Please read the summary in the front matter of this document. / Dissertation (MBA)--University of Pretoria, 2010. / Business Management / unrestricted

Bio-conversion of agricultural wastes provides a viable solution to multiple environmental problems as well as production of natural products. Apple processing for manufacturing juice, pies and sauce results in significant volumes of underutilized by-products. This study aims to optimize the method for producing fermentable sugars from apple processing by-products. The conditions required for pre-treatment, polyphenol removal and enzymatic hydrolysis were optimized. The optimized conditions for dilute sulfuric acid-based hydrothermal pre-treatment were acid concentration of 1.5% (w/v) at 91 oC for 16 min. The final yield of 12.7% fermentable sugars (glucose, fructose and galacturonic acid) was obtained after multistep hydrolysis using commercial cellulase, pectinase and ?-glucosidase at 9, 38 and 8 enzyme units/g FW, respectively. The other optimum conditions were temperature of 40 oC, pH at 4.0 and 24 h of reaction time. These fermentable sugars can further be converted into bio-ethanol and organic acids using specific yeast and bacteria.

A exploração indiscriminada dos combustíveis fósseis vem alertando para o colapso próximo do suprimento de energia. Fontes alternativas vêm sendo exploradas com o propósito de apresentarem-se como combustíveis com o mesmo potencial, além de estarem inseridas em um contexto de desenvolvimento sustentável. O Brasil, por consolidar sua posição com forte mercado agroindustrial e dispor de uma grande variedade de unidades agrícolas possui como subprodutos uma alta quantidade de resíduos, como o sabugo de milho. Assim, buscam-se viabilizar metodologias que tornem a exploração desta fonte economicamente vantajosa para a obtenção de etanol de segunda geração (2G). Novas metodologias vêm propondo o emprego de tensoativos como aditivos tanto no prétratamento quanto na hidrólise enzimática de materiais lignocelulósicos. Neste contexto, o presente trabalho objetivou estudar a hidrólise enzimática do sabugo de milho pré-tratado por ácido diluído na presença de diferentes concentrações do tensoativo Tween 80 em associação com a dosagem do complexo enzimático Cellic CTec2 para a obtenção de um hidrolisado rico em glicose para obtenção de etanol pela levedura Scheffersomyces stipitis CBS 6054 através do processo SHF (Separate Hydrolysis and Fermentation). Os ensaios foram conduzidos de acordo com planejamento experimental 23 com face centrada e 3 repetições no ponto central. As variáveis estudadas foram: concentração de surfactante no pré-tratamento e na hidrólise enzimática e dosagem do complexo enzimático. Os resultados mostraram que o uso do surfactante no pré-tratamento com ácido sulfúrico diluído surtiu maior efeito na remoção de lignina e hemicelulose quando empregado na concentração de 10% (m/m). Nesta condição foi possível observar um aumento (21,1%) na perda de celulose em relação ao pré-tratamento sem a presença de surfactante. A maior diminuição na cristalinidade (81,23%) foi com o uso de 10% do tensoativo. A análise da superfície de resposta permitiu determinar as condições ótimas do processo SHF para obtenção de máximo rendimento em glicose (entre 80 e 90 %) que foi quando a concentração de surfactante no pré-tratamento aumentou de 0 a 10 % (m/m) mantendo-se constante em seu nível superior a concentração de surfactante na hidrolise enzimática (10 % m/m) com redução na dosagem de enzima (25,50 FPU/gmaterial lignocelulósico seco). Nestas condições experimentais obteve-se favorecimento no rendimento em glicose (80,54%) e concentração em glicose (61,98 g/L) no meio reacional concomitantemente com o favorecimento no rendimento em xilose (70,66%). Esta levedura fermentou concomitantemente os açúcares (glicose, xilose e celobiose) a etanol com elevados fator de conversão (0,37 g/g) e produtividade volumétrica (1,02 getanol/L.h). A velocidade especifica máxima de consumo destes açúcares foi favorecida na seguinte ordem: glicose, celobiose e xilose. Após esta fermentação foi obtido um material com uma superfície mais porosa e fragmentada. Este fato evidenciou que o complexo enzimático agiu eficientemente quebrando a celulose cristalina obtendo um material amorfo. Espera-se que este trabalho tenha contribuído para o desenvolvimento de uma tecnologia alternativa para a produção de etanol por via biotecnológica a partir da fração lignocelulósica do sabugo de milho, a fim de mitigar os impactos ambientais intrínsecos ao processo. / The indiscriminate exploitation of fossil fuels has been warning of the near collapse of the energy supply. Alternative sources have been explored with the purpose of presenting themselves as fuels with the same potential, besides being inserted in a context of sustainable development. Brazil, by consolidating its position with a strong agroindustrial market and having a wide variety of agricultural units, has as a by-product a high amount of waste, such as corn cob. Thus, we seek to make feasible methodologies that make the exploitation of this source economically advantageous to obtain second generation etanol (2G). New methodologies have proposed the use of surfactants as additives in both pretreatment and enzymatic hydrolysis of lignocellulosic materials. In this context, the present work aimed to study the enzymatic hydrolysis of diluted-acid pretreated corn cob in the presence of different concentrations of the Tween 80 surfactant in combination with the dosage of the Cellic CTec2 enzymatic complex to obtain a glucose rich hydrolysate to produce ethanol by the yeast Scheffersomyces stipitis CBS 6054 in SHF (Separate Hydrolysis and Fermentation) process. The experiments were conducted according to experimental design 23 with centered face and 3 repetitions at the central point. The variables studied were: concentration of surfactant in the pretreatment and in the enzymatic hydrolysis and dosage of the enzymatic complex. The results showed that the use of surfactant in the pretreatment with diluted sulfuric acid had a greater effect on the removal of lignin and hemicellulose when used at the concentration of 10% (w/w). In this condition, the cellulose content was decreased by 21.1% as compared with the amount presents in the diluted-acid corn cob pretreatment without surfactant. The greatest decrease in crystallinity (81.23%) was with the use of 10% of the surfactant. The response surface analysis allowed to determine the optimum conditions of the SHF process to obtain maximum glucose yield (between 80 and 90%), when the pre-treatment surfactante concentration increased from 0 to 10% (w/w) with a reduction in the enzyme dosage (25,50 FPU/g dry lignocellulosic material) at a higher level than the surfactant concentration in the enzymatic hydrolysis. In these experimental conditions, glucose yield (80.54%) and glucose concentration (61.98 g/L) in the reaction medium were favored concomitantly with xylose yield (70.66%). This yeast concomitantly fermented the sugars (glucose, xylose and cellobiose) to ethanol with high conversion factor (0.37 g/g) and volumetric productivity (1.02 getanol/L.h). The maximum specific velocity of consumption of these sugars was favored in the following order: glucose, cellobiose and xylose. After this fermentation was obtained a material with a more porous and fragmented surface. This fact evidenced that the enzymatic complex acted efficiently breaking down the crystalline cellulose obtaining an amorphous material. It is hoped that this work had contributed to the development of an alternative technology to produce ethanol by Biotechnological route from the corn cob lignocellulosic fraction in order to mitigate the environmental impacts intrinsic to the process.

