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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Liquor to liquor differences and the effects of liquor feed rate on the distribution of condensed phase combustion products of kraft black liquor solids burned in a laminar entrained-flow reactor

Train, Ron 08 June 2001 (has links)
Combustion properties of kraft black liquor solids were studied using a laminar entrained flow reactor. The tendency of black liquors to release fume (compounds containing Na⁺, K⁺, Cl⁻, SO₄²⁻, SO₃²⁻, S₂0₃²⁻ and C0₃²⁻) during combustion were observed at 1000°C. Black liquor solids with a size fraction of 63 to 100 μm were burned in a mixture of 4% 0₂ and 96% N₂ at a residence time of 0.67 seconds. Combustion properties of one black liquor (liquor #3) were studied by varying the solids feed rate from 0.47 to 1.08 g/min (liquor feed rate study). Combustion properties of five North American and Finnish black liquors were studied at a target solids feed rate of 0.73 g/min (liquor to liquor study). Black liquor fuming was observed to be a decreasing function of solids feed rate and an increasing function of excess oxygen. The appearance of char residues varied from black and porous at high solids feed rates to white and dense at low solids feed rates. Combustion may have been enhanced at low solids feed rates by liquor swelling due to a combination of heat and mass transfer effects and limited at high solids feed rates by inter-particle and bulk gas mass transfer limitations. For the liquor to liquor study, black liquors were observed to release fume differently. Chars produced during this study varied in appearance, indicating that the black liquors had unique combustion properties. Variations in temperature and mass transfer effects resulting from liquor swelling properties were likely responsible for the variability in liquor fuming behavior. The liquors that contained the most NaCl and had the highest anionic equivalents as C0₃²⁻ (or other chemical species) produced the most fume. Sodium vaporization varied from 25.2% to 33.7%: Liquors #2 and #5 vaporized the most sodium and also had the lowest concentrations of measured anions in their char residues. Potassium and chloride enrichment factors for the five liquors were slightly lower than those of common industrial boilers. Liquor #3 had a concentration of Cl⁻ that was (roughly) an order of magnitude higher than the other liquors studied; however, it also had the lowest chloride enrichment factor. / Graduation date: 2002
12

Economics of bio-ingredients production from shrimp processing waste in Newfoundland

Tackie, Richard January 2002 (has links)
This thesis examined the economics of producing high value bio-ingredients such as chitin and carotenoprotein from shrimp processing waste in Newfoundland. The shrimp waste in the province was estimated to be at least 37000 tons annually. A survey of shrimp processing plants in the province revealed that the waste generated was relatively pure with little or no foreign material. The economic engineering approach was employed to estimate the production cost of chitin and carotenoprotein at the laboratory and pilot scale levels. At the laboratory scale where 480 kg/year of raw material (shrimp waste) was processed, the cost of chitin and carotenoprotein was found to be $159/kg and $315/kg, respectively. At the pilot scale level, the cost of chitin and carotenoprotem was estimated to be $125/kg and $244/kg, respectively based on volume of 4800 kg/year. Sensitivity analysis was carried out to establish the cost variations due to changes in the quantity of starting raw material, labor cost and cost of laboratory supplies (chemicals and enzymes). The cost of chitin and caroteinoprotein showed a decreasing trend with increasing scale of production. An expert opinion survey was conducted with a selected panel of 9 experts from the shrimp processing industry, chitin related industry, and the academic/research community to determine the potential market of the high-grade chitin/chitosan in Canada. The results showed that the health and nutraceutical industry is the most promising niche for high-grade chit in/chitosan. The survey also indicated that potential market would be high in Ontario and Quebec due to the presence of large health and nutraceutical companies in the big metropolitan areas of these regions.
13

