Liquefied Natural Gas Production Research Articles

Operation optimization of propane pre-cooled mixed refrigerant LNG Process: A novel integration of knowledge-based and constrained Bayesian optimization approaches

Liquefied natural gas (LNG) technology, particularly the propane precooled mixed refrigerant (C3MR) process, has demonstrated efficiency and emerged as a distinctive dual-refrigerant technology widely used in LNG production. However, the liquefaction process is the highest energy-intensive stage within its supply chain as it consumes about 8 % of the LNG energy content. Thus, for the first time, this study proposes systematic knowledge-based and constrained Bayesian optimization approaches to identify the optimal operation of the C3MR process. These approaches optimize both the operational parameters (pressures and flow rates) and the composition of the mixed refrigerant with practical equipment specifications and rigorous constraints. The results show that the specific energy consumption (SEC) is reduced to 0.264 kWh/kgLNG, which is 14.6 %, and 26 % lower than the basic C3MR process (unoptimized case) and typical industrial C3MR processes, respectively. In addition, the optimized SEC in this study is 14.5 % to 38.6 % lower than those reported in the literature. At large-scale LNG production (10,000 tons per day), the reduction in the SEC is translated into an 18 MW decrease in compression power, saving approximately 4.7 million $ per year for each C3MR train. Moreover, the coefficient of performance (COP) of the C3MR process was improved by about 15 %, and the CO2 emissions were reduced by 17 % (7 tons per year) compared to the basic C3MR process, indicating potential advancements in large-scale LNG liquefaction processes.

Assessment of a Full-Electric Floating Liquefied Natural Gas Concept for Harsh Sea State Conditions at Remote Ultra-Deepwater Locations

_ This work describes an offshore gas monetization solution for harsh environmental conditions at ultra-deepwater and remote locations, as an alternative to conventional onshore plants associated with long subsea pipelines for Greenfield projects. Although gas-to-liquids and marine compressed natural gas are initially evaluated, associated gas is supposed to be exported from deepwater floating production storage and offloading units to a central floating liquefied natural gas (FLNG) facility for additional treatment, fractionation, and liquefaction, producing liquefied natural gas (LNG) and liquefied petroleum gas (LPG) for further tandem offloading. To demonstrate the technical feasibility of the proposed FLNG, its key technologies are reviewed, including liquefaction process selection, cargo containment system, station-keeping, offloading, and power generation. A full-electric FLNG is proposed, replacing conventional feed gas power generation systems with inner hull nuclear power modules, envisaging neutral CO2 emissions and earlier first LNG drop milestone achievement. The FLNG general arrangement is developed, along with its internal cargo tanks layout, for preliminary LNG and LPG production rundown and feed gas throughput. Numerical analyses are carried out to show that static and dynamic tilt criteria can be met, even for harsh sea states. Gas import riser configurations for the challenging ultra-deepwater location are outlined, after appropriate FLNG station-keeping analyses, in addition to a feasibility assessment of seawater intake risers, aiming for an overall gas plant efficiency increase. Keywords FLNG; FPSO; LNG/LPG; associated gas; design (general)

Co-benefits of the liquid hydrogen economy and LNG economy: Advances in LNG integrating LH2 production processes

Against the global energy transition towards decarbonization and zero-carbon targets, hydrogen (H2) has emerged as a promising medium for energy storage and transportation in large-scale systems. Simultaneously, liquefied natural gas (LNG), serves as a transitional resource in moving towards cleaner energy sources. Consequently, the integration of LNG into liquid hydrogen (LH2) has garnered significant attention in recent years. This paper comprehensively reviews current research on LH2 production processes by integrating the energy mass of LNG. These processes, which include pre-cooling H2 utilizing the cold energy released from LNG regasification, producing blue H2 from natural gas (NG) derived from LNG regasification, synergistic liquefaction of NG and H2, and simultaneous production of LNG and LH2 from industrial by-products, can markedly increase the thermodynamic efficiency. Furthermore, this study explores potential future developments that could benefit both aspects of the LH2-LNG economy, thereby expanding the scope of related research. The integration of LNG into the LH2 production process through an energy mass approach, aimed at creating a mutually beneficial LH2-LNG economy, is an effective strategy for fostering energy transition. Finally, a brief discussion is presented on the constraints and challenges that may affect the future growth of the global LH2-LNG economy.

