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14 pages, 3471 KiB

Open AccessArticle

Enhanced Methane Production from Anaerobic Co-Digestion of Wheat Straw Rice Straw and Sugarcane Bagasse: A Kinetic Analysis

by Saadia Meraj, Rabia Liaquat, Salman Raza Naqvi, Zeshan Sheikh, Atoofa Zainab, Asif Hussain Khoja, Dagmar Juchelkova and Abdulaziz Atabani

Appl. Sci. 2021, 11(13), 6069; https://doi.org/10.3390/app11136069 - 30 Jun 2021

Cited by 19 | Viewed by 3195

Abstract

Future energy and environmental issues are the major driving force towards increased global utilization of biomass, especially in developing countries like Pakistan. Lignocellulosic residues are abundant in Pakistan. The present study investigated the best-mixed proportion of mechanically pretreated lignocellulosic residues i.e., wheat straw [...] Read more.

Future energy and environmental issues are the major driving force towards increased global utilization of biomass, especially in developing countries like Pakistan. Lignocellulosic residues are abundant in Pakistan. The present study investigated the best-mixed proportion of mechanically pretreated lignocellulosic residues i.e., wheat straw and rice straw (WSRS), bagasse and wheat straw (BAWS), bagasse, and rice straw (BARS), bagasse, wheat straw, and rice straw (BAWSRS) through anaerobic co-digestion. Anaerobic batch mode bioreactors comprising of lignocellulosic proportions and control bioreactors were run in parallel at mesophilic temperature (35 °C) for the substrate to inoculum (S/I) ratio of 1.5 and 2.5. Maximum and stable biomethane production was observed at the substrate to inoculum (S/I) ratio of 1.5, and the highest biomethane yield 339.0089123 NmLCH4/gVS was achieved by co-digestion of wheat straw and rice straw (WSRS) and lowest 15.74 NmLCH4/gVS from bagasse and rice straw (BARS) at 2.5 substrates to inoculum ratio. Furthermore, anaerobic reactor performance was determined by using bio-kinetic parameters i.e., production rate (Rm), lag phase (λ), and coefficient of determination (R2). The bio-kinetic parameters were evaluated by using kinetic models; first-order kinetics, Logistic function model, Modified Gompertz Model, and Transference function model. Among all kinetic models, the Logistic function model provided the best fit with experimental data followed by Modified Gompertz Model. The study suggests that a decrease in methane production was due to lower hydrolysis rate and higher lignin content of the co-digested substrates, and mechanical pretreatment leads to the breakage of complex lignocellulosic structure. The organic matter degradation evidence will be utilized by the biogas digesters developed in rural areas of Pakistan, where these agricultural residues are ample waste and need a technological solution to manage and produce renewable energy. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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13 pages, 4076 KiB

Open AccessArticle

The Impact of Solid Fuel Residential Boilers Exchange on Particulate Matter Air Pollution

by Silvie Koval, Jiri Vytisk, Jana Ruzickova, Helena Raclavska, Hana Skrobankova and Lucie Hellebrandova

Appl. Sci. 2021, 11(12), 5400; https://doi.org/10.3390/app11125400 - 10 Jun 2021

Cited by 2 | Viewed by 2560

Abstract

Combustion processes, including the use of solid fuels for residential heating, are a widespread custom for many households. Residential heating is a significant source of ambient air pollution, yet it varies greatly by geography, meteorologic conditions, the prevalence of the type of solid [...] Read more.

Combustion processes, including the use of solid fuels for residential heating, are a widespread custom for many households. Residential heating is a significant source of ambient air pollution, yet it varies greatly by geography, meteorologic conditions, the prevalence of the type of solid fuel and the technologies used. This study evaluates whether residential heating affects the air quality through modelling three given scenarios of solid fuel boiler exchange at selected locations and comparing the results with measured data. The findings of this study suggest that according to the modelled data, the main air pollution contributor is residential heating since Dolni Lhota (daily average of PM₁₀ = 44.13 μg·m⁻³) and Kravare (daily average of PM₁₀ = 43.98 μg·m⁻³) are locations with no industry in contrast to heavily industrial Vratimov (daily average of PM₁₀ = 34.38 μg·m⁻³), which were modelled for the heating season situation. Nevertheless, actual measurements of PM₁₀ during the same period suggest that the average levels of air pollution were significantly higher than the modelled values for Dolni Lhota by 64% and for Kravare by 51%. Thus, it was assumed that PM long-range or/and transboundary transports were involved. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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23 pages, 2894 KiB