A demanda por energia é crescente devido ao desenvolvimento mundial. A energia renovável advinda de Biomassa, na forma de biocombustível e energia elétrica, tem um papel importante no atendimento desse crescimento, devido às políticas de desenvolvimento sustentável e à pressão das organizações mundiais. Este trabalho tem como objetivo demonstrar que a integração de tecnologias de segunda geração, aproveitamento da celulose, em unidades existentes de processamento de cana-deaçúcar (etanol e energia elétrica), resulta em uma melhor eficiência energética, com um aumento de aproximadamente 25% na produção atual, visto que as unidades existentes convertem apenas sacarose em etanol e utiliza o bagaço apenas como insumo para caldeiras de vapor. Além disso, definem-se as plataformas bioquímica e termoquímica, informando o estado atual das principais tecnologias de segunda geração, realizando uma comparação entre as plataformas. Em seguida, é demonstrada a eficiência energética utilizando quatro cenários: cenário I unidade industrial atual sem aproveitamento do bagaço excedente; cenário II unidade industrial atual com aproveitamento do bagaço excedente; cenário III integração parcial com aproveitamento do bagaço excedente e 50% da palha com a tecnologia de Biomass Integrated Gasification/Gas Turbine (BIG/GT); cenário IV integração total utilizando 100% de bagaço e 50 % da palha com a tecnologia BIG/GT. Na seqüência, é realizado um estudo de caso, que simula a integração da tecnologia BIG/GT em uma usina existente de primeira geração, demonstrando os três cenários finais. Conclui-se que as unidades de processamento de cana-de-açúcar, produtoras de etanol e energia elétrica, existentes podem possuir um melhor aproveitamento energético, melhorando as suas instalações de primeira geração, reduzindo o consumo de vapor através de equipamentos eficientes. Porém, a utilização de tecnologias de segunda geração elevam para outro patamar a eficiência energética da planta, mesmo comparado com a primeira geração otimizada. É válido informar que essas novas tecnologias ainda estão em desenvolvimento, possuindo barreiras tecnológicas a serem ultrapassadas, possibilitando o desenvolvimento de diversas linhas de pesquisa. O conhecimento das tecnologias de segunda-geração, tanto da plataforma bioquímica como da termoquímica, e a consideração da utilização dessas tecnologias em curto prazo, no planejamento de ampliações das plantas existentes ou em novos empreendimentos de processamento de cana-de-açúcar que estão ocorrendo no Brasil, é essencial para um melhor aproveitamento energético da cana-de- açúcar e um bom aproveitamento dos equipamentos que estão sendo implantados. / The demand for energy has been increasing due to world development. Renewable energy of biomass, biofuel and electric energy have an important role to assist this growth, due to sustainable development policies and to the pressure of global organizations. The main aim of this dissertation is to demonstrate that the integration of second-generation technologies, cellulose utilization, in processing sugar cane units (Ethanol and Electric Energy), results in an increase of the energy efficiency, a rise of 25% in the current production, due to the fact that first-generation tecnologies convert only sucrose in ethanol and use the bagasse just as fuel to steam-boiler. Besides, this paper brings the concept of biochemical and thermochemical platforms, informing the second-generation status and making a comparision between the plataforms. After that, it demonstrates the energy efficiency using four scenarios: Scenario I present industrial plant without using the bagasse, Scenario II present industrial plant using the bagasse, Scenario III parcial integration using the bagasse and 50% sugar cane trash with the BIG/GT technology, Scenario IV- total integration using the bagasse and 50% sugar cane trash with the BIG/GT technology. Besides, it makes a case study that simulates the integration of BIG/GT technology in a real first-generation unit, showing the scenarios II, III and IV. It will be concluded that the existent plants of sugar cane processing, producers of ethanol and electric energy, can increase their energy efficiency, improving their instalation of firstgeneration, reducing steam consumption through more efficient equipment. Nevertheless, the application of second-generation technology takes to an even higher level the energy efficiency of the unit than the improved first-generation plant. It is important to inform that these new technologies are still being developed, and have to overcome technological barriers, leading to several research lines. The knowledge of second generation technologies, including thermochemical and biochemical platforms, and the possibility to utilize these technologies in a short period of time to plan the amplifications of the existing plants of sugar cane processing or to new ventures that are being established in Brazil, are essencial to a better sugar cane energetic utilization and good use of equipments that are being implanted.

