The Gas-to-liquids (GTL) processes produce a large fraction of by-products whose disposal or handling ordinarily becomes a cost rather than benefit. As an alternative strategy to market stranded gas reserves, GTL provides middle distillates to an unsaturated global market and offers opportunities to generate power for commercial purposes from waste by-product streams, which normally are associated with increased expenses incurred from additional handling cost. The key concept investigated in this work is the possibility of integrating the GTL process with power generation using conventional waste by-product steam streams. Simulation of the integrated process was conducted with the aim of identifying the critical operating conditions for successful integration of the GTL and power generation processes. About 500 MW of electric power can be generated from 70% of the exit steam streams, with around 20 to 25% steam plant thermal efficiency. A detailed economic analysis on the LNG, stand-alone GTL, and Integrated GTL Power-Generation plants indicates that the integrated system is more profitable than the other options considered. Justifying the technology and economics involved in the use of the by-product streams to generate power could increase the net revenue and overall profitability of GTL projects. This technology may be transferable to GTL projects in the world, wherever a market for generated power exists.

Characterization of jet fuels obtained from sources other than crude oil is a modern area of research that is developing continuously to replace available petroleum-based fuels with ‘drop-in’ alternative fuels. Therefore, reliable composition-property relations are developed to correlate the hydrocarbon compositions of formulated synthetic fuels with their properties to be certified for aviation commercial use. Intensive studies have been initiated at Texas A&M University Qatar in collaboration with industry and academia to study synthetic jet fuels derived from natural gas. These studies are being implemented at its Fuel Characterization Lab where the most advanced testing equipment is used and strict Quality Management and safety systems are followed. This study is divided into two tracks. The first track is focused on conducting experimental investigations using in-house formulated synthetic jet fuels derived from natural gas via Gas-to-Liquid technology and Fischer-Tropsch chemistry. Throughout this research work, these fuels will be referred to as Synthetic Paraffinic Kerosene (SPK). These experimental investigations activities are composed of three phases: the first phase focuses on the influence of SPK building blocks (paraffinic hydrocarbons) on fuels’ properties, the second phase concerns evaluating the role of aromatics and cyclo-paraffins on properties, and the third phase studies the influence of mixing SPK with conventional Jet A-1 derived from crude oil. All of the aforementioned experimental investigations are aimed at building an experimental data bank to assist the efforts of the formulation of new generations of SPKs that meet aviation industry standards. On the other hand, the second track is directed towards the development of mathematical correlations for four properties of high importance to SPK certification. These correlations aim at optimizing fuel composition whereby major physical/chemical properties of ASTM D1655 are met at the lowest cost of composed fuel. The primary findings of this study showed that GTL derived SPK paraffinic constituents can improve certain properties while affecting others negatively, and emphasizing the necessity of aromatics in improving specific properties. Further studies compensating the absence of aromatics and sulfur through blended Jet A-1 revealed a practical solution through jet fuels optimization based on cost and technical effective manners.

This study focuses on upgrading biomass derived syngas for the synthesis of liquid fuels using Fischer-Tropsch synthesis (FTS). The process includes novel gasification of biomass via a tri-reforming process which involves a synergetic combination of CO2 reforming, steam reforming, and partial oxidation of methane. Typical biomass-derived syngas H2:CO is 1:1 and contains tars that deactivate FT catalyst. This innovation allows for cost-effective one-step production of syngas in the required H2:CO of 2:1 with reduction of tars for use in the FTS. To maximize the performance of the tri-reforming catalyst, an attempt to control oxygen mobility, thermal stability, dispersion of metal, resistance to coke formation, and strength of metal interaction with support is investigated by varying catalyst synthesis parameters. These synthesis variables include Ce and Zr mixed oxide support ratios, amount Mg and Ni loading, and the preparation of the catalyst. Reaction conditions were also varied to determine the influences reaction temperature, gas composition, and GHSV have on the catalyst performance. Testing under controlled reaction conditions and the use of several catalyst characterization techniques (BET, XRD, TPR, XAFS, SEM-EDS, XPS) were employed to better explain the effects of the synthesis parameters. Applications of the resulting data were used to design proof of concept solar powered BTL plant. This paper highlights the performance of the tri-reforming catalyst under various reaction conditions and explains results using catalyst characterization.

Within this body of work several series of experiments will investigate the nature of complex combustion in an experimental single-cylinder engine emulating a modern passenger car size compression-ignition (CI) engine. Regimes of single, piloted single and piloted split-main injections will be tested and compared in terms of combustion characteristics, specific emission output and cyclic behaviour to determine how increased injection complexity affects the emissions and output of the modern CI engine. Through these tests, the effect of fuel-line stationary waves will be demonstrated and investigated, showing conclusively that optimised engine calibration is essential to account for injector-generated waves in any multiple injection scenario. This data will then be confirmed with a dedicated analysis using an injector rate measuring tube. The tests will then be expanded to include examination into the behaviour of injector needle-lift standard deviation over its operating cycle, in-cylinder pressure standard deviation behaviour and trends over the combustion cycle as well as IMEP variability. Through these tests a novel method to detect start of combustion will be proposed and compared to conventional methods. Low temperature combustion (LTC) will be tested under incremental injection complexity. Tests will be optimised for combustion phasing and injection pressure, with a view to analysis of emissions, output and cyclic behaviour to establish whether the knowledge gained about conventional combustion holds true under LTC. Optimization of engine parameters will be shown to result in easier to implement LTC regimes with superior emissions characteristics. Finally, LTC tests will be expanded to include 30% and 50% by volume gas-to-liquid fuel (GTL) blends in order to determine whether fuel characteristics further influence emissions, output and cyclic behaviour in LTC through complex injection regimes. How GTL-blend ratio affects trends in emissions and cyclic behaviour will also be examined and compared to conventional diesel fuel.

Thesis (M.Eng. (Development and Management Engineering)--North-West University, Potchefstroom Campus, 2008.

Thesis (M.Eng. (Development and Management Engineering)--North-West University, Potchefstroom Campus, 2008.

Thesis (M.Eng. (Development and Management Engineering)--North-West University, Potchefstroom Campus, 2008.

