Fossil CO2 Research Articles

Impact of fossil-free decentralized heating on northern European renewable energy deployment and the power system

Complying with ambitious EU climate targets, decarbonization pathways for space heat and hot water, in addition to the centralized energy generation sector, are analyzed using the open energy modeling framework, Balmorel. Hybrid systems and simplified consumer preferences are incorporated in the investment choices for decentralized heat. Five scenarios are analyzed: three with varying heat demand developments by 2050, one acknowledging the presence of carbon-neutral gas, and one covering only power and centralized heat sectors for comparison. All scenarios must comply with the EU emission targets in both the Emission Trading System (ETS) and non-ETS sectors by 2030, followed by a linear reduction towards zero fossil CO2 emissions by 2050. The optimization model reveals that the most cost-effective solution is electrification, which requires substantial investment in wind energy infrastructure. In the case of constant decentralized heat demand, the electricity demand will increase by one-third from the current level, consequently quintupling the installed wind capacity. Heat demand seasonality causes challenges leading to extreme high and low seasonal prices, and substantial curtailment in summer. Impacts on the power system have been underestimated because decarbonizing decentralized heat has not been considered. The results also imply a more important role for system integration.

Simulation Analysis of the System Integrating Oxy-Fuel Combustion and Char Gasification

Abstract To explore the feasibility of converting hot flue gas into valuable syngas through char gasification process, Aspen Plus is applied to evaluate the performance of the integrated system including oxy-combustion, pyrolysis, gasification, and flue gas recirculation. The impact of feedstock type (reed straw and municipal solid waste (MSW)), feeding rate (0.1–1 t/h), and flue gas recycle ratio (FGR) (10%–30%) is investigated. The economic analysis of the integrated system is also performed. The results indicate that higher oxygen consumption is required for biomass gasification to reach the same temperature as MSW gasification. The gasification temperature is 750 °C–950 °C under 10%–30% FGR. The CO + H2 content in syngas from biomass gasification is slightly higher than that from MSW gasification. For the integrated system, more natural gas (NG) can be saved and more fossil CO2 can be reduced under biomass gasification. When the feedstock input is 1 t/h, the fossil CO2 emission can be reduced by 70% when taking biomass, the CO2 reduction is double of that when taking MSW. The total OPEX cost can be 26% saved by biomass and 62% saved by MSW due to the government subsidy. If CO2 tax is considered, the advantage of biomass for saving OPEX cost will be more obvious.

ANALYSIS OF THE RELATIONSHIP BETWEEN RENEWABLE ENERGY AND ECONOMIC GROWTH IN SELECTED DEVELOPING COUNTRIES

Whether there is a relationship between economic growth and energy consumption and the direction of this relationship is of great importance in energy policy decision making in countries where the state plays an active role in energy markets. If there is a relationship from energy to growth, conservative policies such as energy taxes, energy-saving, and energy prices will hurt growth. There are many studies in the literature investigating the effects of renewable and non-renewable energy consumption on the economic growth of countries. Since different data, periods, and methods were used in the studies, consensus could not be achieved. Therefore, this issue remains current and continues to be investigated. The main purpose of this study is to determine whether renewable energy consumption has a positive effect on economic growth for selected developing countries (Brazil, India, Indonesia, China, Chile, Mexico, South Africa and Turkey). Fossil energy consumption and CO 2 emissions variables are also included in the model established for this purpose. GMM estimator, one of the dynamic panel data methods, was used for empirical analysis of the relationship between these variables. Keywords: renewable energy consumption, carbon emission, economic growth, Dynamic panel data, GMM method JEL Classifications: O40, Q43, Q40 DOI: https://doi.org/10.32479/ijeep.10397

Biocarbon from bark or black pellets as an alternative for coal in steelmaking – techno-economic evaluation

ABSTRACT In 2018, global crude steel production was approx. 1.8 gigatonnes while its direct CO2 emissions stood at 2 giga tonnes (2017), representing 23.5% of all direct industrial emissions. Globally iron and steel industry (ISI sector) is the second largest emitter after the cement industry while in Finland and Sweden the ISI sector is the largest industrial source of fossil CO2. Biocarbon received from forest sector residues, such as bark, sawdust and lignin, provides an opportunity to a rapid reduction in fossil CO2 emissions in the industry. Use of biocarbon for reduction purposes bestows an asset for both the forest and metals production and processing industry in Finland as well as in the Scandinavian countries. In this study, the focus was on the techno-economic evaluation of biocarbon production (1) from bark-based black pellets produced in a stand-alone plant close to a steel mill and (2) from bark produced in a pulp mill integrated plant. The economics of biocarbon production costs from bark appear promising, providing also an ample source, at an annual potential of up to 95,000 tonnes of biocarbon from a single pulp mill.

