Gas For Electricity Generation Research Articles

Life Cycle Assessment of Solid Recovered Fuel Gasification in the State of Qatar

Gas products from gasified solid recovered fuel (SRF) have been proposed as a replacement for natural gas to produce electricity in future power generation systems. In this work, the life cycle assessment (LCA) of SRF air gasification to energy was conducted using the Recipe2016 model considering five environmental impact categories and four scenarios in Qatar. The current situation of municipal solid waste (MSW) handling in Qatar is landfill with composting. The results show that using SRF gasification can reduce the environmental impact of MSW landfills and reliance on natural gas in electricity generation. Using SRF gasification on the selected five environmental impact categories—climate change, terrestrial acidification, marine ecotoxicity, water depletion and fossil resource depletion—returned significant reductions in environmental degradation. The LCA of the SRF gasification for the main four categories in the four scenarios gave varying results. The introduction of the SRF gasification reduced climate change-causing emissions by 41.3% because of production of renewable electricity. A reduction in water depletion and fossil resource depletion of 100 times were achieved. However, the use of solar technology and SRF gasification to generate electricity reduced the impact of climate change to almost zero emissions. Terrestrial acidification showed little to no change in all three scenarios investigated. This study was compared with the previous work from the literature and showed that on a nominal 10 kg MSW processing basis, 5 kg CO2 equivalent emissions were produced for the landfilling scenarios. While the previous studies reported that 8 kg CO2 produced per 10 kg MSW is processed for the same scenario. The findings indicate that introducing SRF gasification in solid waste management and electricity generation in Qatar has the potential to reduce greenhouse gas (GHG) emission load and related social, economic, political and environmental costs. In addition, the adoption of the SRF gasification in the country will contribute to Qatar’s national vision 2030 by reducing landfills and produce sustainable energy.

Methane Gas Cofiring Effects on Combustion and NO x Emission in 550 MW Tangentially Fired Pulverized-Coal Boiler.

A shift from coal to liquefied natural gas for electricity generation can mitigate CO2 emissions and respond to the intermittent and variable characteristics of renewable energy. With this objective, numerical simulation was performed in this study to determine the optimal position of the methane injector and evaluate the achievable reduction in NOx emissions before applying methane cofiring to an existing 550 MW tangentially fired pulverized-coal boiler (Boryeong Unit 3). The combustion and NOx reduction in the furnace were intensively analyzed based on the methane cofiring rate (up to 40%). The optimal position of the methane injector was found to be inside the oil port based on the spatial distribution of NOx and the stoichiometric ratio along the furnace height. The NOx reduction rate was logarithmically proportional to the methane cofiring rate, and compared to the base case, a 69.8% reduction was achieved at the 40% cofiring rate. In addition, the fraction of unburned char at the boiler outlet was equivalent to that of the existing boiler as the increase in the flow rates of the close-coupled and separated overfire air improved fuel and air mixing. Simultaneously, methane cofiring led to a reduction in the total fuel loss and CO emissions. Finally, this study showed that the recommended optimum cofiring rate was 20% based on the furnace exit gas temperature. Under the 20% methane cofiring condition, the boiler achieved a 57.3% reduction in NOx emissions and a 7.4% improvement in fuel loss.

Investigation of Shale Gas Reserves in The World and A Case Study for Electricity Production from Shale Gas in Turkey

Shale gas reserves, which is globally accepted as unconventional gas resource, scattered around the world and can be used in order to meet the growing energy needs due to limited amounts of conventional resources. Since notable effort has to be put in order to investigate and drill shale gas resources the early decision has to be made carefully, especially considering the economic benefits. Several factors must be considered including the known technically recoverable shale gas amount at the selected region, current technology to drill the shale source and the amount of investment before the extraction of shale gas. In this study, global underground shale gas amount and recent discoveries as well as the potential shale gas areas in Turkey are presented. Benefits of using shale gas for electricity generation and common methods being used during shale gas extraction are studied along with gas and liquid flow mechanisms. At the end, general overview of separation and utilization of shale gas components is schematically presented. In the case study, the potential of electricity generation in the SE Anatolia region in Turkey is estimated with only using methane obtained from the shale gas purification process at the power generation step. According to the estimations, 3337.8 MW electric power may be generated for 50~55 years, at the appropriate gas engine by using 8.5 billion cubic meter shale gas annually.

