Abstract
This thesis discusses the energy use in Eastern Refinery Limited and the possibilities of energy conservation. It illustrates various processes, equipment and system oriented approach of energy conservation. The objective of energy conservation can be achieved by auditing the energy consumed in every process unit and then to save energy, various steps are to be taken including designing more efficient and compact process units like heat exchanger, furnace etc, revamping existing equipment or overall BMRE (Balancing, Modernization and Rehabilitation) This study on energy use and conservation possibilities was carried out in Eastern Refinery Ltd. (ERL), the only petroleum refinery plant in Bangladesh. ERL has five processing unit; the study was kept limited to Crude Distillation Unit, the main unit of the refinery plant. Eastern Refinery Ltd. was designed in the mid-60's and went on stream in 1968. At its early stage energy conservation was not so stringent as it is now in a refinery of 2001. ERL has taken necessary steps to improve the plant's efficiency and to conserve energy. ERL is now processing 1.3-1.4 million MT of crude oil per annum, as against its installed capacity of 1.5 million tons per year.
Furnace is the major consumer of energy, usually obtained by burning hydrocarbon. fuel. It is estimated that total energy consumption of ERL is about 60.54 MMkcal per hour of which distillation furnace alone is consuming near about 28.62 MMkcal/hr (47.27%). It has been found that, the furnace is running with a thermal efficiency about 65 % and operating with about 77 % excess air which is much higher than the designed value(40%). 1-2% improvement in thermal efficiency is possible by reducing excess air to the furnace only and through proper monitoring. It has been found that 1% improvement in thermal efficiency in the furnace will result in energy saving of around 3256 MMkcal per year and savings in terms of money around Tk.22,34, 104.00 per year. Energy consumption in ERL per barrel of Crude oil processing is about 0.05 MM kcal. The overall processing expense of Crude oil is increasing every year. In 1990- 91 financial years it was Tk.32.88 per Barrel and in the year 1999-2000 it increased vii to Tk.58.70 per Barrel. About 4.99 MMkcal heat is wasted to cooling water during cooling products from process unit before transferring to storage tank. Heat exchanger can be placed before LGO and Residue water cooler, to save heat energy of about 3.99MM kcal /hr. A reasonable amount of energy can be saved by increasing flashing rate of crude oil in flashing drum before feeding to furnace, to avoid heating the same in the furnace.
Abstract
The Bakhrabad-Chittagong (BKB-CHT) high pressure gas transmission line was first commissioned in 1983. It is a 175 km long, 24 dia, 960 psig) gas pipeline which was built to supply gas from the Bakhrabad Gas field, Muradnagar, Commilla to Chittagong City Gate Station (CGS), Faujderhat, Chittagong. Gas is being supplied to the consumer of Commilla, Chandpur, Lakhsam, Feni, Maizde, Choumuhoni, Laksmipur, Chittagong as well as the huge area of the South-East part of Bangladesh by the different off-takes along the pipeline.
On stream pigging operation was first accomplished to BKB-CHT pipeline in July, 1990 and second time it was done in February, 1994. Significant amount of condensate, sludge and water were recovered from this pipeline during these operations. After thirteen years, on stream pigging operation to BKB-CHT pipeline was done during 12-13 November, 2007 by Gas Transmission Company Ltd (GTCL). The anticipated amount of condensate, sludge etc. were not recovered from this pipeline during the latest pigging operation. It is therefore necessary to analyse the latest pigging operation to understand the effectiveness, and to find out the reasons for such large differences of the outcomes compared to the previous operations.
The investigation reveals that in the beginning years the gas processing at Bakhrabad Gas Field was inadequate. The pipeline was not being used at its full capacity. Due to these reasons, there was scope for accumulation of large amount of condensate. Therefore during the first and second pigging operations, large amounts of condensate were recovered (7,11,000 and 3,87,000 litres respectively). The third (3) pigging operation however did not yield the anticipated quantities. The probable reasons are:
After the second pigging operation, BKB Gas Field Process Plant are being operated in sufficient capacity.
In 1997, Ashuganj- Bakhrabad 30" pipeline was commissioned. So since 1997, BKB-CHT pipeline have been being operated in actual capacity range.
Since 1997, most of the gas feed to BKB-CHT pipeline was from AB pipeline and this gas was coming from other gas fields such as Titas, Habiganj, Rashidpur, Kailashtila and Jalabad Gas Field. Thus gas from these sources are already processed at origin. Moreover, some liquid is recovered at the Ashuganj Menifold Station. Therefore when the total mix of gas is fed onto BKB-CHT pipeline it is almost dry.
After the second pigging operation, BKB Gas Field, Salda Gas Field and Meghna Gas Field have been supplying dry gas. Sufficient capacity heater are being used at ICS Feni and CGS Faujderhat after second pigging operation.
During the year 2005-2006, average 3000 gallons/month of condensate were collected at CGS Faujderhat and average 1000 gallons/month of condensate were collected at ICS feni. Therefore it is possible that whatever amount of condensate accumulated in the pipeline were removed during this period.
Since 1997, average 225-250 mmscfd gas was supplied through the BKB-CHT pipeline. So condensate and Sludge could not accumulate inside the pipeline and were collected at ICS feni and CGS Faujderhat. So almost all the condensate were collected after the second pigging operation.
