Energy-saving investigation of vacuum reactive distillation for the production of ethyl acetate

2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Ganesh N. Patil ◽  
Nirmala Gnanasundaram

Abstract Ethyl acetate (EtAc) reactive distillation (RD) configurations often use atmospheric pressure, and this operating pressure can be reduced further to conserve energy based on the condenser cooling water temperature. Using the Aspen Plus simulator, two proposed configurations, RD column with stripper and pressure swing reactive distillation (PSRD), were simulated at lower operating pressure. The impact of RD column operating pressure on total energy usage and total annual cost (TAC) was studied. All design parameters were optimized using sequential iterative optimization procedures and sensitivity analysis to minimize the energy cost while maintaining the required product purity at 99.99%. The simulation results showed that the RD column with a stripper is better than PSRD with a saving of 23.17% in TAC and 31.53% in the specific cost of EtAc per kg. Compared to literature results, the proposed configurations have lower reboiler duty requirements and lower cost per kg of EtAc.

Processes ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 1 ◽  
Author(s):  
Guanghui Chen ◽  
Fushuang Jin ◽  
Xiaokai Guo ◽  
Shuguang Xiang ◽  
Shaohui Tao

The traditional two-column reactive distillation (RD) process is used for the production of butyric anhydride, which is synthesized with butyric acid and acetic anhydride via a reversible reaction. In this work, a novel process with a single RD column (SRDC) is designed for the production of butyric anhydride, where the second distillation column for separating excess reactant is removed based on the boiling point profile of the reaction system. Two applications of the proposed SRDC process, namely SRDC with excess butyric acid or acetic anhydride circulating internally, are economically optimized, and the results show that both SRDC processes have a lower total annual cost (TAC) than the traditional two-column process. Furthermore, from the perspective of TAC, the application with an excess feed of butyric acid is better than the application with excess acetic anhydride. The developed technique may also be applied to retrofit other traditional two-column RD processes, where the overhead and bottom products are the lightest and heaviest components of the reaction system, respectively, and no azeotrope is involved in the RD column.


Author(s):  
Ying Wang ◽  
Jumei Xu ◽  
Zuoxiang Zeng ◽  
Weilan Xue ◽  
Zhijie Mao

The purpose of this study was to investigate a continuous process for the recovery of lactic acid from fermentation broth. A reactive distillation process to purify lactic acid by esterification with isoamyl alcohol and hydrolysis was designed and simulated by Aspen. Five columns were included in the process: esterification column, purification column, hydrolysis column, dehydration column and recovery column. Effects of process parameters (operating pressure, feed composition, feed position, number of reaction and separation stages, and reboiler duty) of the esterification column on the yield and purity of lactic ester was evaluated. Further evaluation was carried out to reveal the effects of process parameters of the hydrolysis column on the yield and purity of lactic acid. The total annual cost of the whole process was calculated. Simulation studies are carried out using Aspen Plus RADFRAC module. It was shown that under the optimized condition, the concentration of lactic acid can reach up to 82.4 wt%, and the organic acid impurities were less than 3 ppm. Compared with the traditional usage of methanol and butanol, the isoamyl alcohol process can save about 20% of the total annual cost at the same output of lactic acid. Results obtained in this work can be used for scale-up study of an industrial reactive distillation operation as an efficient and economical alternative to recover lactic acid from fermentation broth.


Author(s):  
Ram Srinivasan

The concept of optimum cooling water temperature rise in a power plant has been introduced in this study as that which corresponds to the highest possible net plant output. Every power plant having a steam turbine exhausting to a water-cooled condenser has a unique optimum cooling water temperature rise. This optimum temperature rise may not be the minimum possible as often inadvertently assumed by power plant designers. This optimum temperature rise is a strong function of the steam turbine exhaust parameters. The author has developed correlations, which will help determine the optimum temperature rise using easily available power plant design parameters. This paper will discuss the details behind this method and show the thermal and financial advantages of designing a plant with this concept. A proper understanding of this concept will enable power plant designers to economically and efficiently size the condenser cooling water system.


