Hydrogenation

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1 - The Effect of Hydrogenation on Physical and Chemical Characteristics of Soyabean Oil
P. Parsania M. Ghavami A. Heydari-Nasab M. Gharachorloo

Hydrogenation of oils might be considered as the largest reaction in the edible oil industry. The reaction consists of the addition of hydrogen at the double bounds of fatty acids. Although for some reasons this might be considered a desirable reaction but for some othe أکثر

Hydrogenation of oils might be considered as the largest reaction in the edible oil industry. The reaction consists of the addition of hydrogen at the double bounds of fatty acids. Although for some reasons this might be considered a desirable reaction but for some others it might create problems in the food and nutrition chain circle due to the formation of saturated and trans fatty acids. Soyabean oil was selected and hydrogenated and physical and chemical properties consisting of acid value, percent free fatty acid, peroxide value, color, Iodine value, induction period, saponification value, percent non saponifiable matter and fatty acid composition were determined and evaluated before and after hydrogenation process. Hydrogenation process has caused reductions in color, Iodine value, unsaturation with increased formation of some trans fatty acids. تفاصيل المقالة

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2 - Promoting effects of calcium on the performance of Cu-MgO catalyst in hydrogenation of furfuraldehyde
Vahid Farzaneh Samira Shirvani Samahe Sadjadi Mohammad Ghashghaee

In the present study, the effects of calcium doping on the performance of the co-precipitated Cu-MgO catalysts prepared with different calcium loadings in the selective hydrogenation of furfuraldehyde were investigated. The results proved that the addition of this promo أکثر

In the present study, the effects of calcium doping on the performance of the co-precipitated Cu-MgO catalysts prepared with different calcium loadings in the selective hydrogenation of furfuraldehyde were investigated. The results proved that the addition of this promoter had a remarkable impact on the catalytic performance. The conversion of furfuraldehyde enhanced up to 83% and the furfuryl alcohol selectivity remained above 96% over the run length on the promoted Cu-Ca-MgO catalyst. However, the conversion level decreased to 60% after 240 min of operation period which was still superior with respect to the negligible conversion with the non-promoted Cu-MgO catalyst. تفاصيل المقالة

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3 - Effect of textural properties of Ni (Nano)-supported catalysts on the selective benzene hydrogenation in the vapor phase
Nastaran Parsafard Mohammad Hasan Peyrovi Mahdi Abdali Hajiabadi

Ni catalysts supported on Nano porous catalysts were prepared by the impregnation method and tested for vapor phase hydrogenation of benzene. The textural and physico-chemical properties of Ni catalysts were characterized by the X-ray diffraction, Fourier-transform infr أکثر

Ni catalysts supported on Nano porous catalysts were prepared by the impregnation method and tested for vapor phase hydrogenation of benzene. The textural and physico-chemical properties of Ni catalysts were characterized by the X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscope and N2 adsorption-desorption analysis. The catalytic evaluation revealed that the best selectivity to benzene (> 84%) and high stability with the low coke deposition (< 1.1%) are related to Ni/Folded Sheets Mesoporous Materials-No. 16. The kinetics of benzene hydrogenation has been examined as a function of benzene and hydrogen pressures at various temperatures. Two kinetic models based on power law and Langmuir-Hinshelwood mechanisms were developed for the reaction and compared with the obtained experimental data. The apparent kinetic parameters were estimated using the multiple regression analysis. Both these models present the good results. تفاصيل المقالة

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4 - Operating condition effect on achieving higher propene yield in propane oxidative dehydrogenation process
Yousef Zeinaly Seyed Mehdi Alavi

Supported vanadia catalyst was successfully synthesized using wet impregnation of gamma-Alumina to study Propane Oxidative Dehydrogenation (POD). The prepared catalysts were characterized with XRD, BET, and TPR tests. In a broad temperature range (340 to 630°C), eff أکثر

