Specific Energy Consumption Values Research Articles

The impact of high effective electrodialytic desalination on acid whey stream at high temperature

Desalination of nanofiltrated acid whey by electrodialysis in the temperature range 15–55 °C was investigated. Increased electrodialysis temperature caused increased total mass flux and electrodialysis capacity while specific energy consumption values were maintained. Weak organic acids removal from whey increased with temperature, leading to an increase in the degree of deacidification from 64.3% to 72.0% when the temperature increased from 15 to 55 °C. Protein losses were not observed at any temperature, and the increase in ED temperature did not affect the protein content of the desalted whey. IR spectroscopy showed that protein deposition occurred mainly in the surface layers of cation-exchange membranes. Conductivity and diffusion permeability of anion-exchange membranes increased after electrodialysis at elevated temperatures due to the enlargement of pores and channels of ion-exchange materials. Protein sorption by cation-exchange membranes significantly compensated for this effect and their transport properties changed to a much lesser extent.

Physicochemical, reconstitution, and morphological properties of red pepper juice (Capsicum annuum L.) powder

The aim of this study is to investigate the influence of the encapsulating agents (maltodextrin (MD), whey protein isolate (WP), and gum arabic (GA)) and their blends (MD + WP, MD + GA, WP + GA, and MD + WP + GA) on the powder yield, drying ratio, productivity, drying rate, physicochemical, bulk, reconstitution, and morphological properties of the red pepper juice powders (RPJP) and to calculate the energy efficiency of the spray dryer. A pilot-scale spray dryer (180/80°C inlet/outlet air temperature, 392kPa atomization pressure, 1.54m3/min air flow rate, and a 12.0 ± 0.2°Bx feeding concentration) was used for the drying experiments. The acceptable powder yield (52.48-94.25%) and specific energy consumption values (7.39-9.72MJ/kg H2O) were obtained. The RPJP presented moisture content and water activity values lower than 10% and 0.367. The red pepper juice powders were found to be highly dispersible (88.34-95.18%), soluble (solubility time and index are 9.75-77.25s and around 99%), and easly wetted (9.75-122.00s). The average particle sizes of the RPJPs were 14.92μm, 19.68μm, 19.36μm, 17.58μm, 19.96μm, 19.41μm, and 18.72μm for RPJP + MD, RPJP + WP, RPJP + GA, RPJP + MD + WP, RPJP + MD + GA, RPJP + WP + GA, and RPJP + MD + WP + GA respectively. Despite the low powder yield and high water activity value, RPJP + MD exhibited superior (bulk density, flowability, cohesiveness, wettability and solubility times) or statistically similar (productivity, moisture content, browning index, porosity, dispersibility, and hygroscopicity) properties compared to other powders.

Binary electrochemical mineralization of heterocyclic nitrogenous compounds: parametric optimization using Taguchi method and mineralization mechanism.

The main objective of the present work was to understand the interactive behaviour of various operating parameters including concentration of pollutants during binary electrochemical mineralization of the two nitrogenous heterocyclic pollutants in the aqueous solution. Indole and pyrrole were selected as pollutants, whereas Pt/Ti was selected as anode and cathode. The effects of different operating parameters like current density, solution conductivity, initial concentration of the pollutants and time were studied. Taguchi method was used to optimize these operating parameters for obtaining the ultimate rate of degradation for the nitrogenous compounds. There were basically two responses, i.e. chemical oxygen demand (COD) degradation and specific energy consumption. These responses were maximized and minimized, respectively. At the optimum condition, removal efficiencies of pyrrole, indole and COD were found to be 46.1%, 62.4% and 61.4%, respectively. The optimum value of specific energy consumption was found to be 159.5kWh per kg COD removed. Possible mineralization pathways are also proposed on the basis of the identified intermediates by gas chromatography coupled with mass spectroscopy. The operating cost was also calculated for the binary lab-scale treatment of the indole and pyrrole and compared with reported cost analysis for the electrochemical treatment.

