Notably, the Nigeria Liquefied Natural Gas (NLNG) project is the pioneer Liquefied Natural Gas (LNG) plant in Nigeria, aimed at both the diversification of the petroleum industry and utilization of the vastly flared n...Notably, the Nigeria Liquefied Natural Gas (NLNG) project is the pioneer Liquefied Natural Gas (LNG) plant in Nigeria, aimed at both the diversification of the petroleum industry and utilization of the vastly flared natural gas resources of the nation. However, large scale energy projects have been known to generate both positive and/or negative impacts. Environmental Management Plans (EMP) have often been the compendium of information on approved mitigations, which normally include activities that could maximize the benefits of the host communities, and it’s not unusual for the Community Development and Corporate Social Responsibility (CDCSR) department of such an organization to be saddled with these contributions. But the activities of Nigeria LNG Ltd.’s CSR department have often been the source of criticism, as well as aspiration for improvement by host communities and other stake holders. This article thus aims to present a comprehensive compendium of NLNG’s CDCSR activities, up to the year 2010, and also highlight the level of satisfaction of the immediate and distant host communities against the level of performance of other donors in the area. Also the arrays of negative socio-economic consequences of the Nigeria LNG Ltd.’s activities were identified based on community perception. The results generally showed that comparatively, NLNG project has made more innovative positive socio-economic and health contributions to its areas of operation than the three tiers of government and other donors (including SPDC and Mobil Producing Nigeria). Surprisingly, agitations against Nigeria LNG Ltd.’s activities have not overshadowed its community development provisions, which have been of major assistance in several communities. There is however a dire need to review several aspects of Nigeria LNG Ltd.’s CDCSR activities, especially in the fulfilment of documented promises, as well as in project conception and community participation, for better completed projects acceptance by indigenous host communities. Conflict management strategies also need to be improved, while the dissatisfaction over benefits in New Finima needs to be urgently addressed.展开更多
Two schemes（scheme Ⅰ and scheme Ⅱ）for designing a district cooling system（DCS）utilizing cold energy of liquefied natural gas（LNG）are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice i...Two schemes（scheme Ⅰ and scheme Ⅱ）for designing a district cooling system（DCS）utilizing cold energy of liquefied natural gas（LNG）are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice is transported to the central cooling plant of the DCS.In scheme Ⅱ,return water from the DCS is directly chilled by LNG cold energy,and the chilled water is then sent back to the central plant.The heat transportation loss is the main negative impact in the DCS and is emphatically analyzed when evaluating the efficiency of each scheme.The results show that the DCS utilizing LNG cold energy is feasible and valuable.The cooling supply distance of scheme Ⅱ is limited within 13 km while scheme Ⅰ has no distance limit.When the distance is between 6 and 13 km,scheme Ⅱ is more practical and effective.Contrarily,scheme Ⅰ has a better economic performance when the distance is shorter than 6 km or longer than 13 km.展开更多
A novel process to recovery natural gas liquids from oil field associated gas with liquefied natural gas (LNG)cryogenic energy utilization is proposed.Compared to the current electric refrigeration process,the propose...A novel process to recovery natural gas liquids from oil field associated gas with liquefied natural gas (LNG)cryogenic energy utilization is proposed.Compared to the current electric refrigeration process,the proposed process uses the cryogenic energy of LNG and saves 62.6%of electricity.The proposed process recovers ethane, liquid petroleum gas(propane and butane)and heavier hydrocarbons,with total recovery rate of natural gas liquids up to 96.8%.In this paper,exergy analysis and the energy utilization diagram method(EUD)are used to assess the new process and identify the key operation units with large exergy loss.The results show that exergy efficiency of the new process is 44.3%.Compared to the electric refrigeration process,exergy efficiency of the new process is improved by 16%.The proposed process has been applied and implemented in a conceptual design scheme of the cryogenic energy utilization for a 300 million tons/yr LNG receiving terminal in a northern Chinese harbor.展开更多
A large portion of world＇s natural gas reserves are ＂stranded＂ resources, the drive to monetize these resources leads to the development of gas-to-liquids （GTL） and liquefied natural gas （LNG） technologies. LNG...A large portion of world＇s natural gas reserves are ＂stranded＂ resources, the drive to monetize these resources leads to the development of gas-to-liquids （GTL） and liquefied natural gas （LNG） technologies. LNG has the advantage of having been developed for the past 40 years and having an excellent safety record. GTL on the other hand is another option with substantial benefits, but its development stage and commercial viability are far behind LNG. This paper presents a techno-economic comparison of GTL with LNG, including technical development, plant efficiency, market potential for the products, and capital cost for the infrastructure. The aim is to give an overall view on both LNG and GTL and provide a perspective on the profitability of these two technologies.展开更多