Supported vanadia catalyst was successfully synthesized using wet impregnation of gamma-Alumina to study Propane Oxidative Dehydrogenation (POD). The prepared catalysts were characterized with XRD, BET, and TPR tests. In a broad temperature range (340 to 630°C), effects of vanadia loading (2.7, 5.4, and 9 wt%) and propane to oxygen ratio (3/1 to 1/3) were investigated on propane conversion as well as propene yield at atmospheric pressure. Results indicate that by increasing the vanadia content the activity of catalyst increases while selectivity to propene decreases monotonically. As the temperature increases from 340°C to 630°C, yield to propene shows ascending behavior in case of all catalyst samples. Yield to propene shows a climax with changing propane to oxygen ratio from 3/1 to 1/3. The yield increases with increase in oxygen partial pressure of feed until equimolar ratio of propane and oxygen, then it declines with further increase of oxygen partial pressure. Higher propene yields were observed at higher temperatures and equimolar feed ratio of propane and oxygen (C3/O2=1/1). A maximum propene yield of 17% was experienced on catalyst with 2.7 wt% vanadia at temperatures at 550°C. تفاصيل المقالة

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5 - Co Catalysts Supported on Activated Clay for Selective Hydrogenation of Acetylene to Ethylene
Aizat Aitugan Sandugash Tanirbergenova Yerbol Tileuberdi Onuralp Yucel Dildara Tugelbayeva Zulkhair Mansurov

This work describes the simplest method of synthesis of a carbonized cobalt catalyst based on an available natural mineral, clay activated with nitric acid, which showed high selectivity and activity in hydrogenation of acetylene to ethylene. Metal catalysts with cobalt أکثر

This work describes the simplest method of synthesis of a carbonized cobalt catalyst based on an available natural mineral, clay activated with nitric acid, which showed high selectivity and activity in hydrogenation of acetylene to ethylene. Metal catalysts with cobalt contents of 5 %-7 % in a bentonite clay carrier from the Tonkeris deposit were synthesised. The physicochemical properties were investigated by means of X-ray powder diffraction (XRD), scanning electron microscope (SEM), IR-Fourier spectrometer. Products were analysed using a Chrom-3700 gas chromatograph and gas chromatography–mass spectrometry (Agilent 7890A/5975C). The catalytic activities of the synthesised cobalt catalysts were investigated using an installation developed for the hydrogenation of acetylene to ethylene in a gaseous medium. Carbon nanofibers with diameters ranging from 57 to 400 nm were visible on cobalt catalyst samples. Selectivity of the modified cobalt-containing catalysts for hydrogenation ranged from 89.62 % to 97 %. Ethylene conversions of 93.58 % were achieved on 7 % Co/SiAl carbonized catalyst, at an optimum temperature of 140 °C. Side reactions are activated when the temperature rises above 180 °C, so the yield of ethylene is reduced. تفاصيل المقالة

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6 - CO Hydrogenation over functionalized AlMCM-41 materials and ZSM-11/5 zeolites as catalysts
B. Smili M. Sakmeche A. Belhakem L. Belgacem C. Tabti

10.30495/ijc.2022.1956221.1928

We studied the reaction in which carbon monoxide is converted to hydrocarbons, and investigated the behaviors and the combination system of catalysts exchanged with platinum and ammonium ions. Experiments were conducted at 1.2 MPa, 523K, and CO/H2=1 ratio. The structure أکثر

We studied the reaction in which carbon monoxide is converted to hydrocarbons, and investigated the behaviors and the combination system of catalysts exchanged with platinum and ammonium ions. Experiments were conducted at 1.2 MPa, 523K, and CO/H2=1 ratio. The structure and the texture of the catalysts, assessed by XRD, BET/BJH, and SEM, exhibited a microporosity for ZSM-5/11 and a micro/mesoporosity for AlMCM-41, which implies a direct effect on the catalytic properties of these materials. The conversions obtained were 60%, 55%, and 50% for Ptn+/H+-catalysts, Ptn+-catalysts, and H+-catalysts respectively. Such conversions could be attributed to the good acidity resulting from the simultaneous presence of Ptn+/H+ at different oxidation states of platinum, which was revealed by XANES PtLIII analysis, and their uniform dispersion within the inner surface and its grain size average conducted by the titration of adsorbed H2-O2. FTIR analysis showed a better distribution of acid sites for bi-exchanged catalysts over mono-exchanged ones, which resulted in a good catalytic activity. These results suggest a strong correlation between the high selectivity of light hydrocarbon products, the ions, and the catalyst types. These differences depended mainly on the facility of forming different products, such as n/iso-alkanes and alkenes. Skeletal isomerization was the main transformation observed on exchanged catalysts, particularly those with Ptn+/H+ ions. A deactivation process of catalysts, versus time-on-stream, begins after 70 minutes, especially for combined exchanged materials. تفاصيل المقالة

