Specific Energy Input Research Articles

Effective practical removal of acetaldehyde by a sandwich-type plasma-in-honeycomb reactor under surrounding ambient conditions

The effective removal of acetaldehyde by humidified air plasma was investigated with a high throughput of contaminated gas in a sandwiched honeycomb catalyst reactor at surrounding ambient temperature. Here, acetaldehyde at the level of a few ppm was successfully oxidized by the honeycomb plasma discharge despite the harsh condition of large water content in the feed gas. The conversion rate of acetaldehyde increased significantly with the presence of catalysts coating on the surface channels. The increased conversion rate was also obtained with a high specific energy input (SEI) and total flow rate. Interestingly, the conversion changed negligibly under the acetaldehyde concentration range from 5 to 20 ppm. However, the conversion rate decreased toward increased water amount in the feed gas. Notably, about 60% of acetaldehyde in the feed was oxidized under SEI of 40 J/L at water amounts ≤ 2.5%, approximately 0.5 g/kWh for acetaldehyde removal. Also, the plasma-catalyst reaction was superior to the thermal reactive catalyst for acetaldehyde removal in airborne pollutants. In comparison with other plasma-catalyst sources for acetaldehyde removal, the energy efficiency under the condition is comparable. Moreover, the honeycomb plasma discharge features high throughput, avoiding pressure drop, and straightforward reactor configuration, suggesting potential practical applications.

Improving the lipid extraction yield from Chlorella based on the controllable electroporation of cell membrane by pulsed electric field

In order to solve the increasingly serious problems of energy and environment, microalgae are used as a raw material for extracting lipids to produce biodiesel. Prior to the extraction of lipids, microalgae were treated with high-voltage pulsed electric field (PEF) to break the cell membrane. It was found that the lipid extraction yield depends on the electric field strength (E) and the specific energy input (Wsp), and has a certain relationship with the cell disintegration rate of Chlorella. The perforation degree of the Chlorella's cell membrane by PEF treatment is controllable, moderate perforation can be ensured by controlling the power parameters. PEF treatment significantly improved the extraction yield of lipids. Compared with the test samples without PEF treatment, PEF treatment increased the lipid extraction yields by up to 166.67%. However, an excessively high voltage will cause the quality of the extracted biodiesel to decrease.

Tuneable material properties of Organosolv lignin biocomposites in response to heat and shear forces

Lignin as a renewable biomacromolecule is considered as a sustainable feedstock for the generation of bioplastics and bioplastic composites. However, during thermoplastic processing, high temperature and mechanical forces are known to promote destructive bond-cleavage in a vast majority of macromolecules due to overheating and internal friction between molecular constituents. This study demonstrates that several material properties (e.g. thermal stability, mechanical properties) of biocomposites with a high Organosolv lignin content (≥50w%) can be tuned by carefully selecting thermal and mechanical energy input during compounding. Organosolv lignin obtained from ensiled grass was shown to undergo in-situ coupling reactions at temperatures below the main degradation point (<200 °C) resulting in an up to 6-fold increase in molecular weight (Mw). The results from Fourier Transform Infrared (FTIR) spectroscopy suggested the formation of ester bonds, which was ascribed to direct esterification reactions, which occur due to energy transfer in the melt phase. When subjecting the extracted lignin to prolonged compounding times, it was shown that higher coupling degrees resulted in a lignin biocomposite with increased stiffness and ultimate tensile stress of about 1800% and 40%, respectively. Temperature was shown to have the highest effect on coupling reactions, whereas the energy transfer by mechanical forces during compounding was lower and followed a non-linear behaviour. In tensile stress–strain curves, biocomposites with high energy input revealed a distinct yield point (16 MPa). Ultra-micro-hardness tests confirmed that the biocomposite became significantly stiffer in response to shear and thermal forces with a reduction in indentation creep Cit of 2.0% to a value of up to 8.5%. Organosolv lignin biocomposites obtained at higher specific energy input (EIN) through thermal energy input and shear forces showed an increased dynamic stiffness Cdyn up to 100%, which was observed by multiple step tests (MST).