Thesis (MScAgric (Genetics))--University of Stellenbosch, 2010. / Includes bibliography. / ENGLISH ABSTRACT: This study aimed to investigate the suitability of spring wheat in the Western Cape as a potential feedstock for a future bio-ethanol industry as well as initiate a pre-breeding effort to develop bioethanol -directed improved lines. Determined primarily on grain yield, disease resistance and, direct as well as indirect assaying of important parameters, material was selected from a base-population for use as male parents. These were crossed with female parents sourced from the Stellenbosch University Plant Breeding Laboratory (SU-PBL) male sterility -mediated marker-assisted recurrent selection (MSMARS) programe. This programe is constituted by an agronomically and disease-resistance - improved population, containing a dominant male sterility gene (Ms3). The progeny of these crosses was used to initiate the production of doubled haploids in order to ultimately derive higher ethanol yielding lines. Multi-location field trial (MLFT) data revealed that 00K60-16-3-3 was the best adapted and highest yielding (2160.95 litres ethanol per hectare) advanced breeding line (ABL). Its performance was not statistically significantly less than first-ranked 03H86-8-2 (2184.62 litres per hectare) and both ABLs significantly (P≤0.05) out-performed six controls in the study. ABL 00K60-16-3-3 was also the most adapted in terms of potential yield in litres per ton of grain. ABL 03H86-8-1 was second recommended for the Western Cape, performing above the expected mean for yield in litres per hectare. Further adaptation of specific ABLs to the two major sub-regions of the Western Cape i.e. the Swartland and Southern Cape including the Rûens was also elucidated. Napier was significantly the highest yielding trial site although none of the considered sites were both stable and high yielding. It was also determined that entry X locality interaction (GxE) was indeed significant across the whole production area regarding litres per hectare as well as its two subregions. This is expected considering the environmentally diverse nature of the region as a whole. Using several entries as examples, relationships between starch, ethanol production in litres ethanol per hectare and litres per ton where grain yield is not taken into consideration were illustrated. Overall applicable relationships other than clear grouped entry differences could not be established. What was clearly demonstrated however, is that the maximization of grain yield is paramount. Highlighted thus, is the individuality of a specific genotype where MLFTs will always be required to quantify genotype potential. / AFRIKAANSE OPSOMMING: Die studie het ten doel gehad om die geskiktheid van lentekoring vir die produksie van bio-etanol in die Wes Kaap te evalueer. Ook het dit ‘n voortelingsprogram geinisieer vir die teel van lyne met verhoogde bio-etanol opbrengs. Materiaal vir gebruik as manlike ouers in ‘n basis-populasie is geselekteer gegrond grootliks op graanopbrengs, siekteweerstand en direkte sowel as indirekte etanolopbrengs kenmerke. Die gekose materiaal is gekruis met vroulike ouers verkry vanaf Stellenbosch Universiteit se Planteteeltlaboratorium (SU-PTL) se manlike steriliteits gedrewe merker bemiddelde herhalende seleksieprogram. Die program is saamgestel uit ‘n verbeterde populasie ten opsigte van siekteweerstand en agronomiese eienskappe. Dit bevat ook ‘n dominante steriliteitsgeen. Die nageslag van die kruisings is aangewend vir die inisiasie van die produksie van verdubbelde haploied lyne vir die verkryging van lyne met verhoogde etanol opbrangs. Die ontleding van data ten opsigte van die multi-lokaliteitsproewe (MLP) het aangetoon dat gevorderde teellyn (GTL) 00K60-16-3-3 die beste aangepas was en ook die hoogste opbrengs (2160.95 liters etanol per hektaar) gegee het. 00K60-16-3-3 was ook nie statisties betekenisvol swakker as die eerste geplaaste 03H86-8-2 (2184.62 liters etanol per hektaar) en beide GTLs was statisties betekenisvol beter (P≤0.05) as die ses kontroles in die studie. GTL 00K60-16-3-3 was ook die beste aangepaste in terme van etanol opbrengs in liters per ton graan. GTL 03H86-8-1 was tweede aanbevole vir die Wes-Kaap met ‘n prestasie bo die verwagte gemiddelde opbrengs in liters per hektaar. Verdere aanpassing van spesifieke GTLs vir die twee mega-omgewings in Wes- Kaap nl. Swartland en Suid-Kaap insluitend die Rûens was ook afgelei. Napier was betekenisvol beter, maar nie enige van die lokaliteite was beide stabiel en hoë opbrengs lokaliteite nie. Dit was ook bepaal dat die inskrywing by lokaliteits interaksie (GXE) betekenisvol was oor die hele produksiegebied ten opsigte van liters per hektaar asook in die twee mega-omgewings afsonderlik. Dit was egter te verwagte gegewe die diverse aard van die omgewings in die streek as geheel. Deur gebruik te maak van verskeie inskrywings as voorbeelde is die verwantskap tussen stysel, etanol produksie in liters etanol per hektaar en liters etanol per ton graan geillustreer sonder om graanopbrengs in ag te neem. Oorhoofs toepaslike verwantskappe anders as duidelike gegroepeerde inskrywings verskille kon nie afgelei word nie. Wat wel duidelik gedemonstreer kon word is dat maksimum graanopbrengs uiters belangrik was. Dit is dus duidelik dat weens die wisselende aard van spesifieke genotipes MLPs altyd van kardinale belang sal wees vir die kwantifisering van ‘n genotipe se potensiaal.

