Thesis (doctoral)--Lund University, 1994. / Added t.p. with thesis statement inserted.

University, Diss., 2002--Mainz.

Techn. University, Diss., 2004--Berlin.

Submitted in complete fulfilment for the Degree of Master of Technology: Biotechnology, Durban University of Technology, 2013. / The continual growth of the global biodiesel industry has resulted in a proportional increase in crude glycerol production. The by-production of glycerol waste during the manufacture of biodiesel has, with recent research, proven to hold use as a feedstock for the production of several commodity chemicals. The conversion of glycerol may be carried out by both chemical as well as biological means. The biological conversion of glycerol surpasses chemical conversion with respect to higher yield and selectivity, normal reaction conditions and the use of cheaper biological catalysts. Many microorganisms are known to convert glycerol to different value added products. This study involved the isolation of bacteria from soil and crude glycerol from a local biodiesel plant. Isolates were then used to convert crude glycerol supplemented with salts and a nitrogen source into commercially viable products. Isolates which successfully degraded glycerol were then identified via 16S PCR. A strain of Klebsiella pneumoniae, which is a known producer of 1,3-propanediol (1,3-PDO), was isolated from soil and two strains of Sphingomonas sp., which is a known gellan producer, was isolated from biodiesel waste. Gellan is an exopolysaccharide used in the food, cosmetic and pharmaceutical industries sold commercially as a product known as Gelrite or Gelzan while 1,3-PDO is an important component of fuels and polyesters (used widely in the petroleum industry) and is currently chemically produced. Using crude glycerol for producing 1,3-PDO is a good solution from an economic as well as ecological point of view. K. pneumoniae, Sphingomonas psueudosanguinis and Sphingomonas yabuuchiae were subjected to a series of shake flask fermentations in order to determine optimal growth conditions. This microoganism was able to successfully produce significant amounts of 1,3-PDO and lactic acid using crude glycerol (80 g/l), without pre-treatment (37 and 6.8 g/l respectively). S psueudosanguinis and S. yabuuchiae were both able to produce two of the highest amounts of gellan gum than that reported by other studies using crude glycerol (80 g/l) as a sole carbon source in a minimal medium (50.9 and 52.6 g/l respectively). / National Research Foundation

Orientador: Sandra Imaculada Maintinguer / Banca: Maria Bernadete Amâncio Varesche Silva / Banca: Valeria Reginatto Spiller / Resumo: A produção de biodiesel levou ao aumento do coproduto gerado desse processo, o glicerol bruto, que devido ao seu excesso, tem ganhado interesse nas transformações biotecnológicas visando à formação de produtos com valor agregado, sendo H2 de maior interesse. Este estudo avaliou o potencial da bioconversão do glicerol bruto, proveniente da produção de biodiesel a partir de óleo de cozinha usado, a hidrogênio por meio de consórcios de bactérias anaeróbias fermentativas. O glicerol bruto foi submetido ao pré-tratamento ácido (pH 3,0, HCl 1,0M) para converter sabões solúveis, considerados inibitórios ao crescimento microbiano, à ácidos graxos insolúveis. Consórcios bacterianos provenientes de estação de tratamento de água residual industrial (I) e sanitária (II e III), além da cultura pura Enterobacter sp. (inóculo IV) foram utilizados como inóculos e reativados em meio de cultivo, pH 7,0, a 37°C por 7 dias, sob condições anaeróbias. Para a obtenção de consórcios bacterianos produtores de H2, o pré-tratamento nos inóculos I, II e III foi realizado por meio do choque térmico (100°C por 15 minutos) com posterior enriquecimento por diluições seriais em meio PYG modificado e pH 5,5. Bacilos Gram positivos e formadores de endósporos foram predominantes. Os consórcios enriquecidos que apresentaram melhores desempenhos quanto à geração de H2, (I) e (II), foram utilizados para as realizações de ensaios, em batelada, em proporções crescentes de glicerol bruto pré-tratado. Nos ensaios de g... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The biodiesel production has led to increase co-product generated in this process, the crude glycerol, which due to its excess, has gained interest in the biotechnological transformations for aimed at formation of value-added products, considering H2 the most interest bioproduct. This study evaluated the potential of bioconversion of crude glycerol from the biodiesel production from used cooking oil, to generate hydrogen through consortia of fermentative anaerobic bacteria. The crude glycerol has been subjected to the acid pretreatment (pH 3.0, 1.0M HCl) to convert soluble soaps, considered inhibitory to microbial growth, to insoluble fatty acids. Consortia from sewage treatment of industrial waste (I) and sanitary waste (II and III), and the pure culture Enterobacter sp. (inoculum IV) were used as inocula and reactivated in growth medium, pH 7.0, at 37°C for 7 days, under anaerobic conditions. To obtain H2-producing bacterial consortia, pretreatment in inocula I, II and III was carried through the thermal shock (100°C for 15 minutes) with subsequent enrichment by serial dilutions in modified PYG and pH 5.5. Gram positive bacillis and spores-forming were predominant. The enriched consortia that showed better performances for the H2 generation, (I) and (II), were used for the assays, in batch mode, varying concentrations in increasing proportions of the crude glycerol pretreated. In the H2 generation assays, 20% of the reaction medium was composed of inoculum (I) and (II) sepa... (Complete abstract click electronic access below) / Mestre

