No description available.

[Truncated abstract] The ‘elemental sulphur’ deposition problem is a fairly recent phenomenon for gas transmission pipelines. Although known for a number of decades to cause plugging in reservoir wellhead facilities, it is since about 1990 that ‘elemental sulphur’ deposition has openly been acknowledged as a problem in natural gas pipelines and other facilities downstream of gas processing plants. Within the past ten years this formation / deposition process has progressively been more widely observed. The increasing trend to have transmission pipeline systems operating at higher pressures is a significant contributing factor in the formation of “elemental sulphur”. This research project has been able to identify the principles and mechanisms associated with the formation and deposition ‘sulphur vapour map’ concept, that only sub ppm levels of sulphur vapour within the gas stream is required to initiate the “elemental sulphur” formation / deposition process. The ‘sulphur vapour map’ can be used in predicting the degree of sulphur vapour desublimation that will occur for given pipeline operating conditions of pressure, temperature and gas composition. This, in turn, will assist in the minimization of the deposition process through the ability to make simple, yet appropriate, modifications to the design of the required pipeline pressure regulation stage. A significant number of other potential contributing factors to this pipeline particle formation and deposition process have also been identified through this research work. From these findings a number of additional recommendations have been made that will assist pipeline operators in minimizing the impact of this deposition problem. These recommendations are based on the operation of the pipeline, and particularly the control of the entry of liquids and other contaminants into the pipeline system. Recommendations for further research into this complex problem are also made.

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Thesis (Ph. D.)--University of Canterbury, 2008. / Typescript (photocopy). Includes bibliographical references (p. 204-220). Also available via the World Wide Web.

Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains ix, 123 p. : ill. (some col.), maps. Includes abstract. Includes bibliographical references (p. 64-65).

Thesis (M.S. in Defense Analysis)--Naval Postgraduate School, June 2010. / Thesis Advisor(s): Tsypkin, Mikhail ; Second Reader: Lober, George. "June 2010." Description based on title screen as viewed on July 14, 2010. Author(s) subject terms: Natural gas, transportation routes, pipelines, power rivalry, energy demand, energy resources, energy policy, energy security, post-Cold war era, Caspian Sea basin, Russian periphery, geopolitical, littoral states, political instability. Includes bibliographical references (p. 53-56). Also available in print.

Thesis (MA)--University of Stellenbosch, 2002. / ENGLISH ABSTRACT: A major concern for Energex, Australia's largest energy utility in South East Queensland, is the escape of natural gas out of their reticulation systems. Within many of the older areas in Brisbane, these networks operate primarily at low and medium pressure with a significant percentage of mains being cast iron or steel. Over many years pipes in these networks have been replaced, yet reports show that unaccounted for gas from the same networks remain high. Furthermore, operation and maintenance budgets for these networks are high with many of these pipes close to the end of their economic life. When operation and maintenance costs exceed the costs of replacement, the Energex gas utility initiates projects to renew reticulation networks with polyethylene pipes. Making decisions about pipe renewal requires an evaluation of historical records from a number of sources, namely: • gas consumption figures, • history of leaks, • maintenance and other related cost, and • the loss of revenue contributed by unaccounted for gas. Financial justification of capital expenditure has always been a requirement for renewal projects at the Energex gas utility, however the impact of a deregulation in the energy utility market has necessitated a review of their financial assessment for capital projects. The Energex gas utility has developed an application that evaluates the financial viability of renewal projects. This research will demonstrate the role of GIS integration with the Energex financial application. The results of this study showed that a GIS integrated renewal planning approach incorporates significant benefits including: • Efficient selection of a sub-network based on pipe connectivity, • Discovery of hidden relationships between spatially enabled alphanumeric data and environmental information that improves decision making, and • Enhanced testing of proposed renewal design options by scrutinizing the attributes of spatial data. / AFRIKAANSE OPSOMMING: 'n Groot bron van kommer vir Energex, Australië se grootste energieverskaffer in Suidoos- Queensland, is die verlies van natuurlike gas uit hul gasdistribusie netwerke. In 'n groot deel van ouer Brisbane opereer hierdie netwerke hoofsaaklik teen lae en medium druk, met 'n aansienlike persentasie van hoofpyplyne wat uit gietyster of staal bestaan. Al is sommige pyplyne in hierdie netwerke met verloop van tyd vervang, maak verslae dit duidelik dat 'n groot deel van die gas in hierdie netwerke steeds langs die pad verlore gaan. Die operasionele - en onderhoudsbegrotings vir hierdie netwerke is boonop hoog, met 'n groot persentasie van die pyplyne wat binnekort aan die einde van hulle ekonomiese leeftyd kom. Wanneer operasionele- en onderhoudsonkostes die koste van vervanging oorskry, beplan Energex se gasvoorsienings-afdeling projekte om verspreidingsnetwerke te hernu met poli-etileen pype. Om sinvolle besluite te neem tydens pyplynhernuwings, word verskeie historiese verslae geraadpleeg, insluitend: gasverbruikvlakke, lekplek geskiedenis rekords, onderhoud- en ander verwante onkostes, asook die verlies van inkomste weens verlore gas. Alhoewel finansiële stawing van kapitale uitgawes nog altyd 'n voorvereiste was tydens hernuwingsprojekte by Energex, het die impak van privatisering op die energieverskaffingsmark dit noodsaaklik gemaak om hulle finansiële goedkeuringsproses vir kapitaalprojekte te hersien. Energex het dus 'n sagteware toepassing ontwikkel wat die finansiële gangbaarheid van hernuwingsprojekte evalueer. Hierdie navorsing sal die moontlike integrasie van geografiese inligtingstelsels (GIS) met dié van Energex se finansiële evalueringspakket demonstreer. Die resultate van hierdie studie toon dat die integrasie van GIS in die hernuwingsproses aansienlike voordele inhou, insluitende: • die effektiewe seleksie van sub-netwerke, gebaseer op pyp konnektiwiteit, • die ontdekking van verskuilde verwantskappe tussen geografies-ruimtelike alfanumeriese data en omgewingsinligting, wat besluitneming vergemaklik, en • verbeterde toetsing van voorgestelde hernuwingsopsies deur die indiepte-nagaan van geografiesruimtelike elemente.

