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Special Issue "Sustainability of Fossil Fuels"

A special issue of Energies (ISSN 1996-1073). This special issue belongs to the section "Energy Sources".

Deadline for manuscript submissions: 31 January 2019

Special Issue Editor

Guest Editor
Prof. Pavel A. Strizhak

Department of Power Engineering National Research, Tomsk Polytechnic University, Tomsk 634050, Russia
Website 1 | Website 2 | E-Mail
Interests: energy; fuels; ignition; combustion chemistry; environmental performance; gas emissions; waste-derived fuels; coal-water slurry; waste to energy; thermal engineering; mathematical modeling; heat and mass transfer

Special Issue Information

Dear Colleagues,

The energy and fuel industries represent an extensive field for the development and implementation of solutions aimed at improving the technological, environmental, and economic performance of technological cycles. In recent years, issues of ecology and energy security have become especially important. Energy is firmly connected with all spheres of human economic life, but, unfortunately, it has an extremely negative (often fatal) effect on the environment and public health. Depletion of energy resources, the complexity of their extraction and transportation are also problems of a global scale. Therefore, nowadays it is especially important to try to take care of nature and think about the resources that are necessary for future generations. For scientific teams in different countries, the development of sustainable and safe technologies for the use of fuels in the energy sector will be a challenge in the coming decades.

In this Special Issue, we will try to provide readers with the results of fundamental and applied research and reviews in the field of energy production from the combustion of fossil fuels (coal, peat, oil), waste-derived fuels and biomass.

We are pleased to invite researchers to contribute to the creation of a Special Issue dedicated to various aspects of sustainable use of fossil fuels, biomass, and waste-derived fuels.

Prof. Pavel A. Strizhak
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access bimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1800 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Waste
  • Combustion of solid, liquid and composite fuels
  • New technologies of fuel combustion
  • Mathematical modeling of fuel combustion
  • Properties of fossil fuels, combustible wastes and biomass
  • Ecological problems of thermal power industry
  • Technical and economic problems of thermal power industry
  • Optimal use of energy resources

Published Papers (12 papers)