Comparing Greenhouse Gas Impacts from Domestic Coal and Imported Natural Gas Electricity Generation in China

In 2019, coal power accounted for 65% of China’s electricity and coal accounted for 71% of its 10.2 GTpa CO2 emissions. To meet its pledge of peak carbon by 2030 and carbon neutrality by 2060, China plans to shift away from coal. Fuel switching to natural gas for electrical generation is an interim solution that is in the portfolio of measures for meeting these goals. However, because of variability in emissions from coal and natural gas supply chains, the potential for benefiting from fuel switching also varies. Here, we use a high-resolution basin-to-power plant analysis for estimating methane and CO2 emissions in natural gas and coal supply chains. We illustrate how the variations in supply chains at the level of the sourcing of natural gas and coal from individual production regions can lead to differences in the effectiveness of fuel switching in reducing greenhouse gas emissions. The analyses are applied to four switching scenarios from domestic coal to imported natural gas at representative power plants in China. Life cycle emission factors for the natural gas supply chains evaluated in this study range from 650 to 1000 kg carbon dioxide/MWh of electricity generated and from 2.3 to 13 kg methane/MWh, depending on the allocation choice, power generation technology, and production region. For the coal supply chain, emissions range from 850 to 1100 kg carbon dioxide/MWh and from 0.4 to 4.0 kg methane/MWh, depending on the power generation technology and production region. We show that for these scenarios, in the short term fuel switching can increase radiative forcing by a factor of 3 or decrease it by 70%, depending on the supply chains, generation technology, and, in the case of natural gas, co-product allocation choices in the supply chain. We also quantify consumptive losses of natural gas over long supply chains and show that fuel switching results in differences in radiative forcing that evolve over time due to the influence of methane emissions.

Natural gas – friend or foe of the environment? Evaluating the framing contest over natural gas through a public opinion survey in the Pacific Northwest

ABSTRACT A fierce debate is raging about the role of natural gas in North America’s energy mix. Once viewed as a bridge fuel for renewable energy, it is increasingly being characterized as hindering the energy transition. We explore public opinions about natural gas, its use and export, among residents in Oregon, Washington and British Columbia. While many of our respondents supported the continued use of natural gas in electricity generation and viewed it as relatively environmentally friendly, they did not feel that the benefits of fracking (increasingly the main source of natural gas production) outweigh its risks. Males, political conservatives, those who prioritized the economy over the environment, and those who didn’t subscribe to anthropogenic global warming felt more favorably toward natural gas. Furthermore, those who saw gas as more environmentally friendly were more supportive of gas usage and export, while those with pro-environmental views were less likely to support it.

Toward sustainable electricity generation mix: an econometric analysis of the substitutability of nuclear energy and hydropower for fossil fuels in Canada

ABSTRACT The dominance of fossil fuels in electricity generation fuel mix continues to undermine the importance of electricity as a critical factor for sustainable economic development. As with most economies of the world, the Canadian fuel mix for electricity generation is dominated by fossil fuels. This scenario creates both environmental and resource sustainability challenges. There are questions marks over the potentials of nonfossil energy sources to address these challenges and ensure a more sustainable electricity generation. This study aims to examine the potentials of nuclear energy and hydropower to substitute the fossil fuels of coal and natural gas in electricity generation for Canada. A trans-log production function was estimated with the ridge regression method to obtain the parameter estimates. The empirical findings show that, with the exception of coal input, all energy inputs have positive output elasticities, which indicate that an increase in the energy inputs will increase output in Canada. The results further provide evidence of positive elasticity of substitution between the non-fossil energy sources and the fossil fuels which give credence to the hypothesis that clean energy sources such as nuclear energy and hydropower have the potential to substitute for the fossil fuels of coal and natural gas the electricity generation process for Canada. The estimates show that the smallest substitution occurs between coal and gas, which is an additional evidence that clean energy has higher chances of substituting fossil fuels. Policies that promote the adoption of more renewable and clean energy sources are recommended in the body of the paper.