Liquefied natural gas(LNG)is regarded as one of the cleanest fossil fuel and has experienced significant developments in recent years.The liquefaction process of natural gas is energy-intensive,while the regasificatio...Liquefied natural gas(LNG)is regarded as one of the cleanest fossil fuel and has experienced significant developments in recent years.The liquefaction process of natural gas is energy-intensive,while the regasification of LNG gives out a huge amount of waste energy since plenty of high grade cold energy(-160℃)from LNG is released to sea water directly in most cases,and also sometimes LNG is burned for regasification.On the other hand,liquid air energy storage(LAES)is an emerging energy storage technology for applications such as peak load shifting of power grids,which generates 30%-40%of compression heat(-200℃).Such heat could lead to energy waste if not recovered and used.The recovery of the compression heat is technically feasible but requires additional capital investment,which may not always be economically attractive.Therefore,we propose a power plant for recovering the waste cryogenic energy from LNG regasification and compression heat from the LAES.The challenge for such a power plant is the wide working temperature range between the low-temperature exergy source(-160℃)and heat source(-200℃).Nitrogen and argon are proposed as the working fluids to address the challenge.Thermodynamic analyses are carried out and the results show that the power plant could achieve a thermal efficiency of 27%and 19%and an exergy efficiency of 40%and 28%for nitrogen and argon,respectively.Here,with the nitrogen as working fluid undergoes a complete Brayton Cycle,while the argon based power plant goes through a combined Brayton and Rankine Cycle.Besides,the economic analysis shows that the payback period of this proposed system is only 2.2 years,utilizing the excess heat from a 5 MW/40 MWh LAES system.The findings suggest that the waste energy based power plant could be co-located with the LNG terminal and LAES plant,providing additional power output and reducing energy waste.展开更多
Liquefied natural gas(LNG) is the most economical way of transporting natural gas(NG) over long distances. Liquefaction of NG using vapor compression refrigeration system requires high operating and capital cost. Due ...Liquefied natural gas(LNG) is the most economical way of transporting natural gas(NG) over long distances. Liquefaction of NG using vapor compression refrigeration system requires high operating and capital cost. Due to lack of systematic design methods for multistage refrigeration cycles, conventional approaches to determine optimal cycle are largely trial-and-error. In this paper a novel mixed integer non-linear programming(MINLP)model is introduced to select optimal synthesis of refrigeration systems to reduce both operating and capital costs of an LNG plant. Better conceptual understanding of design improvement is illustrated on composite curve(CC) and exergetic grand composite curve(EGCC) of pinch analysis diagrams. In this method a superstructure representation of complex refrigeration system is developed to select and optimize key decision variables in refrigeration cycles(i.e. partition temperature, compression configuration, refrigeration features, refrigerant flow rate and economic trade-off). Based on this method a program(LNG-Pro) is developed which integrates VBA,Refprop and Excel MINLP Solver to automate the methodology. Design procedure is applied on a sample LNG plant to illustrate advantages of using this method which shows a 3.3% reduction in total shaft work consumption.展开更多
The production and consumption of natural gas in China has been developing rapidly in recent years.It is expected that the annual growth rate of the demand for natural gas will reach 12% in the next 15 years,and the g...The production and consumption of natural gas in China has been developing rapidly in recent years.It is expected that the annual growth rate of the demand for natural gas will reach 12% in the next 15 years,and the gas consumption in the primary energy will increase from 0.3% to 10% or more by 2020.However,since the supply of natural gas cannot satisfy the requirements,China has begun to build liquefied natural gas(LNG)terminals in the coastal regions such as Guangdong and Fujian,and solve this problem by importing LNG from foreign countries.LNG needs to be transported by LNG ships from abroad.With the rapid growth of global gas production,the volume of LNG trade also increases,and the interregional production increased from 0.3% in 1970 to 26.2% in 2004.So,we need LNG ships more than before.This article puts forward the distribution of LNG ships and the speculation of the future of LNG transportation based on the studies on foreign LNG production,the LNG trade,the building of LNG ships,the LNG transportation,the chain model of LNG distribution,etc.展开更多
Shell-and-tube vaporizers are the most commonly used and dominated types of vaporizers in liquefied natural gas （LNG） realm. Due to efficient performance, shell-side flow in this type of vaporizers has received cons...Shell-and-tube vaporizers are the most commonly used and dominated types of vaporizers in liquefied natural gas （LNG） realm. Due to efficient performance, shell-side flow in this type of vaporizers has received considerable attention and has been investigated extensively. However, the detailed flow structure in the shell needs to be determined for reliable and effective design. Therefore, the objective of this study was to clarify the flow structure in shell by particle image velocimetry （PIV）. Experiments were conducted using two types of model; 15% baffle cut having inlet and outlet positions !n the direction of 90° to the cut and 30% baffle cut having inlet and outlet positions in the direction of 180° to the cut. Each test section is 169 mm in inner diameter and 344.6 mm in length. The flow features were characterized in different baffle cuts with regards to the velocity vector field and velocity distribution. The results show that the flow characteristics of 15% baffle cut type vaporizer are comparable to those of 30% baffle cut type vaporizer.展开更多