Specific Energy Consumption of a Belt Conveyor System in a Continuous Surface Mine

Belt conveyor (BC) transportation systems are considered to be the most effective for handling large volumes of bulk material. With regards to the rules of sustainable development, the improvement of belt conveyor technology is, in many cases, focused on environmental issues, which include the idea of energy usage optimization. The key issue in an energy-efficient transportation system is reducing the value of specific energy consumption (SEC) by increasing conveyor capacity whilst decreasing belt conveyor motion resistance. The main idea of this paper is to conduct an analysis of the modernization of existing belt conveyor transportation systems operated in open-pit lignite mines, in order to achieve relatively small electric energy consumption for a considered transportation task. The first part of the paper investigates the relationship between a conveyor’s SEC and material flow rate for various conveyor design parameters. Then, based on multi-parameter simulations, an analysis of electric energy consumption for a belt conveyor transportation system is carried out. Finally, an energy-saving, environmentally friendly solution is presented.

THE DETERMINATION OF THE DRYING KINETICS AND ENERGY EFFICIENCY OF RED PEPPER (CAPSICUM ANNUUM L.) USING DIFFERENT DRYING METHODS AND MICROWAVE FINISH DRYING

The effects of different drying processes namely microwave (MD), freeze (FD), convective (CD), and vacuum drying (VD) and combined drying methods (FD+MD and CD+MD) on drying characteristics, effective moisture diffusivity, and activation energy of red pepper powder and total energy consumption of dryers were investigated. All drying processes took place in combined form of constant and falling rate periods for all drying experiments except for CD and CD+ MD. In order to determine drying kinetics of red pepper pulp (RPP) seven thin layer drying models were fitted to experimental data and Page (MD, FD, CD, VD, CD+MD) and Logarithmic (FD+MD) models which had the highest R2 and lowest χ2 and RMSE were found to satisfactorily describe the drying behavior of RPP. Findings indicated that compared to FD and CD alone, intermitted dried samples had significantly higher Deff (p<0.05). Specific energy consumption values ranged between 3.13 and 664.52 MJ/kg H2O

Exergy and energy analysis of three biogas upgrading processes

The aim of this work was to provide a complete exergy and energy analysis of three biogas upgrading technologies: amine scrubbing, water scrubbing and membrane separation processes. Biogas production and treatment represents a key-process for the application of Circular Economy principles, since allows to reuse/reconvert industrial by-products or agro-industrial waste in a product that can be used in different energy demanding sectors, after proper cleaning and upgrading processes. The three technologies here reported have been implemented in Aspen Plus flowsheets, and were used to upgrade a biogas to biomethane, meeting the UNIT/TS 11537:2019 standards for Biogas to be injected in the gas grid. Each units of all the simulated processes have been analysed calculating total exergy feed, total exergy produced and exergy loss, distinguishing that lost for irreversibility and as waste. Water scrubbing was characterized by the highest values of exergy efficiency (94.5%) and methane recovery (99%), whereas the lowest exergy efficiency belonged to membrane separation (90.8%) that returned also the largest specific energy consumption (0.94 kWh/m3 STP). Conversely, amine scrubbing was characterized by the lowest specific energy consumption value (0.204 kWh/m3 STP) but by an exergy efficiency of 91.1%.

Pilot scale production of fuel pellets from waste biomass leaves: Effect of milling size on pelletization process and pellet quality

This work investigates the effect of biomass milling size on pelletization process and pellet quality, using garden waste (a non-woody biomass feedstock). Three different milling sizes were considered, viz. ‘as received’ (>25.4 mm), coarse (25.4 mm), and fine (6.25 mm) at a moisture content of around 10% and a die size of 15 mm. The particle size distribution plots showed a significant difference in ‘median particle size diameter’ (D50) for all three cases. Nominal changes in pellet quality parameters (density, dimension, and durability) were observed during pilot scale pelletization with different milling sizes. However, the results showed an increased throughput capacity (29.5 to 60 kg h−1) with decrease in milling size from 'as received' to fine. In addition, the wet disintegration method was performed to analyze the internal particle size distribution of pellets. The results revealed that the difference in D50 values for the internal particle size of produced pellets was insignificant in above cases. Furthermore, the specific energy consumption value reduced from 141.2 to 100.2 kWh ton−1 by reducing biomass milling size from coarse to fine. The production cost reduced by 23% for fine feedstock as compared to coarse while producing pellets under given conditions.

