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To elucidate the role of earth alkaline doping in perovskite-based dry reforming of methane (DRM) catalysts, we embarked on a comparative and exemplary study of a Ni-based Sm perovskite with and without Sr doping. While the Sr-doped material appears as a structure-pure Sm1.5Sr0.5NiO4 Ruddlesden Popper structure, the undoped material is a NiO/monoclinic Sm2O3 composite. Hydrogen pre-reduction or direct activation in the DRM mixture in all cases yields either active Ni/Sm2O3 or Ni/Sm2O3/SrCO3 materials, with albeit different short-term stability and deactivation behavior. The much smaller Ni particle size after hydrogen reduction of Sm1.5Sr0.5NiO4, and of generally all undoped materials stabilizes the short and long-term DRM activity. Carbon dioxide reactivity manifests itself in the direct formation of SrCO3 in the case of Sm1.5Sr0.5NiO4, which is dominant at high temperatures. For Sm1.5Sr0.5NiO4, the CO : H2 ratio exceeds 1 at these temperatures, which is attributed to faster direct carbon dioxide conversion to SrCO3 without catalytic DRM reactivity. As no Sm2O2CO3 surface or bulk phase as a result of carbon dioxide activation was observed for any material - in contrast to La2O2CO3 - we suggest that oxy-carbonate formation plays only a minor role for DRM reactivity. Rather, we identify surface graphitic carbon as the potentially reactive intermediate. Graphitic carbon has already been shown as a crucial reaction intermediate in metal-oxide DRM catalysts and appears both for Sm1.5Sr0.5NiO4 and NiO/monoclinic Sm2O3 after reaction as crystalline structure. It is significantly more pronounced for the latter due to the higher amount of oxygen-deficient monoclinic Sm2O3 facilitating carbon dioxide activation. Despite the often reported beneficial role of earth alkaline dopants in DRM catalysis, we show that the situation is more complex. In our studies, the detrimental role of earth alkaline doping manifests itself in the exclusive formation of the sole stable carbonated species and a general destabilization of the Ni/monoclinic Sm2O3 interface by favoring Ni particle sintering.

Hierarchical zeolite catalysts with a combination of microporous and mesoporous properties have a significant effect on improving catalytic processes. We herein report the synthesis of hierarchical ZSM-5 catalysts using the hydrothermal method with various combinations of multiple templates, including TPABr, CTAB, and F127. By applying response surface methodology for design and optimization of template composition in methanol-to-propylene process, we obtained a quadratic model with statistically significant accuracy. Using this model, we could also predict the propylene selectivity of the synthesized zeolites by altering the template composition. Further characterization of the synthesized zeolites by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, NH3-TPD, and N2 physisorption analysis confirmed that the template composition is a critical parameter with huge effect on crystal structure and morphology, strong and weak acid sites, surface area, and volume of mesopores. Different compositions affected orientation of zeolite crystals and diffraction peaks in the XRD patterns. The simultaneous presence of both mesoporogens in the catalyst structure was necessary to achieve the highest efficiency. Comparing experimental data and modeling results, we found that the combination of templates near the central point had a better performance in MTP process. The highest selectivity to propylene (58.8) was obtained from the optimal catalyst and the highest stability was acquired from the catalyst with central point composition. Improved catalytic performance can be attributed to the hierarchical structure, high mesopore volume, and appropriate acidity.

Synthetic polymers are mostly made of petroleum, remain in the soil for a long time because they are not biocompatible. Production of biodegradable polymers, like poly-beta-hydroxy butyrate (PHB), is a new way to increase degradation rate of polymers in the environment. In this study, five strains of Streptomyces native bacteria were isolated and coded as G2 (Streptomyces ambofaciens Azar411), 6, G8, E17, and N5 and were used for production of PHB. Granules of PHB were observed within all five strains after treatment by prepared nutrient agar culture medium. Nutrient Broth medium was centrifuged at the end of PHB production stage. The amount of produced PHB was analyzed by Gas Chromatography-Mass Spectrometry and calculated by spectrophotometry and weighing method. The effects of six important parameters including carbon and nitrogen sources, pH and temperature of culture medium, shaker speed, and incubation time, on the amount of PHB production were assessed and their optimum values were obtained. Maximum PHB production was obtained in G2 bacteria as 77.51%, of cell dry weight, after 2days at culture medium with same values of parameters as extraction phase except that 1g peptone protease as nitrogen source, and 4 mL aqueous glucose solution as carbon source were used.

Wastewater effluents usually involve dyes that are dangerous for aquatic life and other environments. Many of these dyes are toxic, carcinogenic, and can cause skin and eye irritation. In this study, firstly aminized cellulose acetate was prepared from cellulose acetate and applied for the adsorption of Acid Brown 354 from aqueous solutions. The effects of different parameters including adsorbent dosage, pH, temperature, and initial concentration of dye on adsorption capacity were examined. Results showed that removal efficiency of dye declined by increasing values of all parameters. Finally, maximum removal of dye was achieved in the presence of 0.1 g adsorbent, pH of 2, and 10 mg/L of initial dye concentration at a temperature of 25 °C. Also, different adsorption isotherms were investigated including Langmuir, Temkin, and Freundlich models and results demonstrated that the adsorption isotherm of dye followed the Freundlich model with a correlation coefficient of 0.988 revealing that the bond between the dye and the adsorbent is strong. Finally, kinetic study indicated that the adsorption of dye is exactly governed by pseudo-second-order kinetics explaining that the adsorption process is chemical and the adsorbent can not be reused. HIGHLIGHTS Synthesis of aminized cellulose acetate nanofibers (ACA) with hydrophilic and alkaline properties.; Removal of Acid Brown 354 dye by ACA nanofibers and studying the effect of different parameters.; Investigation of equilibrium isotherms and equilibrium thermodynamic parameters and introducing the best isotherm model.; Study of kinetics and mechanism of the dye removal process and proposing the best kinetic model.

In this study, a reactive distillation column for production of isopropanol was investigated. Firstly, a dynamic model was developed for the process. The model of the process was then programmed, and the process simulated using a base case obtained from the literature. Results showed that distillate contained more than 58 mol% propylene-free isopropanol. In the next step, optimization of some operating variables was performed to maximize concentration of isopropanol in distillate with condenser temperature as constraint, which was considered to be above the freezing point of water. Several simulations were performed by changing operating parameters, and finally optimum isopropanol content in distillate was obtained above 58 mol%. Results of using classic controllers showed that PID controller had the best performance for both condenser temperature set-point tracking and disturbance rejection. This work is licensed under a Creative Commons Attribution 4.0 International License.

The influence of A- and/or B-site doping of Ruddlesden-Popper perovskite materials on the crystal structure, stability, and dry reforming of methane (DRM) reactivity of specific A2BO4 phases (A = La, Ba; B = Cu, Ni) has been evaluated by a combination of catalytic experiments, in situ X-ray diffraction, X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), and aberration-corrected electron microscopy. At room temperature, B-site doping of La2NiO4 with Cu stabilizes the orthorhombic structure (Fmmm) of the perovskite, while A-site doping with Ba yields a tetragonal space group (I4/mmm). We observed the orthorhombic-to-tetragonal transformation above 170 °C for La2Ni0.9Cu0.1O4 and La2Ni0.8Cu0.2O4, slightly higher than for undoped La2NiO4. Loss of oxygen in interstitial sites of the tetragonal structure causes further structure transformations for all samples before decomposition in the temperature range of 400 °C-600 °C. Controlled in situ decomposition of the parent or A/B-site doped perovskite structures in a DRM mixture (CH4:CO2 = 1:1) in all cases yields an active phase consisting of exsolved nanocrystalline metallic Ni particles in contact with hexagonal La2O3 and a mixture of (oxy)carbonate phases (hexagonal and monoclinic La2O2CO3, BaCO3). Differences in the catalytic activity evolve because of (i) the in situ formation of Ni-Cu alloy phases (in a composition of >7:1 = Ni:Cu) for La2Ni0.9Cu0.1O4, La2Ni0.8Cu0.2O4, and La1.8Ba0.2Ni0.9Cu0.1O4, (ii) the resulting Ni particle size and amount of exsolved Ni, and (iii) the inherently different reactivity of the present (oxy)carbonate species. Based on the onset temperature of catalytic DRM activity, the latter decreases in the order of La2Ni0.9Cu0.1O4 ∼ La2Ni0.8Cu0.2O4 ≥ La1.8Ba0.2Ni0.9Cu0.1O4 > La2NiO4 > La1.8Ba0.2NiO4. Simple A-site doped La1.8Ba0.2NiO4 is essentially DRM inactive. The Ni particle size can be efficiently influenced by introducing Ba into the A site of the respective Ruddlesden-Popper structures, allowing us to control the Ni particle size between 10 nm and 30 nm both for simple B-site and A-site doped structures. Hence, it is possible to steer both the extent of the metal-oxide-(oxy)carbonate interface and its chemical composition and reactivity. Counteracting the limitation of the larger Ni particle size, the activity can, however, be improved by additional Cu-doping on the B-site, enhancing the carbon reactivity. Exemplified for the La2NiO4 based systems, we show how the delicate antagonistic balance of doping with Cu (rendering the La2NiO4 structure less stable and suppressing coking by efficiently removing surface carbon) and Ba (rendering the La2NiO4 structure more stable and forming unreactive surface or interfacial carbonates) can be used to tailor prospective DRM-active catalysts.