文摘Notably, the Nigeria Liquefied Natural Gas (NLNG) project is the pioneer Liquefied Natural Gas (LNG) plant in Nigeria, aimed at both the diversification of the petroleum industry and utilization of the vastly flared natural gas resources of the nation. However, large scale energy projects have been known to generate both positive and/or negative impacts. Environmental Management Plans (EMP) have often been the compendium of information on approved mitigations, which normally include activities that could maximize the benefits of the host communities, and it’s not unusual for the Community Development and Corporate Social Responsibility (CDCSR) department of such an organization to be saddled with these contributions. But the activities of Nigeria LNG Ltd.’s CSR department have often been the source of criticism, as well as aspiration for improvement by host communities and other stake holders. This article thus aims to present a comprehensive compendium of NLNG’s CDCSR activities, up to the year 2010, and also highlight the level of satisfaction of the immediate and distant host communities against the level of performance of other donors in the area. Also the arrays of negative socio-economic consequences of the Nigeria LNG Ltd.’s activities were identified based on community perception. The results generally showed that comparatively, NLNG project has made more innovative positive socio-economic and health contributions to its areas of operation than the three tiers of government and other donors (including SPDC and Mobil Producing Nigeria). Surprisingly, agitations against Nigeria LNG Ltd.’s activities have not overshadowed its community development provisions, which have been of major assistance in several communities. There is however a dire need to review several aspects of Nigeria LNG Ltd.’s CDCSR activities, especially in the fulfilment of documented promises, as well as in project conception and community participation, for better completed projects acceptance by indigenous host communities. Conflict management strategies also need to be improved, while the dissatisfaction over benefits in New Finima needs to be urgently addressed.
文摘Two schemes（scheme Ⅰ and scheme Ⅱ）for designing a district cooling system（DCS）utilizing cold energy of liquefied natural gas（LNG）are presented.In scheme Ⅰ,LNG cold energy is used to produce ice,and then ice is transported to the central cooling plant of the DCS.In scheme Ⅱ,return water from the DCS is directly chilled by LNG cold energy,and the chilled water is then sent back to the central plant.The heat transportation loss is the main negative impact in the DCS and is emphatically analyzed when evaluating the efficiency of each scheme.The results show that the DCS utilizing LNG cold energy is feasible and valuable.The cooling supply distance of scheme Ⅱ is limited within 13 km while scheme Ⅰ has no distance limit.When the distance is between 6 and 13 km,scheme Ⅱ is more practical and effective.Contrarily,scheme Ⅰ has a better economic performance when the distance is shorter than 6 km or longer than 13 km.
基金Supported by the National Natural Science Foundation of China(20876056,20536020)the PhD Program Fund from Ministry of Education of China(20100172110016)
文摘A novel process to recovery natural gas liquids from oil field associated gas with liquefied natural gas (LNG)cryogenic energy utilization is proposed.Compared to the current electric refrigeration process,the proposed process uses the cryogenic energy of LNG and saves 62.6%of electricity.The proposed process recovers ethane, liquid petroleum gas(propane and butane)and heavier hydrocarbons,with total recovery rate of natural gas liquids up to 96.8%.In this paper,exergy analysis and the energy utilization diagram method(EUD)are used to assess the new process and identify the key operation units with large exergy loss.The results show that exergy efficiency of the new process is 44.3%.Compared to the electric refrigeration process,exergy efficiency of the new process is improved by 16%.The proposed process has been applied and implemented in a conceptual design scheme of the cryogenic energy utilization for a 300 million tons/yr LNG receiving terminal in a northern Chinese harbor.
文摘A large portion of world＇s natural gas reserves are ＂stranded＂ resources, the drive to monetize these resources leads to the development of gas-to-liquids （GTL） and liquefied natural gas （LNG） technologies. LNG has the advantage of having been developed for the past 40 years and having an excellent safety record. GTL on the other hand is another option with substantial benefits, but its development stage and commercial viability are far behind LNG. This paper presents a techno-economic comparison of GTL with LNG, including technical development, plant efficiency, market potential for the products, and capital cost for the infrastructure. The aim is to give an overall view on both LNG and GTL and provide a perspective on the profitability of these two technologies.