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains x, 61 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 59-61).

Natural gas feeds often contain contaminants such as CO₂, H₂S, H₂O, and small hydrocarbons. Carbon dioxide is a major contaminant reducing the heating value of the gas and causing pipeline corrosion, so CO₂ level should be lowered to below 2% to meet the United States pipeline specifications. Membrane separation technology can be advantageous over cryogenic distillation and amine adsorption in terms of cost and efficiency. The key hurdle to overcome in polymeric membrane separation technology is improvement in selectivity, productivity, and durability without introducing significant additional cost. The ultimate goal of this study is to analyze effects due to polymerization conditions and imidization methods on properties of 1,3-propanediol monoesterified crosslinkable polyimide (PDMC). Hillock, Omole, Ward, and Ma did work on PDMC synthesis; however, variability of polymer properties remains a challenge that must be overcome for industrial implementation of PDMC material. First, reaction temperature and reaction time of polymerization prior to imidization were considered as key conditions to affect molecular weight, crosslinkability and transport properties of polymer. Batches with controlled reaction temperature and time were prepared, and properties of each dense film were measured and optimized in terms of permeability, selectivity, and plasticization suppression. Second, imidization methods for PDMC were also studied. There are mainly two kinds of Imidization: chemical Imidization and thermal Imidization. Surprisingly, thermally imidized PDMC showed 70% higher permeability than chemically imidized samples with minimal acrifice in selectivity. At high reaction temperature during the thermal imidization, transamidation can occur. It is believed that the transamidation led to more randomized sequence distribution in the thermally imidized samples. We thus hypothesize that the higher permeability of the thermally imidized PDMC results from greater uniformity of the sequence distribution, as compared to the chemically imidized sample that does not experience high temperature during imidization. XRD, DSC, DMA, and permeation instruments checked and supported this hypothesis. FTIR, TGA, and NMR ruled out the possibility of an alternate hypothesis related to side reaction. Finally, effects of aggressive feed conditions on both chemically imidized PDMC and thermally imidized PDMC dense film were examined. The aggressive feed conditions include high CO₂ partial pressure, operating temperatures, and exposure to high feed pressure. Testing aggressive feed conditions for dense film should be pursued before pursuing hollow fiber applications, to decouple effects on the basic material from those on the more complex asymmetric morphology. This study enables understanding of the disparity between various previous researchers’ selectivity and permeability values. The work shows clearly that polymerization conditions and imidization methods must be specified and controlled to achieve consistently desirable polymer properties. In addition, for batch scale-up and development to a hollow fiber, this fundamental study should enable production of high molecular weight PDMC with good fiber spinnability and defect-free structure.

No description available.