Thesis (MBA)--Stellenbosch University, 2005. / ENGLISH ABSTRACT: South Africa's main requirements for power are in the form of electricity and liquid fuels The country's electricity is generated mainly from coal while the liquid fuels requirement is mainly from crude oil. Both coal and crude oil use are coming under increasing pressure locally because of pollution and accompanying environmental awareness. Internationally both energy sources are also increasingly being abandoned as preferred energy sources, in first world countries, in favour of cleaner energy sources.ln view of these developments in the macro environment South Africa's gas to liquids refinery built in the early 1990's seems a well placed past investment ahead of its time. This study project looks at the economic feasibility of the continued existence of the PetroSA gas to liquid plant in Mossel Bay.The study looks at South Africa as well as Southern Africa's energy resources , the effect of changing legislation on the future use of energy resources and the economics of the Mossel Bay facility. The study finds that South Africa's abundance of coal reserves, its lack of oil and gas reserves and the slow pace of environmental legislation delivery means that gas is unlikely to become a major source of energy in South Africa.The Mossel Bay gas to liquids plant is profitable but its high fixed costs and certain growth of this cost component means that the continued feasibility of operations is dependant on favourable movements in the exchange rate and oil price. To answer the question about whether to continue operating or close down the analysis found that although although early closure would provide a return of more than 15 percent it would be even more viable financially to make an investment for more gas and continue operations.The main reason for the better than average projected returns is the high oil price .The decision to close down the Mossel Bay plant is not likely to be based on financial considerations alone. The recommendation is thus to continue operations untill 2016.The investment required to secure more gas would , even in the worst case scenario, provide a satisfactory return on investment. / AFRIKAANSE OPSOMMING: Suid Afrika se energie behoeftes is hoofsaaklik vir elektrisiteit en brandstof. Die meerderheid van die land se elektristeit word deur middel van steenkool opgewek terwyl ru-olie gebruik word om brandstof te vervaardig. Beide steenkool en ru-olie word al hoe meer onder druk geplaas as gevolg van besoedeling en 'n meer omgewing bewuste publiek. Op internasionale vlak , in eerste wereld lande word die gebruik van steenkool en ru-olie al hoe meer afgeskaf ten gunsle van skoner kragbronne. In die lig van hierdie verwikkeling in die makro omgewing mag dit op die oog af Iyk of PetroSA se gas na vloeistof aanleg in Mosselbaai, wat reeds in die vroee 1990's gebou is, as 'n goeie destydse strategiese belegging voorkom. Hierdie studie projek ondersoek die ekonomiese lewensvatbaarheid van die voorgesette bestaan van die PetroSA se Mosselbaai gas na vloeislof aanleg. Die studie kyk na Suid-Afrika sowel as die groter Suider Afrika se natuurlike energiebronne, die invloed van verandering in wetgewing op die toekomstige gebruik van energiebronne en die ekonomiese kenmerke van die aanleg in Mosselbaai. Die bevinding van die studie is dat Suid-Afrika se oorvloed van steenkool, sy tekort aan natuurlike gas en die stadige pas waarteen omgewings-wetgewing ontwikkel word, daartoe lei dat gas nie 'n volmatige energiebron in Suid Afrika sal word nie. Die aanleg in Mosselbaai is huidiglik winsgewind maar sy hoe vastekoste en groei hiervan belemmer sy vooruitsigte vanuit 'n finansiele oogpunt. Die winsgewindheid van die aanleg is afhanklik van 'n verswakkende Suid Afrikaanse geldeenheid en verhogende ru-olie pryse. Die vraag onstaan dus of die aanleg moet toemaak en of produksie moet voortgaan. Die ondersoek vind dat alhoewel die sluiting van die aanleg 'n opbrengs van meer as 15 persent sal lewer dit selfs meer finansieel aantreklik is on te belê in meer gas sodat produksie kan voortgaan. Die hoofrede vir die bogemiddelde opbrengs is die hoe oilieprys. Dit is onwaarskynlik dat die oorweging om die Mosselbaaise aanleg sluit suiwer op finansieele oorwegings sal rus. Die aanbeveling is dus om voort te gaan met produksie tot 2016. Die belegging wat nodig is vir meer gas sal selfs onder die mees pessimistiese omstandighede steeds 'n bevredigende opbrengs lewer.

The safety record of most petrochemical industries in the world and Nigeria in particle, has not been able to come down to the maximum allowable range of 0 - 0.1 percent of tolerance on recordable injuries, due to increasing failure rates of equipment within the plant. Investigations on the maintenance audit carried out on the Nigerian Gas Company (NGC) revealed that 85 percent of such failures are directly linked to improper adaptability of an effective maintenance management strategy and plan within the petrochemical industries in Nigeria. Equally, the growth and continuous operation of any plant depends to a large extent on the maintenance of the equipment that refines the Crude Oil and natural Gas. As such, various maintenance management systems have been used over the years for the actualisation of the above purpose but with minimal success. This is evident in the fact that the level of maintenance performance of most Nigerian Petroleum Companies is always on the corrective maintenance model, which indirectly implies that the plant normally breaks down before maintenance management is applied. A critical look at the deficiency of improper adaptability of these maintenance management plans have conspicuously manifested in five major categories of maintenance failures which includes the following; * Failure of safety critical equipment due to lack of maintenance * Human error during maintenance * Static or spark discharge during maintenance in an intrinsically unsafe zone * Incompetence of maintenance staff, and * Poor communication between maintenance and production staff. These gaps as identified in this research must be corrected in the Nigerian Gas Industry if meaningful progress is to be made. Gas – To – Liquid technology is a very complex technology and with natural gas as the basic raw material, the technology not only looks intimidating but also is full of potential hazards. People are naturally afraid of the complex nature of gas in a confined environment (because of its highly combustible nature), its gaseous state makes it more complex for it to be kept under control and at the same time be moved from one form to another at different temperatures and pressures. The maintenance audit carried out on the Nigerian Gas Company (NGC) revealed some major loopholes in the maintenance management strategies adopted in the country. The audit reveals that the degree of adherence to conditions attached towards the maintenance management strategy of this equipment (in this case Gas field equipment) was too poor. Based on the above, this research is meant to improve the existing maintenance management strategy, by developing a Maintenance Management Strategy (MMS) that will be suitable for gas field equipment in the Escravos Gas–To– Liquid (EGTL) plant, planned to be commissioned in Nigeria early 2011. The need to research the above mentioned Maintenance Strategy became imperative due to the fact that the rate at which most of the petrochemical plants in the world are being gutted by fire, mainly due to poor maintenance management systems is alarming. This research work proffered solutions that will reduce or completely eliminate the highlighted problems above. This was based on investigations and analysis carried out in the chosen research area. Models were developed for the actualization of this Improved Maintenance Management Strategy (IMMS), so that the desired safe operability of the gas field equipment in the Escravos Gas–To– Liquid (EGTL) plant will be achieved without maintenance failure of any kind. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2011.