Open AccessArticle

An Influence of the Fuel Type on Element Behaviour in Domestic Boilers with Respect to the Circular Economy

by Helena Raclavská, Pavel Kantor, Jana Růžičková, Marek Kucbel, Barbora Švédová, Karolina Slamová, Šárka Flodrová and Dagmar Juchelková

Appl. Sci. 2021, 11(11), 4980; https://doi.org/10.3390/app11114980 - 28 May 2021

Cited by 2 | Viewed by 2569

Abstract

The use of waste from the regional production of waste wood, waste paper, and cardboard in the form of briquettes may be causing an increase in local emissions, both of major elements and trace elements. When burning paper and cardboard briquettes, more than [...] Read more.

The use of waste from the regional production of waste wood, waste paper, and cardboard in the form of briquettes may be causing an increase in local emissions, both of major elements and trace elements. When burning paper and cardboard briquettes, more than 70% of Mn, Zn, As, and Pb is released into the air from the total content of trace elements in the fuel. The largest amounts of major and trace elements are released when burning paper briquettes (56 g/kg of fuel); half of these amounts are released from burning briquettes from waste wood and coal (23 g/kg of fuel). The pursuit of alternative uses for those cardboard components that are not suitable for recycling cannot be directed to the production of briquettes for residential combustion in the framework of the application of the principles of the circular economy. In particular, the high concentrations of undesirable elements in the emissions released in the gas phase into the atmosphere are an obstacle existing even when the parameters of the PM₁₀ emissions of a boiler are met. This is related to the high ash content of the cardboard (13.5%). Waste paper or cardboard could be added to waste wood at a maximum of 10% to make the pollution produced comparable to the burning of coal briquettes. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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13 pages, 5972 KiB

Open AccessArticle

Dependence of the Flue Gas Flow on the Setting of the Separation Baffle in the Flue Gas Tract

by Nikola Čajová Kantová, Alexander Čaja, Marek Patsch, Michal Holubčík and Peter Ďurčanský

Appl. Sci. 2021, 11(7), 2961; https://doi.org/10.3390/app11072961 - 25 Mar 2021

Cited by 8 | Viewed by 2123

Abstract

With the combustion of solid fuels, emissions such as particulate matter are also formed, which have a negative impact on human health. Reducing their amount in the air can be achieved by optimizing the combustion process as well as the flue gas flow. [...] Read more.

With the combustion of solid fuels, emissions such as particulate matter are also formed, which have a negative impact on human health. Reducing their amount in the air can be achieved by optimizing the combustion process as well as the flue gas flow. This article aims to optimize the flue gas tract using separation baffles. This design can make it possible to capture particulate matter by using three baffles and prevent it from escaping into the air in the flue gas. The geometric parameters of the first baffle were changed twice more. The dependence of the flue gas flow on the baffles was first observed by computational fluid dynamics (CFD) simulations and subsequently verified by the particle imaging velocimetry (PIV) method. Based on the CFD results, the most effective is setting 1 with the same boundary conditions as those during experimental PIV measurements. Setting 2 can capture 1.8% less particles and setting 3 can capture 0.6% less particles than setting 1. Based on the stoichiometric calculations, it would be possible to capture up to 62.3% of the particles in setting 1. The velocities comparison obtained from CFD and PIV confirmed the supposed character of the turbulent flow with vortexes appearing in the flue gas tract, despite some inaccuracies. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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11 pages, 2901 KiB

Open AccessArticle

Simulation of Biomass Combustion with Modified Flue Gas Tract

by Nikola Čajová Kantová, Sławomir Sładek, Jozef Jandačka, Alexander Čaja and Radovan Nosek

Appl. Sci. 2021, 11(3), 1278; https://doi.org/10.3390/app11031278 - 30 Jan 2021

Cited by 9 | Viewed by 2569

Abstract

The combustion of biomass is accompanied by the formation of particulate matter, the presence of which in the atmosphere harms human health. It is important to show the issues of reducing these pollutants and their impact on human health. This article focuses on [...] Read more.

