• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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.
1

VALIDAÇÃO DAS ANÁLISES FÍSICO-QUÍMICAS EXIGIDAS PELA ANP PARA MISTURAS DIESEL – BIODIESEL / PHYSICAL-CHEMICAL VALIDATION ANALYSIS REQUIRED BY ANP FOR MIXTURES DIESEL - BIODIESEL

Folquenin, Elisiane Karam Folador 10 March 2008 (has links)
Made available in DSpace on 2017-07-24T19:37:57Z (GMT). No. of bitstreams: 1 ELISIANE_KARAM2.pdf: 586066 bytes, checksum: 73601aa55e1af89fd793a2a89fd5ed17 (MD5) Previous issue date: 2008-03-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The use of Biodiesel as an additive to diesel in automotive proportion of 2 % v/v is being marketed in Brazil since January 2008. Thus, it is extremely important Know the environmental and commercial impact of samples of B100 produced and mixtures, for example, B2 (stipulated by the ANP - the National Petroleum Agency). The objective this paper is to physical-chemistry analyses of samples B100, obtained of different oil (soya, sunflower and canola) and samples mixtures biodiesel+diesel, obtained ethanolic route for process of transesterification of soya oil. Basic analyses chemical of B100 obtained ethanol route were compared with methanol route. The process of biodiesel transesterification and glycerin separation obtained by methanol route is very quickly ompareted with ethanol route, can not forget the degree of toxicity of methanol and the high cost of methanol in Brazil. The results of color, density, flash point were almost the same within the experimental precision, but the infrared spectral of the samples of B100, in the two cases presented distinct peaks. The chemical analysis of samples of B100, via ethanol route from different oils, has presented different colors and densities, may cause changes of color in the final product, observed that color stipulated by ANP is red. Analysis of samples of B100, made before and after the step of washing and neutralized the pH, showed that the analyses required by the ANP for business this fuel, not relevant differences, allowing produce B100 with less cost, however the omission this step, could lead to oxidation of parts of the automobile, causing damage to consumers and future environmental and economic impact to the country. / A utilização do biodiesel como aditivo ao diesel automotivo em proporção de 2 % v/v está sendo comercializada no Brasil desde janeiro de 2008. Assim, é de extrema importância uma avaliação do impacto comercial e ambiental de amostras de biodiesel B100 produzido e das misturas, como por exemplo, da comercializada, B2 (estipulada pela ANP – Agência Nacional de Petróleo). O objetivo deste trabalho é analisar fisicoquimicamente amostras de biodiesel B100, de diferentes oleaginosas (soja, canóla e girassol) e de diferentes proporções de misturas biodiesel + diesel, amostras de B100 obtidas via rota etanólica do processo de transesterificação do óleo de soja. Análises químicas básicas foram feitas em amostras B100 obtidas via rota etanólica, utilizando-se o óleo de soja com matéria prima e comparadas com a rota metanólica. Ressalta-se que o processo de transesterificação do biodiesel e separação da glicerina, oriundo da rota metanólica é mais rápido, entretanto não se pode esquecer o grau de toxidez do metanol e o elevado custo do metanol no Brasil. Os resultados de cor, densidade, ponto de fulgor foram praticamente os mesmos dentro da precisão experimental, mas os espectros de infravermelho de amostras de B100, nos dois processos apresentaram alguns picos diferenciados. As análises químicas das amostras de combustível B100, via rota etanólica oriundas de diferentes oleaginosas, apresentaram cores e densidades diferentes, podendo causar mudanças de cores no produto final gerado, ressalta-se que e a cor estipulada pela ANP para este tipo de combustível é vermelha. Análises de amostras de B100, feitas antes e após a etapa de lavagem e neutralização do pH, mostraram que as análises exigidas pela ANP para revenda deste combustível, não apresentarem diferenças, o que pode levar o produtor a gerar o B100 com menor custo, entretanto a falta desta etapa, poderá levar a oxidação das peças dos veículos automotores, causando prejuízo aos consumidores e futuro impacto ambiental e econômico ao País.
2