A demanda por energia é crescente devido ao desenvolvimento mundial. A energia renovável advinda de Biomassa, na forma de biocombustível e energia elétrica, tem um papel importante no atendimento desse crescimento, devido às políticas de desenvolvimento sustentável e à pressão das organizações mundiais. Este trabalho tem como objetivo demonstrar que a integração de tecnologias de segunda geração, aproveitamento da celulose, em unidades existentes de processamento de cana-deaçúcar (etanol e energia elétrica), resulta em uma melhor eficiência energética, com um aumento de aproximadamente 25% na produção atual, visto que as unidades existentes convertem apenas sacarose em etanol e utiliza o bagaço apenas como insumo para caldeiras de vapor. Além disso, definem-se as plataformas bioquímica e termoquímica, informando o estado atual das principais tecnologias de segunda geração, realizando uma comparação entre as plataformas. Em seguida, é demonstrada a eficiência energética utilizando quatro cenários: cenário I unidade industrial atual sem aproveitamento do bagaço excedente; cenário II unidade industrial atual com aproveitamento do bagaço excedente; cenário III integração parcial com aproveitamento do bagaço excedente e 50% da palha com a tecnologia de Biomass Integrated Gasification/Gas Turbine (BIG/GT); cenário IV integração total utilizando 100% de bagaço e 50 % da palha com a tecnologia BIG/GT. Na seqüência, é realizado um estudo de caso, que simula a integração da tecnologia BIG/GT em uma usina existente de primeira geração, demonstrando os três cenários finais. Conclui-se que as unidades de processamento de cana-de-açúcar, produtoras de etanol e energia elétrica, existentes podem possuir um melhor aproveitamento energético, melhorando as suas instalações de primeira geração, reduzindo o consumo de vapor através de equipamentos eficientes. Porém, a utilização de tecnologias de segunda geração elevam para outro patamar a eficiência energética da planta, mesmo comparado com a primeira geração otimizada. É válido informar que essas novas tecnologias ainda estão em desenvolvimento, possuindo barreiras tecnológicas a serem ultrapassadas, possibilitando o desenvolvimento de diversas linhas de pesquisa. O conhecimento das tecnologias de segunda-geração, tanto da plataforma bioquímica como da termoquímica, e a consideração da utilização dessas tecnologias em curto prazo, no planejamento de ampliações das plantas existentes ou em novos empreendimentos de processamento de cana-de-açúcar que estão ocorrendo no Brasil, é essencial para um melhor aproveitamento energético da cana-de- açúcar e um bom aproveitamento dos equipamentos que estão sendo implantados. / The demand for energy has been increasing due to world development. Renewable energy of biomass, biofuel and electric energy have an important role to assist this growth, due to sustainable development policies and to the pressure of global organizations. The main aim of this dissertation is to demonstrate that the integration of second-generation technologies, cellulose utilization, in processing sugar cane units (Ethanol and Electric Energy), results in an increase of the energy efficiency, a rise of 25% in the current production, due to the fact that first-generation tecnologies convert only sucrose in ethanol and use the bagasse just as fuel to steam-boiler. Besides, this paper brings the concept of biochemical and thermochemical platforms, informing the second-generation status and making a comparision between the plataforms. After that, it demonstrates the energy efficiency using four scenarios: Scenario I present industrial plant without using the bagasse, Scenario II present industrial plant using the bagasse, Scenario III parcial integration using the bagasse and 50% sugar cane trash with the BIG/GT technology, Scenario IV- total integration using the bagasse and 50% sugar cane trash with the BIG/GT technology. Besides, it makes a case study that simulates the integration of BIG/GT technology in a real first-generation unit, showing the scenarios II, III and IV. It will be concluded that the existent plants of sugar cane processing, producers of ethanol and electric energy, can increase their energy efficiency, improving their instalation of firstgeneration, reducing steam consumption through more efficient equipment. Nevertheless, the application of second-generation technology takes to an even higher level the energy efficiency of the unit than the improved first-generation plant. It is important to inform that these new technologies are still being developed, and have to overcome technological barriers, leading to several research lines. The knowledge of second generation technologies, including thermochemical and biochemical platforms, and the possibility to utilize these technologies in a short period of time to plan the amplifications of the existing plants of sugar cane processing or to new ventures that are being established in Brazil, are essencial to a better sugar cane energetic utilization and good use of equipments that are being implanted.

A exploração indiscriminada dos combustíveis fósseis vem alertando para o colapso próximo do suprimento de energia. Fontes alternativas vêm sendo exploradas com o propósito de apresentarem-se como combustíveis com o mesmo potencial, além de estarem inseridas em um contexto de desenvolvimento sustentável. O Brasil, por consolidar sua posição com forte mercado agroindustrial e dispor de uma grande variedade de unidades agrícolas possui como subprodutos uma alta quantidade de resíduos, como o sabugo de milho. Assim, buscam-se viabilizar metodologias que tornem a exploração desta fonte economicamente vantajosa para a obtenção de etanol de segunda geração (2G). Novas metodologias vêm propondo o emprego de tensoativos como aditivos tanto no prétratamento quanto na hidrólise enzimática de materiais lignocelulósicos. Neste contexto, o presente trabalho objetivou estudar a hidrólise enzimática do sabugo de milho pré-tratado por ácido diluído na presença de diferentes concentrações do tensoativo Tween 80 em associação com a dosagem do complexo enzimático Cellic CTec2 para a obtenção de um hidrolisado rico em glicose para obtenção de etanol pela levedura Scheffersomyces stipitis CBS 6054 através do processo SHF (Separate Hydrolysis and Fermentation). Os ensaios foram conduzidos de acordo com planejamento experimental 23 com face centrada e 3 repetições no ponto central. As variáveis estudadas foram: concentração de surfactante no pré-tratamento e na hidrólise enzimática e dosagem do complexo enzimático. Os resultados mostraram que o uso do surfactante no