scholarly journals Liquid phase dehydration of methyl phenylcarbinol to styrene

2020 ◽  
Vol 61 (1) ◽  
pp. 52-57
Author(s):  
Tulkinbek S. Sitmuratov ◽  
◽  
Lyubov A. Petukhova ◽  
Alexandr A. Petukhov ◽  
◽  
...  

The industrial styrene production by the method of vapor-phase methylphenylcarbinol (MPhC) dehydration was introduced for the first time in our country within the joint propylene oxide and styrene production consisting OAO «Nizhnekamskneftekhim» facility. This process makes it economically feasible to obtain a combined product – propylene oxide and styrene. However, continuous process exploitation at the OAO «Nizhnekamskneftekhim» facility allowed revealing a number of significant faults caused by economic and environmental factors toughening. First of all it is high energy consumption due to high process temperature and high water steam consumption for steam dilution, which affects the increase in the cost of production. In almost all technological scheme areas of this production, high boiling by-products, so-called high boiling components, are formed. One of these problem solution versions is the transfer of production to a new technology of styrene production by MPhC dehydration, which is carried out in the liquid phase at lower temperatures (up to 190 °C) using new homogeneous highly selective catalysts that exclude the by-products formation, including high-boiling components. The principal advantage of this technology is to reduce the cost of marketable styrene by reducing energy costs (heat, recycled water, water vapor, fuel gas, electricity), reducing the metal consumption of the technological scheme and increasing styrene production by reducing the amount of waste. The comparative tests results with three samples of homogeneous catalysts activity in the MPhC dehydration into styrene process are presented in the work. The tests were carried out under conditions of periodically and continuously operating laboratory installations made of glass, equipped with dosing, condensation, separation and collection systems for reaction products. Quantitative composition of reaction products is identified by chromatography methods. As a result of the conducted tests, in the presence of the used catalysts, the process control modes were selected, and the installations efficiency was checked.

2019 ◽  
Vol 60 (12) ◽  
pp. 104-109
Author(s):  
Tulkinbek S. Sitmuratov ◽  
◽  
Lyubov A. Petukhova ◽  
Alexandr A. Petukhov ◽  
◽  
...  

For the first time in our country, the industrial styrene production by the method of vapor-phase methylphenylcarbinol (MPhC) dehydration was introduced within the joint propylene oxide and styrene production, consisting OAO «Nizhnekamskneftekhim» facility. This process makes it economically feasible to obtain a combined product – propylene oxide and styrene. However, continuous process exploitation at the OAO «Nizhnekamskneftekhim» facility allowed revealing a number of significant faults caused by economic and environmental factors toughening. First of all, it is high energy consumption due to high process temperature and high water steam consumption for steam dilution, which affects the increase in the cost of production. In almost all technological scheme areas of this production, high boiling by-products, so-called high boiling components, are formed. One of these problem solution versions is the transfer of production to a new technology of styrene production by MPhC dehydration, which is carried out in the liquid phase at lower temperatures (up to 190 °C) using new homogeneous highly selective catalysts that exclude the by-products formation, including high-boiling components. The principal advantage of this technology is to reduce the cost of marketable styrene by reducing energy costs (heat, recycled water, water vapor, fuel gas, electricity), reducing the metal consumption of the technological scheme and increasing styrene production by reducing the amount of waste. The comparative tests results with three samples of homogeneous catalysts activity in the MPhC dehydration into styrene process are presented in the work. The tests were carried out under conditions of periodically and continuously operating laboratory installations made of glass, equipped with dosing, condensation, separation and collection systems for reaction products. Quantitative composition of reaction products is identified by chromatography methods. As a result of the conducted tests, in the presence of the used catalysts, the process control modes were selected, and the installations efficiency was checked.


2019 ◽  
Vol 2019 (4) ◽  
pp. 7-22
Author(s):  
Georges Bridel ◽  
Zdobyslaw Goraj ◽  
Lukasz Kiszkowiak ◽  
Jean-Georges Brévot ◽  
Jean-Pierre Devaux ◽  
...  