Enhancing value of lobster waste by enzymatic methods

Dauphin, Laurie January 1991 (has links)
In processing lobster, approximately 70% of the body weight is discarded as waste. The solid waste consists of shell, viscera and a small amount of meat. Lobster waste is an excellent source of protein (26.6%) crude fat (2.7%) and pigment (98 $ mu$g/g) on a dry weight basis which could be processed into a stable complex known as carotenoprotein. / Procedures for extraction of carotenoprotein from lobster waste have been developed, along with investigation of its distinctive physicochemical properties. The main factors were: demineralization agents (EDTA, HCl or heat) and precipitation agents ((NH$ sb4$)$ sb2$SO$ sb4$ or HCl). Lobster carotenoprotein recovered under different extraction procedures showed significant differences in terms of quantity and quality of the product recovered. However the procedures did not appear to affect the physical properties and amino acid profiles of carotenoprotein. / Optimal recovery involved treatment with EDTA as demineralization agent and precipitation with (NH$ sb4$)$ sb2$SO$ sb4$. Proximate and amino acid analyses indicated the potential of the recovered lyophilized protein as feed ingredient for cultured salmonids.
14

Sulfur gas release during black liquor burning

Cantrell, James Grady 05 1900 (has links)
Jeffery S. Hsieh
15

Recovery, drying and characterization of carotenoproteins from industrial lobster waste

Tu, Ya. January 1991 (has links)
Lobster waste (including the head and hard carapace, viscera, mandibles and gills) contains approximately 98 $ mu$g/g total astaxanthin, 23% protein, 20% chitin, 34% ash, and 2.2% crude fat on dry weight basis. Carotenoprotein, amounting to 16% of the dry matter was effectively recovered from lobster waste by a trypsin aided process. Air-dried carotenoproteins were enriched in protein by about 108-115%, in crude fat by 540-594% and in carotenoid pigment by about 147-329% as compared with the waste material. Furthermore, the ash and chitin levels in the products were considerably lower than those of the raw material. / Drying characteristics of carotenoprotein was evaluated in a modified air-drier using air temperature (45$ sp circ$C, 55$ sp circ$C or 65$ sp circ$C) and relative humidity (5% and 15%) as main factors. The study indicated that higher temperatures achieved faster drying rates of the product but adversely affected its nutritional composition and/or quality. The proximate compositions of carotenoprotein dried at 45$ sp circ$C and relative humidity of 5% or 15% were comparable with that obtained by freeze drying. / Thus, the process achieved a substantial reduction in the levels of anti-nutrients associated with lobster waste (i.e., ash and chitin) while elevating the levels of carotenoid pigments and essential nutrients such as protein and fat in the recovered product. These characteristics of the tray-dried carotenoprotein suggest that it could be used as an inexpensive source of pigment and protein in diets of cultured salmonid species.
16

Improving the Deviro panel : technical enhancements of a wood fibre-cement composite from paper mill de-inking sludge

Mostert, F. January 1900 (has links)
Thesis (MScFor)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: This research focuses on the utilisation of de-inking sludge from a tissue mill to produce a wood-fibre inorganic composite called the Deviro panel. The study is based on the SA provisional patent 95/9594 by Ysbrandy and Gerischer' and the further research conducted by Crafford'. The patented Deviro panel contains up to 70% de-inking sludge. Cement and a cement extender serve to fortify the composite. The panel's fibre content of 25-30% is significantly greater than encountered in commercial fibre inorganic composites which contain 8-12% fibre by weight. The physico-mechanical characteristics of the Deviro panel compare favourably with resin bonded wood-fibre composites, but less favourably compared to conventional wood and wood-fibre inorganic composites. These properties are strongly dependent on panel density. For instance flexural strength being directly proportional while dimensional stability and hygroscopicity being inversely proportional to density. After confirming the results from the preceding work by Crafford, further improvements were investigated through chemical and curing enhancements. For instance, an autoclaving treatment during the curing period showed an increase in flexural strength. Addition of water glass could be associated with bulking of the panel, which resulted in increased flexural strength and a slight reduction of density. Panel density could be significantly reduced by the addition of Perlite, while inhibiting the concomitant reduction in strength. In addition a pilot production process was developed to produce 1m2 panels, which exhibited similar curing characteristics as the smaller panel units. / AFRIKAANSE OPSOMMING: Hierdie navorsing handeloor die gebruik van ontinkingsslyk van 'n sneespapier meule om die Deviro paneel, 'n houtvesel anorganiese saamgestelde produk, te produseer. Die studie volg uit die SA voorlopige patent 95/9594 deur Ysbrandy en Gerischer en verdere narvorsing deur Crafford'. Die gepatenteerde Deviro paneel bevat tot 70% ontinkingsslyk. Sement en sement-byvoegmiddels dien om die saamgestelde produk te versterk. Die paneel bevat 25-30% vesel wat aansienlik meer is as ander kommersiële anorganiese saamgestelde produkte wat 'n vesel inhoud van 8-12% het. Die megamese eienskappe van die Deviro paneel is vergelykbaar met houtvesel saamgestelde produkte waar hars as kleefiniddel dien, maar vergelyk minder gunstig teenoor konvensionele hout en houtvesel anorganiese saamgestelde produkte. Die paneel se eienskappe is afhanklik van sy digtheid Buig sterkte is eweredig terwyl dimensionele stabiliteit en hygroskopisiteit omgekeerd eweredig aan die digtheid van die paneel is. Die voorafgaande werk van Crafford is eers gestaaf voordat veranderinge aan die chemiese samestelling en drogingsmetodes van die paneel nagevors is. Daar is byvoorbeeld bevind dat, deur die paneel te outoklaveer gedurende die set periode, dit lei tot 'n toename in buig sterkte. Die byvoeging van water glas kan swelling laat plaasvind wat 'n afname in buig sterkte en 'n afname in digtheid tot gevolg het. Digtheid kan ook aansienlik verlaag word deur die byvoeging van Perlite terwyl 'n dienooreenkomstige verlaging in buig sterkte tot 'n mate voorkom word. 'n Loods produksie proses is ook ontwikkel om 'n 1m2 paneel te vervaardig wat dieselfde eienskappe toon as die kleiner paneel.
17

