Carbon Price Evaluation in Power Systems for Flaring Mitigation

This work aims to study the effect of greenhouse gases monetization to promote the reduction of flare gas. We propose to design a cogeneration system that uses natural gas as main fuel and flare gas as complementary fuel. A multi-objective nonlinear programming model is presented to determine the optimal design variables of the cogeneration system. This model maximizes the profit and minimizes the carbon dioxide equivalent simultaneously. The key factor to minimize carbon dioxide emissions is the replacement of natural gas with flare gas. Three different cases, which consider different methods to sponsor flare gas, are compared. The first case seeks to maximize the profit with trading carbon emissions. The second case also looks for maximizing the profit, however, carbon dioxide emissions are penalized by carbon taxes. In the third case, a multi-objective optimization approach based on a compromise solution that balances conflicting priorities on multiple objectives is presented. Results show that these two policy schemes work with some limitations to decrease carbon dioxide emissions. On the other hand, when the approach based on a compromise solution is used, the results show, at the same time, environmental and economic benefits

Operational Risk Assessment of Routing Flare Gas to Boiler for Cogeneration

Flaring is a controlled combustion process in which unwanted or excess hydrocarbon gases are released to flare stack for disposal. Flaring has a significant impact on environment, energy and economy. Flare gas integration to cogeneration plant is an alternative to mitigate flaring, benefiting from utilizing waste flare gas as a supplemental fuel to boilers and or gas turbines. Earlier studies have shown the energy and economic sustainability through integration. However, the impact of flare gas quality on cogeneration plants are yet to be identified. This paper studies the effect of flare gas composition and temperature from an ethylene plant to an existing boiler during abnormal flaring. The study proposes a unique framework which identifies the process hazards associated with variation in fuel conditions through process simulation and sensitivity analysis. Then, a systematic approach is used to evaluate the critical operational event occurrences and their impacts through scenario development and quantitative risk assessment, comparing a base case natural gas fuel with a variable flare gas fuel. An important outcome from this study is the identification of critical fuel stream parameters affecting the fired boiler operation through process simulation. Flare stream temperature and presence of higher molecular weight hydrocarbons in flare streams showed minimal effect on boiler condition. However, hydrogen content and rich fuel-air ratio in the boiler can affect the boiler operating conditions. Increase in the hydrogen content in flare to fuel system can increase the risk contour of cogeneration plant, affecting the boiler gas temperature, combustion mixture and flame stability inside the firebox. Quantitative risk analysis through Bayesian Network showed a significant risk escalation. With 12 hours of flare gas frequency per year, there is a substantial rise in the probability of occurrence of boiler gas temperature exceeding design limit and rich fuel mixture in the firebox due to medium and high hydrogen content gas in flare. The influence of these events on flame impingement and tube rupture incidents are noteworthy for high hydrogen content gas. The study also observed reduction in operational time as the hydrogen content in flare gas is increased from low to high. Finally, to operate fire tube steam boiler with flare gas containing higher amount of hydrogen, the existing cogeneration system needs to update its preventive safeguards to reduce the probability of loss control event

Operational Risk Assessment of Routing Flare Gas to Boiler for Cogeneration

Flaring is a controlled combustion process in which unwanted or excess hydrocarbon gases are released to flare stack for disposal. Flaring has a significant impact on environment, energy and economy. Flare gas integration to cogeneration plant is an alternative to mitigate flaring, benefiting from utilizing waste flare gas as a supplemental fuel to boilers and or gas turbines. Earlier studies have shown the energy and economic sustainability through integration. However, the impact of flare gas quality on cogeneration plants are yet to be identified. This paper studies the effect of flare gas composition and temperature from an ethylene plant to an existing boiler during abnormal flaring. The study proposes a unique framework which identifies the process hazards associated with variation in fuel conditions through process simulation and sensitivity analysis. Then, a systematic approach is used to evaluate the critical operational event occurrences and their impacts through scenario development and quantitative risk assessment, comparing a base case natural gas fuel with a variable flare gas fuel. An important outcome from this study is the identification of critical fuel stream parameters affecting the fired boiler operation through process simulation. Flare stream temperature and presence of higher molecular weight hydrocarbons in flare streams showed minimal effect on boiler condition. However, hydrogen content and rich fuel-air ratio in the boiler can affect the boiler operating conditions. Increase in the hydrogen content in flare to fuel system can increase the risk contour of cogeneration plant, affecting the boiler gas temperature, combustion mixture and flame stability inside the firebox. Quantitative risk analysis through Bayesian Network showed a significant risk escalation. With 12 hours of flare gas frequency per year, there is a substantial rise in the probability of occurrence of boiler gas temperature exceeding design limit and rich fuel mixture in the firebox due to medium and high hydrogen content gas in flare. The influence of these events on flame impingement and tube rupture incidents are noteworthy for high hydrogen content gas. The study also observed reduction in operational time as the hydrogen content in flare gas is increased from low to high. Finally, to operate fire tube steam boiler with flare gas containing higher amount of hydrogen, the existing cogeneration system needs to update its preventive safeguards to reduce the probability of loss control event

