Development of a bench scale single batch biomass to liquid fuel facility
- Authors: Zhang, Yusheng
- Date: 2014
- Subjects: Biomass energy , Renewable energy sources , Energy conversion , Electric power production
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: http://hdl.handle.net/10353/811 , vital:26499 , Biomass energy , Renewable energy sources , Energy conversion , Electric power production
- Description: The research described in this dissertation was motivated by the global demand for energy that is not dependent on coal, oil, natural gas and other non-renewable fossil fuels. The technology used in this project is related to the use of biomass to produce a viable alternative to conventional sources of fuel. A bench scale biomass to liquid (BTL) facility was built and tested. This produced results confirming the feasibility of the BTL process. The findings of the pilot study outlined in this dissertation justified the conclusion that the next step will be to expand the capacity and productivity of the BTL pilot plant to an industrial scale. Biomass comes from a variety of renewable sources that are readily available. In this case, the material used in the fixed bed biomass gasification facility to generate wood gas was agricultural and forestry waste, such as straw and wood chips. The gasifier had the capacity to produce up to 10 cubic metres/hr of gas with a carbon monoxide and hydrogen content of between 20–40% by volume, when it was operated at ambient pressure and with air as the oxidizer. The gas, produced at a temperature above 700º C, was cooled in a quench/water scrubber in order to remove most of the mechanical impurities (tars and water-soluble inorganic particles), condensed and dried with corn cobs before being compressed in cylinders at over 100 bar (g) for use in the Fischer-Tropsch Synthesis (FTS). The syngas was subjected further to a series of refining processes which included removal of sulphur and oxygen. The sulphur removal technology chosen entailed applying modified activated carbon to adsorb H2S with the help of hydrolysis in order to convert organic sulphur impurities into H2S which reduced the sulphur content of the gas to less than 5 ppbv. Supported cobalt catalyst (100 grams), were loaded into a single-tube fixed bed FT reactor with an inner diameter of 50 mm. The reactor was fitted with a heating jacket through which, heated oil ran to cool the reactor during a normal reaction occurring at < 250 ºC, while nitrogen was used in the heating jacket during reduction, which occurred at temperatures up ~ 350 ºC. The FTS reaction was carried out at different pressures and temperatures. Liquid and wax products were produced from the facility. The properties of the liquid and solid hydrocarbons produced were found to be the same as FT products from other feed stocks, such as natural gas and coal.
- Full Text:
- Date Issued: 2014
- Authors: Zhang, Yusheng
- Date: 2014
- Subjects: Biomass energy , Renewable energy sources , Energy conversion , Electric power production
- Language: English
- Type: Thesis , Masters , MSc (Chemistry)
- Identifier: http://hdl.handle.net/10353/811 , vital:26499 , Biomass energy , Renewable energy sources , Energy conversion , Electric power production
- Description: The research described in this dissertation was motivated by the global demand for energy that is not dependent on coal, oil, natural gas and other non-renewable fossil fuels. The technology used in this project is related to the use of biomass to produce a viable alternative to conventional sources of fuel. A bench scale biomass to liquid (BTL) facility was built and tested. This produced results confirming the feasibility of the BTL process. The findings of the pilot study outlined in this dissertation justified the conclusion that the next step will be to expand the capacity and productivity of the BTL pilot plant to an industrial scale. Biomass comes from a variety of renewable sources that are readily available. In this case, the material used in the fixed bed biomass gasification facility to generate wood gas was agricultural and forestry waste, such as straw and wood chips. The gasifier had the capacity to produce up to 10 cubic metres/hr of gas with a carbon monoxide and hydrogen content of between 20–40% by volume, when it was operated at ambient pressure and with air as the oxidizer. The gas, produced at a temperature above 700º C, was cooled in a quench/water scrubber in order to remove most of the mechanical impurities (tars and water-soluble inorganic particles), condensed and dried with corn cobs before being compressed in cylinders at over 100 bar (g) for use in the Fischer-Tropsch Synthesis (FTS). The syngas was subjected further to a series of refining processes which included removal of sulphur and oxygen. The sulphur removal technology chosen entailed applying modified activated carbon to adsorb H2S with the help of hydrolysis in order to convert organic sulphur impurities into H2S which reduced the sulphur content of the gas to less than 5 ppbv. Supported cobalt catalyst (100 grams), were loaded into a single-tube fixed bed FT reactor with an inner diameter of 50 mm. The reactor was fitted with a heating jacket through which, heated oil ran to cool the reactor during a normal reaction occurring at < 250 ºC, while nitrogen was used in the heating jacket during reduction, which occurred at temperatures up ~ 350 ºC. The FTS reaction was carried out at different pressures and temperatures. Liquid and wax products were produced from the facility. The properties of the liquid and solid hydrocarbons produced were found to be the same as FT products from other feed stocks, such as natural gas and coal.