The combustion of biomass is accompanied by the formation of particulate matter, the presence of which in the atmosphere harms human health. It is important to show the issues of reducing these pollutants and their impact on human health. This article focuses on the process of biomass combustion. The used model consists of two parts: the combustion chamber and the flue gas tract. The article shows four types of modification of the flue gas tract designed to reduce the amount of particulate matter in the atmosphere. Baffles are located in the flue gas tract, which is designed to capture the particulate matter. The final model is simulated by turbulent–viscosity models, k-ε realizable model, and then k-ω shear stress transport model. The interaction between turbulence and chemical reactions is expressed by using the Eddy Dissipation Concept model. The results then show different profiles of temperature, velocity, and particle distribution. Based on the evaluated data from two different calculations, it can be concluded that the baffles have a significant effect on the reduction of particulate matter in the atmosphere. The used baffles are able to capture mainly particles with a diameter greater than 100 µm. A significant number of particles with a diameter lower than 100 µm flows from the flue gas tract to the surrounding environment. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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13 pages, 3053 KiB

Open AccessArticle

Thermogravimetric Study of Refuse Derived Fuel Produced from Municipal Solid Waste of Kazakhstan

by Botagoz Kuspangaliyeva, Botakoz Suleimenova, Dhawal Shah and Yerbol Sarbassov

Appl. Sci. 2021, 11(3), 1219; https://doi.org/10.3390/app11031219 - 29 Jan 2021

Cited by 20 | Viewed by 3753

Abstract

Efficient waste management, including proper utilization of municipal solid waste (MSW), is imperative for a sustainable future. Among several management options, pyrolysis and combustion of MSW has regained interest because of improved combustion techniques. This work aims to investigate the thermal conversion and [...] Read more.

Efficient waste management, including proper utilization of municipal solid waste (MSW), is imperative for a sustainable future. Among several management options, pyrolysis and combustion of MSW has regained interest because of improved combustion techniques. This work aims to investigate the thermal conversion and combustion characteristics of refuse derived solid fuel (RDF) samples and its individual compounds collected from Nur-Sultan’s MSW landfills. The waste-derived solid RDF samples originally consist of textile, mixed paper, and mixed plastic. In particular, the samples, including RDF and its three constituent components, were analyzed in the temperature range of 25 to 900 °C, at three different heating rates, by thermogravimetric method. The gross calorific value for RDF derived from Nur-Sultan’s MSW was determined to be 23.4 MJ/kg. The weight loss rates of the samples, differential thermogravimetry (DTG), and kinetic analysis were compared between individual RDF components and for the mixed RDF. Combustion kinetics models were calculated using Flynn–Wall–Ozawa (FWO), Kissinger–Akahira–Sunose (KAS), and Friedman methods. The results revealed that first decomposition of RDF samples was observed at the range of 180–370 °C. Moreover, the activation energy for conversion of RDF was observed to be the highest among the constituent components and gradually decreased from 370 to 140 kJ/kmol. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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8 pages, 1840 KiB

Open AccessArticle

Effect of Paper Sludge and Dendromass on Properties of Phytomass Pellets

by Radovan Nosek, Alexander Backa, Peter Ďurčanský, Michal Holubčík and Jozef Jandačka

Appl. Sci. 2021, 11(1), 65; https://doi.org/10.3390/app11010065 - 23 Dec 2020

Cited by 11 | Viewed by 1755

Abstract

Woody and agricultural wastes are important fuels in many countries, and have the potential of being even more important in the future. The main problems of plant biomass combustion are low ash melting temperatures and increased emissions. The most widely used treatment to [...] Read more.

Woody and agricultural wastes are important fuels in many countries, and have the potential of being even more important in the future. The main problems of plant biomass combustion are low ash melting temperatures and increased emissions. The most widely used treatment to solve the problem of low ash melting point is blending a fuel with an additive. In this work, pellets were produced from wheat straw containing wood sawdust and paper sludge in the following proportions 40:40:20 and 45:45:10 (straw/sawdust/paper sludge). The purpose of this work was to study the influence of sludge and dendromass on the straw pellet parameters and combustion process. The highest calorific value of 15.71 MJ kg⁻¹ was registered for a sample with a 10% paper sludge concentration. The effectiveness of paper sludge was proved, and the ash melting temperature was increased from 1025 to 1328 °C for the same sample. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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15 pages, 1630 KiB

Open AccessArticle

Economic Efficiency Assessment of Using Wood Waste in Cogeneration Plants with Multi-Stage Gasification

by Oleg Marchenko, Sergei Solomin, Alexander Kozlov, Vitaly Shamanskiy and Igor Donskoy

Appl. Sci. 2020, 10(21), 7600; https://doi.org/10.3390/app10217600 - 28 Oct 2020

Cited by 14 | Viewed by 2950

Abstract

The aim of this work is to assess the effectiveness of biomass gasification power plants in Russia (Irkutsk region) and compare them with other types of electricity and heat cogeneration systems. Biomass, which is waste from logging and wood processing, is considered as [...] Read more.