Performance analysis of infrared film drying of grape pomace using energy and exergy methodology

In this study, grape pomace was dried in an infrared film dryer at 40, 45 and 50 °C surface temperatures to investigate the effects of heat transfer mechanism (natural and forced convection) and homogeneous drying on specific energy consumption, drying rate and drying time. Also, energy and exergy efficiencies were calculated. The average specific energy consumption values were calculated as 5.90, 4.49 and 4.07 kWh/kg in natural convection (Group 1) and 11.90, 11.32 and 11.81 kWh/kg in forced convection (Group 2), respectively. The maximum energy efficiency was observed as 54.71% at 45 °C in Group 1. Energy efficiencies at the experiments in Group 1 were found to be nearly 10% higher than Group 2. The maximum exergy efficiency was observed as 38.46% at 50 °C in Group 1, and the average exergy efficiency values for Group 1 and 2 were calculated as 34.84% and 33.76%, respectively. Group 2 experiments provided a faster drying process as expected. However, although forced convection was more effective in terms of drying time, natural convection was found more suitable considering all the performance parameters as a whole. This study offers a solution to dry grape pomace high quality, homogeneously and efficiently for industrial usage.

Energetic, environmental and economic analysis of drying municipal sewage sludge with a modified sustainable solar drying system

Disposal of sewage sludge is an important problem for the sustainability of cities. In recycling process of sewage sludge, a big part of energy demand is consumed in the drying process. Therefore, utilizing clean and sustainable energies in recycling process of sewage sludge can be a good solution. In this work, a drying chamber with transparent cover has been designed and analyzed in the process of drying sewage sludge experimentally and numerically. Also, a conventional drying chamber has been tested and its performance compared with modified drying chamber’s performance. The main purpose of modifying the drying chamber using transparent cover is to harvest more solar energy in the system and consequently reduction in the drying time. Moreover, in the drying tests a single-pass conventional unglazed solar air collector has been combined with the drying chamber. The performance tests of drying systems have been conducted in two various flow rates including 0.010 and 0.014 kg/s. Experimental and numerical findings demonstrated that using drying chamber with transparent cover reduced the drying time significantly. The obtained average specific energy consumption and specific moisture extraction rate values are in the range of 1.77–2.86 kWh/kg and 0.77–1.34 kg/kWh, respectively. Moreover, levelized cost of heating values were found between 1.7 and 2.0 $-ct/kWh for the system which uses drying chamber with transparent cover.

Membrane Distillation Desalination System With Gap Circulation and Cooling Using a Built-in Heat Exchanger

Abstract A comprehensive experimental investigation is conducted to evaluate the performance of a new flux-enhanced compact water gap membrane distillation (WGMD) module design with gap circulation and cooling for water desalination. The new design uses a separate circulation loop to circulate the gap water, and a built-in heat exchanger coil implanted inside the coolant stream channel for cooling the circulated gap water. The WGMD modules with circulation and with circulation and cooling are compared with conventional WGMD without circulation. Variations of distillate flux, temperatures, and energy consumption are presented at different design operating conditions. Circulation and cooling of the gap water greatly enhance the output flux due to gap water motion and increase the temperature difference between membrane surfaces. However, the enhancement in flux was achieved at the expense of energy consumption. Circulation and cooling of gap water are more effective with bigger gap widths. Feed flowrate showed significant effects with gap water circulation and cooling. The electrical specific energy consumption (SEC) showed the best value of 7.9 and 8.8 kWh/m3 at a feed temperature of 70 °C for both conventional WGMD and WGMD with circulation modules, while the best value of SEC for the WGMD module with gap circulation and cooling was 9.4 kWh/m3 at a feed temperature of 80 °C.