Environmental performance of high-efficiency natural gas combined cycle plant

ABSTRACT The aim of this paper is to assess the environmental impact of electricity production from one of the best available gas-fired power plants and to compare it with the current mix of electricity and the supply of electricity from a typical gas plant. The scope of the paper includes gas field exploration, natural gas processing, pipeline transportation, and electricity generation as well as construction and decommissioning of the plant. The influence of efficiency of the plant and natural gas supply from different countries on the results is explored within the sensitivity analysis. The findings indicate that the global warming potential is estimated at 388 g CO2 eq./kWh. The natural gas system described offers major improvements in all considered environmental impacts compared to the typical natural gas electricity generation system, ranging from 4.9% for abiotic depletion potential to 82.1% for acidification potential. Increasing the contribution of natural gas in the electricity mix would reduce only eutrophication, human toxicity, freshwater, and marine aqua ecotoxicity potentials. The lower environmental impacts in this paper are due to the different gas composition, relatively high efficiency assumed as well as the proximity of Turkey to Azerbaijan which reduces transport distances. The results of this study would be of benefit to the future energy market, as natural gas is one of the electricity-producing plants promoted in Turkey.

Evaluation of the efficiency of using liquefied natural gas for electricity generation in the energy-isolated Arctic regions of the Republic of Sakha (Yakutia)

Evaluation of the efficiency of using liquefied natural gas for electricity generation in the energy-isolated Arctic regions of the Republic of Sakha (Yakutia)

Sustainable electricity generation: the possibility of substituting fossil fuels for hydropower and solar energy in Italy

ABSTRACT Electricity remains the most important form of end-use energy consumption and an important factor for economic growth and development. However, electricity generation also constitutes a great source of concern for global warming and climate change with threats to sustainable development as fossil fuels dominate electricity generation fuel mix for most economies of the world. This is exactly the case for Italy with fossil fuels dominating electricity generation fuel mix over the last couple of decades. Thus, there is a need to reverse this trend by increasing the shares of renewable energy sources in the fuel mix. This study, therefore, investigates the potentials for renewable energy sources of hydropower and solar energy to substitute the fossil fuels of coal and natural gas in electricity generation for Italy. Adopting the ridge regression procedure to obtain the parameter estimates, the results provide evidence that substitution is possible among all fuels. While both hydropower and solar energy are found to be substitutable for the fossil fuels, solar energy is found to provide more substitutability than hydropower. This implies that Italy has the potential to gradually move away from the carbon-intensive fossil fuels of coal and gas to more environmental-friendly solar energy and hydropower in the process of generating electricity.

Emerging Trends in Resource-Rich Sub-Saharan Africa and a Spotlight on the Nigerian Transitional Energy Market

Emerging Trends in Resource-Rich Sub-Saharan Africa and a Spotlight on the Nigerian Transitional Energy Market

A bridge too far? The role of natural gas electricity generation in US climate policy

Natural gas has been promoted as a ‘‘bridge’’ fuel toward a low-carbon future by offering near-term emissions reductions at lower cost. Existing literature is inconclusive on the short-term emissions benefits of more abundant natural gas. The long-lived nature of natural gas infrastructure also threatens to lock in emissions levels well above longer-term targets. If natural gas can offer short-to-medium term benefits, how much of a bridge should we build? Using ARTIMAS, a foresighted computable general equilibrium model of the US economy, we interact scenarios developed by the EMF-34 study group related to abundant natural gas, low-cost renewables, and a carbon tax to examine the role of natural gas in a carbon-constrained future. We find that abundant natural gas alone does not have a significant impact on CO2 emissions. We also find that, under a higher carbon tax, natural gas investment of approximately $10 billion per year declines to zero at a tax of about $40/ton and existing natural gas assets face significant risk of impairment. Last, the presence of abundant natural gas lowers the marginal welfare cost of abating small amounts of CO2 but is likely to raise the cost of abatement levels consistent with common climate objectives. The integrated welfare costs of climate policy depend on how much abatement we must undertake.

