This research is a study of the in-situ upgrading of Jobo crude oil using steam, tetralin or decalin, and catalyst (Fe(acac)₃) at temperatures of 250 °C, 275 °C and 300 °C for 24 hours, 48 hours and 72 hours using an autoclave. Viscosity, API gravity and compositional changes were investigated. We found that tetralin and decalin alone were good solvents for heavy oil recovery. Tetralin or decalin at concentrations of 9% (weight basis) could reduce the Jobo crude oil viscosity measured at 50 °C by 44±2% and 39±3%. Steam alone had some upgrading effects. It could reduce the oil viscosity by 10% after 48 hours of contact at 300°C. Tetralin, decalin or catalyst showed some upgrading effects when used together with steam and caused 5.4±4%, 4±1% and 19±3% viscosity reduction compared with corresponding pre-upgrading mixture after 48 hours of reaction at 300°C. The combination of hydrogen donor tetralin or decalin and catalyst reduced the viscosity of the mixture the most, by 56±1% and 72±1% compared with pre-upgrading mixture. It meant that hydrogen donors and catalyst had strong synergetic effects on heavy oil upgrading. We also found that 300 °C was an effective temperature for heavy oil upgrading with obvious viscosity reduction in the presence of steam, hydrogen donors and catalyst. Reaction can be considered to have reached almost equilibrium condition after 48 hours. The GC-MS analysis of the gas component showed that light hydrocarbon gases and CO₂ were generated after reaction. The viscosity reduction from decalin use is larger than that of tetralin because decalin has more hydrogen atoms per molecule than tetralin. A mechanism of transferring H (hydrogen atom) from H₂O and hydrogen donors to heavy oil, which can lead to structure and composition changes in heavy oil, is explained. The study has demonstrated that in-situ heavy oil upgrading has great potential applications in heavy and extra heavy oil recovery.

Despite its many challenges and limitations the concept of in situ upgrading of informal settlements has become one of the most favoured approaches to the housing crisis in the ‘Global South’. Due to its inherent principles of incremental in situ development, prevention of relocations, protection of local livelihoods and democratic participation and cooperation, this approach is often perceived to be more sustainable than other housing approaches that often rely on quantitative housing delivery and top down planning methodologies. While this study does not question the benefits of the in situ upgrading approach, it seeks to identify problems of its practical implementation within a specific national and local context. The study discusses the origin and importance of this approach on the basis of a review of international housing policy development and analyses the broader political and social context of the incorporation of this approach into South African housing policy. It further uses insights from a recent case study in Cape Town to determine complications and conflicts that can arise when applying in situ upgrading of informal settlements in a complex local context. On that basis benefits and limitations of the in situ upgrading approach are specified and prerequisites for its successful implementation formulated. / Trotz vieler Herausforderungen und Beschränkungen gilt das Konzept des in situ upgrading informeller Siedlungen als eine der wichtigsten Herangehensweisen an die Wohnraumkrise im „globalen Süden“. Aufgrund seiner immanenten Prinzipien einer schrittweisen Entwicklung an Ort und Stelle, der Vermeidung von Umsiedlungen, dem Erhalt lokaler Existenzgrundlagen sowie demokratischer Beteiligung und Kooperation, wird oftmals angenommen, dass diese Herangehensweise nachhaltiger ist, als eine quantitativ ausgerichtete Wohnraumversorgung und Top-Down-Planungsansätze. Während diese Studie die Vorteile des in situ upgrading nicht in Frage stellt, zielt sie darauf ab, Probleme der praktischen Umsetzung dieses Ansatzes in einem spezifischen nationalen und lokalen Kontext zu identifizieren. Die Studie diskutiert die Herkunft und die Bedeutung des in situ upgrading auf der Grundlage einer Rückschau auf die Entwicklung internationaler Wohnraumpolitik und analysiert den politischen und sozialen Kontext der Einbettung dieses Ansatzes in die südafrikanische Wohnraumpolitik. Darüber hinaus macht sie sich Einblicke einer kürzlich durchgeführten Fallstudie in Kapstadt zunutze, um Probleme und Konflikte zu erfassen, die bei der Umsetzung des in situ upgrading in einem komplexen lokalen Kontext entstehen können. Auf dieser Grundlage werden die Vorteile wie auch die Beschränkungen des in situ upgrading näher spezifiziert und zentrale Voraussetzungen für eine erfolgreiche Umsetzung des Konzeptes formuliert.

The rising fuel prices, environmental concerns over the emission of greenhouse gases, and the limited availability of fossil fuels led to the current focus on developing alternative fuel sources that are sustainable and environmentally benign. Lignocellulosic biomass, due to its high carbon value, abundance and for being greenhouse gas neutral, is a promising alternative energy resource. Fast pyrolysis of lignocellulosic biomass produces high energy density liquid fuel, called bio-oil, which has the potential as transportation fuel. But, crude bio-oils are chemically complex liquids with high oxygen contents (40 % oxygen content), high viscosity, low pH, low thermal stability, and poor heating values (20 MJ/Kg). Therefore, bio-oils must be substantially upgraded (de-oxygenated) to highly stable, non-corrosive, and high calorific value liquid fuels prior to their use as transportation fuels. This research was conducted to investigate the efficiency of various acid catalysts in upgrading (cracking) the oxygenated pine wood pyrolysis vapors to high quality liquid fuel. Initial catalyst screening studies proved that zeolite acidity and pore structure is essential for effective cracking of pyrolysis vapors. Low space velocities and moderate temperatures were found to be favorable for the deoxygenation of pyrolysis vapors. Various zeolites were tested, of which HZSM-5 with low Si/Al ratio was found to be an effective cracking catalyst. But the use of zeolites resulted in poor liquid yields. Zeolites were promoted with transition metal ions in order to inhibit the secondary cracking reactions occurring on Brönsted acid sites. The metal-promoted biunctional catalysts were found to be the most effective catalysts, among all the catalysts employed in this research, in promoting hydrocarbon forming reactions without adversely affecting the liquid yields. Catalyst coking was unavoidable but the addition of metal ions to zeolites lowered the extent of coking. TG analysis of used catalysts indicated that the catalysts can be regenerated by calcining at 600-650 °C.