The aim of this work is to assess the effectiveness of biomass gasification power plants in Russia (Irkutsk region) and compare them with other types of electricity and heat cogeneration systems. Biomass, which is waste from logging and wood processing, is considered as fuel for gasification plants. As a criterion, the cost of energy is used. Analytical relations are obtained for the cost of electric energy at a given cost of thermal energy and vice versa, thermal energy at a given cost of electric energy. These relationships are applied to assess the economic efficiency and compare small-power plants (up to 200–500 kW) such as mini-combined heat and power (CHP) on fuel chips and fuel pellets, coal-fired CHP and gas and liquid fuel power plants (gas-piston and diesel power plants). The latter are equipped with heat recovery boilers and supply consumers with heat and the electric power simultaneously. The calculation results show that the cost of electricity when using wood fuel is significantly less than the cost of electricity from a diesel power plant due to the use of cheaper fuel. In this regard, for autonomous energy systems of small power, especially near logging points, energy supply from biomass gasification power plants is a preferable solution than the use of diesel power plants. Wood fired energy cogeneration systems (mini-CHP) can also successfully compete with coal and gas power plants if they have cheap wood fuel at their location. With the introduction of carbon dioxide emissions charges, the use of not only wood chips, but also pellets becomes competitive in comparison with coal and gas. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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10 pages, 1919 KiB

Open AccessArticle

Investigation of Pellet Properties Produced from a Mix of Straw and Paper Sludge

by Radovan Nosek, Sebastian Werle, Aleksandra Borsukiewicz, Agnieszka Żelazna and Grzegorz Łagód

Appl. Sci. 2020, 10(16), 5450; https://doi.org/10.3390/app10165450 - 6 Aug 2020

Cited by 16 | Viewed by 2662

Abstract

Global energy consumption is increasing every year, and, despite their many negative impacts, fossil fuels are a major source of energy, but their reserves are gradually depleting. One of the promising but underutilized resources is plant biomass (phytomass). The main problem of plant [...] Read more.

Global energy consumption is increasing every year, and, despite their many negative impacts, fossil fuels are a major source of energy, but their reserves are gradually depleting. One of the promising but underutilized resources is plant biomass (phytomass). The main problem of plant biomass combustion is the low melting temperature of ash, but there are also problems with corrosion of heat exchangers and clogging of heat-exchanging surfaces. This work is concerned with the production of straw pellets in order to increase the melting temperature of ash by adding an additive. The paper sludge contains substances that can increase the melting point of ash and was therefore added to the pellet samples. This additive was mixed with straw in ratios from 90:10, 80:20 and 70:30 (straw/paper sludge). The use of paper sludge showed positive effects on increasing the melting temperature of the ash samples. The deformation temperature of the ash has already risen from 1020 to 1260 °C after the addition of 10% sludge, which is comparable to wood pellets. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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17 pages, 1292 KiB

Open AccessArticle

Spraying of Viscous Liquids: Influence of Fluid-Mixing Mechanism on the Performance of Internal-Mixing Twin-Fluid Atomizers

by Marek Mlkvik, Jan Jedelsky, Heike P. Karbstein and Volker Gaukel

Appl. Sci. 2020, 10(15), 5249; https://doi.org/10.3390/app10155249 - 30 Jul 2020

Cited by 9 | Viewed by 4101

Abstract

The thermal usage of liquid fuels implies their combustion, which is a process strongly influenced by the performance of the atomizer, which disrupts the fuel into drops of the required sizes. The spray quality of the twin-fluid atomizers with internal mixing (IM-TFA) is [...] Read more.

