of polymeric membrane in gas separation and review the efficiency of membrane separation process, laboratory. The modeling results of selectivity and permeability of gases O2, N2, CO2 and CH4 were discussed for different membranes. Another objective of this study was to submit a report on the importance of the statistical analysis and modeling in design and optimizing mixed matrix membranes to separate gas. The D-optimal method was applied to model and optimize the selectivity and permeability due to the main parameters. The obtained results indicated that the permeability of all gases demonstrated an ascending trend when the nanoparticles were increased. Under optimized conditions, the permeability of the gases O2, N2, CO2, CH4 in the membrane of PSF (12)/SiO2 (13.82) was 2.49, 1.113, 12.82 and 0.885 Barrer, respectively. A statistical method was practiced in the current research to design, optimize and separate gas membranes through effective efficiency for different applications.

Exploiting the effects of zirconium-based metal organic framework decorated carbon nanofibers to improve CO2/CH4 separation performance of thin film nanocomposite membranes

Mohammad Mozafari,Ahmad Rahimpour,Reza Abedini 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.85 No.-

The challenges of interfacial defects andfiller uniform dispersion are still preventing the design of mixedmatrix membranes (MMMs) for the purpose of high gas selectivity. In this study, in-situ growth of UiO-66-NH2 on the external surface of carbon nanofibers (CNFs) resulted in the synthesis of a novel CNF/metalorganic framework (MOF) composite which embedded into the pebax selective layer of thin-filmnanocomposite (TFN) membrane. The uniform structure and defect-free interface was observed by FESEManalysis that reveals superior compatibility between polymer chains and CNF/UiO composite. Gassorption analysis was investigated for pristine thinfilm composite (TFC) and TFN membranes and thenthe obtained experimental data were analyzed by Henry–Langmuir and Henry–Freundlich model. Theresults illustrated that gas permeation for the membranes followed the Henry–Freundlich model. Accordingly, synthesized TFN membranes demonstrated a higher CO2 permeability as well as properCO2/CH4 selectivity compared to pristine TFC membrane. For instance, the pure and mixed gaspermeation results of TFN membrane including 3 wt% of CNF/UiO composite represented a high CO2permeability of around 328 (pure gas permeability) and 230 (mixed gas permeability) Barrer andCO2/CH4 selectivity of around 27 (ideal selectivity) and 21 (real selectivity) at feed pressure of 6 bar. Consequently, the TFN membranes exhibit exceptional separation performance in terms of overcomingthe Robeson upper bound. The approach of decoration of MOFs on the surface of CNFs can be effectivetechnique to enhance TFN membranes performance.

Effect of Cu-MOFs incorporation on gas separation of Pebax thin film nanocomposite (TFN) membrane

Mahdi Fakoori,Amin Azdarpour,Reza Abedini,Bizhan Honarvar 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.1

MOF-based membranes, which have appropriate MOF dispersion and suitable interaction, have shown high CO2 permeability and significant CO2/CH4 and CO2/N2 selectivity. In this study, a layer of Pebax was coated on polysulfone (PSF), which this layer incorporated by various content of Cu-MOFs to improve the performance (permeability and CO2/CH4 and CO2/N2 selectivity) of all membranes. Characterization techniques such as SEM, TGA, BET, and gas adsorption verified that Cu-BTC was successfully dispersed into the Pebax matrix. Pure CO2 and CH4 gases permeation experiments were performed to investigate the impact of Cu-MOFs on the gas permeability of prepared MOF-based membranes. The “Pebax” embedded by 15 wt% CuBTC and 15 wt% of NH2-CuBTC over PSF support exhibited higher gas separation performance compared to the pristine one. They demonstrated a CO2 permeability of 228.6 and 258.3 Barrer, respectively, while the blank membrane had a CO2 permeability of 110.6 Barrer. Embedding the NH2-Cu-BTC intensified the interaction between incorporated MOF particles and the polymer phase that led to increase the CO2/CH4 and CO2/N2 selectivity. In addition, the performance of prepared membranes was evaluated at various feed pressures with the range of 2-10 bar. The CO2/CH4 and CO2/N2 separation was enhanced as the feed pressure surged.

