Methanol Research Articles

Metil Alkol (Metanol) İntoksikasyonu

Metanol odunun destrüktif distilasyonundan elde edilen berrak, renksiz ve yüksek derecede toksik bir maddedir. Genellikle endüstriyel çözücülerde, boyalarda, verniklerde, benzin karışımlarında ve otomobillerde çözücü ve antifriz olarak kullanılan metanol, tadı ve kokusundan dolayı içilemeyen bir alkol türüdür. Distile alkollü içkilerin üretimi sırasında yan ürün olarak ortaya çıkabilmektedir. Metanolün kazara ya da intihar amacıyla alınması intoksikasyona neden olabilmektedir. Sıklıkla oral yoldan intoksikasyonlara neden olur, nadiren de inhalasyonla veya cilt yüzeyinden emilimle vücuda alınmaktadır. Metanol intoksikasyonu zaman zaman epidemiler halinde ortaya çıkmaktadır. Metil alkolün metabolitleri toksiktir. Metanol intoksikasyonunda semptomların çoğu metabolik asidoz ile ilişkilidir. Semptomlar genellikle santral sinir sistemi, gözler ve gastrointestinal sistem ile ilgilidir ve latent bir periyodun ardından ortaya çıkar. Körlük ve ölüm gibi çok ciddi sonuçları olabilmektedir. Prognoz metabolik asidozun derecesiyle koreledir. İnsanda metil alkolün toksik dozu geniş bir aralıktadır. Radyolojik incelemelerde ve otopsi çalışmalarında bazal ganglion kanaması ve nekrozu, putamende hemoraji elde edilen bulgulardır. Otopsi yapılan olguların kanındaki metanol düzeyleri oldukça farklılık göstermektedir. Ülkemizde son zamanlarda artan vergiler ve alkollü içki fiyatları nedeniyle bireylerin kendi içkilerini üretmeye başlaması veya sahte içkiye yönelmeleriyle birlikte intoksikasyon vakalarında ve ölümlerde ciddi bir artış söz konusu olmuştur. İntoksikasyon olgularının ve ölümlerin daha fazla artmaması için devletin bir an önce gerekli düzenlemeleri yapıp önlem alması gerekmektedir.

Purification and Characterization of Mannanase from Aspergillus awamori for Fruit Juice Clarification.

Fruit juice clarification is a challenging aspect of beverage industry which needs to be addressed for economical and hygienic production of fruit juices. Current study is focused on the complete purification, characterization and thermodynamic analysis of an efficient mannanase enzyme to analyze its applicability in biological clarification fruit juice. Mannanase production using Aspergillus awamori IIB037 in a 25 L stirred fermenter at pre optimized reaction conditions was carried out. Enzyme purification was carried out via series of steps. Characterization of enzyme along with kinetics and thermodynamic studies was conducted. Purified and characterized enzyme was assessed for its applicability in fruit juice clarification through clarification experiments on fresh apple juice. Purification fold of 3.98 was obtained along with 86.80% purification yield of mannanase with specific activity of 158.16 U/mg. The molecular size of purified enzyme was determined as 66 kDa. The enzyme depicted 56% residual activity at 60°C after 8 hrs. Thermodynamic studies of an enzyme revealed enthalpy of activation (ΔH) and activation energy (Ea) as 30.53KJ/mol, 27.76KJ/mol, respectively. The enzyme activity increased in the presence of ß-mercaptoethanol surprisingly. On the other hand, methyl alcohol, ethanol, Hg2+ and Cu2+ inhibited enzyme activity. The enzyme showed Km and Vmax values of 11.07 mM and 19.08 μM min-1 for Locust Bean Gum (LBG) under optimal conditions. Juice treated with mannanase showed decrease in absorbance and increase in reducing sugar content. The current study demonstrated that mannanase from Aspergillus awamori in its purified form has significant characteristics to be employed industrially for juice clarification.