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Research

Open AccessFeature PaperArticle Igniting Soaring Droplets of Promising Fuel Slurries
Energies 2019, 12(2), 208; https://doi.org/10.3390/en12020208
Received: 24 November 2018 / Revised: 28 December 2018 / Accepted: 31 December 2018 / Published: 10 January 2019
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Abstract
High rates of environmental pollution by boilers and thermal power plants burning coal of different grades are the main reason for active research in the world aimed at the development of alternative fuels. The solution to the formulated problem acceptable in terms of
[...] Read more.
High rates of environmental pollution by boilers and thermal power plants burning coal of different grades are the main reason for active research in the world aimed at the development of alternative fuels. The solution to the formulated problem acceptable in terms of environmental, technical and economic criteria is the creation of composite slurry fuels with the use of fine coal or coal processing and enrichment waste, water of different quality, and oil sludge additive. This study considers modern technologies of burning slurry fuels as well as perspective research methods of the corresponding processes. A model combustion chamber is developed for the adequate study of ignition processes. The calculation of the basic geometric dimensions is presented. The necessity of manufacturing the combustion chamber in the form of an object of complex geometry is substantiated. With its use, several typical modes of slurry fuel ignition are determined. Principal differences of ignition conditions of a single droplet and group of fuel droplets are shown. Typical vortex structures at the fuel spray injection are shown. A comparison with the trajectories of fuel aerosol droplets in real combustion chambers used for the combustion of slurry fuels is undertaken. Full article
(This article belongs to the Special Issue Sustainability of Fossil Fuels)
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Open AccessArticle Genetic Mechanism and Evolution of the Covert Fault Zone and Its Oil-Controlling Mode in Qikou Sag, Eastern China
Energies 2019, 12(1), 98; https://doi.org/10.3390/en12010098
Received: 16 November 2018 / Revised: 20 December 2018 / Accepted: 22 December 2018 / Published: 29 December 2018
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Abstract
Covert fault zone is an important type of geological phenomenon that is closely related to hydrocarbon formation and distribution but has often been overlooked because it lacks obvious fault displacement and fault plane. To meet this challenge, a novel cognitive framework is proposed
[...] Read more.
Covert fault zone is an important type of geological phenomenon that is closely related to hydrocarbon formation and distribution but has often been overlooked because it lacks obvious fault displacement and fault plane. To meet this challenge, a novel cognitive framework is proposed in this study, in which criteria for identifying the existence of covert fault zone are developed based on the regional tectonic backgrounds and geophysical data. The Riedel shear model is then utilized to analyze the genetic mechanism of the covert fault zone. The Mohr-Coulomb theory is also introduced to conduct a structural physical simulation to interpret the evolution process of the covert fault zone. Information about the genetic mechanism and evolution of the covert fault zone is finally combined to determine the oil-controlling mode. The study site is Qikou Sag in Eastern China. It is found that the covert fault zone in Qikou Sag meets four recognition criteria and is generated by the stress transferred from the strike-slip activity of the basement fault. Moreover, it can be concluded that the covert fault zone in Qikou Sag contains five evolution stages and controls the reservoir mainly via three aspects, that is, sedimentary sand, subtle traps and oil accumulation mode. Full article
(This article belongs to the Special Issue Sustainability of Fossil Fuels)
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Open AccessArticle Mechanism Reduction and Bunsen Burner Flame Verification of Methane
Energies 2019, 12(1), 97; https://doi.org/10.3390/en12010097
Received: 5 December 2018 / Revised: 24 December 2018 / Accepted: 24 December 2018 / Published: 29 December 2018
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Abstract
Based on directed relation graph with error propagation methods, 39 species and 231 reactions skeletal mechanism were obtained from Mech_56.54 (113 species and 710 reactions) mechanism of methane. The ignition delay times, laminar flame propagation speed, and important species were calculated using the
[...] Read more.
Based on directed relation graph with error propagation methods, 39 species and 231 reactions skeletal mechanism were obtained from Mech_56.54 (113 species and 710 reactions) mechanism of methane. The ignition delay times, laminar flame propagation speed, and important species were calculated using the simplified mechanism at different pressures and equivalence ratios. The simulation results were in good agreement with that of detailed mechanisms and experimental data. The numerical simulation of the Bunsen burner jet flame was carried out using the simplified methane mechanism, and the simulation results well reproduced the temperature, flow fields and distribution of important species at flame zone. The compact methane reduced mechanism can not only correctly respond to its dynamic characteristics, but also can be well used for numerical simulation, which is of great significance in engineering applications. Full article
(This article belongs to the Special Issue Sustainability of Fossil Fuels)
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Open AccessArticle Closed-Form Solution of Radial Transport of Tracers in Porous Media Influenced by Linear Drift
Energies 2019, 12(1), 29; https://doi.org/10.3390/en12010029
Received: 3 November 2018 / Revised: 10 December 2018 / Accepted: 17 December 2018 / Published: 22 December 2018
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Abstract
A new closed-form analytical solution to the radial transport of tracers in porous media under the influence of linear drift is presented. Specifically, the transport of tracers under convection–diffusion-dominated flow is considered. First, the radial transport equation was cast in the form of