A Highly Selective and Sensitive Calcium(II)-Selective PVC Membrane Based on Dimethyl 1-(4-Nitrobenzoyl)-8-oxo-2,8-dihydro-1H-pyrazolo[5,1-a]isoindole-2,3-dicarboxylate as a Novel Ionophore

Hassan Ali Zamani*,Javad Abedini-Torghabeh,Mohammad Reza Ganjali 대한화학회 2006 Bulletin of the Korean Chemical Society Vol.27 No.6

A Highly Selective and Sensitive Calcium(II)-Selective PVC Membrane Based on Dimethyl 1-(4-Nitrobenzoyl)-8-oxo-2,8-dihydro-1H-pyrazolo[5,1-a]isoindole-2,3-dicarboxylate as a Novel Ionophore

Zamani, Hassan Ali,Abedini-Torghabeh, Javad,Ganjali, Mohammad Reza Korean Chemical Society 2006 Bulletin of the Korean Chemical Society Vol.27 No.6

Dimethyl 1-(4-nitrobenzoyl)-8-oxo-2,8-dihydro-1H-pyrazolo[5,1-a]isoindole-2,3-dicarboxylate has been used as an ionophore and o-nitrophenyloctyl ether as a plasticizer in order to develop a poly(vinyl chloride)-based membrane electrode for calcium ion detection. The sensors exhibit significantly enhanced response towards calcium(II) ions over the concentration range $8.0{\times}10^{-7}\;1.0{\times}10^{-1}$ M at pH 3.0-11 with a lower detection limit of $5.0 {\times}10^{-7}$ M. The sensors display Nernstian slope of 29.5 ${\pm}$ 0.5 mV per decade for Ca(II) ions. Effects of plasticizers, lipophilic salts and various foreign common ions are tested. It has a fast response time within 10 s over the entire concentration range and can be used for at least 2 months without any divergence in potentials. The proposed electrode revealed good selectivity and response for $Ca^{2+}$ over a wide variety of other metal ions. The selectivity of the sensor is comparable with those reported for other such electrodes. The proposed sensor was successfully applied as an indicator electrode for the potentiometric titration of a Ca(II) solution, with EDTA.

CO2/CH4 separation with poly(4-methyl-1-pentyne) (TPX) based mixed matrix membrane filled with Al2O3 nanoparticles

Amir Hossein Saeedi Dehaghani,Mohammad Hadi Nematollahi,Reza Abedini 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.2

The effect of alumina (Al2O3) nano-particles on gas separation properties of poly(4-methyl-1-pentyne) known as TPX was evaluated. Mixed matrix membranes (MMMs) were prepared with various weight percent (5, 10, 15, 20 and 30) of alumina nano-particles through solution casting along with solvent evaporation method. TPX and consequent MMMs were characterized using FT-IR, SEM and TGA methods. The MMMs permselectivities were determined through pure CO2 and CH4 permeation measurement and CO2/CH4 selectivity calculation. SEM images demonstrated the proper dispersion of alumina nano-particles in TPX matrix. Results from gas permeation showed that the permeability of both CO2 and CH4 as well as CO2/CH4 selectivities were increased with increasing alumina content. Significant increase of CO2 permeability (from 157.43 Barrer at 8 bar and no loading of Al2O3 to 527.78 Barrer at 8 bar and 30 wt% loading of Al2O3) and conspicuous enhancement of selectivity, from 7.73 to 12.51, were obtained in TPX MMMs.