Coupling Carbon Capture from a Power Plant with Semi-automated Open Raceway Ponds for Microalgae Cultivation.

In the United States, 35% of the total carbon dioxide (CO2) emissions come from the electrical power industry, of which 30% represent natural gas electricity generation. Microalgae can biofix CO2 10 to 15 times faster than plants and convert algal biomass to products of interest, such as biofuels. Thus, this study presents a protocol that demonstrates the potential synergies of microalgae cultivation with a natural gas power plant situated in the southwestern United States in a hot semi-arid climate. State-of-the-art technologies are used to enhance carbon capture and utilization via the green algal species Chlorella sorokiniana, which can be further processed into biofuel. We describe a protocol involving a semi-automated open raceway pond and discuss the results of its performance when it was tested at the Tucson Electric Power plant, in Tucson, Arizona. Flue gas was used as the main carbon source to control pH, and Chlorella sorokiniana was cultivated. An optimized medium was used to grow the algae. The amount of CO2 added to the system as a function of time was closely monitored. Additionally, other physicochemical factors affecting algal growth rate, biomass productivity, and carbon fixation were monitored, including optical density, dissolved oxygen (DO), electroconductivity (EC), and air and pond temperatures. The results indicate that a microalgae yield of up to 0.385 g/L ash-free dry weight is attainable, with a lipid content of 24%. Leveraging synergistic opportunities between CO2 emitters and algal farmers can provide the resources required to increase carbon capture while supporting the sustainable production of algal biofuels and bioproducts.

Economic and environmental assessment of landfill gas electricity generation in urban districts of Beijing municipality

The present study assesses the electricity generation potential of methane from municipal solid waste through landfill gas to energy technology in 16 districts of Beijing municipality. Municipal solid waste generation potential and methane generation potential from landfills of each of the districts were estimated from 2019 to 2038. Economic viability analysis of landfill gas to energy project based on Net Present Value, Levelized Cost of Energy, and Payback Period was conducted. Besides, environmental impact analysis based on greenhouse gas emissions potential was evaluated. Key results indicate that the generation potential of municipal solid waste during the project period is 55,000 to 2,120,000 tons/year. Chaoyang district has the highest municipal solid waste generation potential, while lower municipal solid waste generation potential was observed in Mentougou district. It is also found that Chaoyang district had the highest electricity generation potential of 8,400,000 to 218,300,000 kWh/year. Findings of the economic feasibility analysis show that landfill gas to energy project is viable in all the districts. However, the project is highly viable in Chaoyang district with more positive net present value ($181,100,000), shorter payback period (1.3years), and lower levelized cost of energy ($0.0613/kWh). Greenhouse gas emission potential of landfill gas without energy recovery was the highest in all the districts. It was realized that landfill gas with energy recovery could reduce greenhouse gas emissions by 72.3% in all the districts. This paper will provide scientific guidance for investment in landfill gas to energy projects in Beijing municipality and other municipalities of China.

Influence of Fluctuations in Fossil Fuel Commodities on Electricity Markets: Evidence from Spot and Futures Markets in Europe

Using a fresh empirical approach to time-frequency domain frameworks, this study analyzes the return and volatility spillovers from fossil fuel markets (coal, natural gas, and crude oil) to electricity spot and futures markets in Europe. In the time domain, by an approach developed by Diebold and Yilmaz (2012) which can analyze the directional spillover effect across different markets, we find natural gas has the highest return spillover effect on electricity markets followed by coal and oil. We also find that return spillovers increase with the length of the delivery period of electricity futures. In the frequency domain, using the methodology proposed by Barunik and Krehlik (2018) that can decompose the spillover effect into different frequency bands, we find most of the return spillovers from fossil fuels to electricity are produced in the short term while most of the volatility spillovers are generated in the long term. Additionally, dynamic return spillovers have patterns corresponding to the use of natural gas for electricity generation, while volatility spillovers are sensitive to extreme financial events.