Produksi Biodiesel tanpa Gliserol dari Minyak Kelapa Sawit dengan Variasi Massa Co-solvent dan Waktu Reaksi

Petroleum fuels are increasingly reduced in line with the increasing industry and population. A potential alternative renewable energy source to replace fuel is biodiesel. The process of making biodiesel that is commonly done is the process of transesterification with glycerol byproducts which is difficult to separate. The method used in this study is the method of interesterification, namely by replacing the methyl alcohol group with a methyl group from methyl acetate with triacetin byproducts. The operating conditions of the process are 250 grams of palm oil mass, 1% wt KOH catalyst mass. oil, reaction temperature 60 ⁰C, stirring speed 800 rpm, mass of co-solvent methyl ester (0, 5, 10, 15, 20% wt. oil) and reaction time (30 minutes, 60 minutes, 90 minutes). The results of the research have been obtained the highest yield with the addition of co-solvent methyl ester of 20% by weight of oil in the reaction time of 30 minutes is 92.43 %.The biodiesel product produced meets SNI 7182:2015 which is an acidic value <0.5 mg-KOH/g.

Synthesis of the ZnO-Ni0.5Zn0.5Fe2O4-Fe2O3 magnetic catalyst in pilot-scale by combustion reaction and its application on the biodiesel production process from oil residual

A magnetic catalyst with composition ZnO-Ni0.5Zn0.5Fe2O4-Fe2O3 was synthesized by a combustion reaction on a pilot-scale and applied in the conversion of residual oil into biodiesel by simultaneous transesterification and esterification reactions (TES). For that, statistical analysis of the factors that influence the process (catalyst concentration, alcoholic route, and temperature) was evaluated by 23 factorial experimental design. The ZnO-Ni0.5Zn0.5Fe2O4-Fe2O3 magnetic catalyst was characterized in terms of the structure, morphology, magnetic, TPD-NH3 acidity analysis and catalytic properties. The results indicate the formation of a catalyst with a surface area of 52.9 m2g−1, and density of the sample was 4.8 g/cm3 which is consisted of a mixture of the phases containing 55.87% Fe2O3, 36.96% Ni0.5Zn0.5Fe2O4, and 7.16% ZnO. The magnetic characterization indicated that the synthesized catalyst is ferromagnetic with magnetization 6.12 emu/g and coercive field of 5.3 G. In the TES reactions, the residual oil was active showing conversion to 96.16% ethyl esters and with a long useful life maintaining sustained activity after two consecutive reuse cycles with the conversion of 95.27%, 93.07% and 76.93%, respectively. The experimental design was significant and presented a 95% reliability level. The statistical analysis identified (+1) and (−1) as higher and lower level variables, respectively. The amount of catalyst used was equal to 5%, at 200 °C in methyl alcohol (alcoholic route). In summary, a new catalyst composed of a mixture of magnetically active phases was developed and successfully applied in biodiesel’s synthesis from residual oil. Undoubtedly these results have a positive and significant impact on the environment and to society as a whole.

New catalyst for biodiesel formation: Synthesis, structural elucidation and quantum chemical calculations of new Ni(II) complexes

New Ni(II) complexes were synthesized from the coordination of the ligands derived from benzo[1,2-c]isoxazoles with Ni(II) cation.. The structure of the new complexes was characterized by elemental analyses, mass, and IR spectra. To gain a deeper insight into the geometry of Ni(II) complexes, the quantum chemical investigation was performed. The obtained results from experimental and theoretical arguments confirmed a square-planar geometry for Ni(II) complexes. These complexes were examined as homogeneous catalysts for the transesterification of corn oil with methanol. The structure of the obtained product was confirmed by 1H NMR analysis. The catalytic results showed that the new Ni(II) complexes can be considered as potential candidates for the development of new catalytic system for biodiesel production.