The thermal usage of liquid fuels implies their combustion, which is a process strongly influenced by the performance of the atomizer, which disrupts the fuel into drops of the required sizes. The spray quality of the twin-fluid atomizers with internal mixing (IM-TFA) is primarily influenced by the two-phase flow pattern inside the mixing chamber. We studied the performance of the four types of the IM-TFA nozzles by the optical diffraction system (Malvern Spraytec) to answer the question of how the mixing chamber design influences the spray quality at low atomizing gas consumption. We tested the effervescent atomizer in outside-in-liquid (OIL) and outside-in-gas (OIG) configurations, the Y-jet nozzle and new nozzle design, and the CFT atomizer when spraying model liquids with the viscosities comparable to the common fuels (

μ = 60 and 143

mPa

\cdot

s). We found that the effervescent atomizer performance was strongly influenced by the configuration of the inlet ports. Although the OIL configuration provided the best spray quality (

D_{32}

= 72

μ

m), with the highest efficiency (0.16%), the OIG nozzle was characterized by unstable work and poor spray quality. Both the devices were sensitive to liquid viscosity. The Y-jet nozzle provided a stable performance over the liquid viscosity spectrum, but the spray quality and efficiency were lower than for the OIL nozzle. Our findings can be used to improve the performance of the common IM-TFA types or to design new atomizers. The results also provide an overview of the tested atomizers’ performances over the wide range of working conditions and, thus, help to define the application potential of the tested nozzle designs. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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32 pages, 511 KiB

Open AccessArticle

Insights into PCDD/Fs and PAHs in Biomass Boilers Envisaging Risks of Ash Use as Fertilizers

by Helena Lopes and Susana Proença

Appl. Sci. 2020, 10(14), 4951; https://doi.org/10.3390/app10144951 - 18 Jul 2020

Cited by 12 | Viewed by 3373

Abstract

Since ashes are a possible source of Persistent Organic Pollutants (POPs) contamination, their application in soils must be subject to more study and control. In this scope, feed residual forest biomasses and biomass ashes, collected along one year in four biomass power stations, [...] Read more.

Since ashes are a possible source of Persistent Organic Pollutants (POPs) contamination, their application in soils must be subject to more study and control. In this scope, feed residual forest biomasses and biomass ashes, collected along one year in four biomass power stations, were characterized mainly for their polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and Polycyclic Aromatic Hydrocarbons (PAHs) contents. The biomasses present concerning levels of Cl (0.04–0.28%) that may lead to PCDD/Fs formation. The biomasses also contain OCDD (29–260 ng/kg) and 1,2,3,4,6,7,8-HpCDD (35 ng/kg) that may contribute to increased Toxic Equivalents (TEQs) of ashes, possibly involving dechlorination and ash enrichment mechanisms. While the WHO₂₀₀₅-TEQs in bottom ashes (14–20 ng TEQ/kg) reaches the proposed limit (20 ng TEQ/kg) for ash use as fertilizers, in fly ashes (35–1139 ng TEQ/kg) the limit is exceeded. PAHs are below 0.02 mg/kg in bottom ashes and 1.5–2.5 mg/kg in fly ashes, complying with the proposed limit of 6 mg/kg. As bottom and fly ash streams may contain different ash flows, a clear definition of ash mixes is required. Correlations between unburned carbon (C), PAHs and PCDD/Fs were not found, which highlights the need for compulsory PCDD/Fs analysis in ashes, independently of their origin, burnout degree or levels of other contaminants. A sensitivity analysis was performed to evaluate the impact of handling non-detected values, which showed more impact for TEQs values close to the proposed regulatory limit of PCDD/Fs. These findings highlight the need to define reporting protocols of analytical results for risk assessments and conformity evaluation. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

12 pages, 2333 KiB

Open AccessArticle

Experimental Study of Entrainment and Mixing of Renewable Active Particles in Fluidized Beds

by Botond Szucs, Mohamed Sobhi Alagha and Pal Szentannai

Appl. Sci. 2020, 10(12), 4268; https://doi.org/10.3390/app10124268 - 22 Jun 2020

Cited by 1 | Viewed by 2001

Abstract

Fluidized bed combustors were initially designed and built basically for the utilization of fossil fuels, mostly coal. The actual worldwide trend of transitioning from fossil fuels to renewables requires sufficient knowledge on the fluid mechanics of these new particle types because of the [...] Read more.

