The solution for the resistance to oxidation of p-toluic acid was solved by the discovery of bromide-controlled air oxidation in 1955 that was led to the implementation of AMOCO process [28-31]. In AMOCO process, the oxidation of para-xylene was conducted using a combination of three ions as a homogeneous catalyst which is cobalt, manganese and bromide ions. Acetic acid and oxygen/air were used as solvent and oxidant, respectively [32]. The common bromide ion sources are hydrobromic acid (HBr) and sodium bromide (NaBr). The oxidation operated at 175-225°C and 15-30 bar of oxygen. The terephthalic acid formed mostly in the form of solid due to the low solubility of terephthalic acid in the acetic acid. AMOCO process successfully gives a promising reaction yield, since more than 98% of para-xylene reacted, while terephthalic acid selectivity yield was about 95% in the reaction time of 8-24 hours (Scheme 3).
Scheme 3. AMOCO commercial process of para-xylene oxidation to terephthalic acid [32].
As shown in Scheme 2, the consecutive oxidations of methyl group take place for p-toluic acid and 4-CBA. In order to gain terephthalic acid as the end product, the purification from impurities including 4-CBA content in crude terephthalic acid must be conducted. In purification process, the crude terephthalic acid (a solid terephthalic acid that has been undergoing centrifugation and drying) will be dissolved in hot water to reduced 4-CBA to p-toluic acid. This reduction process is through catalytic hydrogenation on palladium catalyst. Then, the purified terephthalic acid is obtained [33]. Apart AMOCO process, the other catalytic process to produce terephthalic acid by direct oxidation was widely st...
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...terephthalic acid solubility in water increased linearly proportional with temperature. This situation happens due to the low dielectric constant nature in supercritical water, making it as a good solvent for non-polar substance like para-xylene. Therefore, it can be concluded that the reaction and yield of the reaction could be adjusted by the modification of reaction temperature. As shown in Table 1, the application of sub and supercritical water, could give a greater yield in terephthalic acid, >50%. However, the industrial implementation always demanding the practical application in terms of energy, nature of chemical and operation cost. Even sub and supercrical water could produce high amount of terephthalic acid, but the temperature and pressure applied in this application was far from safe and commercially practical.
Works Cited
Universiti Malaysia PAhang
Solid triphenylmethanol (0.200 g, 0.768 mmol) and sulfuric acid (2 mL) were added to a reaction tube, which was then ground using a glass rod until it dissolved and turned a dark orange color. The mixture was then added dropwise via a glass pipette into another reaction tube containing methanol (1 mL). An extra amount of methanol (2 mL) was used to transfer the rest of the contents of the first reaction tube. Formation of crystals was facilitated by scratching the side of the tube and adding additional methanol until the color changed to an off-white color. The contents of the tube were then vacuum filtered with water and the resulting crude product was weighed and then recrystallized using hot methanol to form triphenylmethyl methyl ether (0.051 g, 0.186 mmol, 24.2%). The melting point was 81 – 83˚
The boiling point of the product was conducted with the silicone oil. Lastly, for each chemical test, three test tubes were prepared with 2-methylcyclohexanol, the product, and 1-decene in each test tube, and a drop of the reagent were added to test tubes. The percent yield was calculated to be 74.8% with 12.6g of the product obtained. This result showed that most of 2-methylcyclohexanol was successfully dehydrated and produced the product. The loss of the product could be due to the incomplete reaction or distillation and through washing and extraction of the product. The boiling point range resulted as 112oC to 118oC. This boiling point range revealed that it is acceptable because the literature boiling point range included possible products, which are 1-methylcyclohexene, 3-methylcyclohexene, and methylenecyclohexane, are 110 to 111oC, 104oC, and 102 to 103 oC. For the results of IR spectroscopy, 2-methylcyclocahnol showed peaks at 3300 cm-1 and 2930 cm-1, which indicated the presence of alcohol and alkane functional group. Then, the peak from the product showed the same peak at 2930 cm-1 but the absence of the other peak, which indicated the absence of the alcohol
The goal of this lab is to exemplify a standard method for making alkyne groups in two main steps: adding bromine to alkene groups, and followed by heating the product with a strong base to eliminate H and Br from C. Then, in order to purify the product obtained, recrystallization method is used with ethanol and water. Lastly, the melting point and IR spectrum are used to determine the purity of diphenylacetylene.
Imperial Oil ltd. Limited (Esso) is a Canadian public corporation that produces crude oil and natural gas. Currently the headquarters are based out of Calgary, Alberta employing over 5000 people, with Exxon Mobil owning 69.6 percent of the company. Imperial Oil ltd. was previously located in Toronto and has recently moved all main facilities over to the Calgary, Alberta headquarters.1 Esso was incorporated in London, ON in 1880 and became a land mark in the development of crude oil and natural gases.1 Its retail business consists of service stations and "On the Run Express and Tiger Express-brand" convenience stores. Esso also owns a 25% portion of Syncrude, which are the world’s largest oil sands.1
Some possible errors raised during the synthesis and spectrometric analysis of TPCP include the insufficient mixing of the hexane and TPCP, in which will result in the low absorbance of the compound. Additionally, the low yield is contributed from the loss of product during filtration.