To evaluate the structural and spectroscopic steering factors of noble metal promotion in the catalytic reduction of NO by CO, a series of La(Cu0.7Mn0.3)0.98M0.02O3−δ (M = Pd, Pt, Ru, Rh) perovskite catalysts is investigated. The materials are synthesized by a sol-gel method and characterized by X-ray powder diffraction (XRD), electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). All metal-promoted perovskites exhibit a comparatively higher activity for catalytic reduction of NO by CO with respect to pure La(Cu0.7Mn0.3)O3−δ . Among all catalysts tested, the La(Cu0.7Mn0.3)0.98Pd0.02O3−δ perovskite shows the highest catalytic activity, which is tentatively related to a combined synergistic effect of improved oxygen vacancy activity and noble metals. Additionally, the redox chemistry of the catalysts in different reducing (H2) and oxidizing (NO, O2) atmospheres is tested. An enhanced kinetic reducibility, especially with Pd, was observed. All the H2-reduced catalysts are capable of reducing NO. At low and intermediate temperatures, the formation of N2O is observed, but at higher temperatures NO is exclusively converted to N2. The introduction of noble metals leads to new adsorption sites for NO. As XPS suggests a tendency for depletion of noble metals in the surface-near regions, while the catalytic activity in NO reduction at the same time appears much improved, directed noble metal promotion with modest amounts especially in surface-near regions during synthesis appears as an encouraging method to economize the use of the latter. This work was performed within the framework of the funding programme IMPULSE Iran Austria, financed by funds of the OeAD fonds and of the Ministry of Science, Research and Technology of the Islamic Republic of Iran. We also thank the SFB F45-N16 special research program for financial support. This work was performed within the framework of the research platform ‘‘Materials and Nanoscience” and the special PhD program ‘‘Reactivity and Catalysis”, both at the University of Innsbruck.

Designing energy conversion systems with high efficiencies and low pollutant emission is essential for sustainable development. A new cogeneration system including a high-temperature proton exchange membrane fuel cell, integrated with a solar methanol steam reformer, and a Kalina cycle is proposed to produce electricity and heat. Using energy, exergy and cost balance, the proposed system is analyzed from the viewpoints of exergy, economy, and environmental impact. A Parametric study is performed and shows that a higher fuel cell temperature is in favor of the total product unit cost and carbon dioxide mass specific emission. Also, the exergy efficiency is maximized, and the total product unit cost as well as the carbon dioxide mass specific emission are minimized at some specific values of anode recirculation ratio. Optimization results show that the average daily exergy efficiency can increase by up to 29.3% and the total product unit cost as well as the carbon dioxide mass specific emission can decrease by up to 17.72% and 16.3%, respectively compared to the corresponding values under the base conditions. It is concluded that combining a Kalina cycle with a high-temperature proton exchange membrane fuel cell along with utilizing solar energy for reforming process yields an efficient energy conversion system with low emission.

