Florian Alain Yannick Pradelle Use of biofuels in compression ignition engines – Potential of diesel-biodiesel-ethanol blends Tese de Doutorado Thesis presented to the Programa de Pós- graduação em Engenharia Mecânica of PUC-Rio in partial fulfilment of the requirements for the degree of Doutor em Ciências - Engenharia Mecânica. Advisor: Prof. Sergio Leal Braga Rio de Janeiro March 2017 Florian Alain Yannick Pradelle Use of biofuels in compression ignition engines – Potential of diesel-biodiesel-ethanol blends Thesis presented to the Programa de Pós- graduação em Engenharia Mecânica of PUC-Rio in partial fulfillment of the requirements for the degree of Doutor em Ciências – Engenharia Mecânica. Approved by the undersigned Examination Committee. Prof. Sergio Leal Braga Advisor Departamento de Engenharia Mecânica – PUC-Rio Prof. Carlos Valois Maciel Braga Departamento de Engenharia Mecânica – PUC-Rio Prof. José Alberto dos Reis Parise Departamento de Engenharia Mecânica – PUC-Rio Profa. Ana Rosa Fonseca de Aguiar Martins Departamento de Engenharia Química e de Materiais – PUC-Rio Prof. Carlos Andre Vaz Junior Universidade Federal do Rio de Janeiro Dra. Marcelle Alves Farias Lubrizol do Brasil Ltda. Dr. Tadeu Cavalcante Cordeiro de Melo Petrobras Prof. Márcio da Silveira Carvalho Vice Dean of Graduate Studies Centro Técnico Científico – PUC-Rio Rio de Janeiro, March 10th, 2017 All rights reserved. Florian Alain Yannick Pradelle Florian Pradelle graduated in chemical engineering in 2012 from École Nationale Supérieure de Chimie de Paris – Chimie ParisTech (Paris, France), and he got his master degree in 2012 from Université Pierre et Marie Curie – Paris 6 (Paris, France). Currently, he is working as researcher in the ITUC / PUC-Rio in the field of energy, dealing especially with problematic involving biofuels in internal combustion engines. Ficha Catalográfica Pradelle, Florian Alain Yannick Use of biofuels in compression ignition engines : potential of diesel-biodiesel-ethanol blends / Florian Alain Yannick Pradelle ; advisor: Sergio Leal Braga. – 2017. 302 f. : il. color. ; 30 cm Tese (doutorado)–Pontifícia Universidade Católica do Rio de Janeiro, Departamento de Engenharia Mecânica, 2017. Inclui bibliografia 1. Engenharia Mecânica – Teses. 2. Motor de ignição por compressão. 3. Misturas diesel-biodiesel-etanol. 4. Miscibilidade. 5. Propriedades físico-químicas. 6. Combustão. I. Braga, Sergio Leal. II. Pontifícia Universidade Católica do Rio de Janeiro. Departamento de Engenharia Mecânica. III. Título. CDD: 621 I dedicate this work to my beloved wife, Renata, and my parents, Annick and Alain. « S'il n'y a pas eu de question, il ne peut y avoir connaissance scientifique. Rien ne va de soi. Rien n'est donné. Tout est construit. » Gaston Bachelard ; La Formation de l'esprit scientifique (1938). Acknowledgments To my wife, Renata, and her family for their incentive and support to complete this present work and their patience during the busy days. I particularly thank my beloved wife for her affection, her inspiration and for her unconditional support (including for the sacrifices she did). To my parents, Annick and Alain, and my brother, Sylvain, for their everlasting incentive and support, even with an ocean between us. To my adviser professor Sergio Leal Braga, for his friendship, confidence, dedication, attention and teaching during all the phase of this work. To Peugeot Citroën do Brasil Automóveis Ltda, in particular Franck Turkovics, for their financial support to part of this work and their contribution leading to the formulation of the additive. To the financial support of the Brazilian agencies CAPES, FAPERJ and of the Departamento de Engenharia Mecânica of PUC-Rio, for the provided grants, without which this work could not have been done. To the Instituto Tecnológico, ITUC / PUC-Rio, in particular professor Ana Rosa Fonseca de Aguiar Martins, Marcos Thomé de Almeida, Luciano Medeiros Pires and Renato Gomes, for the support and their help to solve logistic issues. To Leonardo Costa Braga, Severino A. Wanderley, Nestor Corrêa Cotelo, Fernando Zegarra Sanchez, Gerson