Emissions reduction in LNG production facilities through emerging post-combustion carbon capture and storage technologies

The liquefied natural gas (LNG) sector relies extensively on gas turbines for on-site power generation and to drive refrigeration compressors. They provide an efficient and reliable energy source for LNG operations in remote locations. With upcoming changes to the Safeguard Mechanism in Australia, there is an increased focus on Scope 1 emissions, so management and targeted reduction are a priority to reduce liabilities. Despite technology advancements, gas turbines remain one of the largest sources of carbon dioxide (CO2) emissions in LNG production facilities. Also, in Australia, many facilities are not grid-connected, meaning that displacement of Scope 1 emissions through renewable electricity sourcing is a challenge. To develop deeper cuts in Scope 1 emissions, one solution is to deploy post-combustion carbon capture and storage (CCS) on existing gas turbines, with the potential to reduce associated emissions by over 90%. Globally, a number of LNG facilities are already deploying CCS to permanently store reservoir CO2 from the LNG processing trains. Several Australian LNG facilities are located in close proximity to potential CO2 storage reservoirs, meaning that a coordinated approach to both reservoir and post-combustion CO2 should be considered when sizing pipelines, shipping systems and storage wells to optimise and leverage the required investment. This paper outlines the technological, economic and policy aspects of integrating both reservoir post-combustion CCS on LNG facilities, including barriers and opportunities for deployment. It will discuss new developments and enablers for CCS to be more widely deployed at LNG production sites.

Strategic CO2 management in the energy and petroleum sector for the production of low-carbon LNG: A Qatar Case Study

The imperative to mitigate industrial CO2 emissions amidst global climate change has led to the development of innovative strategies that align economic growth with environmental sustainability. This study introduces a comprehensive CO2 allocation and utilisation framework, designed to reduce the environmental impact on the production of Liquefied Natural Gas (LNG). Demploying a multi-objective Linear Programming (LP) approach, the study introduces a system that dynamically allocates CO2 from a major source to several sinks, each with unique characteristics and requirements. Focusing on the State of Qatar, a major player in the global LNG market, advanced simulation tools, such as Aspen HYSYS and QASR Simulator are utilised to define the parameters of these sinks, ensuring precise and efficient CO2 allocation. An integral component of the model is the incorporation of a carbon tax, considered for both the source and the sinks. The results demonstrate that the profit maximisation objective generated a $23.6 billion annual profit, although with high emissions of 23.37 Mt/year. In contrast, the emission minimisation objective curbed emissions to 19.01 Mt/year at a profit of $1.4 billion. The multi-objective approach garnered $18.6 billion annually with emissions at 22.37 Mt/year. The CO2/LNG metric was used to gauge LNG's environmental footprint. Objective 1 yielded a ratio of 0.3033, while objective 2 achieved the best score at 0.2463. The multi-objective approach balanced both, with a ratio of 0.2905. These findings illuminate the feasibility of optimising industrial practices for producing low-carbon LNG through deliberate CO2 allocation and within a circular economy framework.

LNG as a bridge fuel in the transition to renewable energy: A global perspective

The global energy landscape stands at the precipice of transformation, with a growing consensus on the imperative to shift towards sustainable and renewable sources. Amidst this transition, Liquefied Natural Gas (LNG) emerges as a pivotal bridge fuel, strategically positioned to facilitate the journey towards renewable energy. This review encapsulates the essence of the comprehensive review, delving into the global perspective on LNG's role as a bridge fuel in the renewable energy transition. The narrative unfolds with a contextualization of the pressing need for a renewable energy transition, acknowledging the escalating environmental concerns and the imperative to reduce carbon footprints. It then seamlessly transitions to the concept of LNG as a bridge fuel, elucidating its capacity to serve as a cleaner alternative to traditional fossil fuels and its role in mitigating the challenges associated with intermittent renewable energy sources. Examining LNG's significance on a global scale, the review navigates through key aspects. It scrutinizes the environmental considerations and carbon reduction goals that position LNG as a pragmatic choice in the decarbonization journey. The analysis extends to policy factors influencing LNG demand, unraveling the intricate tapestry of governmental initiatives supporting its adoption and the dynamic interplay with renewable energy policies. Economic drivers take center stage in the exploration of LNG's role as a bridge fuel. The review investigates the cost competitiveness, market dynamics, and the industrial demand propelling its consumption. The comprehensive examination encompasses the expansion of global LNG production capacity, featuring key exporting nations and the technological innovations transforming LNG production processes. Regional dynamics further enrich the narrative, providing insights into LNG's impact on major economies across Asia-Pacific, Europe, and North America. The review culminates in a nuanced exploration of the geopolitical implications surrounding LNG trade, emphasizing its role in geopolitical events, trade agreements, and potential risks for stakeholders. In essence, this review serves as a guide to stakeholders, policymakers, and industry players navigating the complex interplay between LNG and renewable energy in the global quest for a sustainable energy future.