Orientador: Maria Regina Wolf Maciel / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-16T03:15:43Z (GMT). No. of bitstreams: 1 Peres_AnaPaulaGimenez_M.pdf: 2893498 bytes, checksum: 660e046de1120b97974948724435b696 (MD5) Previous issue date: 2010 / Resumo: Biodiesel (alquil éster) é um combustível limpo derivado de fontes renováveis, óleos vegetais ou gordura animal. Sabe-se que, aproximadamente, 10% em peso do óleo vegetal utilizado como insumo na produção de biodiesel é convertido em glicerina, de forma que existem grandes incentivos para a utilização deste subproduto. A pirólise da glicerina residual por sua vez é um processo com grande potencial para a produção de biocombustíveis como hidrogênio (H2) e gás de síntese (matéria prima para produção de combustíveis sintéticos via reação de Fischer-Tropsch) gerando portanto, produtos de alto valor agregado. Assim, neste trabalho, a pirólise foi realizada em um reator de leito fixo utilizando-se glicerina comercial e glicerina residual da produção de biodiesel dos Laboratórios de Otimização, Projeto e Controle Avançado (LOPCA) e de Desenvolvimento de Processos de Separação (LDPS). Primeiramente, foram realizados planejamentos fatoriais fracionários para a determinação das variáveis independentes (temperatura e tempo de reação, vazão de gás de arraste e volume de glicerina) mais significativos no processo. Sendo que o volume de glicerina foi a variável com menor significância, portanto foi excluída do processo. Posteriormente, realizaram-se os experimentos de acordo com o planejamento fatorial completo 23 (com mais três pontos centrais). Foram obtidos dois modelos codificados de primeira ordem que descrevem a conversão de glicerina residual em hidrogênio e gás de síntese em função da temperatura de reação, tempo e vazão de gás de arraste. De acordo com as condições advindas da aplicação da metodologia de superfície de resposta, altas conversões de glicerina em H2 e em gás de síntese, em torno de 45% mol/mol e 80% mol/mol, respectivamente, foram experimentalmente obtidas em: 850ºC, 30min e vazão do gás de arraste 50mL/min. No processo de pirólise da glicerina foram obtidos produtos líquidos, gasosos e cinzas. Em média, obtiveram-se conversões superiores a 85% v/v de glicerina para produtos gasosos, entre eles H2 e CO (gás de síntese) em maior quantidade. Além desses gases, foram encontrados CO2, metano, etileno, etano e propano. Já os produtos líquidos foram basicamente acetaldeído, acetona, metanol e etanol. Através dos cálculos de energia ficou claro que a produção de H2 a partir desse processo é viável energeticamente. Sendo que para um mol de glicerina processada a energia líquida da reação foi 293kJ. / Abstract : Biodiesel (alkyls esters) is a clean burning fuel derived from renewable lipid feedstock such as vegetable oil or animal fat. Glycerin is a by-product from the biodiesel production which represents nearly 10% of product total mass. As the biodiesel production is increasing there exist incentives to use the glycerin as raw material for other processes. The glycerin pyrolysis is a promising way to produce biofuels such as hydrogen and syngas (feedstock used in synthetic fuels production via Fisher-Tropsch reaction) and at same time avoids its accumulation in the environment. Glycerin pyrolysis was carried out in a fixed bed reactor filled with silica-quartz and/or alumina oxide. The raw material considered in this work was pure glycerin and crude glycerin from biodiesel production. Experimental designs were carried out in specific conditions to identify the impact of the main process variables. At first, a fractional factorial experimental design was chosen to analyze the most significant factors (reaction temperature, reaction time, glycerin quantity and flow rate of carrier gas) on the conversion glycerin to hydrogen and syngas. The glycerin quantity was the least significant factor, so it was excluded from further investigation. Afterwards, the experiments were carried out according to a 23 complete factorial design plus three central points. Two first-order models were obtained to predict the crude glycerin conversion in hydrogen and syngas as a function of reaction temperature, reaction time and flow rate of carrier gas. From the surface methodology analysis, high conversions of glycerin into hydrogen and syngas, around 45% mol/mol and 85% mol/mol, respectively, can be obtained under the following conditions 850 º C, 30 min and flow carrier gas, 50ml/min. The best glycerin conversion to gas products was 80% v/v of glycerin. The main gás products were H2 and CO. Besides these gases, CO2, CH4, C2H4 and C3H8 were also obtained in smaller proportions. The liquid product compositions were methanol, ethanol, acetone and acetaldehyde. Through the energy calculations, it becomes clear that production of H2 from this process is energetically feasible. For one mole of glycerol, computed net energy of the reaction was around 293kJ. / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