The water footprint of carbon capture and storage technologies

Carbon capture and sequestration (CCS) is an important technology to reduce fossil CO2 emissions and remove CO2 from the atmosphere. Scenarios for CCS deployment consistent with global climate goals involve gigatonne-scale deployment of CCS within the next several decades. CCS technologies typically involve large water consumption during their energy-intensive capture process. Despite potential concerns, the water footprint of large-scale CCS adoption consistent with stringent climate change mitigation has not yet been explored. This study presents the water footprints (m3 water per tonne CO2 captured) of four prominent CCS technologies: Post-combustion CCS, Pre-combustion CCS, Direct Air CCS, and Bioenergy with CCS. Depending on technology, the water footprint of CCS ranges from 0.74 to 575 m3 H2O/tonne CO2. Bioenergy with CCS is the technology that has the highest water footprint per tonne CO2 captured, largely due to the high water requirements associated with transpiration. The widespread deployment of CCS to meet the 1.5 °C climate target would almost double anthropogenic water footprint. Consequently, this would likely exacerbate and create green and blue water scarcity conditions in many regions worldwide. Climate mitigation scenarios with a diversified portfolio of CCS technologies have lower impacts on water resources than scenarios relying mainly on one of them. The water footprint assessment of CCS is a crucial factor in evaluating these technologies. Water-scarce regions should prioritize water-efficient CCS technologies in their mitigation goals. In conclusion, the most water-efficient way to stabilize the Earth's climate is to rapidly decarbonize our energy systems and improve energy efficiency.

Multi-objective optimization and evaluation of hybrid CCHP systems for different building types

The hybridization between renewable energy and fossil energy in energy supply system is a feasible solution to reduce the fossil energy consumption and CO2 emission. The hybrid CCHP systems that can include gas turbine (GT), absorption unit (ABS), ground source heat pump (GSHP), photovoltaic panels (PV), solar thermal collectors (ST), photovoltaic thermal solar collectors (PVT), battery, water storage tank (WST), are proposed in this study. Two different systems to use solar energy are evaluated: in system A, solar energy is converted into thermal and electric energy by ST and PV, respectively; while in system B, solar energy is converted into thermal and electric energy by PVT. The NSGA-II algorithm is employed to search the Pareto frontier solutions of the multi-objective optimization model that considers economy, energy and environment performances. The TOPSIS method is used as decision making tool for ideal configuration selection. The hybrid CCHP systems for three buildings (hotel, office, market) are optimized and compared under different operation strategies. The results reveal that the system A operating in following electric load (FEL) strategy achieves more benefits for three buildings. Besides, the system configuration and component size are closely related to the building type.

Large and seasonally varying biospheric CO2 fluxes in the Los Angeles megacity revealed by atmospheric radiocarbon

Measurements of Δ14C and CO2 can cleanly separate biogenic and fossil contributions to CO2 enhancements above background. Our measurements of these tracers in air around Los Angeles in 2015 reveal high values of fossil CO2 and a significant and seasonally varying contribution of CO2 from the urban biosphere. The biogenic CO2 is composed of sources such as biofuel combustion and human metabolism and an urban biospheric component likely originating from urban vegetation, including turf and trees. The urban biospheric component is a source in winter and a sink in summer, with an estimated amplitude of 4.3 parts per million (ppm), equivalent to 33% of the observed annual mean fossil fuel contribution of 13 ppm. While the timing of the net carbon sink is out of phase with wintertime rainfall and the sink seasonality of Southern California Mediterranean ecosystems (which show maximum uptake in spring), it is in phase with the seasonal cycle of urban water usage, suggesting that irrigated urban vegetation drives the biospheric signal we observe. Although 2015 was very dry, the biospheric seasonality we observe is similar to the 2006-2015 mean derived from an independent Δ14C record in the Los Angeles area, indicating that 2015 biospheric exchange was not highly anomalous. The presence of a large and seasonally varying biospheric signal even in the relatively dry climate of Los Angeles implies that atmospheric estimates of fossil fuel-CO2 emissions in other, potentially wetter, urban areas will be biased in the absence of reliable methods to separate fossil and biogenic CO2.