基金partial support of UK EPSRC under grants EP/V012053/1,EP/S032622/1,EP/P004709/1,EP/P003605/1 and EP/N032888/1the British Council under 2020-RLWK12-10478 and 2019-RLWK11-10724。
文摘Liquefied natural gas(LNG)is regarded as one of the cleanest fossil fuel and has experienced significant developments in recent years.The liquefaction process of natural gas is energy-intensive,while the regasification of LNG gives out a huge amount of waste energy since plenty of high grade cold energy(-160℃)from LNG is released to sea water directly in most cases,and also sometimes LNG is burned for regasification.On the other hand,liquid air energy storage(LAES)is an emerging energy storage technology for applications such as peak load shifting of power grids,which generates 30%-40%of compression heat(-200℃).Such heat could lead to energy waste if not recovered and used.The recovery of the compression heat is technically feasible but requires additional capital investment,which may not always be economically attractive.Therefore,we propose a power plant for recovering the waste cryogenic energy from LNG regasification and compression heat from the LAES.The challenge for such a power plant is the wide working temperature range between the low-temperature exergy source(-160℃)and heat source(-200℃).Nitrogen and argon are proposed as the working fluids to address the challenge.Thermodynamic analyses are carried out and the results show that the power plant could achieve a thermal efficiency of 27%and 19%and an exergy efficiency of 40%and 28%for nitrogen and argon,respectively.Here,with the nitrogen as working fluid undergoes a complete Brayton Cycle,while the argon based power plant goes through a combined Brayton and Rankine Cycle.Besides,the economic analysis shows that the payback period of this proposed system is only 2.2 years,utilizing the excess heat from a 5 MW/40 MWh LAES system.The findings suggest that the waste energy based power plant could be co-located with the LNG terminal and LAES plant,providing additional power output and reducing energy waste.
文摘Liquefied natural gas(LNG) is the most economical way of transporting natural gas(NG) over long distances. Liquefaction of NG using vapor compression refrigeration system requires high operating and capital cost. Due to lack of systematic design methods for multistage refrigeration cycles, conventional approaches to determine optimal cycle are largely trial-and-error. In this paper a novel mixed integer non-linear programming(MINLP)model is introduced to select optimal synthesis of refrigeration systems to reduce both operating and capital costs of an LNG plant. Better conceptual understanding of design improvement is illustrated on composite curve(CC) and exergetic grand composite curve(EGCC) of pinch analysis diagrams. In this method a superstructure representation of complex refrigeration system is developed to select and optimize key decision variables in refrigeration cycles(i.e. partition temperature, compression configuration, refrigeration features, refrigerant flow rate and economic trade-off). Based on this method a program(LNG-Pro) is developed which integrates VBA,Refprop and Excel MINLP Solver to automate the methodology. Design procedure is applied on a sample LNG plant to illustrate advantages of using this method which shows a 3.3% reduction in total shaft work consumption.
基金Under the auspices of the National Natural Science Foundation of China(No.40671052)
文摘The production and consumption of natural gas in China has been developing rapidly in recent years.It is expected that the annual growth rate of the demand for natural gas will reach 12% in the next 15 years,and the gas consumption in the primary energy will increase from 0.3% to 10% or more by 2020.However,since the supply of natural gas cannot satisfy the requirements,China has begun to build liquefied natural gas(LNG)terminals in the coastal regions such as Guangdong and Fujian,and solve this problem by importing LNG from foreign countries.LNG needs to be transported by LNG ships from abroad.With the rapid growth of global gas production,the volume of LNG trade also increases,and the interregional production increased from 0.3% in 1970 to 26.2% in 2004.So,we need LNG ships more than before.This article puts forward the distribution of LNG ships and the speculation of the future of LNG transportation based on the studies on foreign LNG production,the LNG trade,the building of LNG ships,the LNG transportation,the chain model of LNG distribution,etc.
基金supported by the National Research Foundation of Korea Grant funded by the Korean Government (NRF-2010-013-D00007)2010 Research Professor Fund of Gyeongsang National University,Korea
文摘Shell-and-tube vaporizers are the most commonly used and dominated types of vaporizers in liquefied natural gas （LNG） realm. Due to efficient performance, shell-side flow in this type of vaporizers has received considerable attention and has been investigated extensively. However, the detailed flow structure in the shell needs to be determined for reliable and effective design. Therefore, the objective of this study was to clarify the flow structure in shell by particle image velocimetry （PIV）. Experiments were conducted using two types of model; 15% baffle cut having inlet and outlet positions !n the direction of 90° to the cut and 30% baffle cut having inlet and outlet positions in the direction of 180° to the cut. Each test section is 169 mm in inner diameter and 344.6 mm in length. The flow features were characterized in different baffle cuts with regards to the velocity vector field and velocity distribution. The results show that the flow characteristics of 15% baffle cut type vaporizer are comparable to those of 30% baffle cut type vaporizer.
