Dissertations / Theses on the topic 'Liquid petroleum gas'

Thesis (MEng)--University of Stellenbosch, 2001.
ENGLISH ABSTRACT: The trends in worldwide fuel consumption and availability were studied, these indicated a bigger growth in gaseous fuel use than that of crude oil over the last decade. The economics (cost of converting and running vehicles on LPG) were studied and compared with those of petrol and diesel fuels. The government's approach to LPG taxation and the structure of the fuel price was also considered in an attempt to foresee what the future holds for LPG use in the motor industry. Gas fuelling systems that are currently available were studied and briefly described. The information obtained from the background study was used to help in the conversion of a two litre petrol engine. The engine was equipped to run on petrol Injection, liquid phase LPG injection and LPG carburettion. In-cylinder pressures, exhaust emissions and fuel consumption were amongst the parameters that were recorded for each fuel. The in-cylinder pressure measurements were used to study the combustion characteristics of petrol and LPG. Computer modeling was also used to investigate the trends that were recorded and this gave valuable insight into the different combustion characteristics of each fuel and the effect of gaseous versus liquid supply. For the passenger bus market a 12 litre 6 cylinder diesel engine was converted to LPG operation only. This required several changes to the pistons, cylinder head, inlet manifold and the addition of an electronic ignition system. Some changes had to be made to the squish characteristics of the pistons to make it suitable for homogeneous fuel air mixtures. The reasons for this were studied and described. Dynamometer tests revealed inadequacies in the ignition system that still need to be addressed before the engine can be built into a bus. Recommendations are made as to best utilize LPG in the South African Automotive industry, so as to improve public transport and air quality in some of our cities.
AFRIKAANSE OPSOMMING: 'n Studie van tendense in wêreldwye energieverbruik en besikbaarheid is gedoen. Dit het aan die lig gebring dat die groei in die gebruik van gasagtige brandstowwe in die laaste dekade die van ru-olie oortref het. Die lewensvatbaarheid van Vloeibare Petroleum Gas (VPG) voertuie, ombouing sowel as lopende koste, is bestudeer en vergelyk met die van Petrol en Diesel voertuie. Die regering se benadering tot belasting op VPG en die struktuur van die brandstofprys is ook ondersoek om te bepaal of die gebruik van VPG in n groter skaal as tans lewenvatbaar is. Vir tegniese agergrond is gas aangedrewe voertuie wêreldwyd bestudeer om te sien watter brandstof-voorsiening stelsels en enjins gebruik word. Die verskillende stelsels word bondig beskryf. Hierdie inligting is onder meer gebruik in die ombouing van n twee liter petrolenjin na VPG. Die enjin is toegerus om op beide petrol en VPG te loop terwyl die VPG in gasfase met behulp van 'n vergasser of as vloestof deur brandstof inspuiting toegedien kon word. Ontbrandingskamerdruk, uitlaatgasse en brandstofverbruik is van die parameters wat tydens toetse gemeet is. Die ontbrandingskamerdukmetings is gebruik om die verbrandingskarakteristieke van elke brandstof te bepaal. Nagebootste verbrandingstempos is in n rekeraarprogram gebruik om verskillende verbrandings karakteristieke wat gemeet is te ondersoek en tendense te bevestig. Vir die swaarvoertuigmark is 'n 12 Liter diesel enjin ombebou na VPG gebruik. Die dieselpomp en inspuiters is vervang met elektroniese vonkontsteking en vonkproppe. Die verbrandingskamer moes verander word om spontane verbranding tydens samepersing te voorkom. Die redes hiervoor is ondersoek en beskryf. Dinamo toetse het tekortkominge uitgewys in die elektroniese vonkontstekingsstelsel wat nog nie ten volle aangespreek is nie. Aanbevelings is gemaak om die toenemende gebruik van VPG as motorvoertuigbrandstof in Suid Afrika aan te bevorder om sodoende beter gebruik te maak van die beskikbare energie uit ru olie en ander bronne. Aanbevelings is ook gemaak ten opsigte van die gebruik van VPG in openbare vervoer en verbetering van lug gehalte in sommige stede.