Removal of benzene as a tar model compound from a gas mixture using non-thermal plasma dielectric barrier discharge reactor

In the present work, the decomposition of benzene as a tar model compound was studied in a gas mixture (CO2, H2, CO, and CH4) using a dielectric barrier discharge (DBD) non-thermal plasma reactor. The combined effect of temperature and power was studied to investigate the performance of the DBD reactor. The decomposition of tar compound increased from 49.9 to 96% with increasing specific input energy (SIE) from 2.05 to 16.4 kWh/m3. The major products were lower hydrocarbons (C2–C5) and solid residues. The higher temperature (400 °C) in the presence of plasma (40 W), decreased the conversion of tar compound from 96 to 78%. However, the selectivity of lower hydrocarbons increases substantially to 52%, and the formation of solid residues is significantly reduced. Hence, the problematic solid residues formation can be controlled at a higher temperature during the treatment of gasifier product gas using non-thermal plasma.

Grinding Media Motion and Collisions in Different Zones of Stirred Media Mills

Product fineness during grinding in stirred media mills is mainly influenced by the specific energy input, the stress energy transferred by the colliding grinding media and the stress frequency. The stress energy from grinding media collisions is heterogeneously distributed in stirred media mills. Herein, in order to characterize the stress energy distribution and the local grinding media collision frequencies, the grinding media motion was calculated using discrete element method (DEM) simulations coupled with computational fluid dynamics (CFD). The local grinding media concentration, velocity profiles, grinding media collisions and stress energies were compared for varied total grinding media fillings and stirrer speeds. It was confirmed that the normalized grinding media velocity profile can be used to divide the grinding chamber into four types of zones that allow the modeling of the stress energy distribution. However, the collision frequency showed very different distributions for varied stirrer velocities and grinding media fillings.

Experiments and modeling of atmospheric pressure microwave plasma reforming of a methane-carbon dioxide mixture

Atmospheric pressure microwave plasma reforming was conducted on a methane (CH4) and carbon dioxide (CO2) mixture, and characterized by measuring the temperature of the plasma and gas composition of the reforming product via optical emission spectroscopy (OES) and gas chromatographic measurement. The temperature at the plasma reached as high as 5900 K regardless of the specific energy input, while at microwave power of 2 kW and flow rate of 10 slm, nearly all CH4 and CO2 were converted into hydrogen (H2) and carbon monoxide (CO). The plasma temperature higher than the level achievable from uniform gas heating implied that only a part of the flow will enter the plasma region, and the rest will bypass and mix with the plasma stream downstream. Thus, a reactor network-type simulation was performed by modeling the plasma and surrounding streams, each as a series of perfectly-stirred reactors; the reactors at the same downstream locations interacted for the gas diffusion and heat conduction. The simulation reproduced the measured gas compositions well, revealing that the reforming proceeded as the surrounding gas enters and diffuses out of the plasma stream due to the flow mixing, as well as through the heating of the surrounding stream by the plasma stream.

Soft durum wheat as a potential ingredient for direct expanded extruded products

Soft durum wheat was extruded to assess the influence of independent parameters (moisture content, screw speed, and barrel temperature each) on system responses (back pressure, torque value, and specific mechanical energy input) and product responses (expansion ratio, unit density, water absorption index (WAI) and water solubility index (WSI)). The lowest barrel temperature (120 °C) and moisture content (16%) with the highest screw speed (250 rpm) resulted in the highest specific mechanical energy input, expansion ratio, and water solubility index in the extrudates. Among the three independent parameters evaluated, moisture content was the most influential factor on the system and product responses. Energy efficiency on solubility (EES) was defined, and the notable impact of moisture content on EES was observed. Extrudates made from soft durum wheat had a reasonable expansion ratio, proving its potential usage in snack and cereal products.

Selective Release of Recombinant Periplasmic Protein From E. coli Using Continuous Pulsed Electric Field Treatment.