Anthemis tinctoria L. var. tinctoria L. Bitkisine Ait Fenolik Bileşiklerin LC-ESI-MS/MS ile Miktar Tayini ve Bitkinin Biyolojik Aktivitelerinin Belirlenmesi

Mevcut çalışmada, Tire/İzmir’den toplanan ve halk arasında, boyacı papatyası veya sarı papatya olarak adlandırılan Anthemis tinctoria var. tinctoria bitkisi fenolik profili ve biyolojik aktiviteleri bakımından incelenmiştir. Toplam fenolik ve flavonoit içeriği spektrofotometrik olarak belirlenmiş olup, 30 adet fenolik bileşiğin dedeksiyonu ve miktar tayini LC-ESI-MS/MS cihazı ile yapılmıştır. Bitkinin metanol ekstresine ait asetilkolinesteraz, bütirilkolinesteraz ve tirozinaz enzim inhibisyonları 96 kuyucuklu mikroplaka okuyucu ile saptanmıştır. Ayrıca bitkinin antioksidan kapasite tayini DPPH ve CUPRAC yöntemleriyle belirlenmiştir. Metanol ekstresinin toplam fenolik ve flavonoit miktarları sırasıyla 21.4±4.2 (mg GAE/g ekstre) ve 9.7±2.56 (mg QE/g ekstre) olarak bulunmuştur. Miktar tayininde, fenolik asit olarak 3-hidroksibenzoik asit (1167.3±0.72 µg/g ekstre) ve ferulik asit (845.8±1.98 µg/g ekstre), flavonoit olarak morin (1598.4±2.15 µg/g ekstre) ve kersetin (1416.0±1.83 µg/g ekstre) bileşikleri en yüksek konsantrasyonda bulunmuştur. Asetilkolinesteraz, bütirilkolinesteraz ve tirozinaz enzim inhibisyonlarının IC50 değerleri ise sırasıyla 254.7 ±4.86 μg/mL, 166.2±3.74 μg/mL ve 415.7±1.85 μg/mL olarak hesaplandı. Ayrıca bitkinin antioksidan kapasitesi sırasıyla 302.18±2.74 ve 514.62±3.82 mg TE/g ekstre olarak bulunmuştur.

COMPARISON STUDY OF ANTIOXIDANT, ANTIMICROBIAL AND CYTOTOXIC PROPERTIES OF SECONDARY METABOLITE AND PROTEIN EXTRACTS FROM CLINACANTHUS NUTANS

Objective: The present study aims to evaluate the antioxidant, antimicrobial and cytotoxic properties of the secondary metabolites and proteins extracted from Clinacanthus nutans.
 Methods: Methanol (ME) and acetone (AC) and also protein (PE) extracts were obtained from Clinacanthus nutans. Antioxidant activity of sample extracts was examined by using 1,1-Diphenyl-2-Picrydyl Hydrazyl (DPPH) assay and antimicrobial activity was examined by using the agar diffusion method against Bacillus subtilis, Bacillus cereus, Streptococcus pyrogenes, Escherichia coli, and Pseudomonas aeroginosa bacterial strain. The cytotoxic potential was determined by brine shrimp lethality assay.
 Results: Methanol extract (ME) demonstrated to have the highest antioxidant activity with IC50 value of 98.84 μg/ml, followed by acetone extract (AE) with IC50 value of 134.83µg/ml, and protein extract (PE) with IC50 value of 353.49 µg/ml. Among all of the sample extracts, only methanol crude extracts (ME) displayed moderate inhibition against Gram-positive B. cereus (7.33±1.15 mm) and S. pyrogenes (8.67±0.57 mm) at concentration of 100 mg/ml, while both acetone (AE) and protein (PE) extracts had no activity against all tested microorganisms. All extracts from methanol (ME), acetone (AE) and protein (PE) exhibited significant cytotoxic activity against brine shrimps at LC50 7.2 μg/ml, 1.42 μg/ml and 70.6 μg/ml respectively.
 Conclusion: These data proved that methanol extract from the leaves of Clinacanthus nutans is the most potent among all samples tested and has the potential to be developed as an antioxidant, antimicrobial and cytotoxic agents. Whilst, acetone and protein crude extracts have potent antioxidant and cytotoxicity activities.