Polyethylene terephthalate (PET) is one of the most widely used plastics in manufacture of fibers, films, and drinking bottles, etc. It is one of solid wastes which pollutes urban and marine area and gets a lot of sacrifices from creatures. Thus, its removal from the environment is very important for protecting marine life. Different physical, chemical, and biological methods are studied by authors, but because of environmental and economic reasons, biological methods are preferred. These methods are slow and must combined with one or more physical or chemical methods. In this study, biodegradation of PET by Streptomyces species was assessed. Drinking bottles as PET wastes were firstly powdered and classified into four particle sizes. Then 50 mg of samples of each particle size were taken and treated with a fixed number of microorganisms in a culture medium for 18 days at 28 °C within an incubator, and degradation values of the samples were calculated on certain days. Also, a PET film was prepared from bottles and was exposed to biodegradation to show and compare differences between degradation of powdered and film samples. Results showed that final biodegradation percentages for PET particles sizes of 500, 420, 300 and 212 µm were 49.2%, 57.4%, 62.4%, and 68.8%, respectively. We showed that particle size and reaction time were the most important parameters on biodegradation. Also, by-products of biodegradation were analyzed by GC-MS to verify biodegradation process. Kinetic modeling of biodegradation showed that Michaelis-Menten activation or inhibition model can predict experimental results, more precisely.

Parastoo Delir Kheyrollahi Nezhad; Maged Behkeet; Nicolas Bonmassar; Lukas Schlicker; Albert Gili; Franz Kamutzki; Andrew Doran; Yuanxu Gao; Marc Heggen; Sabine Schwarz; Johannes Bernardi; Bernhard Klötzer; Aligholi Niaei; Ali Farzi; and Simon Penner “Mechanistic In Situ Insights into the Formation, Structural and Catalytic Aspects of the La2NiO4 Intermediate Phase in the Dry Reforming of Methane over Ni-based Perovskite Catalysts”, Applied Catalysis A, Volume 612, (2021), 117984, https://doi.org/10.1016/j.apcata.2020.117984Abstract:We focus on the stability and bulk/surface structural properties of the Ruddlesden-Popper phase La2NiO4 and their consequences for dry reforming of methane (DRM) activity. Fuelled by the appearance as a crucial intermediate during in situ decomposition of highly DRM-active LaNiO3 perovskite structures, we show that La2NiO4 can be equally in situ decomposed into a Ni/La2O3 phase offering CO2 capture and release necessary for DRM activity, albeit at much higher temperatures compared to LaNiO3. Decomposition in hydrogen also leads to an active Ni/La2O3 phase. In situ X-ray diffraction during DRM operation reveals considerable coking and encapsulation of exsolved Ni, yielding much smaller Ni crystallites compared to on LaNiO3, where coking is virtually absent. Generalizing the importance of intermediate Ruddlesden-Popper phases, the in situ decomposition of La-based perovskite structures yields several obstacles due to the high stability of both the parent perovskite and the Ruddlesden-Popper structures and the occurrence of parasitic structures.

