Drying of biological materials in a spout-fluid bed with a draft tube

The possibility of applying a spout-fluid bed with a draft tube and conical bottom was investigated for drying fluid media with a certain content of suspended material was investigated. The major goal who to study the drying of biological materials and products of food the industry. Experimental results concerning the fluidmechanical characteristics of a spout-fluid bed with a centrally situated draft tube and the drying characteristics were obtained on a pilot scale unit, 0.250 m in diameter, with a toed consisting of polyethylene particles 3.6 mm mean diameter and 940 kg/m3 density. Within the regime of the fluid mechanical stability, the system could be used for drying biological suspensions with satisfactory results

Purification technologies for crude biodiesel obtained by alkali-catalyzed transesterification

For commercial application, the ester product of alkali-catalyzed transesterification of vegetable oil or animal fats should be refined after glycerol separation by settling to fulfill the biodiesel standard specifications. This crude biodiesel, after neutralization and methanol removal, should be further cleaned by either one of the following methods: wet washing, dry washing, membrane extraction or using ion liquids. This paper presents a review on the traditional (wet and dry washing) and novel (membrane separation technology and usage of ion liquids) methods of crude biodiesel purification. It also provides a comparison of crude biodiesel purification methods. Each method has its advantages and disadvantages, which should be carefully analyzed when choosing the proper one for refining crude biodiesel

Influence of hydrodistillation rate and hydromodule on chemical composition of juniperus communis l. Essential oil

Essential oils are aromatic, volatile, complex mixtures of various compounds, mainly hydrocarbons (monoterpene and sesquiterpene) and some oxygenated hydrocarbons. Juniper berry essential oil has wide application and high commercial value due to its considerable antimicrobial activities. It is used in medicine, food, cosmetic and pharmaceutical industry and veterinary medicine. Generally, it is obtained by hydrodistillation, technique for the extraction of substances which do not mix or mix very poorly with water and are unstable at their boiling temperatures. It provides high quality of essential oil and also represents a relatively simple, safe and environmentally friendly process. The variations in the chemical composition of the essential oil obtained from juniper berries at various distillation rates (3, 6 and 8 ml/min) and various mass ratio juniper berries-water (hydromodules -1:3, 1: 4 and 1: 5) are presented in this paper. It is important to emphasize that the variations made influence only in quantitative (mass%), but not in qualitative chemical composition (no differences, same 58 components were detected in all experiments). To reflect those effects, only 23 identified components with the content higher than 0.5 mass% were selected, constituted 95-96 mass% of the essential oils. The major constituents of the essential oils were monoterpenes (67.39-71.00 mass%), followed by sesquiterpenes (21.64-24.54 mass%), while the oxygenated monoterpene (1.54-2.42 mas.%) and oxygenated sesquiterpenes (0.89-1.46 mass%) were much less present. According to volatility, the high volatile (boiling point 153-167 degrees C) components are the main constituents of the essential oils (61.69-63.81 mass%), followed by the low volatile (boiling point 252-288 degrees C) components (22.57-26.04 mass%), and the least present medium volatile (boiling point 173-212 degrees C) components (7.24-9.61 mass%). The variations in the mass content of the essential oil at various distillation rates showed clear general trends for all hydromodules (with exceptions at some components). With the increasing of distillation rate, mass% of high and medium volatile components decreased, while mass% of low volatile components increased. This is caused by higher extraction of low volatile components at high distillation rate, which resulted the increasing of their mass%. The variations in the mass composition of the essential oil at various hydromodules showed less expressive trends for all distillation rates. That means it has much less influence on the mass composition than the variation of distillation rate. Therefore, experiments at various distillation rates should be continued in combination with the fractionation of the essential oil by simultaneous hydrodistillation and rectification, including the effects of preparation procedures of juniper berries and defining of optimal energy consumption, i.e., optimal time period of hydrodistillation

Microwave-assisted hydrodistillation of juniper berry essential oil: kinetic modeling and chemical composition

