Evaluation of Infrared Radiation Combined with Hot Air Convection for Energy-Efficient Drying of Biomass

Cost-effective biomass drying is a key challenge for energy recovery from biomass by direct combustion, gasification, and pyrolysis. The aim of the present study was to optimize the process of biomass drying using hot air convection (HA), infrared (IR), and combined drying systems (IR-HA). The specific energy consumption (SEC) decreased significantly by increasing the drying temperature using convective drying, but higher air velocities increased the SEC. Similarly, increasing air velocity in the infrared dryer resulted in a significant increase in SEC. The lowest SEC was recorded at 7.8 MJ/kg at an air velocity of 0.5 m/s and an IR intensity of 0.30 W/cm2, while a maximum SEC (20.7 MJ/kg) was observed at 1.0 m/s and 0.15 W/cm2. However, a significant reduction in the SEC was noticed in the combined drying system. A minimum SEC of 3.8 MJ/kg was recorded using the combined infrared-hot air convection (IR-HA) drying system, which was 91.7% and 51.7% lower than convective and IR dryers, respectively. The present study suggested a combination of IR and hot air convection at 60 °C, 0.3 W/cm2 and 0.5 m/s as optimum conditions for efficient drying of biomass with a high water content.

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A New Re-Fuel System to Process High Water Content Waste to Solid Fuel Using Superheated Steam

ASME 2008 Power Conference ◽

10.1115/power2008-60164 ◽

2008 ◽

Author(s):

Naoki Maruyama ◽

Daisuke Tanaka ◽

Toshiki Shimizu

Keyword(s):

Energy Consumption ◽

Water Content ◽

Solid Fuel ◽

Fossil Fuels ◽

Superheated Steam ◽

High Water ◽

High Water Content ◽

Waste Incinerator ◽

Impact Reduction ◽

Drying System

The increase of waste and the dryness of natural resources including fossil fuels have become serious problems for the sustainable development of industrial activities and our daily living. A great deal of human effort has been put into the careful use of finite resources and environmental impact reduction. The appropriate processing and the effective use of waste are really in demand in light of our social responsibility for manufacturing and energy development. In addition, the construction of a new recycle system for production is also important from the standpoint of the manufacturer’s responsibility. A procedure is being developed to process industrial and municipal wet wastes to solid fuel, called Refuse paper & plastic fuel (RPF), using superheated steam. A drying system using superheated steam is drawing much attention for use with drying high water content materials due to its high thermal efficiency. A material recycle system for processing high water content waste to solid fuel will be introduced in the present study using a demonstration system, and the optimum conditions for the system operation will be examined. The temperature and the quantity of superheated steam required for material drying are evaluated, and the energy consumption and emissions from the system are theoretically estimated and compared. The purpose of this paper is to test-operate a practical waste recycle system, and the results of this new system are compared with the results from a waste incinerator. The effectiveness of a drying system using superheated steam is shown from the standpoint of the reduction of CO2 emissions and energy consumption for the waste processing.

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Quality of Milled Rice from Large-Scale Dried Paddy Rice by Hot Air Combined with Radio Frequency Heating

Processes ◽

10.3390/pr9122277 ◽

2021 ◽

Vol 9 (12) ◽

pp. 2277

Author(s):

Karn Chitsuthipakorn ◽

Sa-nguansak Thanapornpoonpong

Keyword(s):

Moisture Content ◽

Radio Frequency ◽

Block Design ◽

Specific Energy Consumption ◽

Brown Rice ◽

Convective Drying ◽

Control Treatment ◽

Rf Heating ◽

Drying Time ◽

Hot Air

A scaled-up process for paddy drying was developed using hot air (HA) combined with radio frequency (RF) heating. The study was conducted using hot air (control treatment) arranged in descending order in four temperature levels, namely 80 °C at moisture content of 25–26%, 70 °C at moisture content of 20–25%, 60 °C at moisture content of 17–20%, and 50 °C at moisture content of 13–17%, as well as with hot air combined with radio frequency (HA/RF) at different paddy temperatures (45–60 °C) by adjusting the appropriate RF energy when passing through RF heating chamber, namely HA/RF45, HA/RF50, HA/RF55, and HA/RF60. Each treatment was performed in three replicates and data were statistically analyzed in a randomized complete block design. The quality attributes of paddies affected by the drying process were assessed: fissure percentage, color, milling quality, and sensory evaluation. The drying efficiency showed that the drying time and the specific energy consumption could be decreased by up to 54.44% and 23.17% at HA/RF60 and HA/RF45, respectively. As the RF heating temperature increased, the fissure percentage of brown rice kernels at HA/RF45 and HA was not significantly impacted. Regarding color evaluation, combining RF heating and convective drying at all given conditions could be statistically applied in terms of the b*, WI, and ΔE* value. Considering the milling yield of HA as the baseline, head rice yield was maximized at HA/RF45, while bran yield reached the maximum at HA/RF60. The liking score of cooked rice after it was dried using the HA method was the highest. This study concludes that the HA/RF45 was the most appropriate drying condition, and this may provide preliminary exposure to the industrial drying of paddies.