Environmental implications of LNG usage: A comparative review of policies in the USA and Africa

This study presents a comparative review of the environmental implications of Liquefied Natural Gas (LNG) usage in the United States (USA) and Africa, examining the policies that govern LNG-related environmental concerns in these regions. Recognizing the global significance of LNG as a pivotal energy source, the analysis explores the distinct policy landscapes shaping its utilization in two diverse contexts. In the USA, where LNG has emerged as a key component of the energy mix, the study scrutinizes federal and state-level environmental policies. This includes regulations governing the extraction, production, and transportation of LNG, with a focus on mitigating emissions, preserving air and water quality, and ensuring ecological sustainability. The review also encompasses the regulatory frameworks promoting the integration of LNG into the broader strategy for reducing carbon footprints in the country. In contrast, the study delves into the nuanced environmental policies across multiple African nations where LNG is increasingly gaining prominence. Africa, with its unique environmental challenges and diverse regulatory approaches, presents a dynamic landscape for LNG utilization. The analysis explores how environmental policies address the specific needs and challenges of African nations, emphasizing sustainable practices, biodiversity conservation, and community welfare. By undertaking this comparative review, the study aims to highlight commonalities and disparities in the environmental policies governing LNG usage in the USA and Africa. Understanding these variations can contribute to the development of informed and context-specific approaches to LNG-related environmental challenges. Additionally, the study seeks to identify areas for potential collaboration and knowledge exchange, fostering a global dialogue on sustainable LNG practices. Ultimately, the findings aim to inform policymakers, industry stakeholders, and environmental advocates, promoting responsible LNG usage that aligns with both regional and global environmental goals.

Technological innovations in the LNG sector: A review: Assessing recent advancements and their impact on LNG production, transportation and usage

This paper thoroughly explores the recent technological innovations in the Liquefied Natural Gas (LNG) sector, examining their impact on production, transportation, storage, and usage. The study delves into the evolution of the global LNG market, emphasizing the critical role of technological advancements in shaping the industry's future. The aim is to analyze these innovations, assess their environmental and economic impacts, and explore the influence of geopolitical and market dynamics. By employing a comprehensive literature review, the paper utilizes a multi-criteria decision support framework to select relevant technological innovations and assess their impacts. This methodology integrates environmental, social, policy, and economic dimensions, offering a holistic view of the LNG sector's technological landscape. The findings reveal significant advancements in LNG production technologies, such as green ammonia and biogas, enhancing sustainability and efficiency. Innovations in LNG transportation, including optimized carrier fleets and storage systems, have revolutionized the industry, improving economic viability and safety. The emergence of Floating LNG (FLNG) technologies marks a pivotal development, unlocking new gas monetization possibilities. The study also highlights the environmental benefits of these innovations, including reduced greenhouse gas emissions and their synergy with renewable energy systems. The paper concludes that while technological advancements offer substantial benefits, they also present challenges, including high investment costs and regulatory complexities. It recommends continued innovation, strategic collaborations, and supportive regulatory frameworks to fully exploit the potential of LNG technologies. As the global energy landscape evolves, the LNG sector is poised to play a crucial role in the transition to a more sustainable and efficient energy future.