This research has been directed at furthering the utilization of crude glycerol oversupply formed as a by-product from the biodiesel manufacturing process. Phosphorylation of hydroxyl groups is a synthetic route that was investigated for the conversion of glycerol into a glycerol-phosphate (GPE) ester mixture. The process investigated for the synthesis of a GPE product was based on phosphorylation reaction procedures that were previously reported in the literature. The reaction to convert glycerol into a GPE mixture has been thoroughly investigated and the hydrogen chloride gas formed as a reaction by-product has been optimized. The chemical properties of GPE have been studied and discussed together with a mass balance of the overall glycerol phosphorylation process. The phosphate groups contained in polyhydric phosphate molecules have a potential chelating effect on cations. There are several cations that may be chelated by the phosphate ester group of polyhydric phosphate molecules. These cations include ammonium (NH4+), Potassium (K+), Calcium (Ca2+) etc, which are essential as nutrients in plant fertilizer formulations. This research has investigated the use of a GPE synthesized from glycerol in the laboratory and the use thereof as a phosphorus containing base in the formulation and evaluation of Nitrogen, Phosphorus and Potassium (NPK) containing fertilizer solution, Ammonium-Potassium-Glycerol-Phosphate (APGP) fertilizer solution. The APGP fertilizer solution has further been evaluated by growing two week old tomato seedlings under controlled conditions. The performance of the APGP fertiliser solution has been evaluated using design of experiments by comparison with traditionally used liquidAmmonium-Potassium-Phosphate inorganic fertilizer. This fertilizer solution has been prepared in similar manner as APGP formulation with the difference between them being the source of phosphorus. The results have been evaluated using statistic analysis where a significant difference between the evaluated fertilizer formulations was found. The comparative study of these formulations was monitored by the observed plant weights. A blank treatment was used as a control to determine if a significant difference among these formulations was observed. Anova single factor and t-Test methods (Two-Samples assumed of equal variances) are statistical models that were applied to interpret the observed experimental data with respect to wet and dry weighed masses of tomato seedlings. These methods indicated a confirmed conclusion that there was a significant difference between APPO4 solution and APGP solution. The observed data have shown that the APPO4 solution provided significantly better fertigation performance than APGP solution. Consequently, further investigation has been conducted to determine the cause of the poorer performance of the APGP solution. The further study of the APGP fertilizer solution included nutrient stability testing, biological analysis and other observed physical changes of the APGP solution over time. Biological results have revealed the presence of a Fusarium fungus species that has grown and is suspended in APGP fertilizer solution. This microbe species has been observed to play a vital role in consuming fertilizer nutrients. In addition, the observed abnormal plant growth and nutrient decomposition of the APGP formulation has been proposed to be mostly a result of the pathogenicity of the fusarium fungi species that was suspended in the APGP solution. Further work has been proposed in which the effect of such biological contamination is eliminated through adequate sterilization procedures and the APGP formulation re-evaluated.