Analysis of intermittent infrared drying using heat recovery with a novel control methodology

AbstractDrying is one of the most energy consuming process. By using automatic control systems in the industry, a higher quality and energy efficient drying is achieved. There are two main periods in drying process, the constant rate period and the falling rate period. In the falling rate period, it becomes difficult to evaporate water from the product, and this results in high specific energy consumption values and low energy efficiency values. In this study, apple slices were dried in an intermittent infrared dryer with two new developed drying methodologies as a solution to this problem (Model 2 and 3). An Arduino based automatic control system was used for Model 2 and Model 3. Developed models were compared with conventional experiments (Model 1). With Model 2, a constant drying rate was achieved independently of the moisture content. With Model 3, 57% shorter drying time compared to Model 2 and 16% less energy consumption compared to Model 1 was provided. Also using of the Model 3 the energy efficiency increased as 50% and the specific energy consumption decreased as 48% compared to Model 1. This study offers a solution with high efficiency in industrial usage.Practical ApplicationsConventional dryers have low energy efficiency and high specific energy consumption. With two novel drying methodologies developed within the scope of this study, a reduction of 16% in energy consumption and increase of 50% in energy efficiency were observed as an alternative to conventional drying. In addition, a constant drying rate was achieved independently of the moisture content. These drying methodologies offer an applicable solution for drying process with high energy efficiency in industrial food drying systems. Thus, it is foreseen to decrease the energy consumption and increase the efficiency in the drying industry, which constitutes a large part of the industrial energy consumption.

Implementasi Demand Side Management (DSM) Pada Instalasi Pengolahan Air PDAM Mulia Baru

The Mulia Baru Water Treatment Plant (IPA) is one of 6 Water Treatment Plants owned by the Ketapang Regency PDAM that is indicated to use a large amount of electrical energy. From the data obtained during one year (January to December 2017), the average monthly electricity consumption is 128,016,667 kWh with an average.Drinking Water Production Volume per month of 144,119,833 m3. Therefore the average Specific Energy Consumption (SEC) value for 2017 is 0.89. Through the application of the Peak Clipping and Strategic Concervation DSM program, a decrease in peak load occurs at a time interval between 17:00 and 22:00, in this condition a decrease in load of 0.47 (%).For greater savings, it is necessary to schedule the operation of large loads at peak load times.

Minimization of the adverse environmental effects of discarded onions by avoiding disposal through dehydration and food-use

Onion is a commonly used vegetable in the Cuyo Region, Argentina, and important in the world global vegetable production ranking. Production levels often exceed immediate markets of fresh sale, and excesses, although still edible, are currently discarded (mostly incinerated and disposed in landfill, creating numerous environmental hazards). To minimize these adverse environmental problems, this research investigates upgrading the discarded products by dehydration, hence guaranteeing their ultimate food-use. The dehydration process of discarded onion cv. Crioula Roxa was hence studied at 60 and 70 °C, temperatures selected to maintain the main physicochemical characteristics of the onions, while also creating optimum heat and mass transfer coefficients while significantly reducing the energy consumption and CO2 emissions.When using an electrically-heated convective dryer, the Specific Energy Consumption (SEC) values and the CO2 emissions during dehydration at 70 °C are 738.89 kWh.kg−1 and 264.74 kg of CO2 kg−1, respectively. These values are only 41.61 kWh.kg−1 and 2–4 kg of CO2 kg−1 if a solar dryer is applied. The thermal diffusivities were 1.86✕10−10 m2 s−1 (dehydration) and 1.08✕10−10 m2 s−1 (rehydration), showing a weak effect of the dehydration process on the solid structure and properties.

Development of a photovoltaic-thermal solar humidifier for the humidification-dehumidification desalination system coupled with heat pump

To provide both thermal and electrical energies needed for the humidification-dehumidification (HDH) desalination systems independent of fossil fuels, the present study proposed a photovoltaic-thermal (PVT) solar humidifier. The designed humidifier is a double-pass dual-fluid solar collector, which was mounted on a humidification-dehumidification system equipped with a heat pump. Experimental investigation of the system was conducted at different condensation temperatures and seawater flow rates. The results showed that the highest water evaporation in the humidifier was around 4.48 kg (1.06 kg/h/m2 humidifier surface) at the seawater flow rate of 0.15 kg/s and the condensation temperature of 20 °C. Specific electrical energy consumption values varied from 0.22 to 0.53 kWh/kg. The maximum thermal and electrical efficiencies of the PVT humidifier were 75.6 and 11.3%, respectively. The ratio of solar PV electricity to consumed electricity of the system at the different operating conditions was ranged from 0.95 to 1.03. The average freshwater production rates were between 0.56 and 0.99 kg/h/m2 humidifier surface. Economic analysis of the system indicated that the cost of freshwater production with the proposed system is 0.018 US $/kg.