Surface Properties of Ce1-xMnxO2 Catalyst on the Catalytic Activities for Direct Synthesis of DMC from CO2 and Methanol

Surface Properties of Ce1-xMnxO2 Catalyst on the Catalytic Activities for Direct Synthesis of DMC from CO2 and Methanol

Modeling of nitrogen oxides formation in a diesel

Mathematical modeling is an integral part of any scientific and technical research. In the modern world, it is necessary to improve computer technology, calculation methods and programs in order to improve a particular technology. The article offers a mathematical model of formation and decomposition of nitrogen oxides in the engine cylinder and at the time of opening the exhaust valve. The research object was a two-cylinder four-stroke air-cooled diesel engine D-21 running on methyl alcohol and methyl ether of rapeseed oil. These fuels are renewable and differ significantly in their chemical properties from petroleum diesel fuel. Owing to this, their use significantly reduces the emissions of toxic agents such as nitrogen oxides and soot. Theoretical studies have shown high convergence with the data obtained as a result of bench tests.

Efficiency of diesel operation on biofuels

Hazardous emissions into the atmosphere by internal combustion engines have been growing from year to year. In addition, constantly rising prices for oil negatively affect the world economy. It is possible to solve these problems by different ways; one of them is by using biofuels. New alternative fuels are able to ensure energy independence and diminish toxic exhaust emissions significantly. The article considers the issues related to the use of alternative non-petroleum fuels, their influence on diesel operation, economic and environmental performance. The object of the study is a two-cylinder diesel engine D-21, which was simultaneously fed with methyl alcohol and methyl ether of rapeseed oil. Such supply of fuels to the cylinders was carried out using a dual fuel system. The research has shown that the power of the engine operating on biofuels remains at the same level. The volumetric efficiency and the effective efficiency increase under high load conditions. Besides, such toxic agents as nitrogen oxides (NOx) and soot (C) decreased considerably, by 47.4% and 10.42 times respectively.

Speed characteristics of a diesel running on biofuel

Using alternative fuels in diesel engines is a complicated task, as it is necessary to take into consideration further changes in power, economic and environmental characteristics. There are fuels that are very similar as to their chemical properties to conventional petroleum fuel. However, when using them one should bear in mind some of their specific features, such as cetane number, lower heating value, the proportion of carbon, hydrogen, and oxygen in their composition, etc. All of these can have a significant impact on the workflow. The most promising of the samples investigated are renewable alternative fuels, such as methyl alcohol and rapeseed oil methyl ether. The paper presents the results of bench tests of a 2F 10.5/12.0 diesel engine operating on the above-mentioned biofuels. Consideration is given to power, economic and environmental performance of the engine depending on the speed change, and the possibility of using alternative fuels in diesels is assessed.

Environmental performance of biofuel engine

One of the major challenges facing the scientists throughout the globe is searching for alternative kinds of fuels. Investigating new fuels it is necessary to assess power and economic characteristics of an engine as well as its environmental performance. It must be done to improve both - the structural design of the internal combustion engine and alternative fuels themselves not to endamage the ecosphere. The paper below presents the data on the bench tests performed on a diesel engine D-21 operated on biofuel and its effects on exhaust emissions of such substances as nitrogen oxides, soot, total hydrocarbons, carbon dioxide and carbon monoxide. Methyl ether of rapeseed oil was used as the igniter fuel, and the major fuel was methyl alcohol. Simultaneous supply of alternative fuels was carried out by a dual fuel supply system. The obtained data revealed a significant ecological advantage of using alternative fuels over traditional petroleum fuels. At the same time, the power characteristics did not change, but there was an increase in biofuel consumption.

