Presence Of Sulfuric Acid Catalyst Research Articles

Acid Catalyzed Synthesis of substituted-n-((1, 3-diphenyl-1h-pyrazol-4-yl) methyl) benzenamine

A new derivative synthesis of Substituted-N-((1, 3-diphenyl-1h-pyrazol-4-yl) methyl) benzenamine has attempted by using commonly available key starting materials Acetophenone (1) and substituted phenyl hydrazine in presence of sulfuric acid catalyst and alcohol solvent to afford potential antiviral active analogues. The synthesis proceeds through Vilsmeier-Haack reaction followed by reductive amination by using sodium borohydride.

Biobased rigid polyurethane foam prepared from apricot stone shell-based polyol for thermal insulation application, Part 1: Synthesis, chemical, and physical properties

Polyurethane foam is one of the most versatile construction insulation materials because of its low density, high mechanical properties, and low thermal conductivity. This study examined biobased rigid polyurethane foam composites from apricot stone shells, which are lignocellulosic residues. The apricot stone shells were liquefied with a PEG-400 (polyethylene glycol-400) and glycerin mixture in the presence of sulfuric acid catalyst at 140 to 160 °C for 120 min. Rigid polyurethane-type foam composites from the reaction were successfully prepared with different chemical components. Biobased polyurethane-type foam composites were successfully produced from the liquefied apricot stone shells. The FTIR spectra of liquefaction products confirmed successful liquefaction of products and that they are sources of hydroxyl groups. The liquefaction yield (81.6 to 96.7%), hydroxyl number (133.5 to 204.8 mg KOH per g), the highest elemental analysis amount (C, H, N, S, O) (62.08, 6.32, 6.12, 0.13, and 25.35%), and density (0.0280 to 0.0482 g per cm3) of the rigid polyurethane foam composites were comparable to foams made from commercial RPUF composites.

Reduction of FFA in Kapok Randu (Ceiba pentandra) Seed Oil via Esterification Reaction Using Sulfuric Acid Catalyst: Experimental and Kinetics Study

The rapid growth of the population and economy has boosted up the necessity of fuel and energy source. Until now, the world’s dependency on fossil fuel as the primary energy supply is still high. On the other hand, it has been known that the fossil-based oil and gas reserves are shrunk. Hence, it is urgent to develop alternative energy sources, which are renewable and environmentally friendly, to anticipate the energy insufficiency. Biodiesel is among the prospective renewable energy due to its advantages. Biodiesel (fatty acid methyl esters) is a type of biofuel which is derived from vegetable oil or animal fat. There are various vegetable oils that can be used as raw material for biodiesel production. However, non-edible oils are usually preferred to be selected as a biodiesel feedstock to evade the conflict between food and energy needs. Kapok Randu (Ceiba pentandra) seed oil is a type of non-edible oil which is cheap and can be employed as biodiesel feedstock. However, this oil has high free fatty acid (FFA) content (8.89%). Thus, it cannot directly undergo transesterification reaction to produce biodiesel since the FFA will react with alkaline catalyst to produce soap. The FFA content in Kapok Randu seed oil needs to be decreased until it is lower than 2%. Hence, prior to transesterification reaction, esterification of Kapok Randu seed oil with methanol in the presence of acid catalyst should be conducted to decrease the FFA content. In this work, esterification reaction was performed in the presence of sulfuric acid catalyst. The reactions were conducted at the molar ratio of oil to methanol of 1:12 at the temperature of 40, 50, and 60 ℃ for 120 minutes. The optimum reaction conversion was 95.14%, achieved at the reaction temperature of 60 ℃. Kinetics study using homogeneous models was also performed. It was revealed that the reaction was appropriate with the irreversible second order reaction model. The reaction rate constant (k), activation energy (Ea), and frequency factor (A) were 4.95 L / mole.min, 30,799.21 J/ mole and 338.744 / min, respectively.

