Synthesis and characterization of zeolite NaY from rice husk silica

Rice husk silica (RHS) in amorphous phase with 98% purity was prepared from a waste rice husk from rice milling by leaching with hydrochloric acid and calcination. The RHS was used effectively as a silica source for the synthesis of zeolite Y in sodium form (NaY). The zeolite in pure phase was obtained from a two-step synthetic route in which the starting gels were mixed, aged for 24 h at room temperature and crystallized for 24 h at 90 °C. The diameter of single crystal particles from a scanning electron microscope was approximately 1.0 μm, whereas the average particle diameter from laser diffraction particle size analyzer was approximately 10 μm because of the agglomeration of small crystals. Longer crystallization time in this route resulted in a mixed phase containing NaY and zeolite P in sodium form (NaP). In addition, a one-step synthetic route (no aging) was studied and the product was also a mixed phase zeolite.     

Electricity generation from rice husk in Indian rice mills: Potential and financial viability

Rice husk generated as a by-product of rice processing is an important energy resource. The availability of this resource in India has been assessed and the technologies for exploitation of its energy potential in rice processing industry discussed. Nomographs have been developed for estimation of the husk required to meet the energy demand of parboiling, drying and milling operations. The unit cost of electricity using rice husk gasifier-based power generation systems has been calculated and its financial feasibility assessed in comparison with utility-supplied and diesel-generated electricity. With the cost and efficiency data assumed here, the unit cost of electricity produced by rice husk gasifier-dual fuel engine-generator system varies between Rs 2/kWh and Rs 7/kWh. (Note: 35 Rs approximates to $US 1.)     

Electricity generation from rice husk in Indian rice mills: potential and financial viability

Rice husk generated as a by-product of rice processing is an important energy resource. The availability of this resource in India has been assessed and the technologies for exploitation of its energy potential in rice processing industry discussed. Nomographs have been developed for estimation of the husk required to meet the energy demand of parboiling, drying and milling operations. The unit cost of electricity using rice husk gasifier-based power generation systems has been calculated and its financial feasibility assessed in comparison with utility-supplied and diesel-generated electricity. With the cost and efficiency data assumed here, the unit cost of electricity produced by rice husk gasifier-dual fuel engine-generator system varies between Rs 2/kWh and Rs 7/kWh. (Note: 35 Rs approximates to $US 1.)     

Simultaneous biohydrogen (H2) and bioplastic (poly-β-hydroxybutyrate-PHB) productions under dark,photo, and subsequent dark and photo fermentation utilizing various wastes

The present study is focused on bio hydrogen (H₂) and bioplastic (i.e., poly-β-hydroxybutyrate; PHB) productions utilizing various wastes under dark fermentation, photo fermentation and subsequent dark-photo fermentation. Potential bio H₂ and PHB producing microbes were enriched and isolated. The effects of substrate (rice husk hydrolysate, rice straw hydrolysate, dairy industry wastewater, and rice mill wastewater) concentration (10–100%) and pH (5.5–8.0) were examined in the batch mode under the dark and photo fermentation conditions. Using 100% rice straw hydrolysate at pH 7, the maximum bio H₂ (1.53 ± 0.04 mol H₂/mol glucose) and PHB (9.8 ± 0.14 g/L) were produced under dark fermentation condition by Bacillus cereus. In the subsequent dark-photo fermentation, the highest amounts of bio H₂ and PHB were recorded utilizing 100% rice straw hydrolysate (1.82 ± 0.01 mol H₂/mol glucose and 19.15 ± 0.25 g/L PHB) at a pH of 7.0 using Bacillus cereus (KR809374) and Rhodopseudomonas rutila. The subsequent dark-photo fermentative bio H₂ and PHB productions obtained using renewable biomass (i.e., rice husk hydrolysate and rice straw hydrolysate) can be considered with respect to the sustainable management of global energy sources and environmental issues.     

Technological aspects of sunflower biomass and brown coal co-firing

The technological problems occurring in the co-firing of biomass and brown coal (lignite) prompted this research project. During the fuel preparation, accidental self-ignition and explosions were several times reported by power plants operators. The aim of this study was to evaluate brown coal, sunflower husks and sunflower husk pellets as fuels for co-firing in energetic boilers. Sunflower husk had a lower ash content and calorific value than the pellets. The range of the combustion temperatures of the biomass (200–300 °C) was narrower than that of brown coal (200–800 °C). The formation of highly alkaline ash from the biomass resulted in the formation in boiler of agglomerates of ash. The elemental composition, thermogravimetric and biological analyses suggested that the pellets contained synthetic additives difficult to identify. The biological method was proposed for evaluating biomass additives. The use of additional agents in the pelletizing process may influence on the combustion parameters. Mixing biomass with brown coal may occasionally result in self-ignition in the logistic chain. Plastic additives and biological activity may contribute to self-ignition.     