- Full Text:
- Date Issued: 2014
Effects of dietary inclusion of Moringa oleifera leaf meal on growth performance, physico-chemical attributes, oxidative stability and sensory quality of pork
- Authors: Nduku, Xola Pauline
- Date: 2014
- Subjects: Pork -- Quality , Food -- Sensory evaluation , Fatty acids , Moringa , Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11836 , http://hdl.handle.net/10353/d1021281 , Pork -- Quality , Food -- Sensory evaluation , Fatty acids , Moringa , Meat -- Quality
- Description: The objective of the study was to determine growth performance, physico-chemical attributes, oxidative stability and sensory quality of pork from pigs fed one of three dietary treatments, eac containing 0%, 2.5% or 5% (T1, T2 and T3, respectively) Moringa oleifera leaf meal (MOLM). Dietary treatments were formulated to be isonitrogenous and isoenergetic for weaner (6 – 8 weeks) and grower (9 – 13 weeks) phases. Twelve Large White (LW) and 12 Kolbroek (KB) male pigs at 6 weeks of age, initially weighing an average 10 kg, were randomly allocated to one of the dietary treatments, each with four replicates, in individual pens. Feed and water were offered ad libitum. The Longissimus thoracis et lumborum (LTL) muscle of each carcass (n = 24) was sampled for meat quality and fatty acid analyses. Breed differences in measured parameters were observed. In pigs receiving 5% MOLM, the LW had significantly the highest ADFI (P<0.05) than KB pigs. In pigs receiving 2.5% and 5% MOLM, backfat thickness was significantly highest (P<0.05) compared to those receiving 0% MOML. Dietary inclusion of MOLM had no significant effects (P>0.05) on the physico-chemical quality of pork from LW pigs; although it significantly (P<0.05) increased a* and reduced WBSF values in pork from KB pigs. Pork from LW pigs receiving 5% MOLM had significantly increased (P<0.05) n-3 content of the subcutaneous tissue of LW pigs compared to KB, and also when compread to other treatment groups. In both breeds, the composition of PUFA: SFA and n-6: n-3 in the subcutaneous adipose tissue was significantly (P<0.05) lower in T2 and T3 than in T1. The n-3 levels for pork muscle from LW pigs receiving 2.5% and 5% MOLM, and from KB pigs receiving 5% MOLM, were significantly (P<0.05) lower. Inclusions of MOLM significantly (P<0.05) reduced the n-6: n-3 fatty acids in pork from both LW pigs and KB pigs. Consumer scores on sensory attributes (aroma intensity, initial impression of juiciness, first bite, sustained impression of juiciness, muscle fibre and overall tenderness and overall flavor intensity) significantly (P<0.05) increased as the level of MOLM inclusion in the diet increased; and higher scores were observed in fried meat than in boiled for most sensory attributes. It may be concluded that inclusion of MOLM in pig diets up to 5% improved the ADFI, a*, tenderness of pork without adversely affecting the FCR and other physico-chemical quality attributes; and resulted in desired increase in levels of n-3 and reduced the n-6: n-3 fatty acid ratio.
- Full Text:
- Date Issued: 2014
- Authors: Nduku, Xola Pauline
- Date: 2014
- Subjects: Pork -- Quality , Food -- Sensory evaluation , Fatty acids , Moringa , Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11836 , http://hdl.handle.net/10353/d1021281 , Pork -- Quality , Food -- Sensory evaluation , Fatty acids , Moringa , Meat -- Quality
- Description: The objective of the study was to determine growth performance, physico-chemical attributes, oxidative stability and sensory quality of pork from pigs fed one of three dietary treatments, eac containing 0%, 2.5% or 5% (T1, T2 and T3, respectively) Moringa oleifera leaf meal (MOLM). Dietary treatments were formulated to be isonitrogenous and isoenergetic for weaner (6 – 8 weeks) and grower (9 – 13 weeks) phases. Twelve Large White (LW) and 12 Kolbroek (KB) male pigs at 6 weeks of age, initially weighing an average 10 kg, were randomly allocated to one of the dietary treatments, each with four replicates, in individual pens. Feed and water were offered ad libitum. The Longissimus thoracis et lumborum (LTL) muscle of each carcass (n = 24) was sampled for meat quality and fatty acid analyses. Breed differences in measured parameters were observed. In pigs receiving 5% MOLM, the LW had significantly the highest ADFI (P<0.05) than KB pigs. In pigs receiving 2.5% and 5% MOLM, backfat thickness was significantly highest (P<0.05) compared to those receiving 0% MOML. Dietary inclusion of MOLM had no significant effects (P>0.05) on the physico-chemical quality of pork from LW pigs; although it significantly (P<0.05) increased a* and reduced WBSF values in pork from KB pigs. Pork from LW pigs receiving 5% MOLM had significantly increased (P<0.05) n-3 content of the subcutaneous tissue of LW pigs compared to KB, and also when compread to other treatment groups. In both breeds, the composition of PUFA: SFA and n-6: n-3 in the subcutaneous adipose tissue was significantly (P<0.05) lower in T2 and T3 than in T1. The n-3 levels for pork muscle from LW pigs receiving 2.5% and 5% MOLM, and from KB pigs receiving 5% MOLM, were significantly (P<0.05) lower. Inclusions of MOLM significantly (P<0.05) reduced the n-6: n-3 fatty acids in pork from both LW pigs and KB pigs. Consumer scores on sensory attributes (aroma intensity, initial impression of juiciness, first bite, sustained impression of juiciness, muscle fibre and overall tenderness and overall flavor intensity) significantly (P<0.05) increased as the level of MOLM inclusion in the diet increased; and higher scores were observed in fried meat than in boiled for most sensory attributes. It may be concluded that inclusion of MOLM in pig diets up to 5% improved the ADFI, a*, tenderness of pork without adversely affecting the FCR and other physico-chemical quality attributes; and resulted in desired increase in levels of n-3 and reduced the n-6: n-3 fatty acid ratio.