Engineered MSW landfills as a future material resource and a sink for long-term storage of organic carbon

A controlled, highly engineered landfill has many similarities to natural peatlands or other natural anoxic sediment deposits. In anaerobic MSW landfills, generally about 30-50 percent of the total carbon content in the waste can be converted into biogas and be collected as resource for energy or chemical industry. Remaining long-lived organic carbon, e.g. from lignin remains un-degraded, Organic carbon in fossil derived hydrocarbons, like plastics, will remain rather unaffected in the landfill. In a future with less remaining oil resources, landfill mining of these polymers can be valuable, making the landfill to a future “resource bank”. New reactor cell landfill technologies have shown that up to over 90 % of the produced biogas can be collected and used. Approximately 150-250 m3 of biogas per tonne waste can be extracted from a landfill reactor-cell over a 10-year period. Sequestration of a long-lived organic fraction in a landfill, with an annual input of 100 000 tons of waste, can compensate for annual CO2 emissions from about 20 000 to 25 000 cars. If more than about 60 % of produced biogas can be collected from the landfill, it has positive net effects on climate change. If the waste instead would have been incinerated this would lead to major emissions of fossil CO2, as about 30-50 % of the CO2 in the stack gasses from a waste incinerator has fossil origin.

Combined Impact of Demand Response Aggregators and Carbon Taxation on Emissions Reduction in Electric Power Systems

An emission rate-based carbon tax is applied to fossil-fueled generators with a demand response approach called Smart Grid resource allocation (SGRA). The former reduces the capacity factors (CFs) of base load serving fossil-fueled units, while the latter reduces the CFs of peak load serving units. The objective is to quantify the integration of the carbon tax and the SGRA approach on CO2 emissions and electricity prices in a multi-area power grid. We illustrate this using the Roy Billinton test system and the results show potential for significant reductions in fossil fuel-based generation and CO2 emissions.

Evaluation of biomass-based production of below zero emission reducing gas for the iron and steel industry

The present paper focuses on the production of a below zero emission reducing gas for use in raw iron production. The biomass-based concept of sorption-enhanced reforming combined with oxyfuel combustion constitutes an additional opportunity for selective separation of CO2. First experimental results from the test plant at TU Wien (100 kW) have been implemented. Based on these results, it could be demonstrated that the biomass-based product gas fulfills all requirements for the use in direct reduction plants and a concept for the commercial-scale use was developed. Additionally, the profitability of the below zero emission reducing gas concept within a techno-economic assessment is investigated. The results of the techno-economic assessment show that the production of biomass-based reducing gas can compete with the conventional natural gas route, if the required oxygen is delivered by an existing air separation unit and the utilization of the separated CO2 is possible. The production costs of the biomass-based reducing gas are in the range of natural gas-based reducing gas and twice as high as the production of fossil coke in a coke oven plant. The CO2 footprint of a direct reduction plant fed with biomass-based reducing gas is more than 80% lower compared with the conventional blast furnace route and could be even more if carbon capture and utilization is applied. Therefore, the biomass-based production of reducing gas could definitely make a reasonable contribution to a reduction of fossil CO2 emissions within the iron and steel sector in Austria.

What Fluorine Can Do in CO2 Chemistry: Applications from Homogeneous to Heterogeneous Systems.

CO2 chemistry including capture and fixation has attracted great attention towards the aim of reducing the consumption of fossil fuels and CO2 accumulation in the atmosphere. "CO2 -philic" materials are required to achieve good performance owing to the intrinsic properties of the CO2 molecule, that is, thermodynamic stability and kinetic inertness. In this respect, fluorinated materials have been deployed in CO2 capture (physical and chemical pathway) or fixation (thermo- and electrocatalytic procedure) with good performances, including homogeneous (e. g., ionic liquids and small organic molecules) and heterogeneous counterparts (e. g., carbons, porous organic polymers, covalent triazine frameworks, metal-organic frameworks, and membranes). In this Minireview, these works are summarized and analyzed from the aspects of (1) the strategy used for fluorine introduction, (2) characterization of the targeted materials, (3) performance of the fluorinated systems in CO2 chemistry, and comparison with the nonfluorinated counterparts, (4) the role of fluorinated functionalities in the working procedure, and (5) the relationship between performance and structural/electronic properties of the materials. The systematic summary in this Minireview will open new opportunities in guiding the design of "CO2 -philic" materials and pave the way to stimulate further progress in this field.