Supplemental carbon has been successfully added and implemented at biological nutrient removal treatment plants all around the world in order to reach low nitrogen discharge limits. Although, methanol has been the most prevalent external electron donor used due to its low cost and effectiveness, many utilities are moving away from it due to cost volatility, safety issues, and hindered performance in cold weather conditions. Many sustainable and alternative sources are being researched, such as glycerin-based products (Rohrbacher et al., 2009), sugar-based waste products (Pretorius et al., 2007), and effluents from food and beverage industries (Swinarski et al., 2009). Four 22-L sequencing batch reactors (SBRs) were utilized to investigate four different supplemental carbon sources: 100% reagent grade methanol, 100% reagent grade glycerol, bio-diesel glycerol waste, and an industrial waste alcohol. These reactors were operated at 20�"C with a 15 day solids retention time. Intensive profiles were carried out three times a week to monitor performance and collect data to calculate COD consumption: nitrate-nitrogen denitrified (C: N) ratios. The glycerol and bio-diesel glycerol waste reactors performed similarly as they both exhibited significant and consistent nitrite accumulation during the entire experiment. Based on reactor restart, nitrite accumulation was evident and significant within two days after startup and consistent for all further operation. Rapid nitrate to nitrite reduction coincident with COD uptake was also observed. The two glycerol reactors demonstrated an increased carbon demand over time. The commonly reported hypothesis that activated sludge transitions from a generalist population of ordinary heterotrophic organisms (OHO) that use substrate, glycerol in this case, less efficiently, producing low yields and slow growth rates, to a specialist population that use glycerol more efficiently, with higher yields and slightly faster growth rates, was verified. This is known as the generalist-specialist theory. While this hypothesis appears to be supported from an overall analysis of the data, the actual mechanism seems to be intracellular glycerol storage coincident with rapid nitrate to nitrite denitrification, followed by slow nitrite reduction to nitrogen gas. This can possibly lead to degradation of the internally stored glycerol in the aerobic zones of the following cycle, implying a significant economic impact with glycerin addition. Although this has not been investigated further, it is believed that the presence of glycogen-accumulating organisms (GAOs) could be responsible for this intracellular storage of glycerol resulting in partial denitrification and accumulation of nitrite. The methanol and waste alcohol reactors also performed similarly to each other and neither of these reactors exhibited any nitrite accumulation upon carbon addition. The specific denitrification rate (SDNR) of the waste alcohol was slightly higher and increased more rapidly than for the methanol reactor. The C: N for these two reactors was comparable, and methanol was close to the expected value of 4.8 g COD utilized/ g nitrate-N denitrified. The C: N for the waste alcohol during steady state operation was somewhat higher than expected. The waste alcohol exhibited an �"alcoholic�" odor upon addition to the reactors during startup, but this issue diminished as the biomass became acclimated to the waste alcohol. Both industrial waste alcohol and glycerol can be considered viable alternatives to methanol; however, glycerol supplementation for denitrification can be problematic. If the glycerol dose is not optimized, then partial denitrification is observed and will lead to nitrite in the effluent, causing an increased chlorine demand for plants applying chlorine for disinfection. This is thought to occur due to energy limitations resulting from carbon storage and thus, using glycerol at treatment plants performing biological phosphorus removal (BPR) or enhanced biological phosphorus removal (EBPR) might see inefficient removal due to selective carbon utilization by polyphosphate-accumulating organisms (PAOs), or due to competition between PAOs and GAOs. Although denitrification of nitrate to nitrite occurs more quickly with prolonged glycerol addition, it also results in an increased carbon demand which causes a significant impact economically. / Master of Science

With consideration to the crude glycerol surplus driven by the growth in biodiesel manufacturing, alternative uses for biodiesel derived glycerol have become increasingly essential. Anaerobic digestion of the glycerol reduces the chemical oxygen demand of the glycerol waste product, while capturing biogas as an energy source that can be used on site to reduce heating cost at a biodiesel facility. In this thesis, kinetic parameters are extracted from batch experimental data and applied to steady state equations. A flow sheet for the application of anaerobic digestion to biodiesel derived glycerol is developed and explored. The economic analysis of the scenario tracks the capital cost, operating cost, and savings associated with implementing the system.

Master of Science / Department of Animal Sciences and Industry / James S. Drouillard / Two trials were conducted to evaluate effects of crude glycerin, a byproduct of the biodiesel industry, on feedlot performance, carcass characteristics, and diet digestibility in cattle. A third study was conducted to investigate the use of glycerin as a solvent in Maillard reaction processes used to manufacture value added protein meal. In trial 1, crossbred yearling heifers were fed low levels of glycerin (0, 0.5, or 2% of diet DM) in corn finishing diets, or diets that combined corn with soybean hulls and wet distiller’s grains (0 or 2% glycerin). Results indicated that feeding glycerin decreased DMI (P = 0.04), and feeding byproducts increased DMI (P < 0.01) when compared to control without byproducts or glycerin. Feeding byproducts or glycerin decreased the percentage of carcasses that graded USDA Choice or higher (P < 0.05). Other live performance traits and carcass characteristics were similar across treatments. Trial 2 evaluated effects of crude glycerin on growth performance and diet digestibility in heifers fed high forage growing diets. Treatments consisted of 0, 4, or 8% crude glycerin added to growing diets containing corn silage (60% of DM) and wet corn gluten feed. Apparent total tract digestibilities were calculated from total fecal collections. Adding glycerin linearly increased (P = 0.01) feed efficiency over the entire feeding period, and linearly decreased (P = 0.02) DMI for a portion of the feeding period. No other effects of glycerin on animal growth performance were observed. Digestibility measurements indicated that glycerin decreased DM, OM, and NDF intakes linearly (P < 0.01), but did not affect fecal outputs of DM, OM, or NDF. Apparent total tract digestibilities of DM, OM, and NDF therefore decreased linearly (P < 0.01) with increasing levels of glycerin. The third trial involved several experiments, which were conducted to determine if glycerol could be used as a solvent in processes designed to facilitate non-enzymatic browning of protein meals. Results indicated that glycerol may serve as a more suitable solvent for browning processes than water because its chemical and physical properties may enhance browning processes, increase process efficiency, and yield products with superior resistance to microbial degradation.