scholarly journals Dehydration of Ethanol by PSA Process with Pressure Equalization Step Added

Bioethanol ◽  
2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Luz Elena Gomar-Madriz ◽  
Jaime Saucedo Luna ◽  
Medardo Serna-González ◽  
Salvador Hernández-Castro ◽  
Agustin Jaime Castro-Montoya

AbstractIn this work, the ethanol dehydration production process is carried out using the Mathematical Modeling Pressure Adsorption Process. A new model is suggested, it has two equalization steps, and is compared with the Industrial Pressure Swing Process operating cycle. An analysis of the effects of introducing the pressure equalization step is performed on four main response variables: purity, production, recovery and energy consumption and it is compared with the current cycle configuration operating in the industry. We used Aspen Adsorption for the valuation and simulation of the cyclic PSA process. We analyzed and processed the simulation results in Statgraphics Centurion to obtain optimum operating conditions for the process. This evaluation shows that purity decreases slightly, whereas recovery and production increase. The most important thing is that the energy consumption is reduced. These results clearly show that by modifying the operating cycle schema, optimum operating conditions also change. The optimization of the new cycle was executed considering as variables bed pressure, adsorption time and purging flow. We found that a smaller column is more productive for the equalization cycle than that of a 14m bed, which is optimal in the industrial cycle with a consequent reduction in adsorbent material.

2021 ◽  
Vol 58 (02) ◽  
pp. 112-123
Author(s):  
Rakesh Kumar Raigar ◽  
Hari Niwas Mishra

Roasting is one of the thermo-mechanical operation in cereals and oilseeds processing. Low-capacity machine for mechanisation of roasting is necessary for small-scale processing. A conduction-type motorised rotary roaster (8 kg per batch) was designed and developed for roasting of peanuts. Performance of the roaster was evaluated in terms of moisture loss, scorched kernels, and specific energy consumption for accelerated roasting of peanut. The effects of different roasting conditions were studied to determine the optimum operating conditions of the roaster. Quality indices of peanuts as moisture loss (kg.kg-1), scorched kernel (%), and specific energy consumption (kWh.kg-1) were dependent on the operating conditions. The optimum value of moisture loss (0.041± 0.003 kg.kg-1), scorched kernel (0.93± 0.0.004 % ), and specific energy consumption (0.185 ± 0.005 kWh.kg-1) were obtained at roasting temperature of 170°C, roasting time of 15 min, and rotational speed of 20 rpm for roasting peanut. The roasting characteristics of peanut decreased linearly with increase in the temperature and time; and decrease in the rotational speed. The inferior quality parameters were observed at higher temperatures, speed and medium time of roasting. The study indicated optimum roasting temperature of peanut to be 170°C, and further increase in the process temperature had undesirable effects on roasted peanut quality due to high loss of moisture.


Author(s):  
Savita Dubey ◽  
Amita Joshi ◽  
Rashmi Trivedi ◽  
Parmesh Kumar Chaudhari ◽  
Dharm Pal ◽  
...  

Abstract In the current scenario treatment of industrial waste water is big challenge especially waste water that contain high organic load. Hydrogen peroxide assisted electrocoagulation (EC) process provides better result to treat highly polluted wastewater as compared to EC alone. However, hydrogen peroxide is well known as a strong oxidant, which cast a potential threat to human health. To overcome this problem hydrogen peroxide has been used here for treatment of wastewater in small quantity, and that consume during the process. Therefore the harmful effect of hydrogen peroxide in human and aquatic life could be minimized. This work is an attempt to treat biodigester effluent (BDE) using H2O2 assisted EC processes with respect to chemical oxygen demand (COD) and color reductions. To perform this experiment both iron and aluminum electrodes are used as an electrode material in the presence of H2O2. In case of iron electrode the maximum COD and color reduction efficiency of 98.3 and 83.6% was achieved at the cost of 1.5 Wh/dm3 energy consumption while maximum COD and color removal efficiency of 96.8 and 77.1% with 1.7 Wh/dm3 of energy consumption was observed in the aluminum electrode based EC process. A part from this conventional biological process (i.e., activated sludge treatment, ponds, and lagoon etc.) and physiochemical treatment process (i.e., coagulation, adsorption) provided treatment efficiency of 40–80% hence hydrogen peroxide assisted EC process should a better choice to treat distillery effluent. Furthermore, hybrid EC process was also performed with iron used as anode and aluminum as cathode in the presence of H2O2. Iron electrode based peroxi-EC process provided better result at optimum operating conditions; current density of 114 A/m2, initial COD concentration of 12,000 mg/dm3, initial pH of 7.3, H2O2 concentration of 120 mg/dm3, stirring speed of 120 rpm and electrolysis time of 90 min. The cost estimated for operation is 1.56 US $/m3. Finally, sludge analysis and cost optimization are also incorporated in this article.