Alternative Fuels for Internal Combustion Engines

The recent transport electrification trend is pushing governments to limit the future use of Internal Combustion Engines (ICEs). However, the rationale for this strong limitation is frequently not sufficiently addressed or justified. The problem does not seem to lie within the engines nor with the combustion by themselves but seemingly, rather with the rise in greenhouse gases (GHG), namely CO2, rejected to the atmosphere. However, it is frequent that the distinction between fossil CO2 and renewable CO2 production is not made, or even between CO2 emissions and pollutant emissions. The present revision paper discusses and introduces different alternative fuels that can be burned in IC Engines and would eliminate, or substantially reduce the emission of fossil CO2 into the atmosphere. These may be non-carbon fuels such as hydrogen or ammonia, or biofuels such as alcohols, ethers or esters, including synthetic fuels. There are also other types of fuels that may be used, such as those based on turpentine or even glycerin which could maintain ICEs as a valuable option for transportation.

Impacts of ocean acidification under multiple stressors on typical organisms and ecological processes

The oceans are taking up over one million tons of fossil CO2 per hour, resulting in increased pCO2 and declining pH, leading to ocean acidification (OA). At the same time, accumulation of CO2 and other greenhouse gases is causing ocean warming, which enhances stratification with thinned upper mixed layers, exposing planktonic organisms to increasing levels of daytime integrated UV radiation. Ocean warming also reduces dissolved oxygen in seawater, resulting in ocean deoxygenation. All these ocean global changes are impacting marine ecosystems and effects are well documented for each individual driver (pH, oxygen, temperature, UV). However, combined effects are still poorly understood, strongly limiting our ability to project impacts at regional or local levels. Different regions are often exposed (and often adapted) to contrastingly different physical and chemical environmental conditions and organisms, and ecosystems from different parts of the world will be exposed to unique combinations of stressors in the future. Understanding the modulating role of adaptation, species niche and stressors’ interaction is key. This review, being a non-exhaustively explored one, aims to provide an overview on understandings of ecophysiological effects of OA and its combination with covarying drivers, mainly warming, deoxygenation and solar UV radiation. We propose a testable hypothetical model as well as future research perspectives.

Background data for: Timely estimates of India's annual and monthly fossil CO2 emissions

Background data for: Timely estimates of India's annual and monthly fossil CO2 emissions

Background data for: Timely estimates of India's annual and monthly fossil CO2 emissions

Background data for: Timely estimates of India's annual and monthly fossil CO2 emissions

Honey as an indicator of long-term environmental changes: MP-AES analysis coupled with 14C-based age determination of Hungarian honey samples

Several studies show that the elemental content of honey entirely depends on the botanical and geographical origin, but the information is incomplete regarding its time-dependent composition changes. Twenty-six acacia and three honey samples with unknown botanical origin were collected between 1958 and 2018 and analysed for elemental composition by Microwave Plasma Atomic Emission Spectrometry (MP-AES). The elemental analysis was coupled with independent dating method by Accelerator Mass Spectrometry (AMS) to confirm the calendar age of the honey samples and test the possibility of radiocarbon based dating of bee products, which has not been applied before.According to the analytical measurements and statistical analysis, we can conclude that the elemental composition shows change with time in the acacia honey during the last five decades. We have proven that honey preserves carbon isotopic and elemental information of its production time and thus can be applied as an environmental indicator (e.g. trace urban pollutants, precipitation, local industrial or agricultural emission) in reconstruction studies by analysing the non-degradable mineral content. Our results further show that acacia honey is a suitable material for radiocarbon dating, proved by the results compared to the atmospheric radiocarbon bomb-peak. The new approach presented for investigation of honey by radiocarbon-based age determination coupled with elemental analysis can be used in biological, dietary, archaeological or other multidisciplinary studies as well. Some samples show slightly depleted radiocarbon content. This could be an indication of local fossil CO2 emission. Based on these depleted 14C results, honey could be used for atmospheric monitoring of fossil CO2 urban or industrial hot-spots.

