The production of starch based bioplastic from durian seed as polymer matrix with addition of chitosan as filler and sorbitol as plasticizer were investigated. The aim of this research to obtain the effect of hydrochloric acid concentration as chitosan solvent on the mechanical properties of bioplastics included tensile strength, elongation at break, modulus young, functional group using FT-IR, surface morphology using SEM. Starch is the raw material for bioplastics which extracted by the durian seeds, then characterized to determine its chemical composition. The method of bioplastic production used in this research was casting method. Variation of hydrochloric acid concentration used 0.9%v, 1.0%v, 1.1%v, 1.2%v and 1.3%v. Bioplastic were analyzed physical and chemical properties. From the analysis, best condition of bioplastics obtained at hydrochloric acid concentration 0,9%v with temperature 70 o C for tensile strength 10,629 MPa, elongation at break 8,207%, and modulus young 129,514 MPa. From the results of FT-IR analysis indicated O-H group and N-H group on bioplastics due to the addition of chitosan and sorbitol. The results of mechanical properties were supported by Scanning Electron Microscopy (SEM) showed the bioplastic with chitosan as filler and plasticizer sorbitol have the fracture surfaces were a bit rough and jagged.

Empty fruit bunches (EFB) of the oil palm have great potential to be used as industrial fibers in various industries, such as fiber board, mattress and cushion, erosion controller, thermoplastic filler, paper, acoustics control, sound insulator, and animal feed industries. A rotary drum dryer with a flue gas drying medium has been conventionally used to dry EFB fibers. However, this drying system tends to produce highly entangled and blackened fiber. Furthermore, the uneven contact between the flue gas and fiber in the rotary dryer may cause nonuniformity in the moisture content of the product. To overcome this problem, the present work uses superheated steam as the drying medium for EFB fiber drying. The drying experiments were carried out at the following conditions: atmospheric pressure; temperature range 112–172 °C; steam superficial velocity in the range 0.14‐4.3 m/s, distance from steam nozzle to EFB in the range 50–200 mm; and size of holes on plate in the range 10–200 mesh. The initial fiber moisture content was in the range 0.96‐1.46 kg/kg dry basis. The mass loss of EFB fiber during the drying process was periodically measured using an analytical balance connected directly to the wire mesh plate when the steam was diverted momentarily so that the effect of momentum transfer between the steam and the sample holder is minimized. In the temperature range 112–172 °C and at atmospheric pressure, the equilibrium moisture content isotherm is found to follow an exponential equation with coefficient ke = 15.365 kg/kg, ne = —0.001 °C−me and power index me = 1.869. It was found that for maximum moisture removal, the temperature and steam superficial velocity was 142 °C and 0.39 m/s, respectively. The effect of steam velocity is greater than that of steam temperature in decreasing the moisture content. The drying rate initially increases to a maximum and then falls off exponentially thereafter. A new drying model was developed for superheated steam for drying of EFB fiber, which is given by MR = 1 − atnexp(−ktm). The increasing drying rate is largely described by the exponential term with the coefficient k having values ranging from 1.945 to 5.351 s−n and the index m having values ranging from − 0.843 to 1.198. The falling drying rate is largely described by the power law term with the coefficient a ranging in value from 0.453 to 1.027 s−m and the power index n ranging in value from 0.0415 to 0.317. The drying is best carried out with the plate at a distance of 150 mm from the sample holder containing a 50 mesh plate. The superheated steam through the drying system can successfully reduce the moisture content by almost 100% in 15 min without steam condensation during the drying process. Copyright © 2007 Curtin University of Technology and John Wiley & Sons, Ltd.

Conventional drying of the fibers from oil palm empty fruit bunches (EFB) using flue gas from diesel burners frequently causes browning and dust explosion. Replacing the drying medium with superheated steam is expected to improve the quality of EFB fibers as well as improve the safety of the dryer operation. In this study, the effects of steam temperature and steam velocity on the quality of steam-dried EFB fibers was investigated. The drying experiment was carried out at atmospheric pressure with steam superficial velocity in the range of 0.3 to 0.49 m s -1 and temperature in the range of 135 to 200 C. Three quality parameters of the EFB fibers, the color, strength, and microstructure, were used to assess the changes in EFB fiber quality as a result of superheated steam drying. The color of the EFB fiber was either improved or not significantly degraded. The strength of the superheated steam-dried EFB fibers was higher than that of undried and hot air-dried EFB fibers. The microstructure of fresh undried EFB fibers as seen by scanning electron microscopy (SEM) showed the presence of round silica particles of 10-20 mm in diameter all over the EFB fiber strand, which complicates pulping and bleaching. Superheated steam drying successfully removed the silica particles from the EFB fibers at temperatures of at least 200 C and a velocity of steam of at most 0.49 m s À1 , which is better than hammering, which can only remove 88% of the silica particles. The high temperature of the superheated steam loosened the silica particles from their craters. The EFB fibers cracked and split at steam velocities at or above 0.49 m s À1 and high superheated steam temperatures at or above 200 C and as a consequence became weaker at these conditions. The removal of silica particles by superheated steam drying makes the EFB fiber amenable to pulping and bleaching. Superheated steam drying is therefore found to improve the overall quality of EFB fibers compared to hot air drying.

Charcoal is a solid porous material containing 80 - 90 % of carbon being produced from combustion at high temperatures (carbonization ), that the material only carbonized and not oxidized become carbon dioxide. The research is aimed to know the optimum conditions on the process of carbonization from the rice husks. The carbonization process conducted in temperatures 400 oC, 500 oC, and 600 oC with variations in time 30 minutes, 60 minutes, 90 minutes and 120 minutes. Optimum conditions carbonization for rice husk at temperature 400 oC for 120 minutes with a carbon content 41,3 %, moisture content 6,1 %, ash content 32,6 % and volatile matter content 20,5 %.

<p>This study evaluated the performances of solar assisted heat pump dryer (SAHPD) and heat pump dryer (HPD) for drying of <em>Curcuma xanthorrhiza Roxb</em>. The HPD and SAHPD reduced mass of <em>Curcuma</em> from 30.70 kg to 7.85 kg needed 10.5 hours and 8 hours with average temperature and relative humidity 49.2oC and 26.5%, and 57.7oC and 19.8%, for SD and SAHPD respectively. The moisture of Curcuma dried from 3.167 db to 0.065 db with an air mass flow rate of 0.121 kg/s. The SAHPD reduced the drying time about 24% compared to HPD. The drying rate and the specific energy consumption were calculated in an average 1.05 kg/h and 1.36kg/h, and 1.17kWh/kg and 2.07kWh/kg for HPD and SAHPD, respectively. The specific moisture extraction rate and the dryer thermal efficiency were calculated in an average 0.931 kg/kWh and 0.521 kg/kWh, and 61.0% and 34.3% for HPD and SAHPD, respectively. Whereas, the pickup efficiency and the coefficient of performance of the heat pump were calculated in an average 57.5% and 59.2%, and 4.03and 4.35 for HPD and SAHPD, respectively. The SAHPD is capable of drying <em>Curcuma</em> quickly because of the high pickup efficiency and high drying rate.</p>