Application of simulation in determining suitable operating parameters for industrial scale fluidized bed dryer during drying of high impurity moist paddy

A systematic approach has been developed for selecting the suitable drying parameters to be used for drying of high moisture and high impurity paddy with an industrial fluidized bed paddy dryer (10–20 t h−1 capacity) based on targeted specific air flow rate and residence time during two typical paddy drying seasons. A mathematical model was developed by modifying an existing model and was simulated and validated with observed industrial drying data as well as data reported in the literature. Comparison between the observed and simulated results showed that the mathematical model is capable of predicting outlet paddy moisture content and air temperature well. Suitable operating parameters were determined for reducing any initial paddy moisture content (mc) down to 24–25% dry basis (db), the safe mc level after fluidized bed drying to maintain rice quality, to achieve maximum possible throughput capacity of the dryer with corresponding energy consumption. Based on these criteria, bed thickness at 10 cm, specific air flow rate of 0.05 kg kg−1 s−1 (for corresponding bed air velocity of 2.3 m s−1), air temperature of 150 °C and residence time of 1.0 min were found to be suitable drying conditions for reducing paddy mc from 30 to 24.30% (db) in one season while the maximum throughput capacity of 15.7 tonne per hour (t h−1) might be achieved. The specific electrical and thermal energy were 0.48 and 6.15 MJ kg−1 water evaporated, respectively. On the other hand, the dryer capacity was found to be limited to 7.4 t h−1 during drying paddy of higher initial mc (35% db). This approach might provide easy and comprehensive guidelines for selecting suitable sets of operating parameters for any industrial fluidized bed dryer at its possible maximum throughput capacity for drying of freshly harvested high moist paddy with a high level of impurities

Drying performances and milling quality of rice during industrial fluidized bed drying of paddy in Malaysia

Field investigation on the operation of an industrial fluidized bed paddy dryer of 25 t/h capacity available in a processing complex of Padiberas Nasional Berhad (BERNAS) of Malaysia was carried out to assess its drying characteristics, energy consumption and quality of product during two paddy harvesting seasons. A grain drying simulation model was used to predict dryer performance which can be used as a basis for improving drying operations. For the first season (August-September), average drying rate was found to be 538 kg moisture/h to reduce moisture content (mc) from 36.98± 0.89% dry basis (db) to 27.58±0.79% (db) at 100-120°C of drying air temperature with a feed rate (capacity) of 7.75 t/h. In the second season (February-March), average drying rate was found to be 435 kg moisture/h to reduce mc from 28.14 ±0.68% (db) to 22.54 ± 0.69% (db) at 78-90°C drying air temperature with a feed rate of 9.5 t/h. The thermal and electrical energy consumptions were obtained as 7.57 and 0.97 MJ/kg water removed, respectively, for the first season, while 5.92 and 1.2 MJ/kg water removed for the second season. Higher head rice yield and whiteness and lower milling recovery were achieved during the first season than the second season at acceptable milling degree and transparency. Meanwhile, simulation results indicated that the dryer performed better in terms of increased drying capacity during the second than the first season; the dryer could be operated at 150°C to achieve almost double throughput capacity up to 20 t/h for the second season, while for the first season, high mc hindered the capacity to be at or below 7.75 t/h even when using higher a temperature of 160°C to reduce moisture to the desired final moisture of 24-25% (db). proportion of slower vehicles based on users’ opinion poll

Drying kinetics,energy consumption, and quality of paddy (MAR-219) during drying by industrial inclined bed dryer with or without the fluidized bed dryer.

The performances of industrial dryers, namely the inclined bed dryer (IBD) and the fluidized bed dryer (FBD) combined with IBD, in terms of drying kinetics, energy consumption, and quality of paddy were investigated in this study. Drying parameters used in a single-stage paddy drying using IBD and a two-stage drying using FBD combined with IBD were analyzed to assess the existing performances of the drying techniques. The overall performances of the current drying practices exhibited inconsistent results with the operating parameters, such as drying air temperature, drying time, and air flow rate among the drying process lines. Distinct variations in moisture reduction and energy consumption of the drying systems were identified. Poor performance of the industrial fluidized bed dryer was observed in the case of drying in low capacity that caused higher specific energy consumption. However, the quality of milled rice obtained from both drying systems was found to be almost similar. Minimal process time (i.e., up to 24.5% less) was found in the paddy dried with FBD as the first-stage drying, followed by IBD as the second-stage drying