pré-tratamento com ácido sulfúrico diluído surtiu maior efeito na remoção de lignina e hemicelulose quando empregado na concentração de 10% (m/m). Nesta condição foi possível observar um aumento (21,1%) na perda de celulose em relação ao pré-tratamento sem a presença de surfactante. A maior diminuição na cristalinidade (81,23%) foi com o uso de 10% do tensoativo. A análise da superfície de resposta permitiu determinar as condições ótimas do processo SHF para obtenção de máximo rendimento em glicose (entre 80 e 90 %) que foi quando a concentração de surfactante no pré-tratamento aumentou de 0 a 10 % (m/m) mantendo-se constante em seu nível superior a concentração de surfactante na hidrolise enzimática (10 % m/m) com redução na dosagem de enzima (25,50 FPU/gmaterial lignocelulósico seco). Nestas condições experimentais obteve-se favorecimento no rendimento em glicose (80,54%) e concentração em glicose (61,98 g/L) no meio reacional concomitantemente com o favorecimento no rendimento em xilose (70,66%). Esta levedura fermentou concomitantemente os açúcares (glicose, xilose e celobiose) a etanol com elevados fator de conversão (0,37 g/g) e produtividade volumétrica (1,02 getanol/L.h). A velocidade especifica máxima de consumo destes açúcares foi favorecida na seguinte ordem: glicose, celobiose e xilose. Após esta fermentação foi obtido um material com uma superfície mais porosa e fragmentada. Este fato evidenciou que o complexo enzimático agiu eficientemente quebrando a celulose cristalina obtendo um material amorfo. Espera-se que este trabalho tenha contribuído para o desenvolvimento de uma tecnologia alternativa para a produção de etanol por via biotecnológica a partir da fração lignocelulósica do sabugo de milho, a fim de mitigar os impactos ambientais intrínsecos ao processo. / The indiscriminate exploitation of fossil fuels has been warning of the near collapse of the energy supply. Alternative sources have been explored with the purpose of presenting themselves as fuels with the same potential, besides being inserted in a context of sustainable development. Brazil, by consolidating its position with a strong agroindustrial market and having a wide variety of agricultural units, has as a by-product a high amount of waste, such as corn cob. Thus, we seek to make feasible methodologies that make the exploitation of this source economically advantageous to obtain second generation etanol (2G). New methodologies have proposed the use of surfactants as additives in both pretreatment and enzymatic hydrolysis of lignocellulosic materials. In this context, the present work aimed to study the enzymatic hydrolysis of diluted-acid pretreated corn cob in the presence of different concentrations of the Tween 80 surfactant in combination with the dosage of the Cellic CTec2 enzymatic complex to obtain a glucose rich hydrolysate to produce ethanol by the yeast Scheffersomyces stipitis CBS 6054 in SHF (Separate Hydrolysis and Fermentation) process. The experiments were conducted according to experimental design 23 with centered face and 3 repetitions at the central point. The variables studied were: concentration of surfactant in the pretreatment and in the enzymatic hydrolysis and dosage of the enzymatic complex. The results showed that the use of surfactant in the pretreatment with diluted sulfuric acid had a greater effect on the removal of lignin and hemicellulose when used at the concentration of 10% (w/w). In this condition, the cellulose content was decreased by 21.1% as compared with the amount presents in the diluted-acid corn cob pretreatment without surfactant. The greatest decrease in crystallinity (81.23%) was with the use of 10% of the surfactant. The response surface analysis allowed to determine the optimum conditions of the SHF process to obtain maximum glucose yield (between 80 and 90%), when the pre-treatment surfactante concentration increased from 0 to 10% (w/w) with a reduction in the enzyme dosage (25,50 FPU/g dry lignocellulosic material) at a higher level than the surfactant concentration in the enzymatic hydrolysis. In these experimental conditions, glucose yield (80.54%) and glucose concentration (61.98 g/L) in the reaction medium were favored concomitantly with xylose yield (70.66%). This yeast concomitantly fermented the sugars (glucose, xylose and cellobiose) to ethanol with high conversion factor (0.37 g/g) and volumetric productivity (1.02 getanol/L.h). The maximum specific velocity of consumption of these sugars was favored in the following order: glucose, cellobiose and xylose. After this fermentation was obtained a material with a more porous and fragmented surface. This fact evidenced that the enzymatic complex acted efficiently breaking down the crystalline cellulose obtaining an amorphous material. It is hoped that this work had contributed to the development of an alternative technology to produce ethanol by Biotechnological route from the corn cob lignocellulosic fraction in order to mitigate the environmental impacts intrinsic to the process.

MScAgric / Thesis (MSc (Genetics))--University of Stellenbosch, 2009. / ENGLISH ABSTRACT: In the Western Cape small grain cereals, triticale (×Triticosecale Wittmack ex A. Camus) in particular, appear to be among the most promising starch-carrying raw materials for the production of bio-ethanol. A core group of cultivars and lines from the Stellenbosch University Plant Breeding Laboratory spring triticale breeding programme were subjected to initial testing for the purpose of ethanol production. They underwent multi-location field-testing across six (season 2006–2007) and nine (season 2007–2008) locations representing the Western Cape cereal production area. Climatic conditions during the study were characterised as generally favourable, especially in the 2007 season. During the season, trials were visited in order to make in situ observations. Disease susceptibility was given specific attention. After harvesting, grain yield (kg.ha-1), test weight (kg.HL-1), total starch content in whole grain (%), amylose/amylopectin ratio, protein content (%), ethanol output (L.tonne-1) and ethanol yield (L.ha-1) were analysed. Near infra-red reflectance spectroscopy calibration models were developed for moisture and starch contents. The best calibration based on whole grain spectra for moisture content had RPD = 1.691, R2 = 0.657 and SEP = 0.271%, and for starch content RPD = 1.646, R2 = 0.634 and SEP = 1.356%. Calibrations developed from milled grain showed better results for moisture content RPD = 2.526, R2 = 0.843, SEP = 0.182%, and for starch content RPD = 1.741, R2 = 0.673, SEP = 1.277%. These