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7 - Propane Oxidative Dehydrogenation on BiP1-xVxO4 Supported Titania Catalysts
Mbarka Ouchabi Loulidi Ilyasse Mahfoud Agunaou

10.30495/ijc.2022.1971843.1970

The molecularly dispersed BiP1-xVxO4/TiO2 supported materials, with x varying from 0 to 1, were prepared by impregnation of Bismuth, Phosphorus, and Vanadium on a Titanium Oxide TiO2 support. Their structures were characterized by different techniques including X-ray di أکثر

The molecularly dispersed BiP1-xVxO4/TiO2 supported materials, with x varying from 0 to 1, were prepared by impregnation of Bismuth, Phosphorus, and Vanadium on a Titanium Oxide TiO2 support. Their structures were characterized by different techniques including X-ray diffraction, Spectroscopic Raman, temperature-programmed reduction of the catalysts in H2 (H2-TPR), and by the methanol oxidation reaction. This very sensitive technique provided us with relevant information on the nature of the catalytic active sites (acid-base and redox) of the phases dispersed on the support. The characterization results show the structural evolution of BiP1-xVxO4 species, from isolated BiPO4 crystallites for x =0, to BiVO4 crystallites x =1. The oxidation of methanol showed the acidic properties of the BiPO4/TiO2 catalyst, through the formation of dimethyl ether as the major product of the reaction. The substitution of phosphorus by vanadium promotes the formation of formaldehyde, confirming the presence of redox sites. These catalysts were examined in the oxidative dehydrogenation (ODH) of propane to propene. For x > 0.5, dispersed BiVO4 exhibited higher levels of propane ODH than BiPO4 crystallites, consistent with their greater reducibility probed by temperature-programmed reduction of H2 and the presence of redox sites confirmed by methanol oxidation, with good selectivity to propene. Catalysts with x = 0, were less selective to propene due to favorable propylene combustion during its formation. A thorough understanding of the intrinsic catalytic properties of the BiP1-xVxO4/TiO2 oxides and in particular the BiPO4 and BiVO4 crystallites provides relevant information on the structural requirements of the propane ODH reaction, of interest for the design of more efficient Bi-P-V-O based catalysts for propene production. The results show that all substituted catalysts exhibit significant propene selectivity. In addition, the BiP0.7V0.3O4/TiO2 catalyst exhibits high activity with good propene selectivity. This catalytic activity was correlated with high reducibility. تفاصيل المقالة

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8 - Effect of Dietary and Animal Factors on Milk Fatty Acids Composition of Grazing Dairy Cows: A Review
A.I. Roca Fernandez A. Gonzalez Rodriguez

In pasture-based milk production systems, using available farm resources in order to reduce feeding costs, the composition and functional properties of dairy cows’ milk are of considerable importance to the dairy farmer, manufacturer and consumer. Basically, there أکثر