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Separation of Alcohol-Water Mixtures by a Combination of Distillation, Hydrophilic and Organophilic Pervaporation Processes

Membranes ◽

10.3390/membranes10110345 ◽

2020 ◽

Vol 10 (11) ◽

pp. 345

Author(s):

Huyen Trang Do Thi ◽

Peter Mizsey ◽

Andras Jozsef Toth

Keyword(s):

Water Content ◽

Liquid Waste ◽

Cost Effective ◽

High Water ◽

High Water Content ◽

Volatile Components ◽

Aqueous Mixtures ◽

Alcohol Water ◽

Organophilic Pervaporation ◽

The Cost

It can be stated that in the fine chemical industries, especially in the pharmaceutical industry, large amounts of liquid waste and industrial waste solvents are generated during the production technology. Addressing these is a key issue because their disposal often accounts for the largest proportion of the cost of the entire technology. There is need to develop regeneration processes that are financially beneficial to the plant and, if possible, reuse the liquid waste in the spirit of a circular economy, in a particular technology, or possibly elsewhere. The distillation technique proves to be a good solution in many cases, but in the case of mixtures with high water content and few volatile components, this process is often not cost-effective due to its high steam consumption, and in the case of azeotropic mixtures there are separation constraints. In the present work, the membrane process considered as an alternative; pervaporation is demonstrated through the treatment of low alcohol (methanol and ethanol) aqueous mixtures. Alcohol-containing process wastewaters were investigated in professional process simulator environment with user-added pervaporation modules. Eight different methods were built up in ChemCAD flowsheet simulator: organophilic pervaporation (OPV), hydrophilic pervaporation (HPV), hydrophilic pervaporation with recirculation (R-HPV), dynamic organophilic pervaporation (Dyn-OPV), dynamic hydronophilic pervaporation (Dyn-HPV), hybrid distillation-organophilic pervaporation (D + OPV), hybrid distillation-hydrophilic pervaporation (D + HPV), and finally hybrid distillation-hydrophilic pervaporation with recirculation (R-D + HPV). It can be stated the last solution in line was the most suitable in the terms of composition, however distillation of mixture with high water content has significant heat consumption. Furthermore, the pervaporation supplemented with dynamic tanks is not favourable due to the high recirculation rate in the case of tested mixtures and compositions.

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Drying characteristics of eggplant (Solanum melongena L.) slices under microwave-convective drying

Research in Agricultural Engineering ◽

10.17221/13/2015-rae ◽

2016 ◽

Vol 62 (No. 4) ◽

pp. 170-178 ◽

Cited By ~ 4

Author(s):

R.A. Chayjan ◽

M. Kaveh

Keyword(s):

Air Temperature ◽

Microwave Power ◽

Specific Energy Consumption ◽

Solanum Melongena ◽

Moisture Diffusivity ◽

Moisture Ratio ◽

Convective Drying ◽

Air Velocity ◽

Drying Time ◽

Thin Layer Drying

A laboratory scale microwave-convection dryer was used to dry the eggplant fruit, applying microwave power in the range of 270–630 W, air temperature in the range of 40–70°C and air velocity in the range of 0.5–1.7 m/s. Six mathematical models were used to predict the moisture ratio of eggplant fruit slices in thin layer drying. The results showed that the Midilli et al. model had supremacy in prediction of turnip slice drying behavior. Minimum and maximum values of effective moisture diffusivity (Deff) were 1.52 × 10–9 and 3.39 × 10–9 m2/s, respectively. Activation energy values of eggplant slices were found between 13.33 and 17.81 kJ/mol for 40°C to 70°C, respectively. The specific energy consumption for drying eggplant slices was calculated at the boundary of 86.47 and 194.37 MJ/kg. Furthermore, in the present study, the application of Artificial Neural Network (ANN) for predicting the drying rate and moisture ratio was investigated. Microwave power, drying air temperature, air velocity and drying time were considered as input parameters for the model.