To date, high-pressure homogenization is the standard method for cell disintegration before the extraction of cytosolic and periplasmic protein from E. coli. Its main drawback, however, is low selectivity and a resulting high load of host cell impurities. Pulsed electric field (PEF) treatment may be used for selective permeabilization of the outer membrane. PEF is a process which is able to generate pores within cell membranes, the so-called electroporation. It can be readily applied to the culture broth in continuous mode, no additional chemicals are needed, heat generation is relatively low, and it is already implemented at industrial scale in the food sector. Yet, studies about PEF-assisted extraction of recombinant protein from bacteria are scarce. In the present study, continuous electroporation was employed to selectively extract recombinant Protein A from the periplasm of E. coli. For this purpose, a specifically designed flow-through PEF treatment chamber was deployed, operated at 1.5 kg/h, using rectangular pulses of 3 μs at specific energy input levels between 10.3 and 241.9 kJ/kg. Energy input was controlled by variation of the electric field strength (28.4–44.8 kV/cm) and pulse repetition frequency (50–1,000 Hz). The effects of the process parameters on cell viability, product release, and host cell protein (HCP), DNA, as well as endotoxin (ET) loads were investigated. It was found that a maximum product release of 89% was achieved with increasing energy input levels. Cell death also gradually increased, with a maximum inactivation of -0.9 log at 241.9 kJ/kg. The conditions resulting in high release efficiencies while keeping impurities low were electric field strengths ≤ 30 kV/cm and frequencies ≥ 825 Hz. In comparison with high-pressure homogenization, PEF treatment resulted in 40% less HCP load, 96% less DNA load, and 43% less ET load. Therefore, PEF treatment can be an efficient alternative to the cell disintegration processes commonly used in downstream processing.

Impact of specific energy input of a 915 MHz microwave dryer on quality, functional, and physicochemical properties of different rice cultivars

AbstractBackground and objectivesThe 915 MHz industrial microwave has a great penetration depth relative to the 2.45 GHz microwave and holds the potential to achieve one‐pass drying of deeper rice beds within a short drying duration. The objective of this research is to determine the effect of microwave specific energy on the quality, functional, and physicochemical properties of different rice cultivars. Two rice cultivars were used: a medium grain cultivar (Titan) and a long grain hybrid cultivar (XL753) from two different locations (Burdette and Carlisle). Rice samples at harvest moisture content of 20% wet basis were dried using the 915 MHz industrial microwave at specific energies ranging from 360 to 720 kJ per kg of initial wet grain mass (kJ.[kg‐grain]‐1). Rice physicochemical and functional properties were analyzed.FindingsResults indicate that specific energy had a significant effect (p‐value &lt; 0.0001) on moisture removal and head rice yield. On average, increasing specific energy (drying duration 3–4 min, power 4–6 kW) resulted in increased moisture points removed from 2.5% to 7.3% and 3.7% to 7.5% for long grain hybrids and medium grain cultivars, respectively, while head rice yield decreased. Setback and final viscosities increased while peak viscosity decreased with increasing specific energies. Kernel surface lipid and protein content slightly decreased with increasing specific energies, although specific energy did not have a significant effect on these responses. Resistant starch content decreased with increasing specific energy for hybrid rice. Water and oil absorption capacities varied at different specific energies. The most desirable specific energy for moisture removal that maintains rice quality characteristics (relative to control samples) was 525 kJ.[kg‐grain]‐1.ConclusionsThe 915 MHz industrial microwave has the potential to achieve one‐pass drying of rice. A study of the best specific energy for drying different cultivars of rice using this technology is essential to meet the diverse industrial needs for rice drying.Significance and noveltyThis study provides science‐based information on the properties of different rice cultivars dried using the 915 MHz microwave and selection of desirable microwave parameters for rice drying. The technology has a great potential to transform the rice drying industry by decreasing rice drying duration, improving milling yield, and energy efficiency.

Impact of pre-treatment with pulsed electric field on drying rate and changes in spinach quality during hot air drying

This study aimed to compare the impact of a pulsed electric field (PEF) with that of hot water (HW) and control (CONT) on subsequent drying rate, shrinkage, and quality parameters (degradation of l-ascorbic acid (L-AsA) and color) of spinach during hot air drying. PEF pre-treatment was conducted in 2.8 kV/cm of the electric field strength and 27.1 kJ/kg of the specific input energy. We found that the drying rate for PEF sample was increased compared with CONT and HW samples due to the inhibition of shrinkage during drying. Further, degradation of L-AsA and the surface color in PEF sample were significantly inhibited compared with HW sample, therefore we confirmed that PEF treatment could resolve the elution of water-soluble components caused by HW treatment. These findings showed that pre-treatment with PEF is suitable for reducing drying time and producing high-quality dried spinach.