Bibliography: pages 98-101.
This dissertation investigates the demand for illuminating Paraffin (IP) and Liquid Petroleum Gas (LPG) in South Africa, and also tests the energy transition theory. The energy transition process outlines the substitution of fuels that occurs with rural-urban migration. Data on income, IP and LPG prices, demographic trends and IP and LPG volumes are incorporated in models to test the energy transition theory: National and regional projections of demand are derived. Income and price elasticities are derived for testing the energy transition theory, where Engel's Law is applied. The derived price and income elasticities for the regional IP models largely confirm the energy transition process where poorer areas are price inelastic. The models of the urban electrified areas and the predominantly rural areas, produce negative income elasticities which reduce the forecasts and suggest that IP is an inferior good due to the availability of superior electricity or free wood respectively. Electrification will play a role in reducing consumption of IP and LPG. However, it can be concluded that due to the predominant price and income inelasticity of demand, the smooth and exclusive transition from wood to IP and LPG and finally electricity suggested by (Viljoen, 1990) is perhaps misleading. It is more likely that tardiness in substituting one fuel for another will impede the complete transition among fuels and that the use of a range of fuels, even if electricity becomes available, will be maintained for some time as the newly urbanised household moves up the modernisation index. The forecasts for IP and LPG for the period 1992 to 1995, emanating from the econometric models developed here, forecast lower growth in consumption as compared with the recent past. The national forecasts for 1992 to 1995 are half those achieved in the last upturn of 1986 to 1989. LPG forecasts are similarly about 50% lower than the historic period. However, the growth in both products is still forecast to be double the projected GDP growth. The regional IP forecasts show most of the growth occurring in the urban areas and the "homelands" closer to the metropoles. High growth is particularly forecast for the large PWV complex with its dense concentration of population and high rate of immigration. In summary, the transitional fuels will remain important energy sources for some time to come. The variables such as population growth, income and IP and LPG prices are significant in determining demand. In spite of Eskom's ambitious plans to provide "electricity for all" a significant proportion of the population will remain without electricity. It is therefore important for policy-makers to ensure that the prices of IP and LPG paid by the consumer are within income constraints as energy is a basic need.

El presente trabajo realizado se centra en la investigación del impacto tributario que se puede generar por las mermas de GLP en las estaciones de servicio del Cercado de Lima en el periodo 2017. Las mermas son la reducción del volumen o la cantidad, el GLP por ser de naturaleza gaseosa tiende a evaporarse, por lo que la compañía para efectos de sustentar estas pérdidas debe elaborar un informe técnico elaborado por un tercero independiente con el fin de obtener un beneficio para efecto de disminuir la base tributaria para el cálculo de la renta. En el flujo de comercialización del GLP en las estaciones de servicio, el gas es transportado desde el tanque estacionario hasta la máquina surtidora del combustible, en esta línea de secuencia se puede perder gas que pasaría a ser merma por la actividad del negocio. En el desarrollo de este trabajo conoceremos un caso en específico de una compañía que no pudo sustentar las mermas generadas en su ejercicio, ya que la Administración Tributaria consideró inadecuado la solicitud de deducir las mermas por no resultar normal en el negocio. Es aquí donde se genera una controversia acerca del presumible vacío que queda en la norma. Al captar este tema de nuestro interés pasaremos a desarrollar la investigación sobre la actualidad de las estaciones de servicio y qué procedimientos aplican estas compañías respecto al tratamiento sobre las mermas de GLP.
The present work is focused on the investigation of the tax impact that can be generated by the petroleum liquid gas losses in the service stations of the Cercado de Lima in the period 2017. The losses are the reduction of the volume or quantity, the petroleum liquid gas being A gaseous nature tends to evaporate, so that the company for the purpose of sustaining these losses must prepare a technical report prepared by an independent third party in order to obtain a benefit in order to reduce the tax base for the calculation of income. In the petroleum liquid gas marketing flow at the service stations, the gas is transported from the stationary tank to the fuel dispensing machine, in this sequence line gas can be lost that would become depleted by the business activity. In the development of this work we will know a specific case of a company that could not sustain the losses generated in its exercise, since the Tax Administration considered inappropriate the request to deduct the losses for not being normal in the business. It is here that a controversy is generated about the presumable void that remains in the norm. By capturing this topic of our interest, we will develop research on the topicality of service stations and what procedures these companies apply regarding the treatment of the petroleum liquid gas waste.
Tesis