Silvério, Gilson Coutinho Pradanoff, Jorge Ricardo Moura and Bruno Maia from the Laboratório de Engenharia Veicular, LEV / PUC-Rio, for their contribution to the success of engine tests, from the installation and instrumentation of the engine to the realization of the tests. To professor Paulo Roberto de Souza Mendes to allow me to use the resources of the Laboratório de Caracterização de Fluidos and to Gisllane Oliveira, quality manager, for her attention and support. To professor Márcio da Silveira Carvalho to allow me to use the resources of the Laboratório de Micro Hidrodinâmica e Meios Porosos, LMMP / PUC-Rio, and to Felicle Lopez and Ranena Ponce for sharing their experiences. To Marcileny Porto, coordinator of the Centro de Pesquisas e Caracterização de Petróleo e Combustíveis, COPPEComb / UFRJ, and Renato, Monica and Luis Otávio, for their unconditional support to my research. To the Laboratório de Motores e Combustíveis of the Instituto Nacional de Metrologia, Qualidade e Tecnologia, LAMOC / INMETRO, and the Laboratório de Combustíveis e Lubrificantes of the Instituto Nacional de Tecnologia, LACOL / INT, to their contributions to this work. To all people (and they are great in number) who contribute directly and indirectly to this work, in particular the members of the examination committee for their precious advice that led to the final version of this document. Abstract Pradelle, Florian Alain Yannick; Braga, Sergio Leal (advisor). Use of biofuels in compression ignition engines - Potential of diesel-biodiesel- ethanol blends. Rio de Janeiro, 2017. 302p. Tese de Doutorado - Departamento de Engenharia Mecânica, Pontifícia Universidade Católica do Rio de Janeiro. In order to partially replace the demand of fossil diesel fuels, to reduce high import costs and to comply with environmental standards, sustainable policies have led to partially replace diesel fuel by biodiesel. However, other technologies, such as diesel-biodiesel-ethanol mixtures, are being investigated. The major challenge of these mixtures is to improve the miscibility and the stability of alcohol in diesel fuel. In this study, an original additive, from renewable compounds, improved the miscibility of anhydrous ethanol in diesel fuel with 15% by volume of biodiesel and temperature in which stable mixtures were observed. Several physicochemical properties of the additivated mixtures were measured in a large range of ethanol concentration to evaluate aspects of consumption, combustion quality, behavior at low temperature, interaction between the fluid and the surface, and safety. The results showed that blends with, at least 1.0%, by volume of additive and 20% by volume of anhydrous ethanol are stable at temperatures above 10°C and respected most of the current Brazilian specifications for diesel fuel. Experimental tests on a compression ignition engine MWM 4.10 TCA (Euro III) were performed with these mixtures. The results showed that the diesel fuel substitution alters the characteristics of combustion: the increased ethanol content implied an increase of the ignition delay, a faster heat release and a decrease of maximum pressure. Despite these non-optimized conditions for injection and combustion, results showed a better conversion of ethanol chemical energy into brake power, in comparison to the values found in flex fuel spark ignition engine, in addition to a small increase in the indicated efficiency of the engine. Keywords Ignition compression engine; Diesel-biodiesel-ethanol blends; Miscibility; Physicochemical properties; Performance; Combustion. Resumo Pradelle, Florian Alain Yannick; Braga, Sergio Leal. Utilização de biocombustíveis em motores de ignição por compressão - Potencial das misturas diesel-biodiesel-etanol. Rio de Janeiro, 2017. 