The purpose of the experiment was to study the kinetics of the hydrolysis of ester, p-nitrophenyl acetate (NPA) that is catalyzed by the buffer imidazole (Im). In terms of kinetics, specifically speaking, the rate of reaction as determined by the concentration, reaction orders, and rate constant with each species in a chemical reaction. By using the concentration of the catalyst and the temperature, the overall reaction rate was determined. The rate constants of K0, Kobs, and Kcat can be derived via the plotting of the absorbtion at 400nm of p-nitrophenol vs. the concentration of the catalyst imidazole. Lastly, the free energy of activation, ΔGǂ, that is necessary to force the reactant’s transformation of the reactants to the transition state structure will be determined by using the equation ΔGǂ = ΔHǂ – TΔSǂ derived from the Eyring plot.
Z Qin et al modified ammonium polyphosphate (APP) and compared the effect of modification on flame retardant properties of polypropylene along with dipentaerythritol (DPER). The incorporation of modified ammonium polyphosphate (IMAPP) with dipentaerythritol (DPER) at 25 % loading produced LOI 32% with V-0 rating while unmodified APP had LOI 26% and V-1 rating. IMAPP also significantly decreased the PHRR and THR and contributed to the formation of compact intumescent
The freezing point of p-xylene was calculated by taking the average calculated Kf of the three trials of the p-xylene and toluene solution. The average of the three trials was computed as 4.56(C/m) as shown in Table 1, however, the theoretical value was slightly lower than calculated, 4.3(C/m). This resulted in a 6.04% error as shown in Equation 5; possible causes of error could have resulted from adding too much solute or too little solvent, then the calculations would have been off given that the solution was not dilute enough. Having too much solvent could be attributed to having a higher Kf than the theoretical value, given that the solute would not have as much impact on the pure substance, p-xylene. This would raise the Kf value, bringing it closer to the solvent’s Kf. Another source of error resulting in the higher Kf could have resulted from contamination of the solvent or solute, given that it could introduce a polar substance or different molecules which would alter the hydrogen bonding.
The most common form of polyethylene is petroleum based or olefins based; as before mentioned polyethylene compounds have a wide commercial applicability and are made from non-renewable resources (Harding, Dennis, von Blottnitz, Harrison, & S.T.L., 2007). Its manufacturing processes are regarded as energy intensive and release significant amount of CO2 and heat into the atmosphere (Broderick, 2008). Next a little more detailed description of polyethylene’s production processes will be presented, with a focus on the way the material inputs are extracted and synthesized.
In a small reaction tube, the tetraphenylcyclopentadienone (0.110 g, 0.28 mmol) was added into the dimethyl acetylene dicarboxylate (0.1 mL) and nitrobenzene (1 mL) along with a boiling stick. The color of the mixed solution was purple. The solution was then heated to reflux until it turned into a tan color. After the color change has occurred, ethanol (3 mL) was stirred into the small reaction tube. After that, the small reaction tube was placed in an ice bath until the solid was formed at the bottom of the tube. Then, the solution with the precipitate was filtered through vacuum filtration and washed with ethanol. The precipitate then was dried and weighed. The final product was dimethyl tertraphenylpthalate (0.086 g, 0.172mmol, 61.42%).
"The History of Plant Incidents at Formosa Plastics and Past Safety Violations." Industrial Injury Attorneys. http://www.industrialinjuryattorney.com/Industrial-Accident-Blog/2013/May/The-History-of-Plant-Incidents-at-Formosa-Plasti.aspx (accessed April 3, 2014).
Commercial Recuperation Essentially what Hebdige is saying with his statement is that eventually a subcultures generic trademarks will cross over into the mainstream. This will in tern render the original intentions of subversion diluted pastiches of there former representations. The validity of this statement is interesting in two ways. Firstly are subcultures subversive qualities diluted through popularisation?
Edgar Allan Poe's "A Cask of Amontillado" is perhaps the most famous tale of terror ever written. Montresor, the story's narrator, leads the reader through his revenge on Fortunato. Montresor entices Fortunato into the dark recesses of the family catacombs with the promise of a very fine wine. At the climax of the story, Montresor shackles Fortunato to a wall and seals him away forever behind brick and mortar. In all of Poe's short stories he attempts to convey "a certain unique or single effect." "A Cask of Amontillado" expresses its dark view of human intention by using elements of irony, foreshadowing, and metaphor. The first person point of view also lends itself to an exploration of the inner secrets of Montresor.
in this section. Most of the work that is done is cleaning up the body
Toluene hydrodealkylation process is irreversible process and requires catalyst. The catalyst used in this process consist of molybdenum oxides or chromium, platinum oxides or platinum, silica or alumina. Minor reversible side reaction is: