Concerns over environmental impacts and long term availability of liquid fossil fuels means that sourcing alternative, renewable transport fuels has increased in importance. To date, implemented approaches have concentrated on the production of liquid biofuels biodiesel and bioethanol from crops. Even though technology for implementation is readily available in the form of biogas production and upgrading, gaseous fuels have been largely overlooked in the UK. Research completed showed that if produced from indigenous crops using currently viable technology, it is energetically more favourable to produce gaseous fuels rather than biodiesel or bioethanol with gaseous fuels also delivering some emission benefits at end use. To date, the subsidy system supporting biofuel production has not functioned well. Research showed that if the subsidies approached the maximum allowable value, and when produced from waste materials, the production of gaseous fuels can be economic compared to liquid biofuels. Life cycle assessment has showed that utilising biomethane as a vehicle fuel could be an environmentally appropriate approach if the conventional use for biogas of combusting in a combined heat and power plant cannot utilise the majority of the excess heat produced. A two stage process to produce a hydrogen / methane blend was shown to be energetically favourable when utilising wheat feed, although hydrogen production was low. The process was not energetically favourable when food waste was utilised, indicating the importance of optimising process according to feedstock characteristics. Life cycle assessment of electrolytic hydrogen production using a range of energy sources found that electrolysis driven by renewable energy was a valid option for future deployment. However, given current feedstock availability, indigenous biofuel production, regardless of the fuel produced, could only make minor contributions to overall fuel requirements. As such, a range of fuel vectors, or a significantly greater commitment of land resources to fuel production, will be required in the future.

Spark ignition (SI) and compression ignition (CI) engine fuels are characterized by standards developed in 1927 and 1932, respectively. Over the course of these years, modern engines have drastically changed their operating conditions; however, these fuel indexes are still used today with no significant change to their definition. The requirements for fuels in future advanced engines, employing low temperature combustion (LTC) concepts, may be somewhere between gasoline and diesel in terms of their autoignition characteristics. With this focus, this study examines methodologies to bridge the gap between those fuels classified between gasoline and diesel. First, the ignition delay times (IDTs) at various temperatures obtained from an ignition quality tester (IQT), was correlated with the octane index (OI), an anti-knock scale combining the effect of the operating condition and the anti-knock quality of the fuel given by the RON/MON. This study was extended to introduce a new concept of IDT sensitivity (IDS) in an IQT. It was observed that IDS could be correlated with fuel octane sensitivity (OS = RON − MON), offering an additional methodology to estimate RON/MON with an IQT. Chemical kinetics are most sensitive to fuel molecular structure; remarkable progress has been made in covering high carbon-number fuels, relevant to gasoline fuels, for better understanding of the chemical processes that lead to engine knock. To this end, a methodology to relate IDTs calculated from homogeneous batch-reactor simulations with gasoline fuel indexes was developed. This methodology enabled correlation of a kinetic property (i.e., IDT) with RON/MON values. The influence of various components present in gasolines, and their anti-knock quality, was investigated. A spinning band distillation system was utilized to separate the components of various gasolines. Ignition quality and the functional group distribution of various boiling ranges were investigated with an IQT and 1H nuclear magnetic resonance (NMR) spectroscopy. Finally, the importance of physical and chemical fuel properties in fuel stratification in LTC engine concepts was undertaken in a CI engine with a multi hole solid-cone injector. The findings suggest that the physical properties of fuel played a dominant role when fuel stratification occurred in the engine combustion chamber.