Modern society has become reliant on battery powered electronic devices such as cell phones and laptop computers. The standard way of recharging these devices is by connecting to a reticulated electricity supply. In situations with no electricity supply some other recharging method is required. Such a possibility is a small, portable, generator based on fuel cell technology, specifically mini-tubular solid oxide fuel cells (MT-SOFC). MT-SOFCs have been developed since the 1990s but there is limited analysis, discussion or research on developing and constructing a portable generator based on MT-SOFC technology. Such a generator, running on a portable gas supply, requires combining the key aspects of cell performance, a heating and fuel reforming system, and cell manifolds. Cell design, fuel type, fuel flow rate, current-collection method and operating temperature all greatly affected MT-SOFCs performance. Segmenting the cathode significantly increased the power output. Maximum power density from an electrolyte supported MT-SOFC was 140 mW/cm2. The partial oxidation reactor (POR) developed provided the required heat to maintain the MT-SOFCs at an operating temperature suitable for generating electricity. The exhaust gas from the POR was a suitable fuel for MT-SOFCs, having sufficient carbon monoxide and hydrogen to generate electricity. Various manifold materials were evaluated including solid metal blocks and folded sheet metal. It was found that manifolds made from easily worked alumina fibre board decreased the thermal stresses and therefore the fracture rate of the MT-SOFCs. The final prototype developed comprised a partial oxidation reactor and MT-SOFCs mounted in alumina fibre board manifolds within a well-insulated enclosure, which could be run on LPG. Calculated efficiency of the final prototype was 4%. If all the carbon monoxide and hydrogen produced by the partial oxidation reactor were converted to electrical energy, efficiency would increase to 39%. Under ideal conditions, efficiency would be 78%. Efficiency of the prototype can be improved by increasing the fuel and oxygen utilisation ratios, ensuring heat from the exhaust gases is transferred to the incoming gases, and improving the methods for collecting current at both the anode and cathode.

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.