Physical Characterization of Maize Grits Expanded Snacks and Changes in the Carotenoid Profile.

The objective of this work was to evaluate the effects of feed moisture (13-17%, wb) and barrel temperature (120-160°C) on physicochemical properties, and changes in the carotenoid profile of maize grits extruded snacks. The extrudates were obtained in a single-screw extruder, according to a 32 factorial design with two replicates. The linear coefficients of feed moisture and barrel temperature mainly affected the physicochemical properties. On the other hand, the interaction coefficient β112 dominated the change in total carotenoids, lutein, zeaxanthin, and β-carotene. The quadratic coefficients were also important for changes in total color (regarding feed moisture), and for β-cryptoxanthin, specific mechanical energy, and volumetric expansion index (regarding barrel temperature). β-cryptoxanthin and β-carotene increased, whereas lutein and zeaxanthin decreased. The mathematical models developed from responses revealed two feasible operating regions under the domain explored. For a satisfactory process, from a technological and nutritional point of view, it is suggested to extrude at the operating conditions ranging between 13.2-13.7% feed moisture and 120-132°C barrel temperature. Under these conditions, the specific mechanical energy input required was 410-450kJ/kg, and extrudates with a volumetric expansion index greater than 12, a crispness work less than 0.4N.mm, and with moderate increments in the levels of β-carotene and β-cryptoxanthin were produced. The use of richer cultivars in carotenoids could contribute to the production of healthier snacks.

Effect of grinding media properties and stirrer tip speed on the grinding efficiency of a stirred mill

Owing to their high energy efficiency, stirred mills are commonly used in the fine or ultrafine grinding of low-grade and fine disseminated ores to enhance liberation. In this study, batch wet grinding studies were conducted in a stirred mill to evaluate the effect of the grinding media density, grinding media diameter, and stirrer tip speed on the ground products and specific energy input. The population balance model was used to simulate the particle size distribution of the ground products. The results obtained indicated that the breakage rates S1 and S2 were highly dependent on the operating parameters, while the breakage distribution value b21 was independent of the grinding media density and stirrer tip speed. Additionally, it was observed that the yield of the desired size (−45 + 10 μm) of ground products increased with grinding media diameter. With the increase of grinding media density and stirrer tip speed, the time efficiency of the grinding process was improved. Moreover, the attainable region method via a contour plot was used to produce the maximum amount of the desired size with lower energy. Furthermore, the results revealed that the grinding process became energy inefficient when the grinding time was close to the turning point.

Plasma-enhanced low temperature NH3-SCR of NOx over a Cu-Mn/SAPO-34 catalyst under oxygen-rich conditions

In this work, a dielectric barrier discharge (DBD) plasma-enhanced NH3-selective catalytic reduction (NH3-SCR) of NOx over a Cu-Mn/SAPO-34 catalyst at low temperatures (<200 °C) and oxygen-rich conditions (14 vol.%) has been investigated using a two-stage post-plasma-catalytic (PPC) configuration. The results show a maximum NOx removal of 80 % and a 100 % N2 selectivity without NH3 slip or the formation of by-products at a low specific energy input (SEI) of 32 J/L. Adding water vapor (5.7 vol.%) into the plasma NH3-SCR process does not negatively affect the removal of NOx, while the presence of C3H6 enhances the removal of NOx. In situ diffuse reflectance infrared spectroscopy (DRIFTS) combined with optical emission spectroscopic diagnostics has been employed to elucidate the reaction mechanism in the plasma-catalytic removal of NOx. We find that the formation of NO2 via NO oxidation in the first stage plasma gas-phase reaction enhances the Eley-Rideal (E–R) reaction on the surface of the Cu-Mn/SAPO-34 catalyst in the second stage catalytic NH3-SCR of NOx. The Cu-Mn/SAPO-34 catalyst shows stable performance in the plasma-enhanced NH3-SCR of NOx after 5 cycles of catalyst regeneration. This work has successfully demonstrated a promising low-temperature plasma-catalytic solution for the effective NH3-SCR of NOx.