Abstract Advanced jet training still relies on old concepts and solutions that are no longer efficient when considering the current and forthcoming changes in air combat. The cost of those old solutions to develop and maintain combat pilot skills are important, adding even more constraints to the training limitations. The requirement of having a trainer aircraft able to perform also light combat aircraft operational mission is adding unnecessary complexity and cost without any real operational advantages to air combat mission training. Thanks to emerging technologies, the JANUS project will study the feasibility of a brand-new concept of agile manoeuvrable training aircraft and an integrated training system, able to provide a live, virtual and constructive environment. The JANUS concept is based on a lightweight, low-cost, high energy aircraft associated to a ground based Integrated Training System providing simulated and emulated signals, simulated and real opponents, combined with real-time feedback on pilot’s physiological characteristics: traditionally embedded sensors are replaced with emulated signals, simulated opponents are proposed to the pilot, enabling out of sight engagement. JANUS is also providing new cost effective and more realistic solutions for “Red air aircraft” missions, organised in so-called “Aggressor Squadrons”.


RSC Advances ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 5432-5443
Author(s):  
Shyam K. Pahari ◽  
Tugba Ceren Gokoglan ◽  
Benjoe Rey B. Visayas ◽  
Jennifer Woehl ◽  
James A. Golen ◽  
...  

With the cost of renewable energy near parity with fossil fuels, energy storage is paramount. We report a breakthrough on a bioinspired NRFB active-material, with greatly improved solubility, and place it in a predictive theoretical framework.


1969 ◽  
Vol 47 (22) ◽  
pp. 4175-4182 ◽  
Author(s):  
B. D. Boss ◽  
R. N. Hazlett

The 5-h oxidation of n-dodecane at 200 °C by air at 1 atm is reported for experiments in a borosilicate glass reaction chamber equipped with a gas bubbler. The rate of reaction was limited by the rate of oxygen diffusion from the gas phase due to the rapid reaction of dissolved oxygen. The reaction products were analyzed in aliquots taken periodically from the reaction chamber. Chemical analyses, gas–liquid phase chromatography (g.l.p.c.), tandem g.l.p.c.-mass spectroscopy, infrared, and ultraviolet were used to identify products accounting for 98% of the oxygen reacted. The isomer distribution of the dodecenes, dodecanols, and dodecanones formed, as well as the distribution of carboxylic acids, were determined. Three classes of intramolecular reaction products, cyclic ethers, cyclic hydrocarbons, and lactones, were detected. Many volatile products were detected. A filterable precipitate obtained after 10 h of oxidation was studied using infrared attenuated total reflectance techniques. A reaction mechanism is discussed based on current knowledge of other systems, the products identified, and the stoichiometry of the reaction.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Guo-Qun Zhang ◽  
Bo Li ◽  
Mao-Cheng Liu ◽  
Shang-Ke Yuan ◽  
Leng-Yuan Niu

Transition metal phosphide alloys possess the metalloid characteristics and superior electrical conductivity and are a kind of high electrical conductive pseudocapacitive materials. Herein, high electrical conductive cobalt phosphide alloys are fabricated through a liquid phase process and a nanoparticles structure with high surface area is obtained. The highest specific capacitance of 286 F g−1 is reached at a current density of 0.5 A g−1. 63.4% of the specific capacitance is retained when the current density increased 16 times and 98.5% of the specific capacitance is maintained after 5000 cycles. The AC//CoP asymmetric supercapacitor also shows a high energy density (21.3 Wh kg−1) and excellent stability (97.8% of the specific capacitance is retained after 5000 cycles). The study provides a new strategy for the construction of high-performance energy storage materials by enhancing their intrinsic electrical conductivity.