Coconut shell-derived activated carbon and carbon nanotubes composite: a promising candidate for capacitive deionization electrode

Aiming at more efficient use of coconut resources to achieve multi-purpose goals, this work proposes an innovative composite for capacitive deionization (CDI) electrode in desalination applications when using coconut shell-derived activated Carbon (AC) as a matrix into which a certain amount of carbon nanotubes (CNTs) is incorporated. The electrochemical studies show that the optimized 9mAC:1CNTs electrode with a surface area of 630 m2/g has a specific capacitance of 90.2 F/g (at scan rate of 20 mV/s), salt adsorption capacity (SAC) of 14.1 mg/g at 1.0 V. SAC value is retained as high as 95.7% after 100 adsorption–desorption cycles at 1.0/0 V, showing a good cyclic stability of the electrode composites. Moreover, a calculated specific energy consumption (SEC) value of 0.312 kW h/m3 was quite low compared with other CDI electrodes reported in literature. Briefly, the present study indicates that AC-CNTs composite can serve as promising CDI electrode materials for desalination application.

Energy efficiency analyses in a Turkish fabric dyeing factory

ABSTRACT In this study, energy efficiency applications and corresponding energy saving results were evaluated in a Turkish fabric dyeing factory. The relationship between energy consumption and the production were evaluated by regression analysis. They were detailed with energy intensity index (EII), cumulative sum values (CUSUM), specific energy consumption (SEC), and radar chart. The energy efficiency efforts should be initiated from heat and electrical energy, which are the main energy types extensively used in the textile industry. Average energy consumption value of the last four years (2015–2018), which is 7134 TOE is reduced 49% including waste heat, flash steam and cooling water recovery, and insulation in dyeing machines, in the factory due to the implementation of the energy saving actions. Accordingly, a reduction of 25% SEC value is possible. Moreover, production planning has a significant impact on the total energy consumption in terms of full load capacity operation of the dyeing machines, which may cause 23% energy saving that is of great importance.

Full-scale membrane bioreactor process WWTPs in East Taihu basin: Wastewater characteristics, energy consumption and sustainability

Based on the collection and analysis of essential data from wastewater treatment plants (WWTPs) in recent ten years, the work provides the wastewater characteristics and energy consumption performance in full-scale membrane bioreactor (MBR) process in East Taihu basin, China. High-quality effluent was achieved although the influent carbon source was not beneficial to total nitrogen and total phosphorus removal. The average specific energy consumption (SEC) was 0.52 kWh/m3, which was remarkably lower than that of full-scale MBR process in developed countries, however, the average SEC value was higher than that of conventional activated sludge (CAS) process in China. In addition, the SEC value was largely reduced in 2018, and the regulation of suction pump and aeration mode were considered as the main control methods. Energy consumption will increase along with the influent volume, while the elevation of COD and NH4+-N reduction will bring about relatively low energy consumption. Furthermore, sustainability index was established to comprehensively evaluate the performance of full-scale MBR process, meaning that with relatively low permeate ratio of effluent, full-scale MBR process presented to be inferior to CAS process in sustainability and not feasible to be applied in the upgradation and construction of WWTPs.

Layered platforms of Ti4O7 as flow-through anodes for intensifying the electro-oxidation of bentazon