[...] Read more.
A new closed-form analytical solution to the radial transport of tracers in porous media under the influence of linear drift is presented. Specifically, the transport of tracers under convection–diffusion-dominated flow is considered. First, the radial transport equation was cast in the form of the Whittaker equation by defining a set of transformation relations. Then, linear drift was incorporated by considering a coordinate-independent scalar velocity field within the porous medium. A special case of low-intensity tracer injection where molecular diffusion controls tracer propagation but convection with linear velocity drift plays a significant role was presented and solved in Laplace space. Furthermore, a weak-form numerical solution of the nonlinear problem was obtained and used to analyse tracer concentration behaviour in a porous medium, where drift effects predominate and influence the flow pattern. Application in enhanced oil recovery (EOR) processes where linear drift may interfere with the flow path was also evaluated within the solution to obtain concentration profiles for different injection models. The results of the analyses indicated that the effect of linear drift on the tracer concentration profile is dependent on system heterogeneity and progressively becomes more pronounced at later times. This new solution demonstrates the necessity to consider the impact of drift on the transport of tracers, as arrival times may be significantly influenced by drift intensity. Full article
(This article belongs to the Special Issue Sustainability of Fossil Fuels)
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Open AccessArticle An Experimental Study of Combustion of a Methane Hydrate Layer Using Thermal Imaging and Particle Tracking Velocimetry Methods
Energies 2018, 11(12), 3518; https://doi.org/10.3390/en11123518
Received: 9 November 2018 / Revised: 10 December 2018 / Accepted: 13 December 2018 / Published: 17 December 2018
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Abstract
In this paper, the combustion of methane hydrate over a powder layer is experimentally studied using thermal imaging and Particle Tracking Velocimetry (PTV) methods. The experiments are carried out at different velocities of the external laminar air-flow from zero to 0.6 m/s. Usually,
[...] Read more.
In this paper, the combustion of methane hydrate over a powder layer is experimentally studied using thermal imaging and Particle Tracking Velocimetry (PTV) methods. The experiments are carried out at different velocities of the external laminar air-flow from zero to 0.6 m/s. Usually, simulation of methane hydrate combustion is carried out without taking into account free convection. A standard laminar boundary layer is often considered for simplification, and the temperature measurements are carried out only on the axis of the powder tank. Measurements of the powder temperature field have shown that there is a highly uneven temperature field on the layer surface, and inside the layer the transverse temperature profiles are nonlinear. The maximum temperature always corresponds to the powder near the side-walls, which is more than 10 °C higher than the average volumetric temperature in the layer. Thermal imager measurements have shown the inhomogeneous nature of combustion over the powder surface and the highly variable velocity of methane above the surface layer. The novelty of the research follows from the measurement of the velocity field using the PTV method and the measurement of methane velocity, which show that the nature of velocity at combustion is determined by the gas buoyancy rather than by the forced convection. The maximum gas velocity in the combustion region exceeds 3 m/s, and the excess of the oxidizer over the fuel leads to more than tenfold violation of the stoichiometric ratio. Despite that, the velocity profile in the combustion region is formed mainly due to free convection, it is also necessary to take into account the external flow of the forced gas U0. Even at low velocities U0, the velocity direction lines significantly deviate under the forced air-flow. Full article
(This article belongs to the Special Issue Sustainability of Fossil Fuels)
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Open AccessArticle An Integrally Embedded Discrete Fracture Model with a Semi-Analytic Transmissibility Calculation Method
Energies 2018, 11(12), 3491; https://doi.org/10.3390/en11123491
Received: 12 November 2018 / Revised: 11 December 2018 / Accepted: 12 December 2018 / Published: 14 December 2018
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Abstract
The embedded discrete fracture model (EDFM) combines the advantages of previous numerical models for fractured reservoirs, achieving a good balance between calculation cost and simulation accuracy. In this work, an integrally embedded discrete fracture model (iEDFM) is introduced to further improve the simulation
[...] Read more.
The embedded discrete fracture model (EDFM) combines the advantages of previous numerical models for fractured reservoirs, achieving a good balance between calculation cost and simulation accuracy. In this work, an integrally embedded discrete fracture model (iEDFM) is introduced to further improve the simulation accuracy and expand the application of the model. The iEDFM has a new gridding method that can arbitrarily grid the fractures according to the requirements rather than finely subdividing fracture elements. Then, with a more precise pressure distribution assumption inside the matrix blocks, we are able to obtain a semi-analytic calculation method of matrix-fracture transmissibility applied to iEDFM. Several case studies were conducted to demonstrate the advantage of iEDFM and its applicability for intersecting and nonplanar fractured reservoirs, and a 3D case with a modified dataset from a reported seismic survey could be used to demonstrate the potential application of the iEDFM in real field studies. Full article
(This article belongs to the Special Issue Sustainability of Fossil Fuels)
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Open AccessArticle Laboratory Study on Changes in the Pore Structures and Gas Desorption Properties of Intact and Tectonic Coals after Supercritical CO2 Treatment: Implications for Coalbed Methane Recovery
Energies 2018, 11(12), 3419; https://doi.org/10.3390/en11123419