Energy and rice quality aspects during drying of freshly harvested paddy with industrial inclined bed dryer

The performance evaluation of any industrial dryer regarding energy consumption and product quality should be assessed to check its present status and to suggest for further efficient operation. An investigation was carried out to evaluate the impact of drying temperature and air flow on energy consumption and quality of rice during paddy drying with industrial inclined bed dryer (IBD) with average holding capacity of 15 ton in the selected complexes of Padiberas Nasional Berhad (BERNAS)-the national paddy custodian of Malaysia. In reducing paddy moisture content (mc) from 22% to 23% wet basis (wb) down to around 12.5% wb, the final mc, the specific electrical (in terms of primary energy) and the specific thermal energy consumption were found to be varied between 1.44 to 1.95 MJ/kg water evaporated and 2.77 to 3.47 MJ/kg water evaporated, respectively. Analysis revealed that the specific electrical energy consumption was around 20% lesser and the specific thermal energy consumption of IBDs was around 10% higher during drying with air temperature of 41–42 °C than drying with 38–39 °C in reducing paddy mc from 22% to 23% (wb) down to around 12.5% (wb). However, paddy being with almost same initial mc dried using drying temperature of 38–39 °C, IBDs yielded 1–4% higher head rice yield while milling recovery and whiteness were comparable at acceptable milling degree and transparency. The bed air flows between 0.27 and 0.29 m3 m−2 s−1 resulted in higher head rice yield slightly while its effect on drying time was not prominent so much. For paddy with initial moisture content below 23% wb, it is recommended that drying air temperature should not be higher than 39 °C in order to maintain rice quality at reasonable energy consumption

Optimization of spray drying parameters for pink guava powder using RSM

The optimization of pink guava was executed using central composite face-centred design to optimize the spray drying parameters of inlet temperature, maltodextrin concentration (MDC) and feed flow (FF). The experimental results were significantly (p<0.01) fitted into second-order polynomial models to describe and predict the response quality in terms of the final moisture, particle size and lycopene with R2 of 0.9749, 0.9616, and 0.9505, respectively. The final moisture content significantly (p<0.01) decreased with increasing inlet temperature and MDC, whereas the particle size increased. In contrast, the lycopene content significantly (p<0.01) decreased with the higher temperature and increased with increasing MDC. However, according to multiple response optimization, the optimum conditions of 150°C inlet temperature, 17.12% (w/v) MDC and 350 mL/h FF-predicted 3.10% moisture content, 11.23 μm particle size and 58.71 mg/100 g lycopene content. The experimental observation satisfied the predicted model within the acceptable range of the responses

Extraction of fish oil from the skin of Indian mackerel using supercritical fluids.

The total oil was extracted from the ground skin of Indian mackerel (Rastrelliger kanagurta) using various techniques of supercritical fluid extraction (SFE) at 20–35 MPa and 45–75 °C and by the Soxhlet method for comparison. The oil yield increased with pressure and temperature and the highest yields were 24.7, 53.2, 52.8, and 52.3/100 g sample (dry basis) for the continuous, cosolvent, soaking, and pressure swing techniques, respectively, at 35 MPa and 75 °C. The yield from the Soxhlet extraction was 53.6/100 g sample (dry basis). The CO2 consumption was 581.8, 493.6, 484.9 and 290.9 g for the continuous, cosolvent, soaking and pressure swing techniques, respectively, at 35 MPa and 75 °C. The largest recoveries of PUFA, especially the ω-3 family, were achieved from the soaking and pressure swing techniques at 35 MPa and 75 °C. Thus, the pressure swing and soaking techniques are the most effective at extracting the oil from fish skin

Light and temperature effects on sprout yield and its proximate composition and vitamin C content in Lignosus and Mung beans