Study of Regularities and Optimization of the Process of Fir Wood Peroxide Delignification in the Medium of “Acetic Acid – Water” in the Presence of Sulfuric Acid Catalyst

The work describes a one-stage method of cellulose obtaining from fir wood based on peroxide delignification of wood under mild conditions (100 °C, atmospheric pressure) in the presence of acetic acid, water and catalyst of 2% wt. H2SO4. The possibility of obtaining cellulose with a residual lignin content <1% wt. at a low concentration of hydrogen peroxide (3% wt.) in the reaction medium was established. The optimal concentrations of reagents (Н2О2 – 3% wt., CH3COOH – 38.9% wt.) and the duration of the process (4 h) were determined by experimental and calculation methods. This conditions provide a high yield of cellulose product (≥45% wt.) with a low content of residual lignin (<1% wt.). The composition and structure of fir cellulose was studied by chemical analysis and by FTIR and SEM methods. The cellulosic product which was obtained in optimal process conditions is high-quality cellulose

Preparation and characterization of tung oil-based flame retardant polyols

Abstract Three kinds of tung oil-based structural flame retardants polyols (TOFPs) were prepared by new methods in this paper. First, tung oil was used to produce monoglyceride and diglyceride by transesterification with glycerol by sodium methoxide. The products after transesterification were epoxidized by peracetic acid which was in-situ generated from acetic acid and hydrogen peroxide in the presence of sulfuric acid catalyst. And then, TOFPs were prepared from epoxidized alcoholysis tung oil (EGTO) with 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), diethyl phosphate (DEP) and diethanolamine (DEA) by ring-opening reactions, respectively. GPC was used to evaluate the conversion rate, at optimum reaction conditions, selectivity for monoglyceride in transesterification. The influence of different parameters such as temperature, mole ratio or mass ratio on the conversion rate of transesterification and epoxidation were investigated. The molecular structures of TOFPs were characterized by FTIR and 1HNMR. Finally, tung oil-based polyurethane foams (TOPUFs) were prepared by a one-shot process using TOFPs with polyisocyanate. The LOI values of TOPUFs whose content of DOPO-EGTO, DEP-EGTO and DEA-EGTO were 100 wt% can reach to 26.2%, 25.1%, and 24.4%, respectively.

Synthesis Propyl Propanoic from Propanoic Acid by Esterification Reaction

Abstract Synthesis of propyl propanoic had been done. Propyl propanoic was synthesized via esterification of propanoic acid and 1-propanol in the presence of sulfuric acid catalyst with mole ratios of 4:3 to produce propyl propanoic. Structural characterization of products was done by means of IR, 1 H-NMR, GC and GC-MS spectrometers. Esterification of propanoic acid with 1-propanol produced propyl propanoate in 72% yield.

Biobutanediol-mediated liquefaction of empty fruit bunch saccharification residues to prepare lignin biopolyols

Saccharification residue from empty fruit bunch (EFB) was liquefied with bio-butanediol to produce lignin biopolyols for the preparation of biopolyurethane. To substitute petroleum-derived polyhydric alcohols, butanediol isomers (1,4-butanediol, levo-2,3-bio-butanediol, and meso-2,3-bio-butanediol) or PEG#400-blended butanediol isomers were used as liquefaction solvents in the presence of sulfuric acid catalyst. Lignin biopolyols with a conversion of 63.3%, a hydroxyl number of 582.7mgKOH/g and an acid number of 21.7mgKOH/g were obtained under the optimal condition consisting of 25% biomass loading, 3% acid loading, and a temperature of 150°C for 120min when liquefied with 1,4-butanediol/PEG#400 blended solvent (9/1, w/w). When the levo-2,3-bio-butanediol solvent was used in the absence of PEG#400, the highest conversion, 68.9%, was obtained. Lignin biopolyol-based biopolyurethanes were synthesized with toluene diisocyanate. FT-IR analysis revealed that EFB lignin biopolyols liquefied with bio-butanediols were suitable monomers for the preparation of biopolyurethane.