Abstract
Lubricating oil is called the 'Blood of an engine and machine'. The performance, desired service life, energy-economic efficiency of an engine and machine depends on quality of lubricants. However, adequate codes and standards, regulations, policies, guidelines and enforcement towards the effective quality control and application of lubricants are not up to date in Bangladesh. Proper implementation and monitoring of lubricating oil market are not sufficient to control proper management system. Adulteration of lubricating oil is common scenario in Bangladesh lubricating oil market, which causing damage to the durability of engines. Guidelines for law enforcement and punishments are needed to control adulterations. Used lubricants are harmful for environment and thus, the base oil can be used after re-refining for producing blended lubricants after mixing with additives in appropriate proportion.
Therefore, the current study was carried out to study the recent acts, notification, regulations. codes and standards of lubricants used for lubricating oil business. The study was carried out demand and supply trends of lubricants and environment impacts and proper disposal of used lubricants. The study also aimed to detect the opportunities of entering adulterated and sub- standard lubricating oils in the local market. For this purpose, three different categories of adulterated oil samples were collected and tested to conduct comparisons study. The study also reported the base oil recovery process from waste lubricants and its management system.
Based on literature survey it can be seen that globally the latest engine oil service category API (American Petroleum Institute) SN with resource conservation was established for gasoline engine. However, in Bangladesh API SJ, SG/CC category using as the latest lubricant standard for gasoline engine which is not compatible. On the other hand, API CF combined with ACEA 96 E2 and ACEA 96 E2 are the latest lubricant standards used for diesel engine in Bangladesh although those are obsolete according to API and ACEA standards for new model vehicles. Adulterated lubricating oil test results show that the difference between adulterated and original oil is difficult to tell. To find out adulterated lubricating oil, infrared spectrum test is more accurate than other tests. The engines of vehicles are getting damaged within a short service time for using the adulterated lubricants. The lack of regulatory control has led to unscientific disposal of hazardous waste throughout the country, posing serious risks to public health and the environment.
Abstract
Titas Gas Transmission and Distribution Company Limited (TGTDCL) is a gas marketing company, which purchases gas from Bangladesh Gas Field Company Ltd. (BGFCL) and Sylhet Gas Field Company Limited (SGFCL). This gas is transmitted through its own and Gas Transmission Company Ltd's (GTCL) transmission lines to various bulk customers such as Power and Fertilizer Producing Company and distribution network through various City Gate Station (CGS), Town Border Station (TBS), District Regulating Station (DRS) and Metering Regulating Station (RMS) to industrial, commercial and domestic users. In marketing the gas, the company is now facing a major problem, which is known as system loss.
System loss is that portion of gas purchased, which is not accounted for by sales, transfer and company uses or otherwise accounted for. At present the net system loss is approximately 9%. Area wise in some places like Narayangonj, this figure is near about 50%. The present level of system loss needs some reduction to bring it to an acceptable limit.
The main objective of this study is to reduce the unaccountable gas. Identification of various factors related to system loss is carried out. These factors can be classified into two broad classes as a) technical loss, b) non-technical loss. Technical losses are inevitable and the level of the same depends on physical and operating condition of the customer metering stations. Non-technical losses are the man made loss can be many and varies with different factors. The main part of it is pilferage loss through various illegal means like meter tampering, regulator tempering, by pass or un-metered usage etc.
This study covers the definition, classification, calculation, background and present status of system loss. Some of the special causes of system loss with respect to Bangladesh are also discussed. The action program and extended action program to reduce system loss undertaken by TGTDCL and the future plan or recommendation in this regard are also discussed.
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Abstract
Gas hydrates are two or multi-component crystalline materials formed when free water is available in hydrocarbon gases at reduced temperature. When hydrates are formed in the transmission line of natural gas, they reduce the flow efficiency by reducing the effective diameter of the pipe and also create problems in sensing devices of regulating system.
In winter season, Jalalabad Gas T & D System Ltd. faces a severe gas regulation problem from the formation of gas hydrate at Beani Bazar Gas Regulating Station. When the water vapor and condensate containing gas, coming from Beanibazar gas field, is expanded from 1050 to 550 psig in regulating station, there occurs a lot of temperature reduction and formation of gas hydrate in sensing devices.
In this study, gas hydrate and it phase behaviors are described at various temperature and pressure and some techniques are discussed to overcome the problem of gas hydrate formation. As gas consumption in Beanibazar Gas Regulating Station is very low, the economically viable technique would be de-icing system by alcohol injection. Liquid separation system may apply to improve the effectiveness of the applicable method for prevention of gas hydrate formation problem. Hydrate formation may be reduced, if the set pressure of 1" cut regulating stream in Beanibazar gas station is raised up.
Abstract
Use of compressed natural gas (CNG) in vehicles can help reduce the dependence on imported liquid fuel with significant environmental benefits compared to conventional fuels. Natural gas resource in the country can help satisfy the growing energy demand of the road transport sector. The most important aspects of vehicular applications of CNG are presented in this study. Criteria considered include: gas quality, safety, technology. environment, economics and marketing issues.
The octane rating, heating value, Wobbe index, and other properties of natural gas make it suitable for use in vehicle applications in place of the conventional fuel. Natural gas is also a very safe fuel in terms of its properties and containment safety. Environmental benefits provide an important argument for using natural gas in vehicle applications. Natural gas produces significantly less amount of harmful emissions compared to the conventional liquid fuels.
Different types of refueling systems, conversion of the existing petrol and diesel engines to natural gas systems and also the storage of natural gas have been discussed. The analysis shows an excellent return on the investment for conversion of passenger car and city transit buses. Finally, various marketing issues relating to the use of natural gas in vehicles have been discussed.