BACKGROUNDMicrowave-assisted hydrodistillation (MAHD) has widely been used to isolate essential oil from various plant materials, but it has not been applied yet to extract essential oil from juniper berries. The main goals of the present work were to establish a model describing the extraction kinetics and the chemical composition of the essential oil obtained. RESULTSA lower final essential oil yield from juniper berries was obtained by MAHD than by conventional hydrodistillation (HD). No significant differences in chemical compositions of the essential oils extracted by the two techniques were observed. The mechanism of both processes was the same and included fast (washing) and slow (diffusion) distillation of essential oil that occurred simultaneously. CONCLUSIONThe kinetic model involving simultaneous washing and diffusion of essential oil was verified for various plant materials (areal parts of savory and thyme, fennel seeds and juniper berries) for both MAHD and HD that indicated its general importance. For the first time, the kinetic models of MAHD and HD were compared. Knowledge of the juniper berry essential oil yield and the extraction kinetics is of importance from the technological and economics points of view, while the chemical composition determines its use

Removal of Heavy Metals from Aqueous Solution Using Natural and Fe(Iii) Oxyhydroxide Clinoptilolite

The increasing levels of industrial wastewater released to the environment present a serious threat to human health, living resources, and ecological systems. Fe-modified zeolites were developed and tested for removal of Cu2+ and Zn2+ from contaminated water. The surfaces of the naturally occurring zeolite, clinoptilolite, were modified with Fe(III) oxyhydroxides using three different methods, denoted I, II, and III (FeCli(1), FeCli(2), and FeNaCli(1), respectively). The oxyhydroxides were prepared in Method I using 0.1 M FeCl3 center dot 6H(2)O in an acetate buffer (pH = 3.6); in Method II, using 10% FeCl3 center dot 6H(2)O solution in 0.1 M KOH (pH = 10); and Method III was the same as Method I except the clinoptilolite was pretreated with NaCl. Newly synthesized materials from these three methods were then tested for their ability to enhance the sorption capacity for Cu and Zn compared to the natural sample (Cli). Powder X-ray diffraction measurements and the chemical composition of these modified samples confirmed that clinoptilolite maintained its structure while amorphous Fe3+ species were synthesized. The specific surface area (BET method) of both the natural and modified clinoptilolite increased by 2 and 7.5 times for Methods I and II, respectively. Scanning electron microscopy and energy dispersive X-ray spectroscopy revealed that CaO was formed during Method I (FeCli(1)). Throughout the adsorption process, the hydrolysis of CaO and the release of OH- caused the precipitation of Cu and Zn hydroxide, which made the determination of the sorption capacity of FeCli(1) impossible. This phenomenon was avoided in Method III (FeNaCli(1)) because of the absence of exchangeable Ca2+. The adsorption experiments with Method II resulted in double-enchanced adsoprtion capacity. Laboratory batch experiments revealed that the sorption capacities increased in the following order: Cli LT FeCli(2) LT FeNaCli(1), for Cu: 0.121 mmol/g LT 0.251 mmol/g LT 0.403 mmol/g and for Zn: 0.128 mmol/g LT 0.234 mmol/g LT 0.381 mmol/g

Biodiesel production by methanolysis of waste lard from piglet roasting over quicklime

Waste lard from piglet roasting and quicklime (basically CaO) as a priceless fatty feedstock and a cheap solid catalyst, respectively were tested for the biodiesel production by methanolysis in a batch stirred reactor at moderate reaction temperatures (40-60 degrees C) for the kinetic study. For comparison, unheated and heated pork lards, as well as pure CaO, were also included in this study. The mass transfer limitation was observed in the initial period of all methanolysis reactions. The kinetic model combining the changing-and first-order reaction rate laws with respect to triacylglycerols and fatty acid methyl esters (FAMEs), respectively was verified for all three lardy feedstocks and both catalysts. The catalytic activity of quicklime was the same as that of pure CaO. The activation energy was demonstrated to be independent of the feedstock and the catalyst (59.1 +/- 0.6 kJ/mol) but the waste lard reacted faster than the unheated and heated pork lards. At the methanol-to-lard molar ratio of 6:1, the catalyst amount of 5% (based on the lard weight) and the reaction temperature of 60 degrees C, a high FAME concentration in the final ester products (97.5%) within 60 min were achieved with the waste lard and quicklime in two consecutive batches. The same kinetic model was applicable in a continuous packed-bed tubular reactor filled with quicklime bits (2.0-3.15 mm) at the methanol-to-waste lard molar ratio of 6:1, the reaction temperature of 60 degrees C and the residence time of 1 h. Under these conditions, the biodiesel yield was 97.6%, while the FAME concentration in the biodiesel product was 96.5%