Alternative fuels and assessment of their applicability in internal combustion engines

The article summarizes the experience of using alternative fuels as motor fuel in internal combustion engines (ICE). Russia’s long-term energy program provides for measures to save fuel and energy resources, replace oil fuels with natural gas and other alternative fuels of non-oil origin, and expand the use of secondary and non-traditional energy sources. To justify the form of alternative fuels should consider the following factors: motor properties, availability of raw materials for its production in large volumes for a long time, the presence of large technologies, systems of transportation and distribution for the consumer, environmental indicators in the work ICE at this fuel, the cost of production and distribution of fuel. The article considers natural gas, alcohols (methyl and ethyl), hydrogen, ammonia, hydrazine, and synthetic hydrocarbon fuels from shale and coal as the main alternative fuels for replacing fuels of petroleum origin. Taking into account the above factors, the most interesting are natural gas (compressed and liquefied), hydrogen, and methyl alcohol (methanol).

Amfiprotik ve Dipolar Aprotik Çözücülerde 3-(4-Aril) Propiyonik Asit Türevlerinin Asitlik Kuvvetleri

Beş adet 3-(4-aril) propiyonik asit türevinin asitlik özellikleri incelenmiştir. Bu çalışmada amfiprotik çözücülerden etanol, tert‐butanol ve su, dipolaraprotik çözücülerden N,N dimetilformamid (DMF), aseton kullanılmıştır. Bileşikler tetrabutilamonyum hidroksidin (TBAH) metanoldeki çözeltisi ile titre edilmiş ve titrasyonlarda dönüm noktasının belirlenmesinde potansiyometrik metod, asitliğin belirlenmesinde yarı nötralizasyon metodu kullanılmıştır. Titrasyon eğrilerinin beklendiği gibi S şeklinde olduğu belirlenmiştir. Çizelge ve grafikler kullanılarak propiyonik asit türevlerinin amfiprotik ve dipolar aprotik çözücülerdeki asitlik kuvvetleri hesaplanmıştır. Çözücülerde elde edilen pKa değerlerinin farklandırıldığı görülmüştür. Bileşiklerin asitlik kuvvetlerine çözücü, moleküler yapı, otoprotoliz sabiti, dielektrik sabiti ve çözücünün seviyeleme-farklandırma etkileri tartışılmıştır.

Determination the Fatty Acid Composition of the Rumex patientia L. Leaves and in vitro Antimicrobial Activity of their Different Extracts

Rumex patientia L. is from Polygonaceae family and there are 25 species of it in Turkey. Rumex patientia L. has antifebrile, laxative, diuretic, and pain killer properties. In this study, the extraction of the Rumex patientia L. leaf were done and determination the fat content and fatty acid composition by using GC device and to determinate in vitro antimicrobial activity of their different extracts were aimed. On the purpose of detection of antimicrobial activity; Rumex patientia L. leaf was extracted with ethanol, methanol, acetone, petroleum ether and water. Rumex patientia L. leaves was tested their different extracts using Bacillus subtilis, Bacillus cereus, Escherichia coli, Pseudomonas aeroginosa, Pasteurella multocida, Yersinia enterocolitica, Klebsiella pneumoniae, Staphylococcus aureus bacteria and Candida albicans yeast by agar-well diffusion technique. As a result of the study, 26 fatty acid components were detected on Rumex patientia L. leaf. In addition, among obtained extracts the highest antimicrobial activity was formed by methyl alcohol extract on K. pneumoniae bacteria (32mm).

Solubility measurement, solubility behavior analysis and thermodynamic modelling of melatonin in twelve pure solvents from 278.15 K to 323.15 K