Process for the preparation of cis- AND trans-3,7-Dimethyl 2,6-Octadiene-1-OL from crude sulphated turpentine stream

Sathikge, Ndavheleseni David January 2008 (has links)
As part of CSIR Biosciences’ interest in aroma chemicals, the processing of crude sulphated turpentine (CST) into high value aroma products was investigated. The primary target product, linalool, was obtained from a mixture of α- and β-pinene in four steps. It can be transformed into a wide range of high value added aroma chemicals. Isomerisation of linalool in the presence of a transition metal catalyst furnishes geraniol and nerol. The scientific work described in this report was part of a bigger project aimed at developing innovative processes to manufacture aroma, flavour & fragrance chemicals through beneficiation of industrial waste streams and other raw materials, available locally from the Forestry, Paper & Pulp industries. The evaluation of a process for the preparation of precursor aroma, flavour & fragrance compounds, in particular geraniol and nerol, from locally available raw materials and industrial waste streams, was investigated. Preparation of geraniol and nerol from linalool (ex α-pinene stream) was investigated using acids or organometallic complexes as catalysts for the corresponding isomerisation reaction. The investigation was conducted in an effort to find a less costly process utilising milder conditions than via the conventional cleavage of β-pinene to myrcene under extreme pyrolysis conditions (>650°C). The transformation of linalool to geraniol/nerol using mineral acids was found to be dominated by secondary reactions such as dehydration and cyclisation, resulting in poor product selectivities and yields. On the other hand, organometallic complexes, in particular vanadium-based complexes (e.g. (OV(OBu)3) produced satisfactory results in the preliminary assessment (conversion of 79.8 percent and selectivity of 98.3 percent). A set of statistically designed experiments was carried out on the (VO(BuO)3 + [(Bu)4N+]OH¯) catalyst system where three variables were tested, i.e. substrate concentration, temperature, and catalyst loading. The selected model for conversion was significant with the “Probability > F” being < 0.0001. The most important contributing variable to the model for conversion was temperature i.e. 83.9 percent. Temperature was still the most important variable for the selectivity response at 65.0 percent contribution level. The response surface generated for the selectivity response was flat indicating a robust method within the parameter range selected.
18

Recovery, drying and characterization of carotenoproteins from industrial lobster waste

Tu, Ya. January 1991 (has links)
No description available.
19

Enhancing value of lobster waste by enzymatic methods

Dauphin, Laurie January 1991 (has links)
No description available.
20

Economics of bio-ingredients production from shrimp processing waste in Newfoundland

Tackie, Richard January 2002 (has links)
No description available.

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