In pasture-based milk production systems, using available farm resources in order to reduce feeding costs, the composition and functional properties of dairy cows’ milk are of considerable importance to the dairy farmer, manufacturer and consumer. Basically, there are three options for altering the composition and/or functional properties of milk: 1) cow nutrition and grazing management, 2) cow genetics and 3) dairy manufacturing technologies. At the farm levels, manipulation of milk composition only occurs when it is perceived to be more profitable, normally, processing options are the option most considered. Nevertheless, opportunities exist for manipulation of milk composition on the farm to improve the human and physiological properties of milk and dairy products, such as enhanced concentrations of conjugated linoleic acid (CLA), or to improve its milk fatty acids (FA) composition for more efficient processing into a range of dairy products. This review considers the effect of dietary (pasture feeding, lipid feed supplements, seasonal and regional variations) and animal (breed, stage of lactation, parity and animal to animal) factors on milk FA composition of grazing dairy cows. Furthermore, it highlights the relevance that these factors, in the context of an integrative-view, might play on the sustainability of pasture-based milk production systems in humid areas in terms of milk differentiation and higher added value which profit would be directly reached for the milk producer on the farm. تفاصيل المقالة

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9 - Effects of Heat Processing of Soybeans and Linseed on Ruminal Fatty Acid Biohydrogenation <i>in situ</i>
م.س. صمدی ی. چاشنی دل ع. دیرانده ه. دلدار

The aim of this study was to determine and compare in situ biohydrogenation (BH) fatty acids in three forms of soybeans and linseed (raw, extruded and roasted). Nylon bags (5×10 cm) containing 4 g of raw, extruded or roasted soybeans or raw, extruded or roasted li أکثر

The aim of this study was to determine and compare in situ biohydrogenation (BH) fatty acids in three forms of soybeans and linseed (raw, extruded and roasted). Nylon bags (5×10 cm) containing 4 g of raw, extruded or roasted soybeans or raw, extruded or roasted linseed were incubated in the rumen of fistulated ewes for 4, 8, 12 and 24 hours. Results for linoleic acid (C18:2) showed that the extent of BH only in 4h of incubation was significantly higher than other times of incubation in raw linseed (P<0.05). Proportions of linoleic acid (C18:2) were significantly higher for raw compared to extruded and roasted soybeans for 8 and 12 hours of incubation (P<0.05). Amounts of trans-C18:1 (octadecadienoic acid) in all 4 times of ruminal incubation were similar between each three forms of linseed (P>0.05). But proportions of this fatty acid in roasted soybeans were significantly lower than raw and extruded soybeans in 12 h of incubation (P<0.05). No significant difference was observed for extent of linolenic acid (C18:3) BH between three different forms of linseed and soybeans (P>0.05). Differences were not significant between produced cis-9, trans-11 conjugated linoleic acid (CLA) in three forms of linseeds in all times of incubation (P>0.05), but amounts of CLA in 12 and 24 hours of incubation were significantly higher for extruded soybeans (P<0.05). Proportions of stearic acid (C18:0) for the three forms of linseed (raw, extruded and roasted) in all hours of incubation showed no significant difference (P>0.05). The amount of C18:0 after 24 h of incubation was significantly higher for raw soybeans (P<0.05). According to the results, heat processing had better effects on the preservation of linoleic acid compared to linolenic acid in soybeans and linseeds against rumen BH. تفاصيل المقالة

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10 - مطالعه هیدروژندارشدن کربن مونوکسید به فراورده باارزش درحضور کاتالیست های آهن با و بدون پیش-برنده بر پایه گاما آلومینا
ندا چوداری میلانی یحیی زمانی سحر بنی یعقوب علی نخعی پور

کاتالیست های آهن با و بدون پیش برنده در سنتز فیشر-تروپش با روش آغشته سازی تهیه شدند. این کاتالیست ها با توجه به نسبت وزنی به صورت 20%Fe/γ-Al2O3 و 20%Fe/5%Cu/3%Zr/γ-Al2O3 بودند. کاتالیست ها با روش‌های پراش پرتو ایکس (XRD)، تجزیه عنصری با روش پلاسمای جفت شده القایی (ICP)، أکثر