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Investigation of some pretreatments on energy and specific energy consumption drying of black mulberry

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq111120045a ◽

2013 ◽

Vol 19 (1) ◽

pp. 89-105 ◽

Cited By ~ 7

Author(s):

Esmaeili Adabi ◽

Ali Motevali ◽

Ali Nikbakht ◽

Hadi Khoshtaghaza

Keyword(s):

Energy Consumption ◽

Microwave Heating ◽

Specific Energy ◽

Specific Energy Consumption ◽

Ethyl Oleate ◽

Hot Water ◽

Control Treatment ◽

Hot Air ◽

Air Convection ◽

Air Dryer

Massive consumption of energy in drying industry makes it a matter of challenge regarding economical aspects and limited recourses. Several methods for drying including hot air convection, vacuum, infrared and hot air convection-infrared technologies were applied in order to estimate the consumed energy during the drying of mulberry fruit. Moreover, microwave heating, chemical (ethyl oleate and potassium), mechanical (ultrasonic) and blanching (hot water) pretreatments were compared. According to the Results, maximum energy consumption was recorded when no pretreatment was performed. Microwave heating in the hot air convection-infrared dryer resulted in the lowest consumption of energy. Total energy requirement decreased with the temperature in the convection dryer res. Conversely, energy increased with air velocity. The vacuum dryer consumed the highest amount of energy which was measured to be 46.95 kWh while the lowest energy was recorded with using infrared-convective dryers. Also Experimental results showed that minimum and maximum specific energy consumption in the drying of black mulberry were associated with microwave pretreatment in IR-hot air dryer and control treatment in vacuum dryer, respectively. The minimum color change (?E) for drying of black mulberry was found in microwave pretreated samples dried with the vacuum dryer, yet maximum ?E was observed in hot air dryer when no pretreatment was applied.

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A versatile simulator for defrosting, convective and boiling drying during hot air frying process

10.46354/i3m.2021.foodops.003 ◽

2021 ◽

Author(s):

Daniel Goujot ◽

Têko Gouyo ◽

Philippe Bohuon ◽

Francis Courtois

Keyword(s):

Water Content ◽

Water Vapour ◽

Central Compartment ◽

High Water ◽

High Water Content ◽

Peripheral Compartment ◽

Warm Up ◽

Frying Process ◽

Hot Air ◽

Intermediate Compartment

"A versatile simulator takes into account four major stages: defrosting, warm-up, and convective and boiling drying. This dynamic model considers that a frozen prefried french fries has three compartments: a central compartment (#1) with high water content, a peripheral compartment (#3) corresponding to the prefried dry crust, and an intermediate compartment (#2) appears during frying, filled with water vapour. Convective and boiling drying and freezing are modeled. The predicting model has been identified based on the triplicates of three different modalities. The resulting predictions have been experimentally validated."

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Estimation of Moisture Ratio and Specific Energy Consumption for Apple Slices Drying by Convective and Microwave Methods using Neural Network Modeling

10.21203/rs.3.rs-138330/v1 ◽

2021 ◽

Author(s):

Vali Rasooli Sharabiani ◽

Abdi Roozbeh ◽

Mohammad Kaveh ◽

Mariusz Szymanek ◽

Wojciech Tanaś

Keyword(s):

Specific Energy Consumption ◽

Effective Diffusivity ◽

Moisture Ratio ◽

Microwave Drying ◽

Convective Drying ◽

Neural Network Modeling ◽

Drying Methods ◽

Air Velocity ◽

Apple Slices ◽

Drying Technology

Abstract Two different drying methods were applied for dehydration of apple, i.e., convection drying (CD) and microwave drying (MD). The process of convection drying through divergent temperatures; 50, 60 and 70°C at 1.0 m/s air velocity and three different levels of microwave power (90, 180, and 360 W) were studied. In the analysis of the performance of our approach on moisture ratio of apple slices, artificial neural networks (ANNs) was used to provide with a background for further discussion and evaluation. In order to evaluate the models mentioned in the literature, the Midilli et al. model was proper for dehydrating of apple slices in both MD and CD. The microwave drying technology enhanced the drying rate when compared with convective drying significantly. Effective diffusivity of moisture in CD drying (1.95×10−7 - 4.09×10−7 m2/s) was found to be lower than that observed in MD (2.94×10−7–8.21×10−7 m2/s). The Ea values of convective drying and microwave drying were 122.28- 125 kJ/mol and 14.01- 15.03 W/g respectively. The MD had the lowest SEC as compared to CD drying methods. According to ANN results, the best values for predication of MR in CD and MD were 0.9993 and 0.9990, respectively.

