• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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

Potential methods for the characterisation and estimation of oxygenates in fuel

Parkinson, Nina January 1999 (has links)
The development of the quality of gasoline and diesel fuel has never been static. It is no longer newsworthy to say that the world of energy and chemical technology is changing fast. However, these changes are so fast that changes in related technology have to advance at the same speed. Consequently it has been a challenging time for analytical chemists in different types of laboratories involved in the analysis of automotive fuel, such as in the analysis of oxygenates in gasoline, to keep up with all the developments. Since gasoline testing is moving into the stage which requires more advanced technology, laboratories need to be equipped to utilise a range of different techniques in order to suit the peculiarities of the different nature of the samples. During the last few years, the volume of gasoline testing by different bodies such as the independent petroleum laboratories has increased. In practice, laboratories are under considerable pressure to implement the designated analytical regulatory methods, and to constantly improve analytical quality. To help resolve these issues, laboratories sometimes turn to instrument vendors for advice on methodological advances in this type of work. The author has been involved directly with the challenges of this work and has experienced the practical limitations of current methods. Therefore the author has aimed to evaluate various analytical approaches in the study of the characterisation of fuel blending additives and, in particular, oxygenates. This work starts out with an introduction about the development of automobile fuel technology and the use of anti-knock additives throughout the period from the early days to the present. Thereafter further chapters review the current methods applied for the characterisation of these type of fuel additives in gasoline, in particular high performance fuels as used in the motor racing industry. The main aim of this work is to evaluate the strengths and limitations of these methods. The thesis then includes a detailed discussion of different analytical approaches encompassing initially micro-elemental analysis for the direct determination of oxygen content. Then follows the most popular method, gas chromatography, which continues to be the key instrumental technique for the measurement of the main parameters of gasoline. Thereafter follows a study of the GC-MS technique. The next chapter discusses the combustion technique using a Laminar burner to investigate the effect of oxygenates on the reduction of the sooting tendency in diesel. The final method under discussion is the estimation of oxygenates using Nuclear Magnetic Resonance Spectroscopy. Each of the above methods has been used on similar types of samples in different categories. Thus the results may be compared and interpreted using the relevant tables, and correlated against each other. The final part of this work has therefore concentrated on the conclusion of the comparative advantages of each method and its reliability. The main samples used throughout this research work have been actual commercial conventional gasolines and specialised fuels. These have been evaluated against a set of reference standards.
2

Qualidade de gasolinas automotivas através de Espectroscopia Vibracional FT-Raman, combinada com correlação 2D generalizada / The use of Generalized Two-Dimensional FT-Raman Correlation Spectroscopy method to monitor the quality of automotive gasoline

Lima, Kellen Cristina Vilhena January 2005 (has links)
LIMA, Kellen Cristina Vilhena. Qualidade de gasolinas automotivas através de Espectroscopia Vibracional FT-Raman, combinada com correlação 2D generalizada. 2005. 305 f. Tese (Doutorado em Física) - Programa de Pós-Graduação em Física, Departamento de Física, Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2005. / Submitted by Edvander Pires (edvanderpires@gmail.com) on 2015-05-25T22:26:07Z No. of bitstreams: 1 2005_tese_kcvlima.pdf: 10475763 bytes, checksum: e618c6deda94d946c15be6e420912ad1 (MD5) / Approved for entry into archive by Edvander Pires(edvanderpires@gmail.com) on 2015-05-27T18:52:53Z (GMT) No. of bitstreams: 1 2005_tese_kcvlima.pdf: 10475763 bytes, checksum: e618c6deda94d946c15be6e420912ad1 (MD5) / Made available in DSpace on 2015-05-27T18:52:53Z (GMT). No. of bitstreams: 1 2005_tese_kcvlima.pdf: 10475763 bytes, checksum: e618c6deda94d946c15be6e420912ad1 (MD5) Previous issue date: 2005 / It is reported the use of Generalized Two-Dimensional FT-Raman Correlation Spectroscopy (2DCOS-FT-Raman) method to monitor the quality of automotive gasoline in the gas stations. It is presented a procedure to identify the adulteration of automotive gasoline by the illicit addition of ethanol, methanol, aromatic and paraphinic compounds through the analysis of the Raman spectra obtained for different compositions of adulterants added to gasoline “A” type and to gasoline “A” type plus ethanol samples. It is discussed the data preconditioning step, the application of 2DCOS method, and the calibration curves that correlates the integrated intensities of the Raman bands of a given adulterant with its percentage in a given gasoline sample. It shown the protocol for using the 2DCOS-FT-Raman method to verify the adulteration in a given gasoline sample compared with a specific standard. This work emphasizes the flexibility and viability of using this method to have a specific standard for each gasoline distribution firm and also for each new gasoline derived from the refinery. / Relata a utilização da espectroscopia FT-Raman combinada com Correlação 2D Generalizada como método alternativo para a realização do controle de qualidade de Gasolinas automotivas diretamente nos postos de combustível. Apresenta os procedimentos para identificar a adulteração da Gasolina automotiva pela adição irregular de Etanol, Metanol e compostos aromáticos e parafínicos, através da análise dos espectros Raman obtidos para os diferentes adulterantes separadamente, misturados à Gasolina A e misturados à Gasolina A e ao Etanol. Descreve os procedimentos de pré-tratamento sobre os espectros Raman, a aplicação do método de Correlação 2D Generalizada aos sistemas estudados e a determinação das curvas de calibração que relacionam as intensidades integradas das bandas Raman com o teor de adulterante na Gasolina. Apresenta a praticidade de aplicação do método, que possibilita verificar a adulteração da Gasolina automotiva através da comparação entre o espectro Raman da amostra cuja conformidade se deseja verificar com o espectro da amostra padrão. Enfatiza a flexibilidade e a viabilidade de se ter um padrão específico para cada distribuidora, ou até mesmo para cada nova produção de Gasolina da refinaria.
3