کاتالیست های آهن با و بدون پیش برنده در سنتز فیشر-تروپش با روش آغشته سازی تهیه شدند. این کاتالیست ها با توجه به نسبت وزنی به صورت 20%Fe/γ-Al2O3 و 20%Fe/5%Cu/3%Zr/γ-Al2O3 بودند. کاتالیست ها با روش‌های پراش پرتو ایکس (XRD)، تجزیه عنصری با روش پلاسمای جفت شده القایی (ICP)، میکروسکوپی الکترونی روبشی (SEM)، کاهش برنامه ریزی شده گرمایی با هیدروژن (H2-TPR) و روش BET، شناسایی شدند. فعالیت کاتالیست ها در یک واکنشگاه بستر ثابت و در فشار 20 اتمسفر، نسبت H2/CO برابر با 1، دمای 270، 285 و 300 درجه سلسیوس و GHSV برابر با 2، 4 و l.h-1. gcat-1 6 مطالعه شدند. سپس، اثرهای دما، GHSV و پیش برنده های مس و زیرکونیم بر کارایی کاتالیست بررسی شدند. افزایش دما و GHSV موجب تغییر تبدیل CO و گزینش پذیری کاتالست ها نسبت به فراورده ها شد. کاتالیست¬های آهن با پیش برنده، گزینش‌پذیری نسبت به C5+ بالاتری نسبت به کاتالیست بدون پیش برنده داشتند، درحالی که گزینش پذیری نسبت به هیدروکربن های C2-C4 به دلیل استفاده هم زمان از مس و زیرکونیم برای پیش برندگی کاتالیست آهن، کاهش یافت. پیش برنده مس سرعت کاهش Fe2O3 را با ایجاد مکان‌های تفکیک H2 افزایش داد. کارایی کاتالیست های با و بدون پیش¬برنده مورد آزمون واکنشگاهی قرار گرفتند که در آن کاتالیست حاوی پیش برنده کارایی مطلوبی را نشان داد. تفاصيل المقالة

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11 - The influence of alumina used as a support on the catalytic properties of Pt/Sn/Al2O3 systems in the dehydrogenation of isobutane
Sedigheh Vaezifar hossein Faghihian Mehdi kamali

In this research different types of Al2O3 were used as supports to prepare catalysts for dehydrogenation of isobutane to isobutene. These supports were Al2O3 from Merck, Axen and gamma Al2O3 synthesized from Al(OH)3. Sn/Pt/Al2O3 catalysts were prepared by sequential imp أکثر

In this research different types of Al2O3 were used as supports to prepare catalysts for dehydrogenation of isobutane to isobutene. These supports were Al2O3 from Merck, Axen and gamma Al2O3 synthesized from Al(OH)3. Sn/Pt/Al2O3 catalysts were prepared by sequential impregnation, at first Pt and then Sn was deposited. Characterization of catalysts was performed by X-ray powder diffraction (XRD) and thermal analysis (TG/DTG) techniques. Elemental analysis of the catalysts was also carried out by wet chemical analysis using inductively coupled plasma (ICP) technique. Isobutane dehydrogenation was studied in a reactor under atmospheric pressure at 848 K. The conversion, selectivity and yield of the prepared catalysts were calculated. تفاصيل المقالة

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12 - هیدروژناسیون روغن سویا با تکنیک پلاسما سرد تحت شرایط ولتاژ 15 کیلوولت و ترکیب گازی 50% هیدروژن- 50% نیتروژن
ضحی سیرتی مریم قراچورلو حمیدرضا قمی مرزدشتی رضا عزیزی نژاد

مقدمه: به دلیل بالا بودن میزان اسیدهای چرب غیر اشباع در روغن سویا، احتمال رخداد اکسیداسیون در این محصول بالا و کاربرد آن¬ در صنعت غذا محدود می¬باشد؛ لذا جهت افزایش پایداری اکسیداتیو و توسعه کاربردهای غذایی آن، فرایندهای اصلاحی متعددی مورد توجه قرار گرفته است که در این ب أکثر

