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2 Utilization
Published in S. Komar Kawatra, Advanced Coal Preparation and Beyond, 2020
Methyl formate is in turn typically produced industrially by the reaction of methanol with carbon monoxide. Thus, producing formic acid from the reduction of CO2 can be achieved by two primary routes: the direct reduction of CO2 in the presence of hydrogen as shown in Equation 17.8, or indirectly by the formation of a syngas containing CO and the formation of methanol. Syngas, or synthesis gas, is a mixture of gases containing predominantly carbon monoxide and hydrogen and perhaps a small portion of CO2. The direct reduction shown in Equation 17.8 is typically unfavorable, as the reactants are far more entropic than the products – the formation of methyl formate as an intermediate product makes the reaction far more likely to proceed in full (Leitner, 1995; Hietala et al., 2016). CO2+H2→CH2O2
Safety and Flammability Analysis for Fuel–Air–Diluent Mixtures Plant
Published in Mihir Kumar Purkait, Piyal Mondal, Murchana Changmai, Vikranth Volli, Chi-Min Shu, Hazards and Safety in Process Industries, 2021
Mihir Kumar Purkait, Piyal Mondal, Murchana Changmai, Vikranth Volli, Chi-Min Shu
Kondo et al. (2006a, 2006b, 2007) modified Le Chatelier’s formula to provide an empirical equation for evaluating the flammability boundaries of several fuels mixed with inert gases. The parameters of the empirical equation depend on the tested flammable and inert gases and must be experimentally determined. Theories relating flammability limits to heat loss predict a minimum flame temperature, below which the flame cannot propagate (Spalding, 1957; Buckmaster, 1976; Joulin and Clavin, 1976). When estimating the flammability limits of fuels mixed with inert gases, investigators often assume the adiabatic flame temperature is constant for a particular fuel (Shebeko et al., 2002; Vidal et al., 2006; Melhem, 1997; Hansen and Crowl, 2010). When using Melhem’s (1997) method or Hansen and Crowl’s (2010) equations to estimate the flammability boundaries, the adiabatic flame temperatures at the LFL and UFL are required; unfortunately, these temperatures are mostly unknown. A theoretical linear equation was derived describing the flammability boundaries of fuels mixed with inert gases (Chen et al., 2009a, 2009b). The slope of this linear equation must be determined by regressing experimental data (Chen et al., 2009a, 2009b). Recently, a model describing the flammability limits of fuel and diluent mixtures by considering thermal radiation loss was validated (Liaw et al., 2012). The estimated flammability envelopes depend upon the assumed combustion products of the carbon in the fuels, especially at the UFL (Liaw et al., 2012). Chen et al. (2008) observed carbon monoxide (CO) and carbon dioxide (CO2) in the burned gas at the UFL of pure propane. Ju et al. (2001) and Britton (2002) indicated that the measured flammability limits are different when using different experimental apparatuses. The apparatus used to measure the flammability limits includes vertical glass tubes, spherical glass flasks, and spherical explosion vessels. The vertical glass tube and spherical glass flask are open to the atmosphere after the explosion and are regarded as constant pressure systems. However, the spherical explosion vessel is an intrinsic constant volume system. The methods for the estimation of flammability limits are based on the theory of enthalpy change equaling zero. Thus, they were developed for constant pressure systems. In this work, a model to calculate the flammability envelopes of mixtures containing inert gases for a constant volume system is derived. The combustion products at the LFL and UFL were analyzed to verify the assumption of the model. Methyl formate can be used in a variety of reactions to produce industrial products, such as acetic acid, methyl acetate, and other chemicals (Gérard et al., 1998). In semiconductor manufacturing, acetone, methanol, and isopropyl alcohol (IPA) are often used in clean room procedures (Liaw and Chiu, 2003). Thus, acetone, methanol, IPA, and methyl formate diluted with either steam or nitrogen (N2) were selected as samples for model validation.
Ultrasound accelerated solvent-free condensation reaction of rhodanines and carbonyls using Amberlyst 26 as a green and efficient base catalyst
Published in Journal of Sulfur Chemistry, 2023
Duc-Thuan Nguyen, Ngoc-Khoi Pham, Xuan-Triet Nguyen, Thi Xuan Thi Luu, Quynh-Nhi Nguyen Luong
With our ambition for green chemistry and the chemical industry, a solvent-free condensation reaction between rhodanine derivatives and carbonyl compounds catalyzed by a heterogeneous catalyst, Amberlyst 26 (called A26) was developed under ultrasound irradiation (Scheme 1). Amberlyst 26 is an inexpensive commercial polymer and a copolymer of styrene and divinylbenzene, containing the quaternary ammonium group (–CH2N + Me3) with hydroxide counterion. Amberlyst 26 is not only an ion exchange resin, but also a polymolecular solid base catalyst. Due to being safe to use, easy to handle, easy to store, simple to work-up, and highly catalytic recyclable, Amberlyst 26 has been used for several organic reactions such as the hydration of nitrile to synthesize primary amide [30], methanol carbonylation to methyl formate [31], transesterification of propylene carbonate with methanol to dimethyl carbonate were performed [32].
Techno-economic assessment of hydrogen production via dimethylether steam reforming and methanol steam reforming
Published in Indian Chemical Engineer, 2023
Shardul S. Rahatade, Nilesh A. Mali
This work particularly considers Cu–Ni/ γ-Al2O3 for DME hydrolysis even though the catalyst falls into the bifunctional category. Following the hydrolysis, the methanol steam reforming reaction takes place over the metallic Cu/ZnO/Al2O3. There exist two pathways via which methanol steam reforming proceeds, namely via reverse water gas-shift or via the methanol decomposition route both of which are controversial. The clash of interest is due to the formation of the CO which according to some authors should be greater than or equal to that at the equilibrium, which was not observed [10,35–37]. Another mechanism is the one in which the methanol dehydrogenates to form the intermediates methyl formate and hydrogen. The methyl formate then gets hydrolysed to form formic acid and methanol, followed by the formation of carbon dioxide from methyl formate decomposition [38,39].
Transition metal complexes incorporating lawsone: a review
Published in Journal of Coordination Chemistry, 2022
Freeda Selva Sheela Selvaraj, Michael Samuel, Arunsunai Kumar Karuppiah, Natarajan Raman
Apart from being an excellent sensitizer for solar cells and corrosion inhibitor, lawsone is reported to be beneficial in CO2 utilization and as an organic oxidant. CO2 utilization involves the conversion of CO2 to other usable products to reduce the emission of CO2 into the atmosphere. Reduction of CO2 to dimethylformamide and methyl formate or the hydrogenation of CO2 to formic acid using homogenous catalysts are reported for CO2 utilization. Meroliya et al. synthesized lawsone metal complexes of zinc, iron and ruthenium divalent ions and evaluated them as homogenous catalysts for conversion of CO2 into dimethylformamide and methyl formate [81]. It was concluded that the metal complexes of lawsone served as suitable catalysts for reduction of CO2 to dimethylformamide and methyl formate. Higher yield of dimethylformamide was observed in the presence of ruthenium complex as the catalyst. El-Hendawy synthesized lawsone metal complexes such as [UO2(NQ)2], [MoO2(NQ)2], [RuIIICl2(AsPh3)2NQ] and [OsIIICl2(PPh3)2NQ], where NQ = 2-hydroxy 1,4-naphthoquinone, and investigated the role of ruthenium and osmium as organic oxidants for converting primary and secondary alcohols to aldehyde and ketone, respectively. N-methylmorphine-N-oxide was taken as the co oxidant. Ruthenium complex was a more suitable oxidant than the osmium complex [82].