- Full Text:
- Date Issued: 2014
Experiences of agency nurses regarding their placement in private hospitals in East London, Eastern Cape
- Authors: Muller, Jennifer
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11911 , http://hdl.handle.net/10353/d1016054
- Description: The general Australian workforce is becoming increasingly reliant on agency staff due to the diminishing of full-time jobs and the rise in part-time jobs since the recession of 1991-1992. This pattern is also seen in Western countries such as America and the United Kingdom (Peerson et al., 2002:505). The excessive costs of health service adopting a 100% staffing model has created the use of agency nursing to help meet fluctuating and unpredictable health care demands in Australia and overseas; agency staff are used to meet the shortfalls in staff-patient ratios (Peerson et al., 2002:505). Hurst & Smith (2011:287) agree that agency nurse staffing form a large part of the health service in the UK and state that this was unlikely to change because of recruitment and retention problems, high absenteeism, and staff wanting to work casually. In their study, they identified three types of agency nurses: A bank nurse – the hospital’s own employees or those supplied by NHS Professionals, who work when required, usually at short notice; agency nurses provided by commercial organisations, who are equally flexible but less familiar with the ward patients and procedures; and permanent ward staff working paid overtime. In South Africa, this also remains a problem in public and private institutions. The World Health Organization (WHO) states that the minimum ratio for nurses to population is 200:100 000 or 500 people per nurse. According to South African Nursing Council statistics of nursing manpower as at the end of 2008, South Africa has 437 nurses for every 100 000 people. This assumed that all nurses registered with SANC are working in South Africa at the time. Therefore, if the assumed number of staff not working in South Africa is subtracted, the ratio can increase to between 600 and 678 people per nurse (WHO, 2006). Joubert (2009:2) shows that a shortage of nurses contributes to deaths in hospitals in South Africa that would otherwise have been avoidable. The use of agency staff is becoming an appropriate means of providing cost-effectiveness and flexibility to staffing needs.
- Full Text:
- Date Issued: 2014
- Authors: Muller, Jennifer
- Date: 2014
- Language: English
- Type: Thesis , Masters , MSc (Nursing Science)
- Identifier: vital:11911 , http://hdl.handle.net/10353/d1016054
- Description: The general Australian workforce is becoming increasingly reliant on agency staff due to the diminishing of full-time jobs and the rise in part-time jobs since the recession of 1991-1992. This pattern is also seen in Western countries such as America and the United Kingdom (Peerson et al., 2002:505). The excessive costs of health service adopting a 100% staffing model has created the use of agency nursing to help meet fluctuating and unpredictable health care demands in Australia and overseas; agency staff are used to meet the shortfalls in staff-patient ratios (Peerson et al., 2002:505). Hurst & Smith (2011:287) agree that agency nurse staffing form a large part of the health service in the UK and state that this was unlikely to change because of recruitment and retention problems, high absenteeism, and staff wanting to work casually. In their study, they identified three types of agency nurses: A bank nurse – the hospital’s own employees or those supplied by NHS Professionals, who work when required, usually at short notice; agency nurses provided by commercial organisations, who are equally flexible but less familiar with the ward patients and procedures; and permanent ward staff working paid overtime. In South Africa, this also remains a problem in public and private institutions. The World Health Organization (WHO) states that the minimum ratio for nurses to population is 200:100 000 or 500 people per nurse. According to South African Nursing Council statistics of nursing manpower as at the end of 2008, South Africa has 437 nurses for every 100 000 people. This assumed that all nurses registered with SANC are working in South Africa at the time. Therefore, if the assumed number of staff not working in South Africa is subtracted, the ratio can increase to between 600 and 678 people per nurse (WHO, 2006). Joubert (2009:2) shows that a shortage of nurses contributes to deaths in hospitals in South Africa that would otherwise have been avoidable. The use of agency staff is becoming an appropriate means of providing cost-effectiveness and flexibility to staffing needs.
- Full Text:
- Date Issued: 2014
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