A comprehensive review of Liquefied Natural Gas (LNG) market dynamics: Analyzing the current trends, challenges, and opportunities in the global LNG market

This scholarly paper comprehensively analyses the global Liquefied Natural Gas (LNG) market, delving into its multifaceted dynamics and future prospects. The study's background establishes the increasing global importance of LNG, driven by its role in the contemporary energy mix and the evolving landscape of energy production and consumption. The paper aims to dissect current trends, challenges, and opportunities in the LNG market, focusing on its historical evolution, technological advancements, environmental sustainability, economic factors, and geopolitical influences. The paper synthesizes peer-reviewed literature through a meticulous methodology to ensure a broad and in-depth coverage of the subject. The scope encompasses a detailed exploration of the historical milestones of the LNG industry, its role in the energy mix, the impact of technological innovations, and the interplay of environmental, economic, and regulatory factors. The study also scrutinizes the influence of geopolitical dynamics on the global LNG trade. The main findings reveal that technological advancements have significantly reshaped LNG production and distribution, enhancing efficiency and sustainability. Environmental considerations emerge as pivotal in the industry's evolution, with a clear need to balance economic growth with ecological preservation. The economic analysis underscores market volatility influenced by global trade dynamics and geopolitical shifts, highlighting the sector's sensitivity to international events. The paper recommends a strategic focus on innovation, sustainability, and geopolitical engagement to foster the LNG industry's growth. It emphasizes the necessity for adaptive regulatory frameworks and investment in renewable energy infrastructure to support LNG's expanding role in the global energy landscape.

МЕТОДЫ ФИНАНСИРОВАНИЯ СТРОИТЕЛЬСТВА МАЛОТОННАЖНОГО ПРОИЗВОДСТВА СЖИЖЕННОГО ПРИРОДНОГО ГАЗА. СРАВНИТЕЛЬНЫЙ АНАЛИЗ ПРОЕКТНОГО И КОРПОРАТИВНОГО ФИНАНСИРОВАНИЯ

Currently, there is a need to finance the construction of small-scale LNG production for the strategically important direction of gasification of the country, the development of the domestic economy by increasing the efficiency of households, the opportunity to diversify natural gas supplies, localize and develop the technological industry for the construction of liquefied natural gas (LNG) complexes. In a scientific study, using the example of the construction of small-scale LNG, an assessment was made of existing mechanisms and financing tools in Russian practice, problems and risks of the industry were identified, methods and instruments of financing, investment models taking into account budget financing, conditions for attracting and directions for using financing methods at the present stage, A comparative analysis of the most popular types of financing, project and corporate, is considered.

Современное состояние глобального рынка сжиженного природного газа и перспективы реализации российских арктических СПГ-проектов

Transitioning from coal to natural gas and renewable energy sources has become a global trend over the past decade. Despite efforts made by the EU, USA, Japan, and several other nations to replace fossil fuels with alternative sources, significant success in this domain remains elusive, with hydrocarbons continuing to dominate the energy landscape. Notably, the share of liquefied natural gas (LNG), once perceived as a weak alternative to pipeline gas, constituted 56 % of the global gas exports by the end of 2022, with the number of consumer countries reaching 47. This study aims to assess the potential capabilities of key LNG suppliers in increasing production and export volumes to meet the growing demand in the global LNG market. A primary focus is placed on evaluating the capabilities and plans of Russian companies to execute large-scale LNG projects. The research employs methods of systems and statistical analysis, along with economic forecasting. The article discusses the key trends in the global LNG market's development and identifies the factors exerting the most significant impact on its trajectory. An analysis of the current long-term program supporting LNG production in Russia is conducted, highlighting the key support measures available to domestic companies. The practical significance of this study lies in identifying countries poised to increase their production volumes and enter the LNG production and export arena within six to seven years. The research pinpoints key large-scale domestic LNG projects set to make the Russian LNG share in the world market grow from 8 % to 15–17 %. Subsequent steps of this research will involve assessing the prospects for selling Russian and American LNG in the Asia-Pacific (APAC) market.

Optimisation of liquefied natural gas production: genetic algorithm and custom-developed method

This study comprehensively analyses various optimisation techniques applied to Liquefied Natural Gas (LNG) production. Two datasets were used to assess the performance of these techniques, with a focus on improving LNG output. The results revealed that the genetic algorithm exhibited the highest average percentage improvement in the first dataset, achieving a 12% optimisation, followed closely by a custom-developed optimisation method at 11%. Bayesian optimisation showed an average of 4%, while gradient descent demonstrated the lowest optimisation with -2%. Notably, the second dataset displayed even more significant improvements, with the custom optimisation algorithm leading at an average of 32%, surpassing the genetic optimization method's 30%. This study underscores the efficacy of the custom algorithm and its potential for enhancing LNG production, positioning it as a promising alternative to traditional optimisation approaches.