The influence of A- and/or B-site doping of Ruddlesden–Popper perovskite materials on the crystal structure, stability, and dry reforming of methane (DRM) reactivity of specific A2BO4 phases (A = La, Ba; B = Cu, Ni) has been evaluated by a combination of catalytic experiments, in situ X-ray diffraction, X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), and aberration-corrected electron microscopy. At room temperature, B-site doping of La2NiO4 with Cu stabilizes the orthorhombic structure (Fmmm) of the perovskite, while A-site doping with Ba yields a tetragonal space group (I4/mmm). We observed the orthorhombic-to-tetragonal transformation above 170 °C for La2Ni0.9Cu0.1O4 and La2Ni0.8Cu0.2O4, slightly higher than for undoped La2NiO4. Loss of oxygen in interstitial sites of the tetragonal structure causes further structure transformations for all samples before decomposition in the temperature range of 400 °C–600 °C. Controlled in situ decomposition of the parent or A/B-site doped perovskite structures in a DRM mixture (CH4:CO2 = 1:1) in all cases yields an active phase consisting of exsolved nanocrystalline metallic Ni particles in contact with hexagonal La2O3 and a mixture of (oxy)carbonate phases (hexagonal and monoclinic La2O2CO3, BaCO3). Differences in the catalytic activity evolve because of (i) the in situ formation of Ni–Cu alloy phases (in a composition of >7:1 = Ni:Cu) for La2Ni0.9Cu0.1O4, La2Ni0.8Cu0.2O4, and La1.8Ba0.2Ni0.9Cu0.1O4, (ii) the resulting Ni particle size and amount of exsolved Ni, and (iii) the inherently different reactivity of the present (oxy)carbonate species. Based on the onset temperature of catalytic DRM activity, the latter decreases in the order of La2Ni0.9Cu0.1O4 ∼ La2Ni0.8Cu0.2O4 ≥ La1.8Ba0.2Ni0.9Cu0.1O4 > La2NiO4 > La1.8Ba0.2NiO4. Simple A-site doped La1.8Ba0.2NiO4 is essentially DRM inactive. The Ni particle size can be efficiently influenced by introducing Ba into the A site of the respective Ruddlesden–Popper structures, allowing us to control the Ni particle size between 10 nm and 30 nm both for simple B-site and A-site doped structures. Hence, it is possible to steer both the extent of the metal-oxide-(oxy)carbonate interface and its chemical composition and reactivity. Counteracting the limitation of the larger Ni particle size, the activity can, however, be improved by additional Cu-doping on the B-site, enhancing the carbon reactivity. Exemplified for the La2NiO4 based systems, we show how the delicate antagonistic balance of doping with Cu (rendering the La2NiO4 structure less stable and suppressing coking by efficiently removing surface carbon) and Ba (rendering the La2NiO4 structure more stable and forming unreactive surface or interfacial carbonates) can be used to tailor prospective DRM-active catalysts.

In this paper, LaFeO3 perovskite catalysts were synthesized by sol–gel combustion, pechini and co-precipitation methods and studied as catalysts for the catalytic reduction of NO with CO. The perovskite catalysts were characterized by XRD, BET, H2-TPR, SEM and DLS. The pechini synthesized perovskite showed the highest activity among the other catalysts in the catalytic reduction of NO with CO. The excellent catalytic activity of LaFeO3-pechini might be associated with its higher specific surface area, better low-temperature reducibility, more structural defects and more surface oxygen species. For pechini method as the best synthesize method, the effects of synthesis variables on activity of catalysts were studied by response surface methodology. RSM model could predict the experimental data for NO conversions at a good accuracy (R2 = 0.981). The model predicted that the relative importance of variables is as follows: calcination temperature > citrate/nitrate ratio > EG/citrate ratio. Under the optimum condition (citrate/nitrate ratio: 0.61, EG/citrate: 2.92 and calcination temperature: 600 °C), the predicted value of NO conversion (91.1%) was found to be in a good agreement with the corresponding actual value (89%).

Pyrolysis of lower alkanes is among the main industrial methods for the production of light olefins. In this paper, an artificial neural network (ANN) model was developed in order to predict produc...

In this paper, activity of sol–gel synthesized LaB0.5B′0.5O3 (B = Fe, Mn, B′= Fe, Mn, Co, Cu) perovskite catalysts was evaluated in catalytic reduction of NO by CO. Perovskite catalysts were characterized by XRD, BET, H2-TPR and SEM analysis. LaMn0.5Cu0.5O3 has the highest activity among LaB0.5B′0.5O3 perovskite catalysts (88% CO conversion and 93% NO conversion at 350 °C). The superior activity of LaMn0.5Cu0.5O3 over other perovskite catalysts was associated to synergistic effect between Mn and Cu, higher reducibility at low temperature and more structural defects. The Langmuir–Hinshelwood mechanisms were used for Kinetic modeling of reduction of NO by CO. According to kinetic calculations, the most probable mechanism for this process was found to be the one based on dissociation of adsorbed NO (herein referred to as mechanism 1), according to which the experimental data was predicted at correlation coefficient of R2 > 0.99.