Application of Pulsed Electric Fields PEF on Pecan Nuts Carya illinoinensis Wangenh. K. Koch: Oil Extraction Yield and Compositional Characteristics of the Oil and Its By-product

Pecan nut oil is conventionally obtained by mechanical extraction characterized by a low oil extraction yield (OEY) compared to solvent extraction. Pulsed electric fields (PEF) have been employed as a pretreatment to enhance OEY from several oilseeds, but no studies have been found regarding tree nut oil. Hence, PEF was applied at different specific energy inputs (0.5–17.6 kJ kg−1) to evaluate its impact on OEY, oil acidity, and antioxidant capacity (AC), along with total phenolics (TP), condensed tannins (CT), and AC of the by-product generated from oil extraction. Kernels treated by PEF were compared against untreated and soaked kernels due to sample water immersion during PEF processing. The water immersion reduced the initial oil content of soaked and PEF-treated kernels (7.3–11.7%), transferring between 3.8 ± 0.0 and 6.2 ± 0.1 g of oil into the soaking water (\({o}_{SW}\)). OEYTOTAL of soaked and PEF-treated samples was calculated considering \({o}_{SW}\). The application of 0.5 kJ kg−1 increased OEYTOTAL by 21.4 and 17.6% compared to untreated and soaked kernels, respectively, while oil acidity and AC of PEF-treated kernels were within values reported for pecan nut oil. The highest concentration of TP and CT in the by-product was achieved at 0.8 kJ kg−1, increasing 9.5 and 30.1%, respectively, compared to untreated kernels. Results evidenced that PEF processing might be a suitable technology to increase OEY from pecan nuts, but the oil extracted during kernels water immersion must be recovered. Furthermore, the by-product of PEF-treated kernels displayed an enhanced content of phenolic compounds increasing its potential as food ingredient.

Removal of cyclohexane as a toxic pollutant from air using a non-thermal plasma: Influence of different parameters

Non-thermal plasmas (NTPs) are a promising technique for abatement of volatile organic compound (VOC) emissions. In this study, the removal of cyclohexane as a toxic pollutant from ambient air was investigated in a dielectric barrier discharge (DBD) reactor at ambient temperature and atmospheric pressure. The effect of specific input energy (SIE) (1.2–3 kJ/L), carrier gases, residence time (1.2–2.3 s) and concentration (220–520 ppm) was evaluated. This work demonstrated that the removal efficiency of cyclohexane increased with increasing specific input energy and residence time. The removal of cyclohexane decreased with increasing concentration at constant SIE and residence time. The main decomposition products were CO2, H2, and lower hydrocarbons (C1–C4). The maximum removal efficiency (98.2%) was achieved at a specific input energy of 3 kJ/L and a residence time of 2.3 s in humidified air. Moreover, maximum O3 concentrations (<10ppm) were observed at 3.0 kJ/L SIE in dry air. NOX was not detected, in any carrier gas. The effect of the presence of water vapour was investigated to determine whether it would reduce the formation of solid residue in the DBD reactor. One of the key findings was that humidification of the air at 25% entirely prevented the formation of solid deposits in the reactor. Humidification not only improved the removal efficiency of cyclohexane, but also increased the yield of H2 and CO2 selectivity. This was due to the formation of potent OH. radicals. In general, this study demonstrates that cyclohexane vapour in air can be almost 100% decomposed to smaller molecules by a non-thermal plasma DBD reactor by optimizing specific input energy (SIE), residence time, humidity, reactor configuration and plasma properties.