Received: 31 October 2018 / Revised: 26 November 2018 / Accepted: 3 December 2018 / Published: 6 December 2018
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Abstract
Tectonic coals in coal seams may affect the process of enhanced coalbed methane recovery with CO2 sequestration (CO2-ECBM). The main objective of this study was to investigate the differences between supercritical CO2 (ScCO2) and intact and tectonic
[...] Read more.
Tectonic coals in coal seams may affect the process of enhanced coalbed methane recovery with CO2 sequestration (CO2-ECBM). The main objective of this study was to investigate the differences between supercritical CO2 (ScCO2) and intact and tectonic coals to determine how the ScCO2 changes the coal’s properties. More specifically, the changes in the tectonic coal’s pore structures and its gas desorption behavior were of particular interest. In this work, mercury intrusion porosimetry, N2 (77 K) adsorption, and methane desorption experiments were used to identify the difference in pore structures and gas desorption properties between and intact and tectonic coals after ScCO2 treatment. The experimental results indicate that the total pore volume, specific surface area, and pore connectivity of tectonic coal increased more than intact coal after ScCO2 treatment, indicating that ScCO2 had the greatest influence on the pore structure of the tectonic coal. Additionally, ScCO2 treatment enhanced the diffusivity of tectonic coal more than that of intact coal. This verified the pore structure experimental results. A simplified illustration of the methane migration before and after ScCO2 treatment was proposed to analyze the influence of ScCO2 on the tectonic coal reservoir’s CBM. Hence, the results of this study may provide new insights into CO2-ECBM in tectonic coal reservoirs. Full article
(This article belongs to the Special Issue Sustainability of Fossil Fuels)
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Open AccessArticle Retention of Hydraulic Fracturing Water in Shale: The Influence of Anionic Surfactant
Energies 2018, 11(12), 3342; https://doi.org/10.3390/en11123342
Received: 16 October 2018 / Revised: 24 November 2018 / Accepted: 26 November 2018 / Published: 30 November 2018
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Abstract
A tremendous amount of water-based fracturing fluid with ancillary chemicals is injected into the shale reservoirs for hydraulic fracturing, nearly half of which is retained within the shale matrix. The fate of the retained fracturing fluid is raising some environmental and technical concerns.
[...] Read more.
A tremendous amount of water-based fracturing fluid with ancillary chemicals is injected into the shale reservoirs for hydraulic fracturing, nearly half of which is retained within the shale matrix. The fate of the retained fracturing fluid is raising some environmental and technical concerns. Mitigating these issues requires a knowledge of all the factors possibly contributing to the retention process. Many previous studies have discussed the role of shale properties such as mineralogy and capillarity on fracturing fluid retention. However, the role of some surface active agents like surfactants that are added in the hydraulic fracturing mixture in this issue needs to be understood. In this study, the influence of Internal Olefin Sulfate (IOS), which is an anionic surfactant often added in the fracturing fluid cocktail on this problem was investigated. The effect on water retention of treating two shales “BG-2 and KH-2” with IOS was experimentally examined. These shales were characterized for their mineralogy, total organic carbon (TOC) and surface functional groups. The volume of retained water due to IOS treatment increases by 131% in KH-2 and 87% in BG-2 shale. The difference in the volume of retained uptakes in both shales correlates with the difference in their TOC and mineralogy. It was also inferred that the IOS treatment of these shales reduces methane (CH4) adsorption by 50% in KH-2 and 30% in BG-2. These findings show that the presence of IOS in the composition of fracturing fluid could intensify water retention in shale. Full article
(This article belongs to the Special Issue Sustainability of Fossil Fuels)
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Open AccessArticle Impact of Holder Materials on the Heating and Explosive Breakup of Two-Component Droplets
Energies 2018, 11(12), 3307; https://doi.org/10.3390/en11123307
Received: 25 October 2018 / Revised: 20 November 2018 / Accepted: 23 November 2018 / Published: 27 November 2018
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Abstract
The heating of two-component droplets and the following explosive breakup of those droplets have been extensively studied over the most recent years. These processes are of high interest, since they can significantly improve the performance of many technologies in fuel ignition, thermal and
[...] Read more.
The heating of two-component droplets and the following explosive breakup of those droplets have been extensively studied over the most recent years. These processes are of high interest, since they can significantly improve the performance of many technologies in fuel ignition, thermal and flame liquid treatment, heat carriers based on flue gases, vapors and water droplets, etc. Research throughout the world involves various schemes of droplet heating and supply (or, less frequently, injection) to heating chambers. The most popular scheme features the introduction of a two-component or multi-component droplet onto a holder into the heating chamber. In this research, we study how holder materials affect the conditions and integral characteristics of droplet heating and explosive breakup: heating time until boiling temperature; minimum temperature sufficient for droplet breakup; number and size of fragments in the resulting droplet aerosol, etc. Experiments involve droplets that are produced from flammable (oil) and non-flammable (water) components with significantly different thermophysical and optical properties, as well as boiling temperature and heat of vaporization. The most popular elements with the scientific community, such as ceramic, steel, aluminum, copper, and phosphorus rods, as well as a nichrome wire, serve as holders. We establish the roles of energy inflow from a holder to a droplet, and energy outflow in the opposite direction. We compare the holder results with a supporting thermocouple, recording the drop temperature under a heat transfer provided at 350°C. Finally, we forecast the conditions that are required for a significant improvement in the performance of thermal and flame water treatment through the explosive breakup of two-component droplets. Full article