Pyrolysis behavior of a green and clean reductant for suspension magnetization roasting

The use of siderite as a green and clean reductant for the suspension magnetization roasting of refractory iron ores was proposed. In this study, the behavior of siderite, which was pyrolyzed into magnetite and CO, was investigated using chemical analysis, vibrating sample magnetometer, X-ray diffractometry, Mössbauer spectroscopy, scanning electron microscopy, and gas composition analyzer. The roasted product, which contained 15.88% CO and presented a saturation magnetization of 57.10 A m2/kg was obtained at the roasting temperature of 620 °C and the roasting time of 10 min. The pores and cracks of the particles developed gradually and their sizes increased continuously, which rendered the structure of the particles loose and led to a decrease in the amount of energy required for grinding. Approximately half of the amount of FeO, produced via the pyrolysis of siderite was oxidized to magnetite using CO2, and the content of residual FeO in the roasted product was 18.5% by the volume. Particularly, the complete reaction of the roasted product with CO2 increased the saturation magnetization of the product by 16.44%, from 57.07 A m2/kg for the initial roasted product to 66.45 A m2/kg for the final roasted product, and also generated a certain amount of CO. Our study demonstrated that the traditional magnetization roasting of single siderite greatly wasted a large amount of natural reductant (CO). This innovative use of siderite could improve the quality of the roasting products and reduce the consumption of fossil fuels and CO2 emissions.

GHG Emissions and Fossil Energy Use as Consequences of Efforts of Improving Human Well-being in Africa

This paper addresses two shortcomings of existing studies on the interconnection between economic growth, energy use and greenhouse gas (GHG) emissions: the mechanism through which the latter interconnection operates and the existence of geographical spillovers in both fossil energy use and CO2 emissions. Asserting that efforts of improving living conditions create an energy demand and the higher fossil energy use, the higher environmental degradation, we exploit a recursive system of three equations that accounts for regressor endogeneity and spatial spillovers. The empirical results for a sample of 41 Sub-Saharan African (SSA) countries thoroughly support our hypotheses. Thus, contrary to studies linking gas emissions to economic growth, implicitly holding the latter responsible for CO2 emissions, our results suggest that gas emissions are direct consequences of fossil energy use, the latter being driven by efforts of improving living conditions. Such conclusions advocate for environmental management strategies towards an energy transition in SSA, in order to mitigate environmental pollution while improving human living conditions.

Optimization of renewable energy subsidy and carbon tax for multi energy systems using bilevel programming

The use of optimized Multi-Energy Systems, including renewables, combined heat and power units and energy storages, is proven to be effective in the reduction of fossil CO2 emissions. These systems can be efficiently operated to provide electricity, heating and cooling to energy districts and buildings. To increase the share of renewable sources and further decrease CO2 emissions, incentives and/or carbon taxes are set by governments. This work proposes a novel bi-level optimization approach which mimics the actual bilevel decision process to determine the optimal renewable subsidy and carbon tax for small-medium multi-energy systems. At the upper level the government decides the incentives/tax to meet the desired emission reduction target while minimizing its costs and, at the lower level, the owner/operator of the Multi-Energy System decides the optimal design and operation to minimize its Total Annual Cost (sum of investment and operating costs). We devise an efficient heuristic approach to solve the bilevel program and apply the approach to four different real-world applications, namely a university campus, a hospital, an urban district, and an office building.

How Is Mortality Affected by Fossil Fuel Consumption, CO2 Emissions and Economic Factors in CIS Region?

It is widely discussed that GDP growth has a vague impact on environmental pollution due to carbon dioxide emissions from fossil fuels consumed in production, transportation, and power generation. The main purpose of this study is to investigate the relationships between economic growth, fossil fuel consumption, mortality (from cardiovascular disease (CVD), diabetes mellitus (DM), cancer, and chronic respiratory disease (CRD), and environmental pollution since environmental pollution can be a reason for societal mortality rate increases. This study uses the generalized method of moments (GMM) estimation technique for the Commonwealth of Independent States (CIS) members for the period from 1993–2018. The major results revealed that the highest variability of mortality could be explained by CO2 variability. Regarding fossil fuel consumption, the estimation proved that this variable positively affects mortality from CVD, DM, cancer, and CRD. Additionally, any improvements in the human development index (HDI) have a negative effect on mortality increases from CVD, DM, cancer, and CRD in the CIS region. It is recommended that the CIS members implement different policies to improve energy transitions, indicating movement from fossil fuel energy sources to renewable sources. Moreover, we recommend the CIS members enhance various policies for easy access to electricity from green sources and increase the renewable supply through improved technologies, sustainable economic growth, and increase the use of green sources in daily social life.