The safety record of most petrochemical industries in the world and Nigeria in particle, has not been able to come down to the maximum allowable range of 0 - 0.1 percent of tolerance on recordable injuries, due to increasing failure rates of equipment within the plant. Investigations on the maintenance audit carried out on the Nigerian Gas Company (NGC) revealed that 85 percent of such failures are directly linked to improper adaptability of an effective maintenance management strategy and plan within the petrochemical industries in Nigeria. Equally, the growth and continuous operation of any plant depends to a large extent on the maintenance of the equipment that refines the Crude Oil and natural Gas. As such, various maintenance management systems have been used over the years for the actualisation of the above purpose but with minimal success. This is evident in the fact that the level of maintenance performance of most Nigerian Petroleum Companies is always on the corrective maintenance model, which indirectly implies that the plant normally breaks down before maintenance management is applied. A critical look at the deficiency of improper adaptability of these maintenance management plans have conspicuously manifested in five major categories of maintenance failures which includes the following; * Failure of safety critical equipment due to lack of maintenance * Human error during maintenance * Static or spark discharge during maintenance in an intrinsically unsafe zone * Incompetence of maintenance staff, and * Poor communication between maintenance and production staff. These gaps as identified in this research must be corrected in the Nigerian Gas Industry if meaningful progress is to be made. Gas – To – Liquid technology is a very complex technology and with natural gas as the basic raw material, the technology not only looks intimidating but also is full of potential hazards. People are naturally afraid of the complex nature of gas in a confined environment (because of its highly combustible nature), its gaseous state makes it more complex for it to be kept under control and at the same time be moved from one form to another at different temperatures and pressures. The maintenance audit carried out on the Nigerian Gas Company (NGC) revealed some major loopholes in the maintenance management strategies adopted in the country. The audit reveals that the degree of adherence to conditions attached towards the maintenance management strategy of this equipment (in this case Gas field equipment) was too poor. Based on the above, this research is meant to improve the existing maintenance management strategy, by developing a Maintenance Management Strategy (MMS) that will be suitable for gas field equipment in the Escravos Gas–To– Liquid (EGTL) plant, planned to be commissioned in Nigeria early 2011. The need to research the above mentioned Maintenance Strategy became imperative due to the fact that the rate at which most of the petrochemical plants in the world are being gutted by fire, mainly due to poor maintenance management systems is alarming. This research work proffered solutions that will reduce or completely eliminate the highlighted problems above. This was based on investigations and analysis carried out in the chosen research area. Models were developed for the actualization of this Improved Maintenance Management Strategy (IMMS), so that the desired safe operability of the gas field equipment in the Escravos Gas–To– Liquid (EGTL) plant will be achieved without maintenance failure of any kind. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2011.