Solubility of melatonin in twelve mono-solvents including seven alcohols {methanol (MT), ethanol (ET), n-propanol (n-PrA), n-butanol (n-BT), i-butanol (i-BT), n-pentanol (n-PT) and n-hexanol (n-HeA)} and five esters {methyl acetate (MeAC), ethyl acetate (EtAC), n-propyl acetate (n-PrAC), n-butyl acetate (n-BtAC) and n-pentyl acetate (n-PtAC)} was determined by laser monitoring approach from 278.15 K to 323.15 K under 0.1 MPa. The experimental results indicate that the mole solubility of melatonin shows a positive relation with temperature variation. The solubility of melatonin in the twelve pure solvents at 298.15 K has order: MT (0.03570) > ET (0.02536) > n-PrA (0.01965) > n-BT (0.01524) > n-PT (0.01450) > i-BT (0.01267) > n-HeA (0.01136) > MeAC (0.008498) > EtAC (0.006587) > n-PrAC (0.004280) > n-BtAC (0.003410) > n-PtAC (0.02990). Moreover, the miscibility behavior of melatonin was further analyzed by the Hansen solubility parameter (HSP). The solvent effect of melatonin in tested pure solvents was investigated by using the KAT-LSER model. The four thermodynamic models including two-Suffix Margules, NRTL, NRTL-SAC and UNIQUAC models were applied to correlate the experimental solubility data of melatonin. Furthermore, the dissolution thermodynamic properties including the apparent standard dissolution enthalpy (ΔdisHo), the apparent standard dissolution entropy (ΔdisSo) and the apparent standard Gibbs energy change (ΔdisGo) of melatonin in investigated solvents were calculated by van't Hoff equation.

Pengaruh Perbedaan Pre-Treatment terhadap Stabilitas Karotenoid dan Fenol pada Ekstrak Sargassum duplicatum selama Penyimpanan

Karotenoid, fukosantin dan fenol merupakan senyawa yang terkandung pada rumput laut Sargassum duplicatum. Senyawa-senyawa ini berperan dalam menghambat radikal bebas. Namun, kemampuan penghambatan radikal bebas senyawa ini mempunyai kestabilan yang rendah, terutama terhadap perlakuan suhu. Tujuan penelitian ini adalah untuk menentukan pengaruh pre-treatment suhu tinggi (blanching) dan suhu rendah (pembekuan) serta perlakuan terbaik yang dapat mempertahankan stabilitas senyawa aktif pada ekstrak metanol rumput laut selama penyimpanan. Metode penelitian yang digunakan adalah experimental laboratories menggunakan rancangan acak lengkap (RAL) faktorial 2x5 yaitu pola terbagi menjadi faktor suhu pengolahan (suhu tinggi dan suhu rendah) dan lama penyimpanan (0, 2, 4, 6, dan 8 hari). Blanching dilakukan pada suhu 95 oC sedangkan pembekuan pada suhu -27 oC. Hasil penelitian menunjukkan karotenoid, fukosantin, dan senyawa fenol dengan perlakuan blanching lebih stabil dibandingkan perlakuan pembekuan. Berdasarkan hasil penelitian menunjukkan bahwa adanya interaksi antara pre-treatments dan lama penyimpanan yang berpengaruh nyata terhadap nilai total karotenoid, kandungan fukosantin, total kandungan fenol, dan nilai perubahan warna (ΔE).

Serious Adverse Health Events, Including Death, Associated with Ingesting Alcohol-Based Hand Sanitizers Containing Methanol - Arizona and New Mexico, May-June 2020.