Holzforschung ◽  
2008 ◽  
Vol 62 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Krishna K. Pandey ◽  
Tapani Vuorinen

Abstract The etherification of phenolic groups has been found to inhibit photodegradation in wood and lignin rich pulps. The precise understanding of kinetics of chemical reaction between lignins or their model compounds and the etherifying agent is the first step for developing a viable modification procedure. In this study, we have investigated the reaction of lignin model compounds (namely, phenol and guaiacol) with propylene oxide in aqueous media. The kinetics of etherification reaction was studied under varying pH conditions in the temperature range 30–60°C. The etherified reaction products were characterized by gas chromatogram-mass spectrum (GC-MS). The extent of etherification of phenols and the rate of chemical reaction was followed by UV-Visible absorption spectroscopy. The reaction between lignin model compounds and propylene oxide was indicated by a rapid reduction in the absorbance accompanied by the development of a new band corresponding to etherified products. The reaction kinetics was investigated at pH ∼12 under the condition of excess concentration of propylene oxide. The reaction followed first order kinetics and rate constants increased linearly with an increase in the temperature and concentration of propylene oxide. The MS fragment data of reaction product support the proposed reaction scheme. The activation energy of the reaction of propylene oxide with phenol and guaiacol, calculated with the Arrhenius equation, was 56.2 kJ mol-1 and 45.4 kJ mol-1, respectively.


1959 ◽  
Vol 52 (3) ◽  
pp. 364-368 ◽  
Author(s):  
W. Bolton

1. The efficiency of food conversion by pullets and yearlings fed on high- and low-energy diets has been determined.2. Egg production was slightly higher by birds fed the low-energy diet for both pullets and yearling hens; pullets laid more eggs than yearling hens.3. For each age, the gross food intake was greater for birds fed the low-energy diet; the consumptions of digestible protein, non-protein digestible energy and metabolizable energy were the same for both diets and both ages of bird.4. The food cost per dozen eggs was slightly greater in the yearling year when the cost of rearing the pullets was ignored, and about the same when it was included.5. The efficiency of utilization of digestible energy and protein showed only a slight decrease from the pullet to the yearling year.6. The variation in the composition and digestibility of eighteen consecutive mixes of the highenergy diet and twenty-five of the low-energy diet was: crude protein 2%, non-protein digestible energy 5% and metabolizable energy 0·4 kg. cal./g. The digestibility of the crude protein and oil was 87%, for both diets; carbohydrates were 81% digestible in the high-energy diet and 59% in the low-energy diet.


2013 ◽  
Vol 291-294 ◽  
pp. 1573-1576
Author(s):  
Yuan Sheng Huang ◽  
Lu Tong Li

Based on the input-output theory, the paper using the comparable price energy input-output table,quantitatively estimates the implicit carbon emissions of each industrial department,and analyzes the growth of the implicit carbon emissions of the resident consumption through the structure decomposition.Conclusion indicates:From 1992 to 1997, the mean of the implicit carbon emissions of each industrial department in Xinjiang had been rising; From 1997 to 2007, the mean of the implicit carbon emissions of each industrial department had been declining;The implicit carbon emissions of Hydropower industry, the fire power and other seven similar industrial department were higher than that of each industrial department so that Xinjiang should strengthen monitoring on the high energy consumption.The implicit carbon emissions of the resident consumption was still in the trend of ceaseless growth and all of that states clearly that the economic grows at the cost of the increase of the greenhouse gas emissions.Xinjiang should introduce foreign advanced production technology,further optimizing the structure of the resident consumption.


2015 ◽  
Vol 15 (1) ◽  
pp. 22-33 ◽  
Author(s):  
Saravanan Dhanushkodi ◽  
Vincent H. Wilson ◽  
Kumarasamy Sudhakar

Abstract Cashew nut farming in India is mostly carried out in small and marginal holdings. Energy consumption in the small scale cashew nut processing industry is very high and is mainly due to the high energy consumption of the drying process. The drying operation provides a lot of scope for energy saving and substitutions of other renewable energy sources. Renewable energy-based drying systems with loading capacity of 40 kg were proposed for application in small scale cashew nut processing industries. The main objective of this work is to perform economic feasibility of substituting solar, biomass and hybrid dryer in place of conventional steam drying for cashew drying. Four economic indicators were used to assess the feasibility of three renewable based drying technologies. The payback time was 1.58 yr. for solar, 1.32 for biomass and 1.99 for the hybrid drying system, whereas as the cost-benefit estimates were 5.23 for solar, 4.15 for biomass and 3.32 for the hybrid system. It was found that it is of paramount importance to develop solar biomass hybrid dryer for small scale processing industries.


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