Optimized methods for obtaining cellulose and cellulose sulfates from birch wood

The methods of obtaining cellulose and cellulose sulfates from birch wood based on the use of one-step catalytic delignification of wood by hydrogen peroxide in acetic acid–water medium were studied. The conditions of birch wood oxidative delignification by acetic acid/hydrogen peroxide mixtures in the presence of sulfuric acid catalyst were optimized in order to obtain an acceptable yield of cellulose product with low content of residual lignin. Cellulose extracted from birch wood by green method was used for preparation of cellulose sulfates in dioxane solution. The homogeneous sulfation of obtained cellulose by chlorosulfonic acid in dioxane allows to reduce the fragmentation of polymer and to synthesize cellulose sulfates with a finer and more homogeneous structure as compared to cellulose sulfates prepared by heterogeneous sulfation in harmful pyridine. Obtained samples of cellulose and cellulose sulfates were characterized by XRD, SEM, AFM, NMR, FTIR, Raman, XPS and chemical methods.

High-Purity Chlorine Dioxide Generation Process from Sodium Chlorate by Using Waste Molasses

A new chlorate-based chlorine dioxide generation process was developed by using waste molasses as reductant in the presence of sulfuric acid catalyst. The optimum technological condition was determined as 80 oC, 50% sulfuric acid, molasses and sodium chlorite weight ratio of 1:4. The best conversion rate and purity of chlorine dioxide was 73.8% and 95.1%, respectively. Chlorite was found in the reacting mixtures, and major reactions of in process were inferred. The results obtained provides a new way for waste molasses comprehensive utilization and chlorine dioxide generation.

OPTIMASI KONSENTRASI ASAM SULFAT DAN KECEPATAN PENGADUKAN PADA PROSES HIDROLISIS AMPAS TEBU MENJADI FURFURAL

ABSTRACT Hydrolysis of bagasse in the presence of sulfuric acid catalyst to produce furfural was studied. This objective of this work was to study the effects of catalyst consentration and stirrer speed on yield of furfural. The experiment were conducted by reacting bagas-se with sulfuric acid in a three neck flask sized 500 mL equipped with stirrer, heater, condenser, and thermometer. The reaction condition studied were catalyst concentration ranging from 4% to 20% and stirrer speed from 100 rpm to 500 rpm at reaction temperature 100oC and reaction time 120 minutes. The concentration of furfural was analyzed to calculate the yield of furfural. The analysis of bagasse obtained that the water content of 6.76% and pentosan content of 18.86%. The results show that yield of furfural reached a maximum at the catalyst concentration of 8% is 5.79% and the yield of furfural reached an optimum at the stirrer speed of 400 rpm is 6.29%.

Effect of Pinus radiata Bark Polyphenols on Phenol Liquefaction of Cellulose in the Presence of p-Toluene Sulfonic Acid Catalyst

Abstract The influence of Pinus radiata bark polyphenol components in the phenol liquefaction of P. radiata bark was investigated using p-toluene sulfonic acid (PTSA) and sulfuric acid (SA) as acid catalysts. A series of the phenol liquefaction reactions were carried out using mixtures of pure cellulose with increasing amounts of hot-water extract (HWE) of P. radiata bark—the polyphenol-rich component of bark. The yields of liquefied product reactions and combined phenol amounts in them were determined, and the liquefaction residues were also analyzed for determination of acid-soluble and insoluble polyphenols and residual cellulose fractions. The yield of cellulose liquefaction decreased linearly with increasing amounts of HWE with the effect being more pronounced for SA than for PTSA. The combined phenol amount increased with liquefaction yield increases for both SA and PTSA catalysts, but at liquefaction yield levels above 83 percent, more phenol was combined for SA catalyst than for PTSA catalyst. The liquefaction residues contained lower cellulose and higher polyphenol components for SA catalyst than for PTSA catalyst at the same liquefaction time. The results indicate that the bark polyphenol components can significantly interfere in the acid-catalyzed bark phenol liquefaction reactions by their excessive condensation with cellulose and/or phenol, especially in the presence of SA catalyst.