Simulation of boil-off gas recovery and fuel gas optimization for increasing liquefied natural gas production

In a natural gas liquefaction plant, boil-off gas (BOG) is generated in both liquefaction and loading processes. During the holding mode (no loading operation), the fuel gas supply, including the BOG generated in the liquefaction process, is less than the fuel gas demand. Therefore, make-up gas is added to the fuel gas system. BOG recovery systems are designed to absorb the maximum amount of BOG during liquefied natural gas (LNG) loading to ships (loading mode). Additional BOG is generated during the loading process (loading mode). At this stage, the fuel gas supply is higher than the demand. To avoid fuel gas flaring, BOG from the liquefaction process is reduced by cooling the LNG from the main heat exchanger (MHE) to a lower temperature, which consequently reduces LNG production by more than 1%. This study aimed to optimize liquefaction, storage, loading, fuel gas and BOG recovery processes to increase LNG production. In this study, a natural gas liquefaction plant producing 8 mtpa (million tonnes/ year), where LNG production was limited by the capacity of the BOG recovery system and fuel gas demand, was modelled using UniSim software. In the model, the optimization of BOG recovery during the holding mode increased LNG production by 46,850 tonnes/ year. The volumetric flow rate of BOG generated during LNG loading was reduced by decreasing the temperature of the ship’s cargo tanks, decreasing the loading pumps’ discharge pressure, reducing the discharge pressure of the ship’s compressors, and reducing the loading rate. This study shows that BOG generated during loading can be significantly reduced by around 50% from the initial rate, which increases LNG production by around 36,576 tonnes/ year. In total, the potential production increase from BOG recovery and fuel gas optimization was around 90,260 tonnes/ year or equivalent to 1.4 cargo of LNG per year.

Process analysis and optimization of high-N2 natural gas liquefaction

The demand for natural gas (NG) is increasing rapidly due to the world energy crisis. Liquefied Natural Gas (LNG) technology is one of the most flexible and reliable supply solutions, which has already been a major research hotpot in energy use. However, NG with high-N2 content lowers the gas calorific value and value of the gas and increases the energy consumption for production and transport. To address this issue, this study established nitrogen removal from the NG process using a single-column cryogenic distillation process based on Aspen HYSYS® in this study. An expanding refrigeration process using N2-CH4 was selected to provide the required cold energy for this plant, and the process power consumption and LNG specific power consumption was used as evaluation indicators. Results from sensitivity analysis showed that by the increase of natural gas feed temperature T1, the distillation column operation pressure Pc, and refrigerant high pressure P3, the LNG specific power consumption also demonstrated an increasing trend. The variables of natural gas inlet pressure P1, the outlet temperature of natural gas from pre-cooler T2, the ratio of return RR, the methane content ZCH4, the temperature of refrigerant after pre-cooler T4 and refrigerant low pressure P5 had a negative impact on the LNG specific power consumption. After conducting an optimization algorithm, the minimum LNG specific power consumption was determined to be 56.17 kJ/mol. Exergy analysis demonstrated that the total exergy destruction was 2076.13 kW. The compressor and expander components accounted for 31.57% and 26.29% of the total exergy losses respectively. This research provides valuable insights into optimizing LNG production processes by mitigating the impact of high nitrogen content, and it contributes to the advancement of LNG technology and energy efficiency in the industry.

Consideration of liquefied natural gas as an alternative source of gas supply to Ukraine