2021 ◽  
Vol 12 (1) ◽  
pp. 318
Author(s):  
Mati Ullah Shah ◽  
Muhammad Usman ◽  
Syed Hassan Farooq ◽  
In-Ho Kim

This paper reports the theoretical findings of the new modified type of tuned liquid column ball damper (TLCBD), called a tuned liquid column ball spring damper (TLCBSD). In this new modified form, the ball inside the horizontal section of the damper is attached to the spring. Furthermore, two types of this modified version are proposed, known as a tuned liquid column ball spring sliding damper (TLCBSSD) and a tuned liquid column ball spring rolling damper (TLCBSRD). In the former, the rotational motion of the ball attached to the spring is restricted, whereas in the latter, the ball attached to the spring can translate as well as rotate. Mathematical models and optimum design parameters are formulated for both types. The performance of these new modified damper versions is assessed numerically and subjected to harmonic, seismic, and impulse loadings. The results show that the performance of the newly proposed dampers is relatively better than traditional TLCBDs in harmonic and seismic excitations. The peak response reduction soon after the impact load becomes zero is comparatively better in TLCBSDs over TLCBDs. Overall, the newly proposed passive vibration control devices performed excellently in structure response reduction over TLCBDs.


Author(s):  
E. I. Akulinin ◽  
◽  
O. O. Golubyatnikov ◽  
A. N. Labutin ◽  
D. S. Dvoretsky ◽  
...  

On the basis of the Dubinin theory of micropore volume filling, a mathematical model of dynamics of pressure swing adsorption processes for synthesis gas separation has been developed. The model takes into consideration the influence of the processes of mass and heat transfer in gas and solid phases on the kinetics of diffusion transfer of adsorbate (carbon dioxide, carbon monoxide, hydrogen) in the adsorbent layer and accounts for all devices included in the process diagram (adsorber, compressor, vacuum pump, valves, throttle, receiver). Numerical studies of the process of separation of synthesis gas and concentration of hydrogen in a four-adsorber unit with granulated zeolite adsorbent 13X were carried out by methods of mathematical modeling: the influence of disturbing influences (composition and temperature of the initial hydrogen-containing gas mixture), regime parameters (cycle duration, pressure at the compressor outlet, pressure at the vacuum pump inlet, backflow coefficient) and design parameters (length of the adsorbent bulk layer and inner diameter of the adsorber) on the purity of the product hydrogen, its recovery rate and productivity of the unit were studied. The most dangerous disturbances and the most effective regime parameters of pressure swing adsorption process of synthesis gas separation were determined. It is established that the increase of temperature from 298 to 323 K and decrease of hydrogen concentration from 68 to 48 % (vol.) in initial gas mixture result in ~10 % lower efficiency of the unit due to the decrease of product hydrogen recovery rate. Practical recommendations on effective choice of operation regimes of an adsorption unit to ensure the achievement of required purity of product hydrogen at the level of 99.99 % (vol.), regardless of the impact of disturbances are formulated.


2019 ◽  
Vol 8 ◽  
pp. 54-56
Author(s):  
Ashmita Dahal Chhetri

Advertisements have been used for many years to influence the buying behaviors of the consumers. Advertisements are helpful in creating the awareness and perception among the customers of a product. This particular research was conducted on the 100 young male and female who use different brands of product to check the influence of advertisement on their buying behavior while creating the awareness and building the perceptions. Correlation, regression and other statistical tools were used to identify the relationship between these variables. The results revealed that the relationship between media and consumer behavior is positive. The adve1tising impact on sales and there is positive and high degree relationship between advertising and consumer behavior. The impact on advertising of a product of electronic media is better than non-electronic media.


2021 ◽  
Vol 17 (4) ◽  
pp. 1-26
Author(s):  
Md Musabbir Adnan ◽  
Sagarvarma Sayyaparaju ◽  
Samuel D. Brown ◽  
Mst Shamim Ara Shawkat ◽  
Catherine D. Schuman ◽  
...  

Spiking neural networks (SNN) offer a power efficient, biologically plausible learning paradigm by encoding information into spikes. The discovery of the memristor has accelerated the progress of spiking neuromorphic systems, as the intrinsic plasticity of the device makes it an ideal candidate to mimic a biological synapse. Despite providing a nanoscale form factor, non-volatility, and low-power operation, memristors suffer from device-level non-idealities, which impact system-level performance. To address these issues, this article presents a memristive crossbar-based neuromorphic system using unsupervised learning with twin-memristor synapses, fully digital pulse width modulated spike-timing-dependent plasticity, and homeostasis neurons. The implemented single-layer SNN was applied to a pattern-recognition task of classifying handwritten-digits. The performance of the system was analyzed by varying design parameters such as number of training epochs, neurons, and capacitors. Furthermore, the impact of memristor device non-idealities, such as device-switching mismatch, aging, failure, and process variations, were investigated and the resilience of the proposed system was demonstrated.


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