Forest harvesting and the carbon debt in boreal east-central Canada

Conversion of carbon-rich, primary boreal landscapes to managed ones through clearcut-based silviculture has the potential to decrease landscape-level carbon storage and thereby incur a significant carbon debt. We calculated carbon debts and payback periods associated with production of wood pellets to replace coal, oil and natural gas in electricity generation for such landscape conversion in boreal east-central Canada. Local forest inventory information in combination with the Carbon Budget Model (CBM-CFS3) was used to estimate biomass and dead wood carbon stocks after fire or clearcutting, and resulting age- and disturbance-specific carbon stock estimates were used to populate simulated landscapes. Based on empirical information, we investigated a range of fire-return intervals in the primary landscapes (114–262 years), harvest rotation ages (80–100 years) and conversion efficiency factors (0.17–0.71 tonnes fossil fuel carbon eliminated per tonne harvested wood carbon). After a first rotation of harvesting, carbon stocks declined 33–50% relative to stocks in the natural, fire-dominated landscapes and payback periods ranged from 92 to 757 years. The type of fossil fuel had the strongest effect on payback periods: under average efficiencies, ranges were 122–207, 156–268 and 278–481 years for coal, oil and natural gas respectively. These calculations suggest that under a wide range of assumptions, clearcut-based management of boreal primary landscapes to produce wood pellets to replace fossil fuels in electricity generation will result in net emissions of greenhouse gases to the atmosphere for many decades.

US shift from coal to natural gas saved lives and crops

The shift from coal to natural gas for electricity generation in the US has saved tens of thousands of lives and bumped up yields of three major crops, says a recently published analysis (Nat. Sustainability 2020, DOI: 10.1038/s41893-019-0453-5). The electricity sector’s fuel switch between 2005 and 2016 lowered its emissions of particulate matter and precursors to ground-level ozone, according to the analysis by Jennifer A. Burney, an environmental scientist and professor of global policy and strategy at the University of California San Diego. Both ozone and fine particulate pollution are linked to health problems and they depress crop production. Burney estimates that improvements in air quality from 2005 to 2016 due to fuel shifting for electricity production saved about 38,000 lives and increased yields of corn, soybeans, and wheat by a total of 169 billion liters. Air pollution from coal-fired plants that operated during the same period caused more than

Feasibility economic analysis for electricity generation in internal combustion engine sets using landfill gas in Lagos State

The main objective of this paper is to analyze the economic feasibility landfill gas for electricity generation in Lagos State. In this paper, methane emissions are estimated by applying the First Order Decay model to landfills in Lagos over the latest data available by Lagos Bureau of Statistics. Documented waste-in-place in Lagos State from 1990 to 2014 can be approximated to 51 million tons of waste disposed. An engineering economic analysis was used which was adapted from US EPA’s Landfill methodology. Based on the US EPA’s Landfill methodology, we calculated that a total of landfill gas of 4,736.37 mmcf/yr can be generated. Therefore, considering the use of internal combustion engines, a total of 202,720,789 kWh of electricity can be generated annually. The NPV results were mostly negative and positive at N18.75 and N36.49 unit prices respectively. Further analyses revealed that the breakeven price was N29.17 per unit of electricity at 10% discount rate and a life span of 15 years. It becomes imperative that electricity from this source requires government subsidy as other economic benefits abound.