This work details the fabrication and performance of a sensor for ammonia gas, based on conducting polymer. The fabrication procedure consists following steps; polyaniline synthesis via oxidative polymerization technique, then a sensitive polyaniline film was deposited on a printed circuit board and finally, polyaniline microdevice were assembled on an interdigitated electrode arrays to fabricate the sensor for amomonia gas detection. Response time of this chemiresistive devices and humidity impact were examined for NH3 sensitivity and compared with commercial gas sensors (Taguchi Model 826). Data export from sensor to the computer was carried out via data logger model ADC-24 and analyzed using SPSS software. The sensor was found to have a rapid (t = 40 s) and stable linear response to ammonia gas in the concentration range of interest (50–150 ppm) under room temperature operation condition. It was reviled also reliable results to the variation of environment humidity. Power consumption, sensitivity, dimension, flexibility and fabrication cost were used as most important parameters to compare the new polymer based device with those of other similar works and the results showed that small size, low cost, flexibility, low power consumption and high sensitivity are from the benefits of this innovative device. In real-time application conditions flexible polyaniline based gas sensor with polyimide substrate in thickness 0.25 mm exhibits relatively good performance and accurate evaluation of food spoilage.

A recycling open channel reactor was utilized for removal of organic contaminant of malachite green with flow rate of 5 mL/min. TiO 2 nanoparticles and FeSO 4 powder immobilized on metal-foam (MF) were applied as a photo-Fenton catalyst. Glucose oxidase (GOx) was also coupled with catalyst for in-situ generation of hydrogen peroxide. Furthermore, UV (6 W) lamp was used as a light source to carried out photo-bio-Fenton reaction in the reactor. Several experiments were carried out to study the influence of various combination of affecting processes on decolorization of the pollutant. Removal of 84.37% of malachite green was obtained in GOx/TiO 2 /Fe 2+ /MF process under UVA-LED during 20 min.

In this study, LaMn1−xFexO3 (x = 0, 0.3, 0.5, 0.7, 1) and La0.8A0.2Fe0.7Mn0.3O3 (A = Sr, Cs, Ba, Ce) perovskite oxides were synthesized by sol–gel method and their activities were evaluated in catalytic reduction of NO by CO. Perovskite catalysts were characterized by XRD, BET, H2-TPR, XPS and SEM. Synthesized perovskites present a high activity for the catalytic reduction of NO by CO, LaMn0.3Fe0.7O3 Show the highest activity among LaMn1−xFexO3 perovskite catalysts (71 % CO conversion and 82 % NO conversion at 350 °C). The effect of partial substitution of Sr, Cs, Ba and Ce in A-site was also examined on the structure and catalytic activity of LaMn0.3Fe0.7O3 perovskite catalyst. La0.8Sr0.2Fe0.7Mn0.3O3 and La0.8Ce0.2Fe0.7Mn0.3O3 present the highest activities among La0.8A0.2Fe0.7Mn0.3O3 perovskites. The introduction of Sr2+ and Ce4+ in A-site of perovskite change the reducibility of B-site cations and Fe4+/Fe3+ and Mn4+/Mn3+ ratios, and increase Oads/Olatt ratio and these factors create structural defects in perovskite which lead to higher catalytic activities. Financial supports from the Iran National Science Foundation (INSF) are gratefully acknowledged.

Catalytic oxidation of toluene over perovskite-type oxides of the general formula LaMn1-xBxO3 (B=Cu, Fe and x=0, 0.3, 0.7) and La0.8A0.2Mn0.3B0.7O3 (A=Sr, Ce and B=Cu, Fe) was investigated, where the catalysts were synthesized by sol-gel auto combustion method. The catalysts were characterized by XRD, BET, H2-TPR, XPS, and SEM. Obtained XRD patterns confirmed the perovskites to be single-phase perovskite-type oxides. Specific surface areas of perovskites were obtained between 25-40m2/g. The perovskite catalysts showed high activity for the toluene oxidation. Based on the results, Fe-containing perovskite catalysts exhibited higher activity than Cu-containing perovskite catalysts. The substitution of Sr and Ce in A-site of the perovskite catalysts enhanced their activity for toluene oxidation. Among different synthesized catalysts in this research, La0.8Ce0.2Mn0.3Fe0.7O3 has the highest activity. Nearly complete elimination of toluene was achieved at 200 °C with this catalyst. Based on Langmuir–Hinshelwood mechanisms, kinetic studies were conducted on toluene oxidation, indicating LH-OS-ND (adsorption of reagents on same types of sites and non-dissociative adsorption of oxygen) as the most probable mechanism which could predict the experimental data with correlation coefficient of R2=0.9952.