Pulsed electric fields (PEF) treatment to enhance starch 3D printing application: Effect on structure, properties, and functionality of wheat and cassava starches

This work evaluated the impact of PEF on the structure, properties, and functionality of wheat and cassava starches focusing on 3D printing application. Aqueous starch suspensions were PEF-treated using three different combinations of field strength and total specific energy input (T1:15 kV/cm;25 kJ/kg; T2:25 kV/cm;25 kJ/kg; and T3:25 kV/cm;50 kJ/kg). The three conditions had the same effect on cassava starch (no damage on granules surface, reduction of peak apparent viscosity, firmer gels), while T3 promoted a greater effect on wheat starch (fractures on granules surface, reduction in peak apparent viscosity, and firmer gels). T3 condition was selected for further evaluation, revealing depolymerization, reduction of relative crystallinity, and gelatinization enthalpy, but no changes in functional groups. PEF-treated wheat starch resulted in 3D printing with a smoother surface and different texture, while PEF-treated cassava starch showed the same performance of native starch. Therefore, PEF affects differently each source, potentially enhancing 3D printing applications.

A novel energy efficient path for nitrogen fixation using a non-thermal arc.

Plasma-assisted nitrogen fixation is a promising sustainable and clean alternative to the classical Haber–Bosch process. However, the high energy consumption and low production rate of plasma-assisted nitrogen fixation limit its application. This study shows that the non-thermal (non-equilibrium) enhancement of the arc plasma significantly reduces the energy consumption of nitrogen fixation. The highest energy efficiency with high NO selectivity is observed with a low specific energy input (SEI). However, the highest production rate is reached at a high SEI. The studied process offers high NO selectivity (up to 95%) with low energy consumption (∼48 GJ per tN) at 0.1 kJ L−1 SEI, which is much lower than the previously reported value of plasma-assisted atmospheric nitrogen fixation and is close to that of the Haber–Bosch process.

Impacts of Specific Power of Microwave at 915 MHz Frequency on Drying and Milling Characteristics of Parboiled Rough Rice

HighlightsThis research investigated the feasibility of using a microwave (MW) set at 915 MHz frequency to dry high moisture content (MC) parboiled rough rice at 44.3% MC dry basis (d.b.).The research evaluated the impacts of specific power delivered during the drying of parboiled rough rice using a MW on post-drying milling characteristics.The volumetric heating phenomenon provided by MW offered a method to quickly remove 23.1% points of moisture from parboiled rough rice in one-pass to a MC of 21.2% d.b., with minimal impacts on the kernel quality.The findings suggest that increased MW specific powers have a positive effect on rice MC reduction but negatively affects the rice milling characteristics, especially the head rice yield.The study recommended that MW specific powers exceeding 2.92 kW.[kg-DM]-1 should not be exceeded during drying of parboiled rough rice to preserve the rice milling yields.ABSTRACT. The objectives of this research were to study the impacts of specific power of MW generated at 915 MHz frequency to dry high MC parboiled rough rice on moisture removal and milling characteristics of the parboiled rough rice. Long-grain rough rice of the cultivar (cv.) Mermentau at harvest MC of 31.6% dry basis (d.b.) was parboiled by soaking at 73°C for 3 h and then steamed at 67 kPa for 10 minutes. Following the parboiling process the sample was subjected to the MW drying. The drying was accomplished at MW specific powers that ranged from 1.10 to 8.77 kW. [kg-DM] -1 and 0.37 to 2.92 kW. [kg-DM] -1 (power per unit dry matter mass of the grain). These treatment levels of MW specific power were varied by heating parboiled rough rice for 2 and 6 minutes (min) at MW powers that ranged from 1 to 24 kW. The process of parboiling increased the rough rice MC to 44.3% dry basis (d.b.). During the MW drying, as the specific power increased, the general tendency was for rough rice final moisture content (FMC), milled rice yield (MRY) and head rice yield (HRY) to decrease while the drying rate increased. Parboiled rough rice samples treated with a specific power of 8.77 kW.[kg-DM] -1 while maintaining specific energy input at 0.29 kWh.[kg-DM] -1 had least-square means FMC, drying rate, MRY and HRY of 19.7% d.b. (S.D ± 1.1%), 12.3% d.b. [min-1] (S.D ± 0.8%) (2 min drying duration), 68.18% (S.D ± 1.70%) and 67.51% (S.D ± 0.73%) respectively. However, treatment at a lower specific power of 2.92 kW.[kg-DM] -1 while maintaining the same specific energy input of 0.29 kWh.[kg-DM]-1) resulted in least-square means FMC, drying rate, MRY and HRY of 21.2% d.b. (S.D ± 0.5%), 3.9% d.b. [min-1] (S.D ± 0.1%) (2 min drying duration), 73.22% (S.D ± 0.84%) and 73.21% (S.D ± 0.21%) respectively. The increased drying rates for treatments with higher specific power was associated with higher treatment powers and shorter treatment durations. Higher specific powers negatively impacted the observed MRY and HRY. The findings suggest that increased MW specific powers have a positive effect on rice MC reduction but above a certain threshold of specific power (2.92 kW.[kg-DM]-1) may negatively affect the milling characteristics of the parboiled rice. When used to dry high MC parboiled rough rice, rice processors should know that there exists an optimum drying rate that if exceeded the milled rice quality is negatively affected thus generating an economic loss to the parboiled rice industry. The volumetric heating phenomenon provided by microwave (MW) offers a means to quickly dry high MC parboiled rough rice. This can translate to considerable economic savings for the rice processor who often experiences low drying rates because of limited drying capacity, especially at peak rice harvest times. When drying rates are optimized, rice processors can expect minimal impacts on the kernel quality which can also be translated to considerable economic savings for the rice processor. Keywords: 915 MHz microwave, Microwave drying, Milling Quality, Parboiled rice, Specific power.