谷壳制备的白炭黑研制Ce-MEL分子筛及其吸附性能的研究

以谷壳制备的白炭黑为硅源、四丁基溴化铵(TBAOH)为模板剂,按0.05Na2O∶SiO2∶0.35TBAOH∶40H2O∶(0.001-0.1)Ce(NO)3.6H20的摩尔比,170℃下水热晶化48h合成了Ce-MEL分子筛,并采用XRD、SEM等手段对合成分子筛进行表征。吸附性能结果表明,Ce-MEL分子筛的投加量为2.5g/L、pH为7、振荡时间为2h时吸附效果较好,脱色率达到88.5%。     

Utilization of mesoporous molecular sieves synthesized from natural source rice husk silica to Chlorinated Volatile Organic Compounds (CVOCs) adsorption

The adsorption of trichloroethylene (TCE), tetrachloroethylene (PCE), and carbon tetrachloride was studied over our synthesized mesoporous material, MCM-41, from rice husk silica source, abbreviated as RH-MCM-41. More than 99% silica for RH-MCM-41 synthesis was extracted from rice husk under refluxing in HBr solution and then calcined at 873 K for 4 hours. RH-MCM-41 possessed surface area around 750-1,100 m²/g with a uniform pore size with an average diameter of 2.95 nm, narrow range of pore distribution and somewhat hexagonal structure, similar to properties of parent MCM-41. The adsorption of CC1₄ to RH-MCM-41 was stronger than that of TCE and PCE. The adsorption capacity of RH-MCM-41 for CVOCs (chlorinated volatile organic compounds) was higher than commercial mordenite and activated carbons.     

Effect of lignin removal on mechanical,thermal, and morphological properties of polylactide/starch/rice husk blend used in food packaging

The aim of this work was to investigate the possibility of using cost‐effective natural filler in a biodegradable polymer and find new set of materials for green biocomposites to be used in food packaging. In this regard, rice husk (RH) and bleached rice husk (BRH) have been used in the form of powder and the effect of lignin removal on mechanical and thermal properties of prepared composites with poly(l ‐lactide) and starch were studied. Using FTIR technique, the lignin removal from RH has been approved. The tensile, charpy impact, and hardness tests were implemented to investigate the mechanical properties. It was concluded that filler caused increase both in the toughness and the Young modulus of samples. It was also found that the lack of lignin in BRH samples improves the mechanical properties. It was clearly observed that the BRH samples show larger modulus, charpy impact strength, and hardness compared to those filled with RH. Despite larger values for the elongations at break of RH samples, the mechanical properties showed a significant improvement (between 25 and 50% improvements) on lignin removal. The differential scanning calorimetry thermograms revealed an improvement in crystallization behavior and reduction of T_g from 47 to 31°C in the case of BRH‐filled samples. Finally, due to the removal of toxic lignin in the samples and modification of mechanical properties by this method, the BRH could have the ability of wide use in the bioplastics and food packaging industries. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41095.     

Changes occurring during the parboiling of upland rice and in the maceration water at different temperatures and soaking times

The objective of this work was to investigate the influence of temperature and soaking time on the quality of grains from two upland rice cultivars. Response surface methodology and a central compound rotational design were used. The data obtained for the cultivars BRS Primavera and BRS Sertaneja varied, respectively, between 27.7–55.0% and 26.0–51.7% for the Husk‐Splitting Index; between 0.8–5.0% and 0.0–4.0% for the incidence of ‘banana’ grains; between 0.0–2.0% and 0.0–1.2% for non‐gelatinised grains; and between 0.2–0.7% and 0.2–0.8% for soluble solids in the maceration water. Because BRS Primavera grains had a narrower shape, they absorbed the water faster and consequently presented a greater amount of physical defects, although the losses to the water were smaller than BRS Sertaneja.     

Controlled atmosphere storage of pomegranate

Pomegranates cv. Mollar were stored for up to 8 weeks at 5 °C and above 95% relative humidity (RH) in air and in controlled atmospheres of 10% O₂ and 5% CO₂, 5% O₂ and 5% CO₂, 5% O₂ and 0% CO₂ and 5% O₂ and 0% CO₂ ethylene-free. Storage was followed by a shelf-life period of 6 days at 20 °C in air. Respiratory activity slightly declined during storage at 20 °C, from 12 to 8 ml CO₂ · kg^–1 · h^–1 and was around 4 ml CO₂ · kg^–1 · h^–1 at 5 °C showing a non-climacteric pattern. When compared with color at harvest, an increase in thea ^* value in the juice from pomegranates stored in 10% O₂ and 5% CO₂ was observed. This supports that view that juice red colour can increase in intensity during storage. Controlled atmosphere storage reduced weight loss, the risk of decay and the severity of husk scald (except at 10% O₂ and 5% CO₂). The relatively low control of husk scald at 5% O₂ disagrees with the level proposed previously for Wonderful cv.; Mollar cv. seems to be more sensitive to scald than other varieties. No symptoms of black spots or membranose and no off-flavours were detected at any time. However after a period of shelf-life storage, the controlled atmosphere caused a slight reduction (lower than in air-stored fruit) in titratable acidity, reducing sugars and vitamin C and an increase of the soluble solids content/titratable acidity (maturity index) without differences among the various gas compositions studied. The maturity index must be considered to be a good criterion of pomegranate maturity for sweet varieties.