Investigating The Potential Of Recycling Flared Hydrocarbon Gas In An Industrial Burner

Flare gas is considered a global environmental concern. Flaring contributes to wasting limited material and energy resources, economic loss and greenhouse gas emissions. Utilizing flared gas as fuel feed to industrial cracking furnaces grants advantages in terms of fuel economy and emissions reduction. This work presents the results obtained by ANSYS fluent simulation of a flared hydrocarbon gas utilized in a steam cracking furnace of ethylene process. The work focused on simulating the flue gas side in a steam cracking furnace of the ethylene process when combusting hydrocarbons flare gas. The flared stream assumed to be inlet from both primary and secondary staged fuel nozzles. The simulation results illustrate the detailed temperature profiles along the furnace flue gas side. It also investigates the influence of flare stream composition and Wobbe Index (WI) influence on temperature profil

Operational Risk Assessment of Routing Flare Gas to Boiler for Cogeneration

Flaring is a controlled combustion process in which unwanted or excess hydrocarbon gases are released to flare stack for disposal. Flaring has a significant impact on environment, energy and economy. Flare gas integration to cogeneration plant is an alternative to mitigate flaring, benefiting from utilizing waste flare gas as a supplemental fuel to boilers and or gas turbines. Earlier studies have shown the energy and economic sustainability through integration. However, the impact of flare gas quality on cogeneration plants are yet to be identified. This paper studies the effect of flare gas composition and temperature from an ethylene plant to an existing boiler during abnormal flaring. The study proposes a unique framework which identifies the process hazards associated with variation in fuel conditions through process simulation and sensitivity analysis. Then, a systematic approach is used to evaluate the critical operational event occurrences and their impacts through scenario development and quantitative risk assessment, comparing a base case natural gas fuel with a variable flare gas fuel. An important outcome from this study is the identification of critical fuel stream parameters affecting the fired boiler operation through process simulation. Flare stream temperature and presence of higher molecular weight hydrocarbons in flare streams showed minimal effect on boiler condition. However, hydrogen content and rich fuel-air ratio in the boiler can affect the boiler operating conditions. Increase in the hydrogen content in flare to fuel system can increase the risk contour of cogeneration plant, affecting the boiler gas temperature, combustion mixture and flame stability inside the firebox. Quantitative risk analysis through Bayesian Network showed a significant risk escalation. With 12 hours of flare gas frequency per year, there is a substantial rise in the probability of occurrence of boiler gas temperature exceeding design limit and rich fuel mixture in the firebox due to medium and high hydrogen content gas in flare. The influence of these events on flame impingement and tube rupture incidents are noteworthy for high hydrogen content gas. The study also observed reduction in operational time as the hydrogen content in flare gas is increased from low to high. Finally, to operate fire tube steam boiler with flare gas containing higher amount of hydrogen, the existing cogeneration system needs to update its preventive safeguards to reduce the probability of loss control event

Prospects and Challenges of Green Hydrogen Economy via Multi-Sector Global Symbiosis in Qatar

Low carbon hydrogen can be an excellent source of clean energy, which can combat global climate change and poor air quality. Hydrogen based economy can be a great opportunity for a country like Qatar to decarbonize its multiple sectors including transportation, shipping, global energy markets, and industrial sectors. However, there are still some barriers to the realization of a hydrogen-based economy, which includes large scale hydrogen production cost, infrastructure investments, bulk storage, transport & distribution, safety consideration, and matching supply-demand uncertainties. This paper highlights how the aforementioned challenges can be handled strategically through a multi-sector industrial-urban symbiosis for the hydrogen supply chain implementation. Such symbiosis can enhance the mutual relationship between diverse industries and urban planning by exploring varied scopes of multi-purpose hydrogen usage (i.e., clean energy source as a safer carrier, industrial feedstock and intermittent products, vehicle and shipping fuel, and international energy trading, etc.) both in local and international markets. It enables individual entities and businesses to participate in the physical exchange of materials, by-products, energy, and water, with strategic advantages for all participants. Besides, waste/by-product exchanges, several different kinds of synergies are also possible, such as the sharing of resources and shared facilities. The diversified economic base, regional proximity and the facilitation of rules, strategies and policies may be the key drivers that support the creation of a multi-sector hydrogen supply chain in Qatar. Copyright 2021 Eljack and Kazi.This paper was made possible by NPRP grant no. 10-0205-170347 from the Qatar National Research Fund (a member of Qatar Foundation).Scopu

Techno-economic-environmental optimisation of natural gas supply chain GHG emissions mitigation