Alcohol-based hand sanitizer is a liquid, gel, or foam that contains ethanol or isopropanol used to disinfect hands. Hand hygiene is an important component of the U.S. response to the emergence of SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19). If soap and water are not readily available, CDC recommends the use of alcohol-based hand sanitizer products that contain at least 60% ethyl alcohol (ethanol) or 70% isopropyl alcohol (isopropanol) in community settings (1); in health care settings, CDC recommendations specify that alcohol-based hand sanitizer products should contain 60%-95% alcohol (≥60% ethanol or ≥70% isopropanol) (2). According to the Food and Drug Administration (FDA), which regulates alcohol-based hand sanitizers as an over-the-counter drug, methanol (methyl alcohol) is not an acceptable ingredient. Cases of ethanol toxicity following ingestion of alcohol-based hand sanitizer products have been reported in persons with alcohol use disorder (3,4). On June 30, 2020, CDC received notification from public health partners in Arizona and New Mexico of cases of methanol poisoning associated with ingestion of alcohol-based hand sanitizers. The case reports followed an FDA consumer alert issued on June 19, 2020, warning about specific hand sanitizers that contain methanol. Whereas early clinical effects of methanol and ethanol poisoning are similar (e.g., headache, blurred vision, nausea, vomiting, abdominal pain, loss of coordination, and decreased level of consciousness), persons with methanol poisoning might develop severe anion-gap metabolic acidosis, seizures, and blindness. If left untreated methanol poisoning can be fatal (5). Survivors of methanol poisoning might have permanent visual impairment, including complete vision loss; data suggest that vision loss results from the direct toxic effect of formate, a toxic anion metabolite of methanol, on the optic nerve (6). CDC and state partners established a case definition of alcohol-based hand sanitizer-associated methanol poisoning and reviewed 62 poison center call records from May 1 through June 30, 2020, to characterize reported cases. Medical records were reviewed to abstract details missing from poison center call records. During this period, 15 adult patients met the case definition, including persons who were American Indian/Alaska Native (AI/AN). All had ingested an alcohol-based hand sanitizer and were subsequently admitted to a hospital. Four patients died and three were discharged with vision impairment. Persons should never ingest alcohol-based hand sanitizer, avoid use of specific imported products found to contain methanol, and continue to monitor FDA guidance (7). Clinicians should maintain a high index of suspicion for methanol poisoning when evaluating adult or pediatric patients with reported swallowing of an alcohol-based hand sanitizer product or with symptoms, signs, and laboratory findings (e.g., elevated anion-gap metabolic acidosis) compatible with methanol poisoning. Treatment of methanol poisoning includes supportive care, correction of acidosis, administration of an alcohol dehydrogenase inhibitor (e.g., fomepizole), and frequently, hemodialysis.

Synthesis of propylene glycol methyl ether catalyzed by imidazole polymer catalyst: Performance evaluation, kinetics study, and process simulation

An imidazole polymer (divinylbenzene-vinylimidazole) catalyst (P-DVB-VIM) was developed for production of the eco-friendly solvent propylene glycol methyl ether (PGME) by the propoxylation reaction of propylene oxide (PO) with methanol (ME). The catalyst was characterized in detail by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) analysis. 1H NMR was used to characterize the structural features of the catalyst precursor, i.e., the linear polymer of vinylimidazole (PVIM). An “electrophile nucleophile dual activation” ring-opening mechanism was proposed based on the “cooperative effect” of the reactant and PVIM. The catalytic performance was investigated and optimized at 100–130 ℃ using an autoclave batch reactor. The results reveal that the P-DVB-VIM shows excellent catalytic performance, exhibiting the highest turnover frequency (TOF) number at 120 °C within 45 min. The reaction kinetics was systematically studied using the pseudohomogeneous (PH) kinetic model. The kinetic parameters were determined by non-linear regression analysis of the experimental data. Validation of the model showed that the experimental data were in good agreement with the predicted outcomes. Moreover, based on the proposed kinetic model, steady-state simulations of the production of PGME in a fixed-bed reactor were carried out to determine the optimal design parameters, thus providing a useful guide for the design and production of PGME on the industrial scale.

MODEL AND SIMULATION OF PARTIAL OXIDATION OF METHANOL TO FORMALDEHYDE ON FeO/MoO3 CATALYST IN A CATALYTIC FIXED BED REACTOR

A two-dimensional mathematical model was developed for a porous heterogeneous catalytic fixed bed reactor. The model took into account the effect of heat generated by adsorption of reactants on the catalyst surface and heat transfer from the fluid phase to the surroundings which have significant effect on reactor performance especially at reactor hotspot. The developed model predicted the partial oxidation of methanol to formaldehyde on FeO/MoO3 catalyst, a complex reaction system. Excellent agreement was achieved when the resultant simulated results were compared with experimental data in the literature. The proposed model predicted the location of hotspot at a dimensionless distance of 0.4413 (= 0.0309 m) the same as the experiment value but with a temperature of 619 K compared with experimental value of 622 K. The conventional heterogeneous and pseudo-homogeneous models predicted the hotspot temperature to be about 8 K and 34 K lower than the experimental value respectively.