calibrations are suitable for rough screening of samples. In the 2006 season, starch yield was highly positively correlated with grain yield (R2 = 0.988, P <0.001). Both starch yield and grain yield were positively correlated with days to heading (R2 = 0.533 and R2 = 0.556, respectively; P <0.001). The 2007 season was characterised by a generally higher starch yield (2952– 3142kg.ha-1, 95%CI) compared to the 2006 season (2077–2315kg.ha-1, 95%CI). Starch yield was strongly positively correlated with grain yield (R2 = 0.975, P <0.001). Test weight demonstrated weak positive correlation with ethanol yield (R2 = 0.238, P <0.01) and grain yield (R2 = 0.279, P <0.001). Mean ethanol output ranged between 466–477L.tonne-1 at the 95%CI. Ethanol output was demonstrated to be more dependent on starch and other polysaccharides accessibility to enzymatic digestion than on the total starch content as such. The best lines for ethanol output in the 2007 season were G2, D3 and H2 for the Swartland region, and D3, G2 and D1 for the Overberg region. The best triticale lines under investigation showed their potential from a biological point of view to be a suitable crop for ethanol production in the Western Cape, with the achieved ethanol yield ranging between 2446–2625L.ha-1 at the 95%CI. For the Swartland region the best genotypes for ethanol yield were D1, H1 and D2, and for the Overberg H1 and G2. The 23 best lines were selected from the elite and senior blocks, and then used for the establishment of a recurrent massselection pre-breeding block. / AFRIKAANSE OPSOMMING: In die Wes-Kaap is kleingrane, meer spesifiek korog (×Triticosecale Wittmack ex A. Camus), van die mees belowende styseldraende rou-materiale vir die produksie van bio-etanol. ‘n Kern versameling van kultivars en telerslyne van die Universiteit van Stellenbosch se Planteteeltlaboratorium se lente korogteeltprogram is blootgestel aan aanvanklike toetsing met die doel om etanol produksie te meet. Die materiaal het veldtoetsing ondergaan oor verskeie lokaliteite gedurende die 2006–2007 (ses lokaliteite) en 2007–2008 (nege lokaliteite) seisoene wat verteenwoordigend was van die Wes-Kaapse produksie gebied. Klimaatstoestande gedurende die studie kan beskryf word as gunstig, veral gedurende die 2007 seisoen. Gedurende die groeiseisoen is proeflokaliteite gereeld besoek ten einde in situ observasies te kon maak, siektevatbaarheid het veral aandag geniet. Na die oes van proewe was graanopbrengs (kg.ha-1), hektolitermassa (kg.HL-1), totale-styselinhoud in heelgraan (%), amilose/amilopektien-verhouding, proteïeninhoud (%), etanolopbrengs (L.ton-1) en etanolopbrengs per hektaar (L.ha-1) gemeet. Naby-infrarooispektroskopie kalibrasies was ontwikkel vir vog- en styselinhoud. Die beste kalibrasies vir heelgraan voginhoud het ‘n RDP = 1.691, R2 = 0.657 en SEP = 0.271% en vir styselinhoud RPD = 1.646, R2 = 0.634 en SEP = 1.356% opgelewer. Die kalibrasies gebaseer op meel was aansienlik beter vir voginhoud RPD = 2.526, R2 = 0.843 en SEP = 0.182%, sowel as vir styselinhoud RPD = 1.741, R2 = 0.673 en SEP = 1.277%. Die kalibrasies is bruikbaar vir aanvanklike sifting van monsters. 5 Gedurende die 2006 seisoen het styselinhoud en graanopbrangs ‘n baie hoë korrelasie (R2 = 0.988, P <0.001) getoon. Beide stysel- en graanopbrengs was positief gekorreleerd met dae tot aar (R2 = 0.533 en R2 = 0.556; P <0.001). Die 2007 seisoen is gekenmerk deur ‘n hoër styselopbrengs (2952– 3142kg.ha-1, 95%VI) teenoor die 2006 seisoen (2077–2315kg.ha-1, 95%VI). Styselopbrengs was positief gekorreleerd met graanopbrengs (R2 = 0.975, P <0.001). Hektolitermassa het swak korrelasie getoon met etanolopbrengs (R2 = 0.238, P <0.01) en graanopbrengs (R2 = 0.279, P <0.01). Gemiddelde etanolopbrengs het gewissel tussen 466–477L.ton-1 by 95%VI. Data het aangedui dat etanolopbrengs meer aangewese is op stysel en ander polisakkariedverbindings se ensiematiese toeganklikheid eerder as totale stysel aanwesig. Die beste lyne wat etanolopbrangs betref in 2007 was G2, D3 en H2 vir die Swartland en D3, G2 en D1 vir die Overberg. Van die koroglyne wat deel was van die ondersoek het goeie potensiaal getoon, uit ‘n suiwer biologiese oogpunt, as gewas vir die produksie van etanol in die Wes-Kaap met ‘n gerealiseerde etanolopbrengs in die omgewing van 2446-2625L.ha-1 by 95%VI. In die Swartland was die beste genotipes D1, H1 en D2 en in die Overberg H1 en G2. Die beste 23 lyne is geselekteer uit die elite en senior telingsblokke en aangewend in die vestiging van ‘n herhalende-seleksie voortelingsblok.

[ES] El presente trabajo de investigación está centrado en la valorización y la mejora del bioetanol, empleando catalizadores heterogéneos, en un reactor de flujo continuo a escala de laboratorio. En primer lugar, en los laboratorios del Departamento de Química Industrial de la Universidad de Bolonia (Unibo), se ha estudiado la conversión catalítica del etanol en fase gaseosa sobre catalizadores basados en hidroxiapatitas (HAP). Los ensayos catalíticos se llevaron a cabo alimentando un reactor de lecho fijo a escala de laboratorio, empleando el catalizador en forma de pellets y una mezcla de etanol/He, en el rango de temperatura de 300-600 ºC. El interés se focalizó en la formación de productos de alta condensación, con el fin de obtener una mezcla orgánica que pueda ser empleada como bio-combustible. Tras seleccionar las condiciones de reacción, se sintetizaron y probaron diferentes hidroxiapatitas con capacidad de intercambio iónico que poseen metales de transición (Fe, Cu) y metales alcalinotérreos (Sr) en su composición. Mientras que las HAP conteniendo metales de transición actúan esencialmente como catalizadores ácidos, produciendo principalmente el producto de la deshidratación del etanol, el etileno, el catalizador de Sr-HAP permite la formación de una mezcla de reacción compleja, la cual necesita de una mayor optimización para cumplir con los requisitos adecuados para su posterior empleo como biofuel. A continuación, en los laboratorios del Instituto de Tecnología Química (ITQ) de la Universidad Politécnica de Valencia (UPV), el estudio se centró en dos materiales catalíticos diferentes, el óxido de zirconio y la sepiolita, una arcilla natural abundante en España. Ambos materiales se han probados para la transformación de etanol, en el rango de temperatura de 300-450 ºC, empleando un reactor de lecho fijo a escala laboratorio, con el catalizador en forma de pellets, y usando una mezcla de etanol/N2. Los catalizadores con óxido de zirconio se prepararon mediante dos métodos diferentes, precipitación e hidrotermal, variando algunos de los parámetros de