In this study, we prepared Ti4O7 porous electrodes with continuous layered structures characterized by different layer-to-layer distance (from 2 to 10 μm) but the same total void fraction (88–90%), to modulate the electrodes' permeability and the volumetric electrochemical surface area (from 90 to 840 cm2 cm−3). These platforms were evaluated as anodes in the electro-oxidation (EO) of bentazon in a three-electrode cell under galvanostatic conditions, operated both in traditional batch (TB) or batch recycle flow-through (BRFT) modes. The performance was significantly enhanced when the liquid was recirculated through the lamellar structure of the electrodes. In BRFT mode, the electrode interlayer gap was found to be a key factor to control the bentazon and total organic carbon (TOC) conversions. For the best conditions evaluated (BRFT, 10 μm-interlayered Ti4O7 electrodes with a volumetric surface area of 90 cm2 cm−3), the effect of the applied current (1 or 3 mA) and liquid flow rate (10, 12 or 14 mL. min−1) was investigated. Specific energy consumption (SEC) values were estimated to reveal the performance of each of the EO treatments from an energetic point of view. The use of 10 μm-interlayered Ti4O7 electrodes at 1 mA in BRFT mode at a flow rate of 14 mL min−1 showed the best results, yielding 85% bentazon removal, 57% mineralization and SEC values of 0.006 kWh.gTOC−1 after 6 h of treatment. This contribution highlights the use of layered Ti4O7 electrodes as a promising strategy for intensifying EO processes, pointing to a trade-off between the accessibility to the internal electrode structure and the volumetric electrode surface area to enhance the contact between the target molecules and the hydroxyl radicals physisorbed on the electrode surface, while minimizing simultaneously the energy requirements.

Improving energy efficiency using the most appropriate techniques in an integrated woolen textile facility

The textile industry has a high share in the total energy consumption of the manufacturing industry, especially in global textile supplier countries. Energy consumption and air emissions can be reduced at the source with detailed cleaner production and energy efficiency applications in textile production processes. In this study, energy efficiency studies were carried out in an integrated woolen textile facility. In this context, energy consumptions were analyzed based on the main production and other preparatory processes by detailed onsite investigations. Specific electricity, thermal energy, and air emissions were calculated based on the production processes of the facility. In addition, specific energy consumption values were compared with similar textile facilities to evaluate energy saving potentials and opportunities. A list consisting of 85 energy efficiency techniques was prepared to reduce energy consumption and air emissions in the facility. These techniques were evaluated and prioritized in terms of techno-economic feasibility, potential savings, and environmental benefits using a systematic decision-making model. Ultimately, it was decided to apply the following priority energy efficiency techniques (a total of 13): process optimization, the establishment of a process-based energy monitoring and control system, the recovery of waste heat, the optimization of steam boilers, the modification of radio frequency (RF) dryers, the modification of fan motors in the ventilation-humidification system, the proper positioning of compressors, the installation of a compressor monitoring system, and an air emission treatment system. It was found that with the application of such techniques, electricity, thermal energy, and air emissions could be reduced by 8–27%, 12–28%, and 23–45%, respectively. Based on the financial analysis, the payback periods of the priority energy efficiency techniques were found to be generally less than 36 months.

Parboiled Paddy Drying with Different Dryers: Thermodynamic and Quality Properties, Mathematical Modeling Using ANNs Assessment.

The effect of hybrid infrared-convective (IRC), microwave (MIC) and infrared-convective-microwave (IRCM) drying methods on thermodynamic (drying kinetics, effective moisture diffusivity coefficient (Deff), specific energy consumption (SEC)) and quality (head rice yield (HRY), color value and lightness) characteristics of parboiled rice samples were investigated in this study. Experimental data were fitted into empirical drying models to explain moisture ratio (MR) variations during drying. The Artificial Neural Network (ANN) method was applied to predict MR. The IRCM method provided shorter drying time (reduce percentage = 71%) than IRC (41%) and microwave (69%) methods. The Deff of MIC drying (6.85 × 10−11–4.32 × 10−10 m2/s) was found to be more than the observed in IRC (1.32 × 10−10–1.87 × 10−10 m2/s) and IRCM methods (1.58 × 10−11–2.31 × 10−11 m2/s). SEC decreased during drying. Microwave drying had the lowest SEC (0.457 MJ/kg) compared to other drying methods (with mean 28 MJ/kg). Aghbashlo’s model was found to be the best for MR prediction. According to the ANN results, the highest determination coefficient (R2) values for MR prediction in IRC, IRCM and MIC drying methods were 0.9993, 0.9995 and 0.9990, respectively. The HRY (from 60.2 to 74.07%) and the color value (from 18.08 to 19.63) increased with the drying process severity, thereby decreasing the lightness (from 57.74 to 62.17). The results of this research can be recommended for the selection of the best dryer for parboiled paddy. Best drying conditions in the study is related to the lowest dryer SEC and sample color value and the highest HRY and sample lightness.