In this paper, catalytic oxidation of CO over perovskite-type oxides LaMn1−xBxO3 (B = Cu, Fe and x = 0, 0.1, 0.3, 0.5) were investigated. The perovskite catalysts were synthesized by sol–gel method and characterized by XRD, BET, H2-TPR, XPS and SEM. XRD patterns showed that the samples are single-phase perovskite. By introduction of Cu and Fe in the structure, Specific surface area of LaMnO3 was decreased, but the reducibility and oxygen vacancy were increased. The synthesized perovskite catalysts show high activity for the CO oxidation. Substitution of Mn by Cu and Fe enhanced the catalytic activity. The cu-containing perovskites showed a higher activity in CO oxidation compared with Fe-containing perovskites. The LaMn0.7Cu0.3O3 perovskite showed the highest activity among the synthesized perovskites (T50 and T90 % of 110 and 142 °C). The excellent activity of LaMn0.7B0.3O3 was associated to reducibility at low temperature, more oxygen vacancies and synergistic effect between Cu and Mn. The apparent activation energies were obtained and LaMn0.7Cu0.3O3 as the most active catalyst, has the least activation energy compared with other synthesized catalysts.

In this study, sponge-like and M-substituted (M: Mn, W and Ce) sponge-like MFI zeolites were successfully synthesized by seed-assisted hydrothermal technique. The special bi-functional organic surfactant of C22-6-6Br2 with multi-ammonium groups was separately synthesized and used as structure directing agent (SDA). The prepared catalyst samples were examined in methanol to propylene (MTP) process and demonstrated superior catalytic performance compared to conventional H-ZSM-5 and M-substituted MFI zeolite nanosheets. The W-substituted sponge-like MFI zeolite effectively showed the most enhanced catalytic activity with complete methanol conversion, propylene selectivity of 56.3%, total selectivity of light olefins of 88.3% and catalytic life-span of 161 h. Moreover, to increase propylene selectivity, bi-metallic and tri-metallic sponge-like MFI zeolites were successfully synthesized via seed-assisted hydrothermal method by utilizing central composite design (CCD) strategy. For optimizing promoter compositions in lattice of bi-metallic and tri-metallic sponge-like MFI zeolites, the incorporated response surface methodology (RSM)-CCD technique and also an intelligent approach namely neuro-genetic method were applied. It was deduced that optimal bi-metallic sponge-like MFI zeolite suggested by neuro-genetic approach approved the highest propylene selectivity (66.7%). Synthesized catalysts were appropriately characterized by XRD, FE-SEM, EDX, TEM, FT-IR, N2 adsorption/desorption and NH3-TPD analyses which comparatively approved high specific surface area and dominant meso-porosity.

Object-oriented modeling methodology is used for encapsulating different methods and attributes of data reconciliation (DR) in classes. Classes which are defined for DR, cover steady-state, dynamic, linear and nonlinear DR problems. Two main classes are Constraints and DR and defined for manipulating constraints and general DR problem. The remaining classes are derived from these two classes. A class namely DDRMethod is developed for encapsulating all common attributes and methods needed for any DDR method. Developed DR software and the method of performing dynamic DR are discussed in this paper. Two illustrative examples of Extended Kalman Filtering and artificial neural networks are used for DDR and two classes of DDRByKalman and NetDDRMethod developed by inheritance from DDRMethod class for these two methods. Performance of the proposed method is investigated by DDR of temperature measurements of a distillation column.

The prospect of LNG could become a major global energy source is one of the most debated issues. The Liquefied Natural Gas (LNG) supply chain and the properties that make this fuel environmental friendly is in high demand for energy supply. In this paper, at first, the process of converting the natural gas to LNG was simulated; then, the process is optimized to archive minimum energy consumption per ton of LNG produced. Using a three stage exchanger is the best way for minimization of energy consumption in LNG production unit. Outlet pressure from the compressor and also type of refrigerant in cooling system is very effective on rate of energy conservations. The best mass fraction for refrigerants in liquefaction cycle are 0.88 for methane and 0.12 for ethane. For subcooling cycle that fraction is defined as 0.6 for methane and 0.4 for nitrogen. The optimized pressure in outlet of compressors in liquefaction cycle is 650 kPa; also, for the subcooling cycle is 1800 kPa. The amount of consumed energy was 14.91 kW per ton of produced LNG.