The objectives of this study were to analyze the effects of drying employing three different heat sources on drying kinetics and to evaluate qualities of parboiled rice after drying. Drying temperature was varied between 60 and 100C. Power of infrared (IR) heat source was fixed at 1,000 and 1,500 W and air flow rate was fixed at 1.0 ± 0.2 m/s. The three drying strategies composed of hot air (HA), IR and combined HA + IR drying. The experimental results were simulated using various equilibrium moisture content models and the mathematical drying model for prediction of drying kinetics and evaluation of effective diffusion coefficient (Deff) followed by Fick's law of diffusion. The results revealed that Deff values of HA and IR drying were in the range of 10−12–10−11 m2/s and relatively depended on temperature. For quality evaluation, conclusions reached that head rice yield using HA + IR drying had the highest value, while yellowness and whiteness of the parboiled rice are significantly affected by drying condition (P > 0.05). Practical Applications These results suggested that combined hot air and infrared (HA + IR) drying offers a great potential for preserving Leb Nok Pattani parboiled rice. Drying kinetics and quality aspects determined that IR drying is more efficient than the other drying method. However, the color degradation in the grain kernel is an issue for quality measurement.

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A simple wire-plate electrostatic precipitator (ESP) was constructed in order to test the efficiency of collecting smoke particles from combustion of rubber-wood that is used as a source of biomass energy. The ESP contains a maximum of 15 collection plate electrodes and 20 wire electrodes per row between plates. The maximum input voltage of the Wheatstone bridge circuit using a high-voltage neon transformer was 13.5 kV (DC). The gap between plates and the distance between wires were adjustable. Results from the field test in a furnace indicate that the device could be used for a period of about one hour before cleaning the electrodes was required. The collection efficiency was decreased during the course of wood burning as the dust loading increased. Maximum efficiency was near 80% during the initial period. The distance between the collection plate electrodes had a greater influence on efficiency than the distance between the wire electrodes. The cleaning system used in this experiment was made from a row of PVC pipes to allow water to discharge radially to the plate electrodes on both sides. This system was equipped with the case of maximum collection efficiency that had a 50 mm gap between collection plate electrodes and a 64 mm distance between wire electrodes. Efficiency was increased after 120 minutes and maintained a collection efficiency of about 60%. This ESP is suitable for small and medium-sized enterprises (SMEs) to alleviate the release of detrimental chemicals such as PAHs into the atmosphere.

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Please cite this article as: Palamanit A., Khongphakdi P., Tirawanichakul T., Phusunti N. Investigation of yields and qualities of pyrolysis products obtained from oil palm biomass using an agitated bed pyrolysis reactor.

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Asymmetric polysulfone (PSF) gas separation membranes were prepared at different conditions such as non‐solvent concentration, evaporation time (ET) and coagulation bath temperature (CBT). In addition, effects of low‐pressure DC glow discharge plasma on the characteristics of PSF membranes were investigated. PSF membranes both before and after plasma treatment were characterized by several techniques, including contact angle measurement, scanning electron microscope (SEM), dynamic mechanical thermal analysis (DMTA), and atomic force microscopy (AFM). Furthermore, the performance of membranes was evaluated in terms of permeability of CO2, CH4, O2, and N2 gases. The ideal selectivity of CO2/CH4 and O2/N2 and surface free energy was calculated. Results showed that the EtOH concentration, ET and CBT affect the morphology of PSF membranes. For membranes prepared from a casting solution consisting of PSF 26.0, NMP 28.0, THF 28.0, and EtOH 18.0 wt % and ET for 3 min, the maximum selectivity of untreated membrane is about 69.76 and 12.59 for CO2/CH4 and O2/N2, respectively. After plasma treatment, the ideal selectivity is receded; however, the CO2/CH4 is still higher than 40.41 at pressure of 5 bars. Finally, preparation conditions and DC glow discharge plasmas have significant effects on the characteristics of the PSF membranes and result in an increase of the gas permeation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42116.