The object of research is the energy sector of Ukraine, specifically the gas supply system of the national economy. One of the most problematic places is the dependence of the Ukrainian economy on the import of natural gas (NG). Ukraine is rich in various natural resources, in particular, in natural and associated gas. However, own wells for NG extraction are not enough for gas supply to industrial enterprises and the population. Therefore, part of the necessary gas is imported. In the course of the study, methods of alternative supplies were analyzed, namely, liquefied natural gas (LNG), options for its supply with subsequent regasification were analyzed. The global market for liquefied natural gas (LNG) was studied and it was shown that the production and consumption of LNG is constantly increasing. Since Ukraine is part of Europe, and the main suppliers of LNG for European countries are the USA and Norway, one of the options for gas supply for Ukraine considered the supply of LNG to the territory of Poland by sea transport, its regasification and subsequent transportation to consumers through existing pipelines. The second option is the supply of LNG to the Ukrainian coast of the Black Sea. To do this, it is necessary to study prospective transportation routes, build logistics and terminals for receiving and regasifying LNG. Since the depth of the channels from the Mediterranean to the Black Sea is small, the option of supplying natural gas from Central Asia by pipeline to the Black Sea coast of Georgia, its liquefaction, transportation by sea and regasification is proposed. This option requires significant capital expenditures for the construction of a natural gas liquefaction plant on the territory of Georgia and a regasification complex on the Ukrainian coast or a floating terminal. In the course of the work, LNG quality criteria used in the world were studied, and it was noted that for the purchase and use of LNG in Ukraine, it is necessary to develop own standards for controlling its composition. Because the technology of providing the consumer with natural gas using LNG is more flexible than pipeline transport. Its implementation will make it possible to provide Ukraine with natural gas in the required quantities and, if necessary, to promptly change the volume of deliveries.

Liquid hydrogen storage and regasification process integrated with LNG, NGL, and liquid helium production

Hydrogen (H2) is a clean energy carrier and has recently gained significant attention. Efforts are being made to promote liquid hydrogen (LH2) owing to its long-time storage, transportation, and high-purity end-use requirements. LH2 storage and regasification is an essential step in the H2 supply chain. This study proposes a novel integrated energy system that produces liquefied natural gas (LNG), natural gas liquids (NGL), and liquid helium (LHe) utilizing the cold energy of LH2. A well-known process simulation software (Aspen Hysys® v11) is employed to simulate the integrated process. The optimal design variables are found through the Aspen Hysys® built-in Mixed optimization technique. The optimal design shows a specific energy consumption of 0.347 kWh/kg with exergy destruction of 43.3 MW. The required volume of the spherical tank for LH2 storage is 6.3 m3. The results of the lifecycle cost analysis show that the Levelized cost of producing LNG, NGL, and LHe is 0.50 USD/kg, 0.56 USD/kg, and 98.0 USD/kg, respectively. The conclusion of this study suggests that the proposed process can improve the overall H2 supply chain by effectively utilizing LH2 for LNG, NGL, and LHe production.

Energy Demand and the Potential Role of Imported Liquefied Natural Gas (LNG) in Bangladesh

ABSTRACT: The rapid economic progress of Bangladesh is associated with a swiftly rising demand and energy consumption. Future economic growth will undoubtedly require a proportionate increase in energy availability within affordable prices. Bangladesh is inherently energy-scarce and heavily dependent on imported energy, primarily fossil fuels. Several approaches and strategies were attempted over time to mitigate the energy shortage. Some of them were reasonably successful, while others failed. In this study, we first examine the historical developments of the energy sector in Bangladesh since its independence and then use three approaches – triple exponential smoothing, vector autoregression, and the Cochrane-Orcutt AR(1) process to forecast the energy demand. Data for this study were taken from various sources, including British Petroleum, International Gas Union, International Energy Agency, Bangladesh Bureau of Statistics, World Bank, Petrobangla, and Energy Information Agency of the United States. As expected, each model predicts an exponential growth of energy demand in Bangladesh. We then explored the possibilities of mitigating such projected energy demand. Various studies show that Bangladesh has some potential for producing energy from renewable sources, i.e., solar, hydro, wind, wave, and others. However, such possibilities are limited, and many are still in their infancy. Although an increase in renewable energy is desirable from an environmental perspective, it alone will not meet Bangladesh's growing energy demand. At least in the short term, Bangladesh must rely on imported fossil energy. Among the fossil energy sources, LNG is by far the cleanest. With the development of technology, liquefaction, transportation, and regasification, LNG production, transportation, and use are becoming less expensive. Progressively more natural gas-producing countries are joining LNG production and export, contributing to the market's competitiveness. Though historically tied to the oil market, LNG markets are becoming more and more independent because of the increasing number of participants from both the demand and supply sides. Given that both its global price and negative impact on the environment are relatively lower than other fossil fuels, imported LNG should be the fuel of choice for Bangladesh. Government policies should focus on both importing LNG and expanding renewable energy resources.