Author(s):  
Husnu Kerpicci ◽  
Onur Poyraz ◽  
Tolga N. Aynur ◽  
Ismail Teke

In this study, an experimental setup was built to evaluate the energy consumption of a freezer compartment by varying the runtime (i.e. the ratio of the compressor ON time to the total cycle time) of the system with the evaporation temperature and the airflow rate. Evaporation temperature and the normalized airflow rate were varied from −25°C to −28°C and from 0.8 to 1.4, respectively, thus the effects of these parameters on the runtime of the freezer were evaluated in a wide range of operating conditions. In addition, an empirical model that estimates the runtime within ± 4% compared to the experimental data was presented. By using the empirical model, optimum operating conditions (i.e. evaporation temperature and airflow rate) for the freezer were found with an energy saving of %13.8.


2015 ◽  
Vol 6 (1) ◽  
pp. 50 ◽  
Author(s):  
Raúl Prada-Núñez ◽  
Cesar Augusto Hernández-Suárez

ResumenLas series temporales se usan para estudiar la relación de una variable consigo misma a lo largo del tiempo en intervalos regulares; se consideró el consumo energético de España durante una muestra de 5 días, recurriendo a diversos modelos deterministas se buscaba modelar su comportamiento de la forma más ajustada. Se utiliza el diseño de experimentos para calibrar los parámetros del modelo de HoltWinters validando aquellos efectos que resultan significativos en la minimización del MAPE, con el fin de identificar las Condiciones Operativas Óptimas del modelo. Por último, se evaluan diversos modelos ARIMA aplicados a los residuos obtenidos del modelo de Holt Winters para convertirlo en ruido blanco, utilizando la metodología Box-Jenkins.Palabras claves: modelo Holt-Winters, modelos ARIMA, Series de tiempo. AbstractTime series are used to study the relationship of a variable with itself over time at regular intervals. Energy consumption in Spain was considered for a sample of five days, using various deterministic models sought to model their behavior in the most accurate way. The design of experiments is used to calibrate the model parameters Holt-Winters validating those effects that are significant in minimizing MAPE,in order to identify the optimum operating conditions of the model. Finally, various ARIMA models applied to residues obtained from Holt-Winters model to make it white noise, using the Box-Jenkins methodology are evaluated.Keywords:  Holt-Winters model, ARIMA models, Time series.


2020 ◽  
Vol 5 (1) ◽  
pp. 563-572
Author(s):  
Iman Golpour ◽  
Mohammad Kaveh ◽  
Reza Amiri Chayjan ◽  
Raquel P. F. Guiné

AbstractThis research work focused on the evaluation of energy and exergy in the convective drying of potato slices. Experiments were conducted at four air temperatures (40, 50, 60 and 70°C) and three air velocities (0.5, 1.0 and 1.5 m/s) in a convective dryer, with circulating heated air. Freshly harvested potatoes with initial moisture content (MC) of 79.9% wet basis were used in this research. The influence of temperature and air velocity was investigated in terms of energy and exergy (energy utilization [EU], energy utilization ratio [EUR], exergy losses and exergy efficiency). The calculations for energy and exergy were based on the first and second laws of thermodynamics. Results indicated that EU, EUR and exergy losses decreased along drying time, while exergy efficiency increased. The specific energy consumption (SEC) varied from 1.94 × 105 to 3.14 × 105 kJ/kg. The exergy loss varied in the range of 0.006 to 0.036 kJ/s and the maximum exergy efficiency obtained was 85.85% at 70°C and 0.5 m/s, while minimum exergy efficiency was 57.07% at 40°C and 1.5 m/s. Moreover, the values of exergetic improvement potential (IP) rate changed between 0.0016 and 0.0046 kJ/s and the highest value occurred for drying at 70°C and 1.5 m/s, whereas the lowest value was for 70°C and 0.5 m/s. As a result, this knowledge will allow the optimization of convective dryers, when operating for the drying of this food product or others, as well as choosing the most appropriate operating conditions that cause the reduction of energy consumption, irreversibilities and losses in the industrial convective drying processes.


Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3966
Author(s):  
Jarosław Mamala ◽  
Michał Śmieja ◽  
Krzysztof Prażnowski

The market demand for vehicles with reduced energy consumption, as well as increasingly stringent standards limiting CO2 emissions, are the focus of a large number of research works undertaken in the analysis of the energy consumption of cars in real operating conditions. Taking into account the growing share of hybrid drive units on the automotive market, the aim of the article is to analyse the total unit energy consumption of a car operating in real road conditions, equipped with an advanced hybrid drive system of the PHEV (plug-in hybrid electric vehicles) type. In this paper, special attention has been paid to the total unit energy consumption of a car resulting from the cooperation of the two independent power units, internal combustion and electric. The results obtained for the individual drive units were presented in the form of a new unit index of the car, which allows us to compare the consumption of energy obtained from fuel with the use of electricity supported from the car’s batteries, during journeys in real road conditions. The presented research results indicate a several-fold increase in the total unit energy consumption of a car powered by an internal combustion engine compared to an electric car. The values of the total unit energy consumption of the car in real road conditions for the internal combustion drive are within the range 1.25–2.95 (J/(kg · m)) in relation to the electric drive 0.27–1.1 (J/(kg · m)) in terms of instantaneous values. In terms of average values, the appropriate values for only the combustion engine are 1.54 (J/(kg · m)) and for the electric drive only are 0.45 (J/(kg · m)) which results in the internal combustion engine values being 3.4 times higher than the electric values. It is the combustion of fuel that causes the greatest increase in energy supplied from the drive unit to the car’s propulsion system in the TTW (tank to wheels) system. At the same time this component is responsible for energy losses and CO2 emissions to the environment. The results were analysed to identify the differences between the actual life cycle energy consumption of the hybrid powertrain and the WLTP (Worldwide Harmonized Light-Duty Test Procedure) homologation cycle.


2020 ◽  
Vol 10 (10) ◽  
pp. 3566
Author(s):  
Mary Angélica Ferreira Vela ◽  
Juan C. Acevedo-Páez ◽  
Nestor Urbina-Suárez ◽  
Yeily Adriana Rangel Basto ◽  
Ángel Darío González-Delgado

The search for innovation and biotechnological strategies in the biodiesel production chain have become a topic of interest for scientific community owing the importance of renewable energy sources. This work aimed to implement an enzymatic transesterification process to obtain biodiesel from waste frying oil (WFO). The transesterification was performed by varying reaction times (8 h, 12 h and 16 h), enzyme concentrations of lipase XX 25 split (14%, 16% and 18%), pH of reaction media (6, 7 and 8) and reaction temperature (35, 38 and 40 °C) with a fixed alcohol–oil molar ratio of 3:1. The optimum operating conditions were selected to quantify the amount of fatty acid methyl esters (FAMEs) generated. The highest biodiesel production was reached with an enzyme concentration of 14%, reaction time of 8 h, pH of 7 and temperature of 38 °C. It was estimated a FAMEs production of 42.86% for the selected experiment; however, best physicochemical characteristics of biodiesel were achieved with an enzyme concentration of 16% and reaction time of 8 h. Results suggested that enzymatic transesterification process was favorable because the amount of methyl esters obtained was similar to the content of fatty acids in the WFO.


The Analyst ◽  
1999 ◽  
Vol 124 (5) ◽  
pp. 713-719 ◽  
Author(s):  
R. P. W. Scott ◽  
Thomas E. Beesley

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