CO2 separation over light gases for nano-composite membrane comprising modified polyurethane with SiO2 nanoparticles

Mohammdad Hadi Nematollahi,Shahryar Babaei,Reza Abedini 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.5

Owing to the potential of polymeric and nanocomposite membranes for industrial application in CO2 capturing and gas separation processes, permeation properties of CO2, N2 and O2 through the polymer matrix have been an object of extensive research. We measured the permeation rates of gases (pure and mixed gas) within a novel nanocomposite membrane composed of poly tetramethyleneglycol (PTMG), hexamethylene diisocyanate (HDI), and diamine chain extender, 4,4- methylenebis(2-chloroaniline) (MOCA) at various silica loadings and operating conditions. The novel polyurethane was prepared by a two-step bulk polymerization technique based on the molar ratios of the used constituents 1 : 3 : 2 for PTMG: HDI :MOCA, respectively. The FTIR spectra indicated that the extent of phase separation decreased by increase in the SiO2 content. From the DSC and XRD analyses, the existence of small crystalline areas within the soft and hard segments of matrix was proved. High thermal stability of new nanocomposites was authenticated by a 90 oC increase in the decomposition temperature upon including the SiO2 particles into the polymer matrix. By providing a longer diffusion path, a reduction in the permeation of penetrants occurred after the incorporation of SiO2 content. By raising the temperature from 25 to 45 oC, the gas permeation value of CO2, O2 and N2 rose steeply: 35, 54 and 81% in neat PU and 49, 64 and 137% in PU containing 15 wt%, respectively. Conversely, the obtained results for increasing the feed gas pressure from 6 to 10 bar revealed that the penetration of non-condensable gases, O2 and N2, decreased while the permeation rate of CO2 polar gas surged dramatically. Nevertheless, a simultaneous increment in the selectivity amounts of both gas pairs was revealed. For the gaseous mixtures, the trend of changes in permeability and selectivity values were almost identical with those of pure gas: decrease in permeation, and vice versa increase in gas pair selectivity. Eventually, the separation results of the prepared membranes indicated a strong tendency to move towards Robeson’s line by incorporation of SiO2 nanoparticles into the matrix of membranes.

Investigating the Au-Cu thick layers Electrodeposition Rate with Pulsed Current by Optimization of the Operation Condition

Babaei, Hamid,Khosravi, Morteza,Sovizi, Mohamad Reza,Khorramie, Saeid Abedini The Korean Electrochemical Society 2020 Journal of electrochemical science and technology Vol.11 No.2

The impact of effective parameters on the electrodeposition rate optimization of Au-Cu alloy at high thicknesses on the silver substrate was investigated in the present study. After ensuring the formation of gold alloy deposits with the desired and standard percentage of gold with the cartage of 18K and other standard karats that should be observed in the manufacturing of the gold and jewelry artifacts, comparing the rate of gold-copper deposition by direct and pulsed current was done. The rate of deposition with pulse current was significantly higher than direct current. In this process, the duty cycle parameter was effectively optimized by the "one factor at a time" method to achieve maximum deposition rate. Particular parameters in this work were direct and pulse current densities, bath temperature, concentration of gold and cyanide ions in electrolyte, pH, agitation and wetting agent additive. Scanning electron microscopy (SEM) and surface chemical analysis system (EDS) were used to study the effect of deposition on the cross-sections of the formed layers. The results revealed that the Au-Cu alloy layer formed with concentrations of 6gr·L^-1 Au, 55gr·L^-1 Cu, 24 gr·L^-1 KCN and 1 ml·L^-1 Lauryl dimethyl amine oxide (LDAO) in the 0.6 mA·cm^-2 average current density and 30% duty cycle, had 0.841 ㎛·min^-1 Which was the highest deposition rate. The use of electrodeposition of pure and alloy gold thick layers as a production method can reduce the use of gold metal in the production of hallow gold artifacts, create sophisticated and unique models, and diversify production by maintaining standard karats, hardness, thickness and mechanical strength. This will not only make the process economical, it will also provide significant added value to the gold artifacts. By pulsating of currents and increasing the duty cycle means reducing the pulse off-time, and if the pulse off-time becomes too short, the electric double layer would not have sufficient growth time, and its thickness decreases. These results show the effect of pulsed current on increasing the electrodeposition rate of Au-Cu alloy confirming the previous studies on the effect of pulsed current on increasing the deposition rate of Au-Cu alloy.