Surface modified cellulose obtained by acetylation without solvents of bleached and unbleached kraft pulps

Heterogeneous acetylation to a low extent of bleached and unbleached commercial kraft pulps was performed with acetic anhydride without solvents and in the presence of sulfuric acid catalyst. The process was conducted in an effort to change the polarity of studied kraft pulps and to improve their compatibility with synthetic polymers without changing their fibrous structure. It was observed that the fiber morphology does not change up to a reaction time of 3 h for both investigated materials. The hydrophilic character of the bleached pulp was decreased by acetylation to a low extent, while the unbleached material showed an initial increase of water retention capacity. At higher degrees of modification, both pulps exhibited similar hydrophilic properties. For both materials, an initial slightly increased susceptibility to enzymatic attack with cellulase from Trichoderma reesei was observed, however the acetylated bleached cellulose fibers were more susceptible to enzymatic attack than those of the unbleached material.

Biodiesel production from crude rice bran oil and properties as fuel

This research reported on the successfully production of biodiesel by transesterification of crude rice bran oil (RBO). The process included three-steps. Firstly, the acid value of RBO was reduced to below 1 mg KOH/g by two-steps pretreatment process in the presence of sulfuric acid catalyst. Secondly, the product prepared from the first process was carried out esterification with an alkaline catalyst. The influence of four variables on conversion efficiency to methyl ester, i.e., methanol/RBO molar ratio, catalyst amount, reaction temperature and reaction time, was studied at this stage. The content of methyl ester was analyzed by chromatographic analysis. Through orthogonal analysis of parameters in a four-factor and three-level test, the optimum reaction conditions for the transesterification were obtained: methanol/RBO molar ratio 6:1, usage amount of KOH 0.9% w/w, reaction temperature 60 °C and reaction time 60 min. In the third step, methyl ester prepared from the second processing step was refined to become biodiesel. Fuel properties of RBO biodiesel were studied and compared according to ASTM D6751-02 and DIN V51606 standards for biodiesel. Most fuel properties complied with the limits prescribed in the aforementioned standards. The consequent engine test showed a similar power output compared with regular diesel but consumption rate was slightly higher. Emission tests showed a marked decrease in CO, HC and PM, however, with a slight increase in NO X .

πSynthesis and evaluation of a series of α‐hydroxy ethers derived from isopropyl oleate

AbstractSeveral fatty derivatives with bulky moieties were prepared by treatment of epoxidized isopropyl oleate with a number of alcohols in the presence of sulfuric acid catalyst to provide a series of α‐hydroxy ethers in good yield. The materials were analyzed for cold flow performance through cloud point and pour point determinations. The most promising α‐hydroxy ether produced in this study, with respect to both low temperature behavior and economic criteria, was isopropyl 9(10)‐(2‐ethylhexoxy) 10(9)‐hydroxystearate, which has a cloud point of −23°C and pour point of −24°C.

Synthesis of lanthanum tris (mono-i-octyl phthalate) and its thermal stability for polyvinyl chloride

A novel type of thermal stabilizer—lanthanum tris (mono-i-octyl phthalate) (LTMP) was synthesized by double-decomposition reaction of sodium mono-i-octyl phthalate with lanthanum chloride at 60 °C. Sodium mono-i-octyl phthalate was prepared by sodium hydrate and mono-i-octyl phthalate prepared by reaction of isooctyl alcohol and phthalic anhydride in the presence of sulfuric acid catalyst at 110 °C. The yield of lanthanum tris (mono-i-octyl phthalate) is about 84.5%. Its thermal stabilities were measured by heat-ageing oven test when incorporated into PVC. The experimental results show that the heat stability time is about 40min at 190 °C when adding 3phr (per hundred resin) to PVC. The thermal stability of this product is better than that of Ca-Zn complex and basic lead salt stabilizers, and equal to that of dibutyltin diaurate.