Natural gas utilization in China: Development trends and prospects

It has been an important objective in China’s energy development strategy to accelerate the promotion of natural gas utilization, cultivate main sources of natural gas, and increase the proportion of natural gas consumption. Based on the analysis of the development of natural gas utilization in China over the past 3 decades by means of classified and comparative research, this paper reveals the shift in the development pattern of China’s natural gas utilization structure from the domination of industrial gas and chemical gas to a relative balance among industrial fuel, urban gas, and power generation gas. Sustained and steadily growing natural gas is an important basis for the rapid growth of natural gas utilization. Maintaining moderate growth in the natural gas transmission and distribution network is an important guarantee for the rapid growth of natural gas utilization. The slowdown in the world’s economic growth has not caused any significant adverse impact on the rapid growth in China’s electricity generation gas. The natural gas utilization policy has no effect on the adjustment of industrial fuel gas any longer. Industrial fuels and chemical gas are greatly subject to natural gas prices. Based on China’s energy consumption targets for 2020 and 2030, this paper estimates the gas consumption of major gas areas and their development position, namely, more development space for industrial fuels, still rapid growth in urban gas but hardly major breakthroughs in gas proportion, rapid growth in power generation gas and a more prominent role in peak shaving, sustained high growth in transportation gas and challenges from new energy and low oil prices, and a significant decline but still a large scale in chemicalgas.

Sustainability assessment of gas based power generation using a life cycle assessment approach

PurposeIndia is a developing economy along with an increasing population estimated to be the largest populated country in about seven years. Simultaneously, its power consumption is projected to increase more than double by 2020. Currently, the dependence on coal is relatively high, making it the largest global greenhouse gas emitting sector which is a matter of great concern. The purpose of this paper is to evaluate the environmental impacts of the natural gas electricity generation in India and propose a model using a life cycle assessment (LCA) approach.Design/methodology/approachLCA is used as a tool to evaluate the environmental impact of the natural gas combined cycle (NGCC) power plant, as it adopts a holistic approach towards the whole process. The LCA methodology used in this study follows the ISO 14040 and 14044 standards (ISO 14040: 2009; ISO 14044: 2009). A questionnaire was designed for data collection and validated by expert review primary data for the annual environmental emission was collected by personally visiting the power plant. The study follows a cradle to gate assessment using the CML (2001) methodology.FindingsThe analysis reveals that the main impacts were during the process of combustion. The Global warming potential is approximately 0.50 kg CO2 equivalents per kWh of electricity generation from this gas-based power plant. These results can be used by stakeholders, experts and members who are authorised to probe positive initiative for the reduction of environmental impacts from the power generation sector.Practical implicationsConsidering the pace of growth of economic development of India, it is the need of the hour to emphasise on the patterns of sustainable energy generation which is an important subject to be addressed considering India’s ratification to the Paris Climate Change Agreement. This paper analyzes the environmental impacts of gas-based electricity generation.Originality/valuePresenting this case study is an opportunity to get a glimpse of the challenges associated with gas-based electricity generation in India. It gives a direction and helps us to better understand the right spot which require efforts for the improvement of sustainable energy generation processes, by taking appropriate measures for emission reduction. This paper also proposes a model for gas-based electricity generation in India. It has been developed following an LCA approach. As far as we aware, this is the first study which proposes an LCA model for gas-based electricity generation in India. The model is developed in line with the LCA methodology and focusses on the impact categories specific for gas-based electricity generation.

Managerial flexibility in levelized cost measures: A framework for incorporating uncertainty in energy investment decisions

Many irreversible long-run capital investments entail opportunities for managers to respond flexibly to changes in the economic environment. However, common levelized cost measures used to guide decision-making, such as the levelized cost of electricity, implicitly assume that the values of random economic variables are known with certainty when investment decisions are made. This assumption implies, often incorrectly, that managerial flexibility carries zero value. This paper improves levelized cost measures by deriving an expansion that accounts for both uncertainties in relevant variables and the value of managerial flexibility in responding to them. This method is applied to quantify the value of flexibility in two example decision problems. In one, an operator of a natural gas electricity generation facility evaluates whether to invest in carbon capture capabilities. Another considers retirement decisions for U.S. nuclear plants. These examples illustrate that simplified cost metrics can inaccurately guide decision-making by inflating cost estimates relative to the proposed levelized cost measure that accounts for uncertainty and flexibility.