Renewable liquid transport fuels from microbes and waste resources

Jenkins, Rhodri January 2015 (has links)
In order to satisfy the global requirement for transport fuel sustainably, renewable liquid biofuels must be developed. Currently, two biofuels dominate the market; bioethanol for spark ignition and biodiesel for compression ignition engines. However, both fuels exhibit technical issues such as low energy density, poor low temperature performance and poor stability. In addition, bioethanol and biodiesel sourced from first generation feedstocks use arable land in competition with food production, and can only meet a fraction of the current demand. To address these issues it is vital that biofuels be developed from truly sustainable sources, such as lignocellulosic waste resources, and possess improved physical properties. To improve and control the physical properties of a fuel for specific application, one must be able to tailor the products formed in its production process. All studies within this thesis, therefore, have the aim of assessing the fuels produced for their variability in physical property, or the aim of directing the process considered to specific fuel molecules. In Chapter 2, spent coffee grounds from a range of geographical locations, bean types and brewing processes were assessed as a potential feedstock for biodiesel production. While the lipid yield was comparable to that of conventional biodiesel sources, the fatty acid profile remained constant irrespective of the coffee source. Despite this lack of variation, the fuel properties varied widely, presumably due to a range of alternative biomolecules present in the lipid. Though coffee biodiesel was produced from a waste product, the fuel properties were found to be akin to palm oil biodiesel, with a high viscosity and pour point. The blend level would therefore be restricted. In Chapter 3 the coffee lipid, as well as a range of microbial oils potentially derived from renewable sources were transformed into a novel aviation and road transport fuel through cross-metathesis with ethene. Hoveyda-Grubbs 2nd generation catalyst was found to be the most suitable, achieving 41% terminal bond selectivity under optimum conditions. Metathesis yielded three fractions: an alkene hydrocarbon fraction suitable for aviation, a shorter chain triglyceride fraction that upon transesterification produced a short chain biodiesel fuel, and a multifunctional volatile alkene fraction that could potentially have application in the polymer industry. Though there was variation for the road transport fuel fraction due to the presence of long chain saturates, the compounds fell within the US standard for biodiesel. The aviation fraction lowered the viscosity, increased the energy density, and remained soluble with Jet A-1 down to the required freezing point. Oleaginous organisms generally only produce a maximum of 40% lipid, leaving a large portion of fermentable biomass. In Chapter 4, a variety of ethyl and butyl esters of organic acids – potentially obtainable from fermentation – were assessed for their suitability as fuels in comparison to bioethanol. One product, butyl butyrate, was deemed suitable as a Jet A-1 replacement while four products, diethyl succinate, dibutyl succinate, dibutyl fumarate and dibutyl malonate, were considered as potential blending agents for diesel. Diethyl succinate, being the most economically viable of the four, was chosen for an on-engine test using a 20 vol% blend of DES (DES 20) on a chassis dynamometer under pseudo-steady state conditions. DES20 was found to cause an increase in fuel demand and NOx emissions, and a decrease in exhaust temperature, wheel force, and CO emissions. While fermentation is generally directed to one product, producing unimolecular fuels, they do not convert the entirety of the biomass available. An alternative chemical transformation is pyrolysis. In Chapter 5, zeolite-catalysed fast pyrolysis of a model compound representative of the ketonic portion of biomass pyrolysis vapour – mesityl oxide – was carried out. The aim of this study was to understand the mechanistic changes that occur, which could lead to improved bio-oil yields and more directed fuel properties of the pyrolysis oil. While HZSM-5 and Cu ZSM-5 showed no activity for hydrogenation and little activity for oligomerisation, Pd ZSM-5 led to near-complete selective hydrogenation of mesityl oxide to methyl isobutyl ketone, though this reduced at higher temperatures. At lower temperature (150-250 °C), a small amount of useful oligomerisation was observed, which could potentially lead to a selective pyrolysis oligomerisation reaction pathway.

Page generated in 0.0936 seconds