The use of Generalized Two-Dimensional FT-Raman Correlation Spectroscopy method to monitor the quality of automotive gasoline. / Qualidade de gasolinas automotivas atravÃs de Espectroscopia Vibracional FT-Raman, combinada com correlaÃÃo 2D generalizada.

Kellen Cristina Vilhena Lima 16 December 2005 (has links)
Relata a utilizaÃÃo da espectroscopia FT-Raman combinada com CorrelaÃÃo 2D Generalizada como mÃtodo alternativo para a realizaÃÃo do controle de qualidade de Gasolinas automotivas diretamente nos postos de combustÃvel. Apresenta os procedimentos para identificar a adulteraÃÃo da Gasolina automotiva pela adiÃÃo irregular de Etanol, Metanol e compostos aromÃticos e parafÃnicos, atravÃs da anÃlise dos espectros Raman obtidos para os diferentes adulterantes separadamente, misturados à Gasolina A e misturados à Gasolina A e ao Etanol. Descreve os procedimentos de prÃ-tratamento sobre os espectros Raman, a aplicaÃÃo do mÃtodo de CorrelaÃÃo 2D Generalizada aos sistemas estudados e a determinaÃÃo das curvas de calibraÃÃo que relacionam as intensidades integradas das bandas Raman com o teor de adulterante na Gasolina. Apresenta a praticidade de aplicaÃÃo do mÃtodo, que possibilita verificar a adulteraÃÃo da Gasolina automotiva atravÃs da comparaÃÃo entre o espectro Raman da amostra cuja conformidade se deseja verificar com o espectro da amostra padrÃo. Enfatiza a flexibilidade e a viabilidade de se ter um padrÃo especÃfico para cada distribuidora, ou atà mesmo para cada nova produÃÃo de Gasolina da refinaria. / It is reported the use of Generalized Two-Dimensional FT-Raman Correlation Spectroscopy (2DCOS-FT-Raman) method to monitor the quality of automotive gasoline in the gas stations. It is presented a procedure to identify the adulteration of automotive gasoline by the illicit addition of ethanol, methanol, aromatic and paraphinic compounds through the analysis of the Raman spectra obtained for different compositions of adulterants added to gasoline âAâ type and to gasoline âAâ type plus ethanol samples. It is discussed the data preconditioning step, the application of 2DCOS method, and the calibration curves that correlates the integrated intensities of the Raman bands of a given adulterant with its percentage in a given gasoline sample. It shown the protocol for using the 2DCOS-FT-Raman method to verify the adulteration in a given gasoline sample compared with a specific standard. This work emphasizes the flexibility and viability of using this method to have a specific standard for each gasoline distribution firm and also for each new gasoline derived from the refinery.

Page generated in 0.0638 seconds