While the natural gas (NG) suppliers are under unprecedented pressure to reduce their Greenhouse Gas (GHG) footprint, various emissions reduction technologies have become available. Comparing their GHG mitigation performance and cost effectiveness has thus become increasingly relevant. This research developed a novel and accurate set of tools for GHG emissions estimation and for the cost assessment of emissions mitigation options for NG chains. These were combined in a first time proposed techno-economic and environmental optimisation framework to identify effective and cost efficient GHG emissions reduction options for NG operations in a regional context. The Life Cycle Assessment (LCA) methodology was used to develop inventory models for: offshore production and pre-processing, onshore processing and liquefaction, offshore pipeline transport and offshore Liquefied Natural Gas (LNG) transport. The modular life cycle inventory models developed provide significant advances compared to previously developed models: (i) they capture the impact of different operational practices, technologies and climatic conditions on the emissions, (ii) emission estimations are made for the whole life of facilities, historically and with future projections, using a combination of material balance and engineering calculations; these are configured to the specifics of facilities analysed increasing substantially estimation accuracy, (iii) they enable the assessment of uncertainty for emission estimations. The models were validated using industry data for five NG chains with operations in Norway (2), UK, Australia and Bolivia. A methodology to compare the cost effectiveness of different emissions reduction technologies through Marginal Abatement Cost Curves was also developed for a large range of CO2 and CH4 emissions mitigation options. The cost models developed account for capital and operational expenditure, as well as effects on revenues and tax liabilities. The approach was validated using three of the NG operations studied, located in Norway (2) and Australia. Finally, a mixed-integer multi-objective optimisation model was developed to identify regional opportunities for GHG emissions reduction and cost minimisation in offshore upstream NG value chains through (i) joint power generation and (ii) connection with offshore wind farms. This model was tested for a set of 12 offshore platforms located in the UK Southern North Sea obtaining a 25% reduction of the network’s cumulative CO2 emissions over a ten year future period. This research has proven for the first time that there can be significant difference in GHG performance between neighbouring NG facilities, or within the same facility in consecutive years, found to be up to 54 and 44%, respectively. Moreover, it has shown that the embodied GHG footprint of NG product delivered at different markets will vary significantly even when it is originating from a single source. Thus, generic or regional averages, often employed by LCA practitioners, are not reliable for the industry’s own reporting and for regulatory purposes. In this context, policy makers should consider that imported NG may arrive with embodied GHG footprints varying by more than 50%. Moreover, to effectively identify which NG value chains or regions offer comparatively lower GHG footprints, it is necessary to perform value chain specific LCA studies, using real operational data at a unit process granularity. Regarding emissions reduction options and cost considerations, while integration with renewables and efficiency improvements could perform well for conventional offshore operations, in unconventional onshore operations, targeting well completions, casing and tank vents were shown to have a higher GHG reduction potential. The offshore Norwegian, onshore Norwegian and onshore Australian industry facilities studied were found to have added individual mitigation potential of 2,522, 346 and 13,947 ktonnes CO2 equivalent over investment horizons of 5, 15 and 10 years respectively. All the sites studied were also found to have abatement options with negative implementation costs. The industry and policy makers should, thus, consider that abatement potentials and costs vary significantly by facility depending on its characteristics and context.The implementation of the novel life cycle assessment and cost assessment tools developed in this research and the multi-objective techno-economic and emissions reduction optimisation framework enable for the first time GHG reporting of substantially increased accuracy and unique evidence in support of the efforts industry aims to employ to reduce their effects on the climate.Open Acces

Multi-objective optimization methodology to size cogeneration systems for managing flares from uncertain sources during abnormal process operations

Flaring is common practice in industries to reduce the risk during abnormal situations, to maintain the product quality or to operate safely during process start up and shut down. Due to its large negative impacts on the environment and society, various protocol and steps, i.e., Kyoto protocol, the United Nations Environment Programme, have been created for future mitigation. There is significant amount of heating value lost during flaring events. A cogeneration (COGEN) system can use waste flare streams as fuel to generate heat and power within a process. The objective of this work is to develop an optimization framework for sizing a COGEN unit to manage flares from uncertain sources by minimizing the overall cost and emissions of greenhouse gases. Multi-objective trade-offs between the economic, environmental, and energetic aspects are presented through Pareto fronts for a base case ethylene plant using a stochastic optimization technique based on genetic algorithm. 2015 Elsevier Ltd.This paper was made possible by NPRP grant No. 5-351-2-136 from the Qatar National Research Fund (a member of Qatar Foundation).Scopu

Towards COP27: The Water-Food-Energy Nexus in a Changing Climate in the Middle East and North Africa

Due to its low adaptability to climate change, the MENA region has become a "hot spot". Water scarcity, extreme heat, drought, and crop failure will worsen as the region becomes more urbanized and industrialized. Both water and food scarcity are made worse by civil wars, terrorism, and political and social unrest. It is unclear how climate change will affect the MENA water–food–energy nexus. All of these concerns need to be empirically evaluated and quantified for a full climate change assessment in the region. Policymakers in the MENA region need to be aware of this interconnection between population growth, rapid urbanization, food safety, climate change, and the global goal of lowering greenhouse gas emissions (as planned in COP27). Researchers from a wide range of disciplines have come together in this SI to investigate the connections between water, food, energy, and climate in the region. By assessing the impacts of climate change on hydrological processes, natural disasters, water supply, energy production and demand, and environmental impacts in the region, this SI will aid in implementation of sustainable solutions to these challenges across multiple spatial scales

Energy. A continuing bibliography with indexes, issue 26, 1 April - 30 June 1980

This bibliography lists 1134 reports, articles, and other documents introduced into the NASA Scientific and Technical Information System from April 1, 1980 through June 30, 1980