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Kinetic parameters identification of conductive enhanced hot air drying process of food waste

Thermal Science ◽

10.2298/tsci200312223m ◽

2020 ◽

pp. 223-223

Author(s):

Mihailo Milanovic ◽

Mirko Komatina ◽

Ivan Zlatanovic ◽

Nebojsa Manic ◽

Dragi Antonijevic

Keyword(s):

Food Industry ◽

Convective Drying ◽

Diffusivity Coefficient ◽

Drying Method ◽

Drying Process ◽

Air Velocity ◽

Drying Time ◽

Hot Air ◽

Air Temperatures ◽

Drying Curves

The efficient utilization of waste from food industry is possible after thermal treatment of the material. This treatment should be economically feasible and compromise the energy efficient drying process. The main goal of this investigation is to determine drying characteristics of nectarine pomace as a waste from food industry. The measurements were performed in an experimental dryer by combined conductive-convective drying method with disk-shaped samples of 5, 7 and 10mm thickness and 100 mm in diameter at the air temperatures of 30, 40, 50, 60 and 70oC, hot plate temperatures of 50, 60 an 70oC and air velocity of 1.5 m/s. The drying curves were compared to a few semi-theoretical mathematical models. The Logarithmic model showed the best correspondence. On the basis of experiments, it is determined that the drying process takes place in a falling rate period and it is accepted that the main mechanism of moisture removal is diffusion. The effective coefficient of diffusion was determined using experimental results by calculating the slope of the drying curves. Drying time and equilibrium moisture are determined for each experiment. Analysis of drying curves showed that the conductive-enhanced drying method reduces drying times and increases the diffusivity coefficient. The character of drying rate curves for conductive-enhanced drying was analyzed and compared with pure convective drying of nectarine pomace.

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Effect of microwave, infrared, and convection hot-air on drying kinetics and quality properties of okra pods

International Journal of Food Engineering ◽

10.1515/ijfe-2021-0125 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Hany S. EL-Mesery ◽

Mona A. Elabd

Keyword(s):

Energy Consumption ◽

Air Temperature ◽

Specific Energy ◽

Specific Energy Consumption ◽

Drying Methods ◽

Air Velocity ◽

Rehydration Ratio ◽

Drying Time ◽

Shrinkage Ratio ◽

Hot Air

Abstract Okra pods were dried using the following drying regimes; microwave (MWD), infrared (IRD) and convective hot-air drying (CHD). The objective of this investigate was to report the influences of drying methods on okra quality under different drying conditions. Data analysis showed that rehydration ratio and colour change increased with increase in drying air temperature and air velocity while specific energy consumption and shrinkage ratio decreased with increase in drying air temperature under (CHD). The rehydration ratio and colour of dried okra increased with increase in both infrared intensity but it also increased with a decrease in air velocity under (IRD). In the MWD method, drying time, specific energy consumption and shrinkage ratio decreased with increases in microwave power while the rehydration ratio and colour increased. Optimum drying period, specific energy consumption, colour, shrinkage and rehydration ratio were obtained for microwave drying. The model of Midilli et al. is the greatest for describing the drying curves of okra under all the drying processing conditions.

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Experimental Investigation to Evaluate the Effective Moisture Diffusivity and Activation Energy of Cassava (Manihot Esculenta) under Convective Drying

Applied Science and Engineering Progress ◽

10.14416/j.asep.2021.10.008 ◽

2021 ◽

Author(s):

Pathiwat Waramit ◽

Bundit Krittakom ◽

Ratinun Luampon

Keyword(s):

Activation Energy ◽

Type Equation ◽

Moisture Diffusivity ◽

Experimental Results ◽

Effective Moisture Diffusivity ◽

Convective Drying ◽

Air Velocity ◽

Drying Time ◽

Hot Air ◽

Effective Moisture

Investigation of effective moisture diffusivity (Deff) and activation energy (Ea) of cassava were conducted under convective drying at temperature and velocity of 60, 70 and 80 °C, and 1.0, 1.5 and 2.0 m/s, respectively. In the experiment, cassava was sliced into 3 mm-thickness and dried under given conditions until mass was saturated. Deff and Ea were described by Fick’s second law and Arrhenius-type equation, respectively. The experimental results indicated that the increase in Deff was significantly affected by increasing the hot air temperature and velocity. The slope method was used to calculate average Deff, and results were found to range from 3.83 × 10–9 – 9.86 × 10–9 m2/s. The Ea was found to decrease with an increase in hot air velocity, ranging from 21.23– 24.92 kJ/mol. Additionally, Moisture content (Mw) and Drying rate (DR) were also used to describe the drying kinetics. From the experimental results, Mw and DR decreased with an increase in drying time. DR increased with an increase in temperature and velocity causing Mw to rapidly decrease and drying time to reduce. The highest DR was found to be 0.55 gwater/min at temperature of 80 °C and velocity of 2.0 m/s.

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