Bean sprout is used as vegetables. The present study investigated the effect of temperature and light on seed germination and sprout yield, and proximate (crude protein, crude fat, crude fibre, nitrogen free extract and ash) composition of sprout in Lignosus (Dipogon lignosus (L.) Verdc.) and Mung (Vigna radiata Wilczek) beans. Three temperatures (ambient, 25o and 30oC) and two light regimes; continuous dark, (CD) and continuous dark alternated by ½ hour light daily, (DAL) were used for seed germination and bean sprout yield. Data were collected 24, 48, 72, 96 and 120 hours after setting the presoaked seeds in the petri dishes. Of the temperature regimes, generally better seed germination and sprout fresh weight (yield) were observed at 25oC in Mung bean and 30oC in Lignosus bean. Germination and sprout yield were similar under CD and DAL. Both under CD and DAL, sprout yield was higher after 120 hours compared to 96 hrs after germination in both the beans. Proximate composition of dry seeds and their sprouts was also determined. Irrespective of species, crude protein content was significantly higher in sprout (average of 29.33%) than dry seed (average of 24.33%).Vitamin C was significantly higher in Lignosus bean sprout (20.93 mg 100g-1) compared to Mung bean sprout (9.52 mg 100g-1). This is the first world report on Lignosus bean sprout. It may be concluded that better sprout yield and good protein content were obtained at 25oC in Mung bean and 30oC in Lignosus bean after 120 hrs of germination irrespective of dark and light

Sterilization and extraction of palm oil from screw pressed palm fruit fiber using supercritical carbon dioxide

The supercritical carbon dioxide (SC-CO2) was successfully used in the complete sterilization as well as simultaneous extraction of oil from screw pressed palm fruit fiber. The studies were conducted at different temperatures (40, 50, 70 °C) and pressures (13.7, 20.7 MPa) for 60 min of extraction period. The bacteria, gram negative (Bacillus), present in the sample was completely killed at 20.7 MPa and 50 °C. Palmitic and oleic acid were found to be the major fatty acids in extracted oil. More saturated fatty acid were extracted at 50 °C and lower operating pressure (13.7 MPa). The unsaturated components, such as linoleic and oleic acids were extracted at higher pressures of 27.6 and 34.5 MPa, respectively. The fatty acids composition of the extracted oil analyzed using gas chromatography–mass spectrometry (GC/MS) includes caprylic, capric, lauric, myristic, palmitic, margaric, stearic, oleic, linoleic, linolenic, arachidic and gadoleic acids

Gelatinization properties of sago and wheat flour mixtures

Gelatinization or pasting properties of sago-wheat flour mixtures (10-50% sago) were studied for mixtures of sago-high protein wheat flour (HPW), sago-medium protein wheat tlour (MPW) and sago-low protein wheat flour (LPW). Gelatinization temperature (TG)increased as the sago portion in HPW, MPW and LPW increased. The peak temperature (Tp) and peak viscosity (Vp) increased with increasing sago in the sago-wheat mixtures. The setback values (5B) in sago-LPW mixtures were higher than in sago-HPW and sago-MPW mixtures. The setback viscosities (Vs) were not much different for any mixtures or control flours. The breakdown viscosities (VB) increased with increased sago in the mixtures. The breakdown value (BD) increased with increased sago in the sago-wheat mixtures

Hard cocoa butter replacers from mango seed fat and palm stearin

The blending effects of mango seed fat (MSF), extracted using supercritical fluid, and palm stearin (PS) to formulate hard cocoa butter replacers (CBRs), were investigated. The triglycerides (TG), thermal properties and solid fat content (SFC) of the formulated blends were determined using different chromatographic and thermal techniques. All the blends had three main TGs; namely, 1,3-dipalmitoyl-2-oleoylglycerol (POP) (8.6 to 17.7%), 1-palmitoyl-2-oleoyl-3-stearoyl-glycerol (POS) (12.6 to 19.6%), and 1,3-distearoyl-2-oleoyl-glycerol (SOS) (37.2 to 31.4%), with SOS being the major component. The melting peak temperatures gradually increased and shifted towards higher temperatures with PS. The crystallization onset temperatures increased, while the offset decreased with PS. The SFC did not drop to 0% at 37.5 °C, which was shifted to 0% at and above 40 °C for some blends. The studies revealed that CBRs could be prepared by blending MSF and PS, and they could be utilized by chocolate manufacturers in tropical countries