Orientador: Antonio Carlos Bannwart
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica e Instituto de Geociencias
Made available in DSpace on 2018-08-12T11:22:37Z (GMT). No. of bitstreams: 1 Santos_GuilhermeRosariodos_M.pdf: 4731485 bytes, checksum: 22f7c73b5cfe98d8ceda0b200e009a5f (MD5) Previous issue date: 2006
Resumo: Um dos problemas cruciais no atual cenário da indústria nacional de petróleo é a medição das vazões de óleo, gás e água produzidos por cada poço. Este problema se agrava no contexto da produção de óleos pesados sob condições offshore em águas profundas, dadas as condições adversas desse ambiente, alta viscosidade do óleo, formação de emulsões com água, dificuldade natural para sua elevação e escoamento, entre outras. Excetuando os casos em que um poço é testado, quando então sua produção pode ser determinada na superfície, não se dispõe atualmente de sistemas e métodos de medição simples, confiáveis e não-intrusivos para as vazões de cada poço. O presente trabalho investiga a utilização de técnicas de ultra-som para fins de monitoramento do filme de água em escoamentos gás-líquido e líquido-líquido. O objetivo deste trabalho é desenvolver uma ferramenta de medição de espessura instantânea do filme líquido em escoamentos gás-líquido e líquido-líquido utilizando técnicas de ultra-som. A medição do tempo de trânsito do sinal acústico ultra-sônico através de uma camada de material - líquido, gás ou sólido - permite a obtenção da espessura local e instantânea dessa camada, a partir do conhecimento da velocidade de propagação do som nesse meio, através de calibração prévia. Assim, por meio de diversos experimentos com diferentes pares de fluidos e padrões de escoamento, pretende-se definir as melhores condições para utilização do ultra-som para esse fim. Os tempos de trânsito podem ser detectados através dos picos de amplitude gerados quando os pulsos refletidos atingem o receptor. A utilização do ultra-som é uma técnica não intrusiva e não-invasiva, isto é, não causa perturbações ao escoamento, possibilitando ainda medições in situ em tempo real de grandezas de escoamentos múltifásicos presentes inclusive na indústria do petróleo. Este estudo mostrou ser possível a aplicação da técnica de ultra-som paia escoamentos gás-líquido, uma vez que a diferença de impedância acústica permite que grande ,parte do pulso incidente seja refletida na interface entre os dois meios líquidos. Em escoamentos líquido-líquido, o monitoramento da espessura de filme é mais difícil, sendo necessário o uso de recursos computacionais mais robustos. A pequena diferença de impedância acústica entre os líquidos, muitas vezes, dificulta a captação do pulso correspondente à interface entre os meios líquidos. Um outro fator agravante é a presença de emulsões em escoamentos líquido-líquido ou óleos com viscosidades maiores. Nessas situações, a atenuação do pulso refletido na interface entre os dois meios líquidos é ainda maior.
Abstract: One of the most important problems in the current scenario of petroleum industry is the flow rate measurements of oil, gas and water produced by each well. This problem becomes more complicated in the context of heavy oils production under offshore conditions in deepwater, due to the adverse environment, high oil viscosity, formation of emulsion with water, difficulties for its lift and flow, etc. Excepting the cases in which a well is being tested, when its flow rate can be determined at the surface, it does not exist any simple, reliable and non-intrusive system or measurement method for flow rate of an individual well. The present work looks over an application of ultrasonic techniques for monitoring of water film in gas-liquid and liquid-liquid flows. The specific purpose of this work is to develop a toei for instantaneous thickness measurement of liquid film in gas-liquid and liquid-liquid flows by ultrasonic techniques. The transit time measurement of an acoustic signal through a material layer (solid, liquid or gas) allows its local and instantaneous evaluation, knowing the ultrasound propagation speed for each medium from previous calibration. ln this way, through several experiments with different fluid pairs and flows pattems, it intends to establish the better conditions for application of the ultrasound technique. The transit times can be detected through the amplitude peaks generated when the reflected pulses reach the receiver. The ultrasound application is a non-invasive and non-intrusive technique, that is, it does not cause any disturbance in the flow, allowing in situ measurements in real time of many parameters of multiphase flows inc1uding the petroleum industry. This study showed the possibility of applying a pulse-echo technique t6 the gas-liquid flows, because the acoustic impedance difference allows the majority of incidem,t ultrasound be reflected in the gas-liquid interface. The monitoring of liquid films thickness is more difficult in liquid-liquid flows, being necessary the use oi rugged computational resources. The low difference of acoustic impedance between liquids can make more difficult the reception of a pulse which corresponds to the liquid-liquid interface. Another difficulty occurs when emulsions are formed or the oil is highly viscous. ln these situations, the attenuation of reflected ultrasound from the liquid-liquid interface is still larger.
Mestrado
Explotação
Mestre em Ciências e Engenharia de Petróleo

碩士
國立中興大學
機械工程學系
88
Due to lower Exhaust Emission, the LPG vehicle is more helpful to improve the deteriorated air quality than gasoline vehicle, especially in the urban area. Recently, all LPG application was used in the automobile issue, not in motorbike. However, in the urban area, motorbike was more influential for air pollution than automobile. The following article is mentioned about experiment of engine and test of altered motorbike. New fuel system will be designed in this article as well. The new fuel system will be tested on the dynamometer, firstly and then on the exhaust emission of LPG motorbike, which was included the controlled CO, HC, NOX and other harmful but uncontrolled gas. From the result, it will offer more effective standard for evaluating air quality in the urban area, where was replaced using LPG in motorbike. The workings in this experiment are (1). Design of LPG fuel system. (2). Test of altered motorbike. (3). Measure of exhaust emission in LPG motorbike. Designs of fuel system are included: fuel tank, fuel wire system, LPG reduced pressure valve, evaporator, flow control valve, mixer design and fuel temperature control system. In the exhausted gas composition, HC was analyzed by GC/MS. The burned gasoline was with 21% of ethylene, 11% of 1-propene, 2-methyl, 8% of propene and 7% of ethane. The burned LPG was with 62% of propane, 11% of ethylene, 9% of n-butane and 6% of ethane. Therefore, the OFP (Ozone Forming Potential) of LPG engine was 20% lower than that of gasoline engine. Results of experiments showed that there is no significant difference in torque and power between LPG engine and gasoline engine in low and medium RPM. But, in high RPM, the performance curve of LPG engine was 27% lower than that of gasoline engine. Furthermore, the CO and HC emission in the waste gas was not as good as gasoline engine. The main reasons were the effect of fuel property and that the fuel system and mixer did not function well.