síntesis (pH, naturaleza de la base), y empleando algunos metales de transición como elementos dopantes (Ti, Y). La presencia de un elemento dopante en la estructura de la zirconia favorece la estabilización de las fases tetragonal y cúbica frente a fase monoclínica. Todas las muestras exhibieron un comportamiento ácido. Resulta interesante que la zirconia dopada con 5%mol de Ti exhibe un comportamiento catalítico diferente, produciendo el dietiléter como principal producto a 300ºC, mientras que los otros catalizadores producen principalmente etileno, ambos, productos de la deshidratación del etanol. Por otra parte, se ha estudiado el efecto de las propiedades ácido-base de la sepiolita, modificada con metales alcalinos (Na, K, Cs) y cargas de metal variables (2, 4, 5, 7, 14 wt%), y de las propiedades redox de la sepiolita, como soporte de CuO o NiO, sobre la conversión catalítica de etanol a n-butanol. Las sepiolitas tratadas térmicamente actúan principalmente como catalizadores ácidos, produciendo preferentemente productos de deshidratación del etanol (etileno y dietiléter). Mientras que la presencia de un metal de transición no favorece la producción de n-butanol, la presencia de un metal alcalino en el sistema catalítico parece ser crucial para la formación de n-butanol. Los mejores resultados en términos de actividad (conversión de etanol, 59%) y selectividad (30%) de n-butanol se han obtenido a 400 ºC y un tiempo de contacto, W/F, de 2 g/mL·s, con el catalizador basado en sepiolita calcinada a 500 ºC, y modificada con 7 wt% de cesio, mediante impregnación en fase acuosa. / [CA] El present treball de recerca està centrat en la valorització i la millora del bioetanol, emprant catalitzadors heterogenis, en un reactor de flux continu a escala de laboratori. En primer lloc, en els laboratoris del Departament de Química Industrial de la Universitat de Bolonya (Unibo), s'ha estudiat la conversió catalítica de l'etanol en fase gasosa sobre catalitzadors basats en hidroxiapatitas (HAP). Els assajos catalítics es van dur a terme alimentant un reactor de llit fix, a escala de laboratori, contenint el catalitzador en forma de pèl·lets amb una mescla d'etanol/He, en el rang de temperatura de 300-600 °C. L'interés es va focalitzar en la formació de productes d'alta condensació, amb la finalitat d'obtindre una mescla orgànica que puga ser emprada com a bio-combustible. Després de seleccionar les condicions de reacció, es van sintetitzar i van provar diferents hidroxiapatitas amb capacitat d'intercanvi iònic que posseeixen metalls de transició (Fe, Cu) i metalls alcalinotérreos (Sr) en la seua composició. Mentre que les HAP contenint metalls de transició actuen essencialment com a catalitzadors àcids produint principalment el producte de la deshidratació de l'etanol, l'etilé, el catalitzador de Sr-HAP permet la formació d'una mescla de reacció complexa, la qual necessita d'una major optimització per a complir amb els requisits adequats per a la seua posterior ocupació com biofuel. A continuació, en els laboratoris de l'Institut de Tecnologia Química (ITQ) de la Universitat Politècnica de València (UPV), l'estudi es va centrar en dos materials catalítics diferents, l'òxid de zirconio i sepiolita, una argila natural abundant a Espanya. Tots dos materials s'han provats per a la transformació d'etanol en el rang de temperatura de 300-450 °C, emprant un reactor de llit fix a escala laboratori, contenint el catalitzador en forma de pèl·lets, i usant una mescla d'etanol/N2 Els catalitzadors amb òxid de zirconio es van preparar mitjançant dos mètodes diferents, precipitació i hidrotermal, variant alguns dels paràmetres de síntesis (pH, naturalesa de la base), i emprant alguns metalls de transició com a elements dopants (Ti, Y). La presència d'un element dopant en l'estructura de la zircònia afavoreix l'estabilització de les fases tetragonal i cúbica enfront de fase monoclínica Totes les mostres van exhibir un comportament àcid. Resulta interessant que la zircònia dopada amb 5%mol de Ti exhibisca un comportament catalític diferent, produint el dietiléter com a principal producte a 300 °C, mentre que les altres mostres produeixen principalment etilé, tots dos, productes de la deshidratació de l'etanol. D'altra banda s'ha estudiat l'efecte de les propietats àcid-base de la sepiolita, modificada amb metalls alcalins (Na, K, Cs) i càrregues de metall variables (2, 4, 5, 7, 14 wt%), i de les propietats redox de la sepiolita, com a suport de CuO o NiO, sobre la conversió catalítica d'etanol a n-butanol. Les sepiolites tractades tèrmicament actuen principalment com a catalitzadors àcids, produint principalment productes de deshidratació de l'etanol (etilé i dietiléter). Mentre que la presència d'un metall de transició no afavoreix la producció de n-butanol, la presència d'un metall alcalí en el sistema catalític sembla ser crucial per a la formació del n-butanol. Els millors resultats en termes d'activitat (conversió d'etanol, 59%) i selectivitat (30%) de n-butanol s'han obtingut a 400°C i un temps de contacte, W/F, de 2 g/ml·s amb el catalitzador compost de sepiolita calcinada a 500 °C, i modificada amb 7 wt% de Cs. / [EN] The present research work focused on the valorisation and upgrading of bio-ethanol over heterogeneous catalysts in a lab-scale continuous gas-flow system. Firstly, in the laboratories of the Department of Industrial Chemistry of the University of Bologna (Unibo), the catalytic ethanol gas-phase conversion was studied over hydroxyapatite (HAP) based catalysts. Catalytic tests have been carried out in the temperature range 300-600°C by feeding an ethanol/He mixture into a quartz lab-scale fixed bed reactor of pelletized catalyst. The focus was placed on enhancing the formation of higher condensation products in order to obtain an organic mixture with application as bio-fuel. After choosing the reaction conditions, ion-exchanged hydroxyapatite with transition metals (i.e., Fe, Cu) and alkaline earth metal (i.e., Sr) have been synthesized and tested. While the transition metal-exchanged HAP acted essentially as acid catalysts, yielding mainly the dehydration product of ethanol, ethylene, the Sr-HAP catalyst led to the formation of a complex reaction mixture the composition of which need further optimization in order to fill the requisite to be used as fuel-blend. Then, in the laboratories of the Institute of Chemical Technology (ITQ) of the Polytechnic University of Valencia (UPV), the study focused on two different catalytic materials, zirconium oxide and the natural clay sepiolite. Both the materials have been tested into the ethanol transformation carrying