(This article belongs to the Special Issue Sustainability of Fossil Fuels)
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Open AccessArticle Activation of the Fuels with Low Reactivity Using the High-Power Laser Pulses
Energies 2018, 11(11), 3167; https://doi.org/10.3390/en11113167
Received: 8 October 2018 / Revised: 30 October 2018 / Accepted: 13 November 2018 / Published: 15 November 2018
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Abstract
In this paper we have proposed the simple and effective approach to activation of the low reactivity industrial fuel which can be used immediately inside the furnace. The high-power laser pulses initiates partial gasification of the fuel together with its ultra-fine atomization. The
[...] Read more.
In this paper we have proposed the simple and effective approach to activation of the low reactivity industrial fuel which can be used immediately inside the furnace. The high-power laser pulses initiates partial gasification of the fuel together with its ultra-fine atomization. The gas-aerosol cloud surrounding the initial coal-water slurry droplet can consist of approximately 10% (after absorption of hundred pulses) of the initial droplet weight. The ratio of the syngas and aerosol weights is like 1:2 when pulse intensity is higher than 8 J/cm 2 . The size and velocity distributions of the ultra-fine aerosol particles were analysed using the original realization of the particle tracking velocimetry technique. Full article
(This article belongs to the Special Issue Sustainability of Fossil Fuels)
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Open AccessFeature PaperArticle The Main Elements of a Strategy for Combined Utilization of Industrial and Municipal Waste from Neighboring Regions by Burning it as Part of Composite Fuels
Energies 2018, 11(10), 2534; https://doi.org/10.3390/en11102534
Received: 26 August 2018 / Revised: 20 September 2018 / Accepted: 21 September 2018 / Published: 22 September 2018
Cited by 1 | PDF Full-text (3655 KB) | HTML Full-text | XML Full-text
Abstract
An experimental study has been conducted into the ignition and combustion processes of composite fuel droplets fed into a heated muffle furnace on a holder. Consistent patterns and characteristics of physical and chemical processes have been established for a group of fuel compositions:
[...] Read more.
An experimental study has been conducted into the ignition and combustion processes of composite fuel droplets fed into a heated muffle furnace on a holder. Consistent patterns and characteristics of physical and chemical processes have been established for a group of fuel compositions: wet coal processing waste (a mixture of fine coals and water) 85% + municipal solid waste (wood, or plastic, or rubber) 10% + used oil 5%. Burning a coal-water slurry instead of dry coal dust is characterized by a positive environmental effect. Adding used oil to a coal-water slurry results in better energy performance characteristics of the composite fuel during combustion. Adding fine municipal solid waste (MSW) to the fuel composition makes it possible to effectively recover it by burning in boiler furnaces with energy performance characteristics of combustion and environmental characteristics of flue gases that are as good as those of composite fuel compositions without MSW. Sustainability of the composite fuel ignition process and complete burnout of liquid and solid combustible components have been determined. The values of the guaranteed ignition delay times for droplets with a size (diameter) of about 2 mm have been established for the composite fuel compositions under study in the ambient temperature range 600–1000 °C. The minimum values of ignition delay times are about 3 s, the maximum values are about 15 s under the near-threshold ignition conditions. The obtained findings enabled to elaborate the main elements of the strategy for combined recovery of industrial and municipal waste by burning it as part of composite fuels. Full article
(This article belongs to the Special Issue Sustainability of Fossil Fuels)
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Open AccessArticle Impact of Forest Fuels on Gas Emissions in Coal Slurry Fuel Combustion
Energies 2018, 11(9), 2491; https://doi.org/10.3390/en11092491
Received: 15 August 2018 / Revised: 17 September 2018 / Accepted: 17 September 2018 / Published: 19 September 2018
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Abstract
Anthropogenic emissions from coal combustion pose a serious threat to human wellbeing. One prospective way to solve this problem is by using slurry fuels instead of coal. The problem is especially pressing in China and Russia, so these countries need reliable experimental data
[...] Read more.
Anthropogenic emissions from coal combustion pose a serious threat to human wellbeing. One prospective way to solve this problem is by using slurry fuels instead of coal. The problem is especially pressing in China and Russia, so these countries need reliable experimental data on the SOx and NOx emissions reduction range more than others do. The experiments in this research are based on the components that are typical of Russia. Experimental research was conducted on the way typical forest fuels (ground pine needles, leaves and their mixtures, bark, sawdust, and charcoal) affect the gas emissions from the combustion of slurry fuels based on the wastes. It was established that using forest fuels as additives to coal-water slurries reduces SOx and NOx emissions by 5–91% as compared to coal or to slurries based on used turbine oil. It was revealed that even small concentrations of such additives (7–15%) could result in a several-fold reduction in SOx and NOx. The higher the temperature, the more prominent the role of forest biomass. The calculated complex criterion illustrates that forest fuels increase the performance indicator of fuel suspensions by 1.2–10 times. Full article
(This article belongs to the Special Issue Sustainability of Fossil Fuels)
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