مقدمه: به دلیل بالا بودن میزان اسیدهای چرب غیر اشباع در روغن سویا، احتمال رخداد اکسیداسیون در این محصول بالا و کاربرد آن¬ در صنعت غذا محدود می¬باشد؛ لذا جهت افزایش پایداری اکسیداتیو و توسعه کاربردهای غذایی آن، فرایندهای اصلاحی متعددی مورد توجه قرار گرفته است که در این بین فرایند هیدروژناسیون با استفاده از تکنولوژی نوین پلاسمای سرد جهت تولید روغن نیمه هیدروژنه با اسیدهای چرب ترانس بسیار پایین، مورد توجه قرار گرفته است. مواد و روش¬ها: در این پژوهش به بررسی اثر استفاده از پلاسمای سرد تخلیه مانع دی الکتریک سطحی با استفاده از تیمار 13 ساعته، ولتاژ 15کیلوولت و گاز هیدروژن 50% و نیتروژن 50% بر روی خصوصیات فیزیکیوشیمیایی روغن سویا پرداخته شد. در بازه¬های زمانی مشخص از نمونه¬های تیمار شده نمونه برداری گردید و ترکیب اسیدهای چرب، اندیس یدی، ضریب شکست، محتوی کارتنوئید، نقطه ذوب، اندیس پراکسید، محتوی توکوفرول و محتوی استرول آن¬ها اندازه گیری شد. یافته¬ها: نتایج حاصله نشان داد که در اثر استفاده از تیمار پلاسمای سرد تخلیه مانع دی الکتریک سطحی 13 ساعته، محتوی اسیدهای چرب غیر اشباع از 62/58% به 24/40%، محتوی کارتنوئید ازpmm 38/26 به ppm 32/6، ضریب شکست از 4672/1 به 4400/1، اندیس یدی حدود از 64/129 به 45/100، میزان استرول کل از pmm 51/2636 به pmm 86/2315 به طور معناداری کاهش و عدد پراکسید از 4/2 به 8/5 meq O2/kg oil و نقطه ذوب به C° 7 افزایش یافتند(p<0.05). همچنین میزان اسیدهای چرب ترانس تولید شده به صورت بسیار جزئی (85/0 %) مشاهده گردید. نتیجه گیری: با توجه به نتایج بدست آمده از بررسی¬های صورت گرفته، می¬توان از تیمار پلاسما دی¬بی¬دی سطحی به عنوان فناوری نوین جهت هیدروژناسیون روغن¬ها به همراه رنگبری استفاده نمود. تفاصيل المقالة

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13 - Investigation of Fe-Cu-Sr/ γ-Al2O3 catalyst performance in Fisher- Tropsch synthesis: Pressure effect
Marziyeh Rahimi Mashkaleh Yahya Zamani sahar baniyaghoob Ensiyeh Ganji Babakhani

Fischer-Tropsch synthesis (FTS) is conducted on the catalysts such as Al2O3, SiO2, TiO2 and ZrO2 supported with metals like Co, Fe or Ru. While hydrogen to CO ratio is low, the Iron supported catalysts are more useful to produce alkenes, branched hydrocarbons and oxygen أکثر

Fischer-Tropsch synthesis (FTS) is conducted on the catalysts such as Al2O3, SiO2, TiO2 and ZrO2 supported with metals like Co, Fe or Ru. While hydrogen to CO ratio is low, the Iron supported catalysts are more useful to produce alkenes, branched hydrocarbons and oxygenates due to Iron's water-gas-shift (WGS) activity. The aim of this article is to produce C5+ hydrocarbon product from synthetic gas using Fe-Cu-Sr/ γ-Al2O3 nano-sized catalyst. The nano iron-based catalyst was synthesized by wet impregnation method. The synthesized catalyst (18Fe/4Cu/2Sr/ γ-Al2O3) was characterized by XRD, BET, ICP, SEM and H2-TPR techniques. Effect of reaction pressure on the product selectivity and catalyst activity was investigated in CO hydrogenation reaction. The nano catalyst was loaded in a fixed-bed reactor and tested in pressure of 16 and 20 atm, at temperature of 290 oC, with H2/CO ratio of 1 and GHSV of 2 l.h-1.g cat-1. The results demonstrated that with increasing reaction pressure, the CO conversion and C5+ selectivity increased from 63.8% and 44.03% to 78.3% and 46.2%, respectively. تفاصيل المقالة

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