Phenol-Formaldehyde Plywood Adhesive Resins Prepared With Liquefied Bark of Black Wattle(Acacia mearnsii)

ABSTRACT In this study, whole bark and tannin-free bark from black wattle were liquefied in phenol in the presence of sulfuric acid catalyst. The resulting solutions were reacted with formalin in basic solution to yield resol resins that had 33% of the phenol replaced by liquefied bark. Preparation of three-ply Southern Pine plywood showed that the resins made with liquefied whole bark performed better than those prepared with tannin-free bark. At low veneer moisture content, panels bonded with the best liquefied bark resin had properties similar to panels bonded with the commercially available phenol-formaldehyde resins that were tested.

Starch‐derived glycol and glycerol glucosides prepared by reactive extrusion processing

AbstractPreviously, starch‐derived glycol and glycerol glucosides were prepared by batch‐reaction processes and had excellent potential as chemical intermediates for a wide range of products. However, more efficient processes for preparation of these derivatives are needed. In this present work, a modern corotating, intermeshing, twin‐screw extruder with a barrel length/screw diameter (L/D) ratio of 43: 1 was used to study the reaction of starch with ethylene glycol and glycerol in the presence of sulfuric acid catalyst at elevated temperatures. A fully continuous process was used. Variables that were investigated included temperature (140–180°C), glycol or glycerol/starch AGU mol ratio (1.5–4.0), starch feed rate (5–30 lb/h), screw speed (100–475 rpm), residence time, specific energy, and several types of commercial cornstarch and corn flour products. Rates and extents of reaction that occurred in the barrel were determined by analyzing samples that were quenched just prior to extrusion. The major glucosides were quentitated by high‐performance liquid chromatography. Results of this study show that starch can be continuously, rapidly, and efficiently converted to glucosides in 90% yield at high production rates. Such processing is expected to be technically feasible for the reaction of a wide range of polyhydroxy alcohols with various starch substrates.

Carboxylation of Isobutene with Carbon Monoxide and Water in the Presence of Sulfuric Acid Catalyst

Carboxylation of zso-butene with carbon monoxide and water to produce branched C5 acid (trimethyl acetic acid) as the main product was studied under various reaction conditions in the presence of concentrated sulfuric acid. The aim of this work was to observe the influence of reaction conditions, such as the catalyst acid concentration, and the amount of the catalyst, reaction temperature, the amount of the solvent (n-hexane) etc, on the yield of carboxylic acids.High carbon monoxide pressure favored carboxylation between 10kg/cm2 and 50 kg/cm2, and the yield of carboxylic acids increased with the decrease of reaction temperature between 4 and 93°CCarboxylation was predominant under the sulfuric acid concentration of 90% and higher. However, the yield of carboxylic acids decreased under the acid concentration of 98% and higher, presumably due to the lack of water in the reaction zone which is necessary to stabilize the carboxylated intermediates. Under the acid concentration below 93%, the produced carboxylic acids showed the increasing tendency to dissolve in n-hexane solvent with the decrease of the acid concentration.

Syntheses of N-Vinylphthalimide Derivatives

Reaction of N-(1-chloroethyl) phthalimidej and thioglycolic acid at room temperature caused dehydrochlorination and gave N-(1-carboxymethylmercaptoethy1) phthalimide with good yield. This substance can be esterified easily with alcohols in the presence of sulfuric acid as a catalyst.An addition reaction of thioglycolic acid to N-vinylphthalimide in the presence of sulfuric acid catalyst was followed by Markownikoff's rule and formed an α-addition product, N-(1-carboxymethylmercaptoethyl) phthalimide. Similarly, methyl and ethyl thioglycolate gave additive products.

Epoxidation of methyl oleate with hydrogen peroxide

SummarySimple addition of hydrogen peroxide to a 10 molar excess of glacial acetic acid in the presence of sulfuric acid catalyst gave about 90% conversion to peracetic acid in the peracid preforming step.Improved hydrogen peroxide efficiency in the epoxidation step was obtained by using a 0.9:1 molar ratio of preformed peracetic acid to methyl oleate. Under these conditions most of the peracetic acid was used in forming the epoxide.Stainless Steels 304, 316, 321, 329, and 430 are satisfactory as materials of construction from the standpoint of both corrosion resistance and effect on the reaction.