out the catalytic tests in the temperature range 300-450 °C by feeding an ethanol/N2 mixture into a quartz lab-scale fixed bed reactor of pelletized catalyst. Zirconium-oxide based catalysts have been prepared through two different methods, precipitation and hydrothermal, by varying some synthetic parameters (i.e., pH, the nature of the base) and by adding a transition metal as dopant agent (i.e., Ti and Y). The presence of a dopant into the zirconia structure favoured the stabilization of the tetragonal or cubic phase against the monoclinic one. All samples exhibited acidic behaviour. Interestingly, 5%mol Ti-doped zirconia exhibited a different catalytic behaviour yielding diethyl ether as major product at 300°C, while all the others samples produced mainly ethylene, both dehydration products of ethanol. The effect of acid-base properties of sepiolite, using alkali metals (i.e., Na, K, Cs) with different metal loading (i.e., 2, 4, 5, 7, 14 wt%) as promoters, and of the redox properties of sepiolite-supported CuO or NiO, on the catalytic conversion of ethanol into n-butanol has been investigated. Thermal treated sepiolite samples mainly acted as acid catalyst, yielding preferentially the dehydration products of ethanol (ethylene and diethyl ether). While the presence of a transition metal did not favour n-butanol production, the presence of an alkali metal into the catalytic system appeared to be crucial for n-butanol formation. Best results in terms of activity (ethanol conversion, 59%) and n-butanol selectivity (30%) where obtained at 400ºC and a contact time, W/F, of 2 g/mL·s over the catalyst consisting of sepiolite calcined at 500ºC modified with 7 wt% of cesium. / Balestra, G. (2022). Valorization of Bio-Alcohols into Added Value Chemicals [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/184991

石化能源逐漸耗竭引人關注，再加上「京都議定書」對溫室氣體排放之全球性管制，促使世界各國重視各種新能源與替代性能源，並積極投入應用與研究開發。生質燃料已成為全球許多國家的戰略性資源，其發展除可開發自產綠色能源，提高能源自主比例，並能結合能源、農業、環保、產業等共同發展。面對全球生質燃料產業急速成長，台灣自不能自外於節能減碳的永續發展趨勢。 為驗證政府推動生質燃料政策的環境條件及業界投入狀況，本研究以次級資料分析方法進行國內、外之發展現況及趨勢分析；透過學者、專家、政府業務執行主管及業者之深度訪談，藉由訪談之資料歸納國內發展情形，對照現有生質燃料政策推動目標之發展模式，並以五力分析架構及SWOT評估方法評估生質燃料產業發展之競爭力。 本研究的主要發現包括：1.影響我國生質燃料的發展，最主要的關鍵要素是料源成本、價格補貼及市場保證；2.在推廣生質燃料的策略作法上，絕大多數主張應依政府政策規劃目標循序漸進推動；3.業者在發展生質燃料過程中，面臨最大的困難在於政策的不確定及原料的掌握不足；4.產業發展初期仍應以國內產製優先，不足部分再開放進口；5.生質柴油料源中，目前以廢食用油最具價格競爭力，麻瘋果油次之，藻類則是長期看好的料源。生質酒精部分，依國內廠商最可行技術而言，以甘蔗酒精較具價格競爭力，狼尾草居次，纖維素作物則是長期看好者。6.現階段的政策目標，在生質柴油部分的推廣比例仍以B2為佳，生質酒精則以E3為國產料原的最大量。長期來看，生質燃料產業的擴展，一定要以非糧食作物為優先，關鍵環節在於纖維酒精技術及藻類開發技術有突破，推廣比例及市場規模才有再擴張的空間。 就研究分析所得，提供下述政策建議：1、政府需訂定明確的政策目標；2.成立再生能源國家型計畫，加速推動生質燃料發展；3.政府率先投資第二代生質燃料產業；4.需建構生質燃料永續發展的制度性設計；5.確立以本國產製為優先之政策宣示；6.強化節能減碳教育宣導，讓消費者建立信心並接受。在業界策略上建議：1.必須提升料源掌握度與開發多元料源，並降低生產成本；2.業者須加強與通路商籌組供油策略聯盟；3.生質酒精業者可採合資或合作生產方式切入市場，取得先占地位；4.積極參與第二代生質燃料的研發與技術銜接。 / Petrochemical energy shortage is an issue that has been gradually gaining attention. Global regulation of greenhouse gases emission set by the Kyoto Protocol has also called attention to new and alternative energy sources, as well as the active involvement of individual countries in new energy application and research development. Biofuel has now become a strategic resource in many countries. Additional development of alternative energy can not only help increase the amount of domestic green energy and its ratio to traditional energy, synergy is also created causing the equal development of energy, agriculture, environmental production, and industrial growth. In face of the rapid growth of the biofuel industry worldwide, Taiwan must not exclude itself from the trend of sustainable development in energy conservation and CO2 reduction. To access the conditions of government policy in biofuel promotion and industry involvement, this study used secondary data analysis methods to analyze the current trend and status of national and international development. Through information gathered from in-depth interviews with academics, experts, government executives, and industry members, current domestic developments are compared to existing models of biofuel policy, promotion, and objectives. The competitiveness of biofuel industry development is further evaluated using SWOT assessment and Five Power Analysis. The main findings of this study include the following: 1) The key elements affecting national biofuel development are raw material costs, price subsidies, and market guarantees. 2) In biofuel promotion strategies, a vast majority should be made gradually and according to government policy planning objectives. 3) In biofuel development, the biggest challenges the industry faces are policy uncertainties and the lack of raw materials. 4) In initial industry development, domestic production should be a priority, allowing imports only when in demand. 5) In raw materials for bio-diesel, recycled oils are currently the most competitive in value, followed by Jatropha oil, while algae is seen as having long-term potential. According to the most viable technology offered by domestic manufacturers, sugarcane ethanol is the most competitive in value for bio-ethanol, followed by Chinese Pennisetum, while agricultural waste is seen as having long-term potential. 6) In the current stage of policy objectives, B2 is still more adequate in the promotion of bio-diesel, and E3 is the main domestic raw material for bio-ethanol. In the expansion of biofuel industry in the long run, priority must be given to non staple crops, while the key lies in cellulosic ethanol and algae oil development technology. Only then can there be room for further expansion in promotional proportion and market scale. The following policy recommendations are provided based on analysis of the study: 1) Clear policy goals must be set by the government. 2) Establish nation-wide plans for renewable energy, and accelerate the promotion of biofuel development. 3) Government must take initiatives in second-generation feedstock investments. 4) A systematic design must be built for the sustainable development of biofuel. 5) Policy declarations must be made to ensure the priority of domestic production. 6) Strengthen education in energy conservation and CO2 reduction, and build consumer confidence and acceptance. Recommendations for industry strategies: 1) It is essential to increase control of raw materials, develop multi-source materials, and lower production costs. 2) The industry must strengthen its strategic alliances with distributor in oil supply. 3) The biofuel industry may partake in joint ventures or cooperative efforts to get a head start when entering the market. 4) Actively participate in the research and development and technology adaptation of second-generation feedstock.