Lignocellulosic Analysis of Corncob Biomass by Using Non-Thermal Pulsed Electric Field-NaOH Pretreatment

In recent years, the second-generation bioethanol and advanced bio-based material production from biomass are focused on the pretreatment process by separating cellulose components from other components such as lignin and hemicellulose. Therefore, a physicochemical pretreatment method is needed by applying a non-thermal pulsed electric field (PEF) and alkali methods to increase the cellulose availabilities with a short process and low energy input. The aim of this study was to analyze the lignocellulose content of corncob biomass by using non-thermal pulsed electric fields (PEF) and NaOH pretreatment. The pretreatment factors used were the electric field strength of PEF and the pretreatment time. Analysis of the structure and elements of the lignocellulose based on the characteristics of the gravimetric method and SEM-EDX for untreated and treated samples. The results showed that pretreatment of corncobs biomass by using PEF optimally at an electric field strength of 9 kV/cm and pretreatment time of 60 seconds that was increasing cellulose of 40.59% when compared with the control and also decreasing the hemicellulose and lignin content of 12.9% and 2.02%, respectively. Under these conditions, the energy per pulse and specific input energy of PEF required 0.0205 J and 8.72 kJ/L, respectively. The microstructure analysis by using SEM-EDX showed significantly visual differences and was an increase in the percentage of C and O atoms between untreated and treated corncob biomass. Furthermore, the corncob biomass treated by using non-thermal PEF and alkali can become effective and efficient for the next process into cellulose-derived products.Keywords: corncob biomass; pulsed electric field; NaOH; pretreatment; cellulose

Polyurethane foam: A novel support for metal oxide packing used in the non-thermal plasma decomposition of CO2

Regarding the growing rate of CO2 emission into the environment which is accompanied by environmental issues, its recovery and utilization are of great importance, but the existing conventional methods are not sufficiently economical due to high energy requirements. Thus, in this study, low temperature CO2 dissociation through a packed dielectric barrier discharge (DBD) plasma reactor is investigated. Three-dimensional polyurethane foam (PU foam) with inter-connected porous structure is incorporated in the discharge volume of the DBD for the first time to evaluate its effects on the conversion and efficiency. In addition, for further improvement of the process, various packing materials including BaTiO3, TiO2, CeO2, ZrO2, CaO, Al2O3, Fe3O4, and SiO2 are coated over the PU foam and the corresponding results are compared. Results demonstrate that the foam-filled configuration can boost the conversion and energy efficiency relative to empty plasma. Interestingly, the plasma performance enhances more remarkably when the packing materials are coated over the foam. According to the results, presence of packing materials can exert physical effects over the performance of plasma. BaTiO3 exhibits the best performance regarding its highest effects. The highest obtainable conversion for the BaTiO3-coated configuration at the Specific Energy Input (SEI) of 60 kJ/L is nearly 27.4 %, showing 124 and 203 % enhancement in comparison with foam-filled and empty plasma configurations, respectively.