MODERNIZATION OF THE NATURAL GAS LIQUEFACTION CYCLE AT GAS DISTRIBUTION STATIONS

The possibility of developing the liquefied natural gas (LNG) market in the Russian Federation can be realized by increasing the projects of low-tonnage LNG production. The development of LNG production projects at gas distribution stations should be a priority, since in this case it is possible to implement various production schemes: expander, throttle or cycle with a vortex pipe. To assess the efficiency of the use of low-tonnage LNG production at gas distribution stations (GDS), the dynamics of changes in maximum and minimum pressure values in the main gas pipeline, as well as the distribution of GDS by seasonal change in pressure drop and throughput are presented. To assess the operability and applicability of the work, a design model of the natural gas liquefaction throttle cycle was built and numerical modeling of its operation was carried out at seasonal fluctuations in pressures and GDS costs, which showed a strong dependence on these fluctuations and a low degree of natural gas liquefaction. In order to further modernize the liquefaction cycles of natural gas, modeling was carried out according to the turbo expander cycle, which also showed a dependence on seasonality, but a higher degree of liquefaction of natural gas, which during modeling reached more than 8%. The final stage was the construction of a design model of the combined technology — throttling and turbo expander cycles, as well as numerical modeling, which showed the possibility of increasing the liquefaction of natural gas at GDS to 19%, but the impact of seasonal fluctuations also remains significant. Summing up, it can be said that the work has worked out options for the transition from the throttle cycle to the throttle-expander and turbo-expander, as a result of which it was concluded that the operation of each cycle is effective, due to which it is possible to expand the LNG production network at the GDS at various input pressures, flow rates and the required degree of liquefaction of natural gas.

Tiny trains – new hope? Or the same issues in a smaller box?

The report card from Australia’s decade-long liquefied natural gas (LNG) construction boom makes for sobering reading. From 2009 to 2019, there were 15 new trains turned on, which lifted LNG production to a record 77 million tonnes in 2019. They are clearly big plants, with big production trains and with big capital expenditure to match. But the plants seemed to come with big problems. Not just in construction, but sometimes in production too. Now times have changed. Advances in technology, together with new market dynamics, have sparked new interest in small trains. A number of projects in the USA are now being proposed with multiple smaller units rather than the big trains that have dominated the last decade. For Australian owners and operators a new questions emerges. Do these ‘tiny trains’ represent a new step on the journey to a more efficient and effective commercialisation of region gas? Or will the new trains deliver the same issues, just in a smaller box? This paper provides: lessons learned from the Australian LNG boom between 2009 and 2019, an overview of the new ‘small train’ technologies including real world examples, a discussion of the risks and benefits of this approach, a case study from US owners/operators and discussion of where this approach might suit the needs of Australian LNG. The paper will appeal to oil and gas producers, major contractors and service providers.

Improving energy efficiency during LNG plant turndown operation

The Karratha Gas Plant (KGP) is one of the most advanced, integrated gas production systems in the world, producing liquefied natural gas (LNG), domestic gas, condensate and liquefied petroleum gas (LPG). The KGP has an export capacity of 16.9 Mtpa, with five LNG processing trains, two domestic gas trains, six condensate stabilisation units and three LPG fractionation units. Following more than 35 years of production from North West Shelf (NWS) fields, the KGP has entered an operating phase where it is more frequently operating in turndown operation. The energy intensity of an LNG production train is often the lowest at maximum production capacity. Should the LNG train become feed gas constrained for extended periods of time, energy intensity increases due to baseload energy required to run the process equipment and physical constraints on equipment turndown. A structured approach has been applied at the KGP to realise improvements in energy intensity in turndown operation through building a strategy, identifying focus areas, energy accounting and benchmarking, data presentation, review and improve cycles, and leadership. The strategy and focus areas are linked to specific actions across different operating timeframes. Review and improve cycles, and leadership help to cultivate an energy efficiency-focused culture and continuous identification of opportunities and barriers to the strategy. Central to all pillars of the strategy is energy accounting, benchmarking and data visualisation which provide value, performance and materiality insights. The benefits can often be realised with limited financial and resource investment, can provide high value return on both emissions performance and reduced fuel consumption.