Drastic reductions of greenhouse gas emissions are required to limit the severe risks associated with a changing climate. One measure is to disrupt the fossil-fuel dependency in the transport sector, but it appears difficult and costly in comparison to other measures. Vehicles and fuels are available, but no single alternative can replace petrol and diesel in all parts of the transport system. None of them are ideal regarding all of the following aspects: vehicle performance, fuel production potential, sustainability, infrastructure, technology development and economy. Instead, several fuels are needed. In this thesis, the aim is to investigate the role of methane and hydrogen in a fossil- free vehicle fleet in Sweden, and compare them with other fuels in terms of well-to-wheel energy efficiency and economy. Processes for producing methane from biomass, waste streams from pulp mills and electricity are studied with techno-economic methods. Furthermore, well-to-wheel studies and scenarios are used to investigate the fuel chains and the interaction with the energy and transport systems. Effects of policy instruments on the development of biogas in the Swedish transport sector are also analysed and policy instruments are suggested to increase the use of methane and to introduce hydrogen and fuel cell electric vehicles. The results reveal that tax exemptions and investment support have been and will continue to be important policy instruments, but that effective policy instruments are needed to develop fuelling infrastructure and to support alternative vehicles. Electricity will be an important transport fuel for several reasons; the electric powertrain enables high energy efficiency and electricity can be produced from various renewable energy sources. Nevertheless, other fuels will be needed as complements to electricity. The results reveal that methane and hydrogen and associated vehicles may be necessary to reach a fossil-free vehicle fleet in Sweden. These fuels have several advantages: -        The function of the vehicles resembles conventional vehicles but with lower local and global emissions. -        Methane is a well proven as a transport fuel and hydrogen infrastructure and FCEVs, are commercial or close to commercialisation. -        They enable high well-to-wheel energy efficiency. -        They can be produced from renewable electricity and act as energy storage. / <p>QC 20150929</p>

[pt] O transporte de petróleo e de seus derivados através do modal dutoviário é bastante comum na indústria petrolífera. O Oleoduto do Recôncavo-Sul da Bahia (ORSUB) é um poliduto que transporta diesel, gasolina e GLP do Terminal de Madre de Deus até os terminais de Jequié e Itabuna. Esses produtos são inseridos no poliduto em forma de bateladas sequênciais, o que gera as interfaces entre os produtos. Essas interfaces são segregadas e armazenadas em tanques exclusivos. A Agência Nacional de Petróleo ao longo do tempo vem restringindo cada vez mais as especificações dos produtos derivados do petróleo comercializados no país. Com isto, há a tendência natural do aumento das interfaces entre os produtos movimentados no poliduto, para a garantia de que estes atendam a legislação vigente. Estudos demonstram que os custos provenientes da geração de interfaces são altos e constituem um item importante na composição dos custos variáveis do modal dutoviário. Deste modo, reduzir o tamanho destas interfaces deve sempre ser um dos objetivos que o operador logístico responsável pela movimentação no duto deve buscar. Nesta pesquisa foram estudadas as interfaces geradas entre a gasolina e o GLP no ORSUB. Foi utilizado o software ConBate para a estimativa do tamanho da interface e o simulador de processos Petrox, para estimar a qualidade da interface. Com estas duas ferramentas desenvolvidas pelo Centro de Pesquisa da Petrobras (Cenpes) foram comparadas os tamanhos das interfaces geradas nas operações reais, com os tamanhos das interfaces ideais. / [en] The transportation of oil and its derivatives through modal pipeline is quite common in the oil industry. The pipeline Recôncavo-Sul Bahia (ORSUB) is an oil pipeline that transports gas oil, gasoline and LPG from Terminal Madre de Deus to the terminals Jequié and Itabuna. These products are inserted into the oil pipeline in the form of batches, which generates the interfaces (transmix) between products. These transmix are segregated and stored in dedicated tanks. Over time, The National Petroleum Agency (ANP) is increasingly restricting the specifications of petroleum products sold in the country. With this, there is the natural tendency of increased interfaces between the products moved in pipeline, to ensure that they meet current legislation. Studies show that the costs arising from the generation of interfaces are high and constitute an important item in the cost composition variables modal pipeline. Thus, reducing the size of these interfaces should always be a goal that the logistics operator responsible for moving the product should look. In this research we studied the interfaces generated between gasoline and LPG in ORSUB. ConBate software was used to estimate the size of the interface and process simulator Petrox to estimate the quality of transmix. With these two tools sizes of the interfaces generated in actual operations and the sizes of the interfaces ideal were compared.