碩士
國立高雄應用科技大學
工業工程與管理系碩士在職專班
101
Gas is a universal source of energy and it has also become an indispensable supply in the lives of Taiwanese people. The gas industry was established in the Taiwanese society since over half a century ago, however due to the gas industry being a rather dangerous industry; the government has placed many restrictions on operating licenses. Therefore, it is not as popular as other industries. Even though many people use gas, but very few people truly understand it. This includes operators where even they do not truly know the nature of gas. Therefore, even though the industry has been established for over 50 years, its operating methods and structure has not changed much nor progressed. In recent years, with the rapid development of industries and technology, this industry is gradually replaced by other energy sources and becoming a twilight industry. This study investigates the operational problems with which the industry is faced. Gases are the general term for gaseous fuels, which includes liquefied petroleum gas, natural gas and coal gas. This study mainly focuses on operating liquefied petroleum gas and aims to investigate the difficulties faced and the current situation of this gas. Furthermore, this study aims to improve on problems therein and create new methods and products. At the same time, write up and submit the application for the new patent instruction, which is in accordance with relevant regulations of new patent applications of the Intellectual Property Office of the Ministry of Economic Affairs R.O.C, to protect the intellectual property and feasibility. There are a many new patents related to gas products in Taiwan, however most of them are impractical or have cost to consider, thus there are limitations to actually use the patented product on the market. Therefore, this study will aim to improve this problem and retrieve other patents that may be similar to the one in this study, which can be used as a reference and be analyzed. Then recreate a newly modeled patent, which will then be implemented into the current industry.

This thesis proposes modeling phase behavior, including the solid phase, during gas processing. Failure to accurately predict solid phase formation or freezing of CO2, hydrates, and water ice causes plugging and equipment failure. Vapor-liquid-solid phase behaviors of hydrocarbons are modeled using the Perturbed Chain-SAFT (PC-SAFT) equation of state in the presence of carbon dioxide at cryogenic temperatures. PC-SAFT does an excellent job predicting vapor-liquid equilibria (VLE), vapor-solid equilibria (VSE), and liquid-solid equilibria (LSE) using binary interaction parameters fit to the vapor-liquid equilibria data. Using these parameters produces excellent results for LSE and VSE for hydrocarbon + carbon dioxide systems over the entire range of measured temperatures and pressures. Predicting accurate solid phase behavior will help in design and optimization of processes for cryogenic systems especially when data are lacking at process conditions. Further, modeling at extreme high temperatures and pressures demonstrates the usefulness of PC-SAFT for deepwater reservoirs.

碩士
逢甲大學
經營管理碩士在職學位學程
107
Although the trading methods and services of the domestic LPG (commonly known as gas) retail market have the advantage of convenience, but due to the liberalization of open gas trade, the competition is becoming increasingly fierce and the market is saturated, and the unscrupulous traders are squandering two and no licenses. The problem of price-cutting competition and other issues, on the other hand... consumer safety awareness and lifestyle changes and the requirements of the competent authorities to implement compliance with regulations, so it is necessary to change the face of the gas industry through the right strategy. The problems and dilemmas brought about the successful transformation of the gas industry, the market is stable, consumers can have fair trade, and the social home environment is safe. This study takes the case study method as the main axis for the original conditions of the case company, and analyzes the dilemma and opportunity with the five-force analysis and SWOT analysis, and then finds out the key success factors to formulate relevant strategies, as the case company improves the current situation. Problems and dilemmas, which in turn lead to the safest home environment in society and sustainable operation. Through research and analysis, it is inferred to solve the key success factors of the problems and dilemmas facing the gas industry, formulate short-, medium- and long-term target strategies, and at the same time find out the specific models of the case companies that have sufficient core values of sustainable development and advantages at this stage. Then optimize, so that the case company is more standing in the leader of the gas industry.