302p. Tese de Doutorado - Departamento de Engenharia Mecânica, Pontifícia Universidade Católica do Rio de Janeiro. Para substituir parcialmente a demanda em óleo diesel de origem fóssil, reduzir os elevados custos de importação e respeitar as normas ambientais, políticas sustentáveis já levaram a substituir parcialmente óleo diesel por biodiesel. Entretanto, outras tecnologias, como as misturas diesel-biodiesel-etanol, estão sendo investigadas. O principal desafio dessas misturas consiste em melhorar a miscibilidade e a estabilidade do álcool no óleo diesel. No presente trabalho, formulou-se um aditivo original, a partir de compostos renováveis, que permitiu melhorar a faixa de concentração de etanol anidro dentro de óleo diesel com 15 % em volume de biodiesel e de temperatura onde observa-se misturas estáveis. Diversas propriedades físico-químicas das misturas aditivadas foram medidas em uma larga faixa de concentração de etanol para avaliar os aspetos de consumo, qualidade da combustão, comportamento a baixa temperatura, interação entre fluido e superfície, e segurança. Os resultados obtidos mostraram que misturas com, pelo menos, 1,0 % em volume de aditivo e até 20% em volume de etanol anidro são estáveis para temperaturas superiores a 10°C e respeitam a maioria das especificações brasileiras atuais para óleo diesel. Ensaios experimentais em um motor de ignição por compressão MWM 4.10 TCA (Euro III) foram realizados com estas misturas. Os resultados obtidos mostraram que a substituição do óleo diesel altera as características da combustão: o crescente teor de etanol leva ao aumento do atraso de ignição, à liberação de calor mais rápida e à diminuição da pressão máxima. Mesmo nessas condições não otimizadas de injeção e de combustão, os resultados mostraram uma melhor conversão da energia química no etanol para produzir potência efetiva, comparado com os valores encontrados nos motores flex fuel de ciclo Otto, além de um pequeno aumento no rendimento térmico do motor. Palavras-chave Motor de ignição por compressão; Misturas diesel-biodiesel-etanol; Miscibilidade; Propriedades físico-químicas; Desempenho; Combustão. Table of contents 1 Introduction 29 1.1. Brazilian Energy Matrix 29 1.2. Biofuels in Compression Ignition (CI) Engines 35 1.3. Potential of Ethanol-Diesel Blends (E-Diesel) 37 1.4. Potential of Diesel-Biodiesel-Ethanol (DBE) Blends 38 1.5. Brazilian Experience 40 1.6. Objectives 42 1.7. Performed Activities and Organization of the Thesis 43 2 Literature Review 47 2.1. Blend Stability Issue 47 2.1.1. Miscibility of Ethanol in Diesel Fuel 47 2.1.2. Additive-Based Strategies 54 2.1.3. Commercial Additives for E-Diesel 64 2.2. Blend Properties Issues 66 2.2.1. Viscosity 66 2.2.2. Lubricity 68 2.2.3. Cetane Number 72 2.2.4. Specific Gravity 75 2.2.5. Heating value 76 2.2.6. Wetting Properties: Surface Tension and Contact Angle 76 2.2.7. Fuel Oxygen Content 77 2.2.8. Flammability Limits, Flash Point and Auto-ignition Temperature 78 2.2.9. Cold Properties: Cloud Point, Cold Filter Plugging Point (CFPP) and Pour Point 81 2.2.10. Materials Compatibility Issue 83 2.3. Combustion Characteristics 83 2.4. Pollutants Emission 88 2.5. Partial Conclusion 90 3 Experimental Section 91 3.1. Formulation of an Additive to Blend Commercial Additivated Diesel B7 Fuel with Hydrous and Anhydrous Ethanol 91 3.1.1. Materials 91 3.1.2. Methodology 95 3.2. Formulation of an Additive to Blend Diesel B0 fuel with Variable Anhydrous Ethanol and Biodiesel’s Content 98 3.2.1. Materials 98 3.2.2. Methodology 100 3.3. Assessment of Some Physicochemical Properties for Anhydrous Ethanol – Diesel B15 Blends 103 3.3.1. Materials 103 3.3.2. Methodology 103 3.4. Evaluation of the Engine Efficiency Running on Diesel B15 Fuel Blended with up to 20 vol% of Anhydrous Ethanol and 1.0 vol% of Additive. 117 3.4.1. Materials 117 3.4.2. Methodology 127 4 Calculation Procedure 130 4.1. Design of Experiments: Doehlert design 130 4.2. Engine and Combustion Parameters 134 4.2.1. Geometrical Properties 135 4.2.2. Fuel and Air Consumption 135 4.2.3. Brake Power (P ), Brake Mean Effective Pressure (BMEP) b and Indicated Mean Effective Pressure (IMEP) 137 4.2.4. Combustion Characteristics 138 4.2.5. Efficiency Calculation: Fuel Conversion Efficiency (η ), f Volumetric Efficiency (η ), Indicated Efficiency (η ) and Mechanical v i Efficiency (η ) 140 m 4.3. Uncertainties 141 4.3.1. Experimental Uncertainties 141 4.3.2. Propagated Uncertainties 141