Fluidized bed combustors were initially designed and built basically for the utilization of fossil fuels, mostly coal. The actual worldwide trend of transitioning from fossil fuels to renewables requires sufficient knowledge on the fluid mechanics of these new particle types because of the significant differences in their shapes, sizes, densities, and homogeneities. This article presents experimental results on the particle entrainment and mixing of some industrially relevant fuels such as solid refused fuel/refuse derived fuel (SRF/RDF), bark, sunflower shell, and wheat shell. The measurements were performed on a lab-scale fluidized bed experimental facility. The results show that sunflower shell is entrained in the highest degree; however, at very low velocity, the entrainment of wheat shell is the most intensive. The entrainment behaviors of the investigated SRF and bark samples are similar. On the other hand, the mixing results showed that the SRF has relatively high mass fractions in the bottom and centeral regions of the fluidized bed at low superficial velocities, while at elevated velocities, the entire mass of this fuel is shifted upwards. Interestingly, just the opposite tendency can be observed in cases of all other investigated biomass fuels. Finally, the nonspherical renewable active particles have markedly higher concentrations in the bottom region of the bed compared to spherical ones. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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19 pages, 8263 KiB

Open AccessArticle

Combustion and Performance Study of Low-Displacement Compression Ignition Engines Operating with Diesel–Biodiesel Blends

by Guillermo Valencia Ochoa, Carlos Acevedo Peñaloza and Jorge Duarte Forero

Appl. Sci. 2020, 10(3), 907; https://doi.org/10.3390/app10030907 - 30 Jan 2020

Cited by 29 | Viewed by 2999

Abstract

This study investigated the influence of different biodiesel blends produced from residual sunflower oil and palm oil from agroindustry liquid waste on the characteristics of the combustion process, performance, and emissions in a single-cylinder diesel engine. For the analysis of the combustion process, [...] Read more.

This study investigated the influence of different biodiesel blends produced from residual sunflower oil and palm oil from agroindustry liquid waste on the characteristics of the combustion process, performance, and emissions in a single-cylinder diesel engine. For the analysis of the combustion process, a diagnostic model was developed based on the cylinder pressure signal, which allows the calculation of the heat release rate, the accumulated heat rate, and the temperature in the combustion chamber. This is to assess the influence of these parameters on engine emissions. The experiments on the diesel engine were carried out using five types of fuel: conventional diesel, two biodiesel blends of residual palm oil (PB5 and PB10), and two biodiesel blends formed with palm oil and sunflower oil residues (PB5SB5 and PB10SB5). The engine was running in four different modes, which covered its entire operating area. Experimental results show that the in-cylinder pressure curves decrease as the percentage of biodiesel in the fuel increases. Similarly, the results showed a decrease in the heat release rate for biodiesel blends. The diagrams of the accumulated heat release curves were larger for fuels with higher biodiesel content. This effect is reflected in the thermal efficiency of biodiesel blends since the maximum thermal efficiencies were 29.4%, 30%, 30.6%, 31.2%, and 31.8% for PB10SB5, PB5SB5, PB10, PB5, and diesel, respectively. The emission analysis showed that the blends of biodiesel PB5SB5 and PB10SB allowed a greater reduction in the emissions of CO, CO₂, HC, and opacity of smoke in all the modes of operation tested, in comparison with the blends of biodiesel PB5 and PB10. However, NOx emissions increased. In general, biodiesel with the percentage of residual sunflower oil does not cause a significant change in the combustion process and engine performance, when compared to biodiesel that includes only residual palm oil. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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25 pages, 4179 KiB

Open AccessFeature PaperReview

Renewable Waste-to-Energy in Southeast Asia: Status, Challenges, Opportunities, and Selection of Waste-to-Energy Technologies

by Maw Maw Tun, Petr Palacky, Dagmar Juchelkova and Vladislav Síťař

Appl. Sci. 2020, 10(20), 7312; https://doi.org/10.3390/app10207312 - 19 Oct 2020

Cited by 19 | Viewed by 9001

Abstract

Rapid urban population growth that boosts increased waste generation and electricity demand has led to a possible alternative waste-to-energy solution in Southeast Asia. Despite some issues related to the development of the waste-to-energy sector such as public perception, all stakeholder involvement, public–private partnerships, [...] Read more.

Rapid urban population growth that boosts increased waste generation and electricity demand has led to a possible alternative waste-to-energy solution in Southeast Asia. Despite some issues related to the development of the waste-to-energy sector such as public perception, all stakeholder involvement, public–private partnerships, funding, and climate factors, some Southeast Asian countries have made a reasonably successful step toward the developed technologies. Therefore, this study aimed to highlight an overview of the waste-to-energy sector in Southeast Asian countries to specify the status, challenges, opportunities, and selection of the technologies suited for the specific country. In order to achieve this aim, the study collected, synthesized, and evaluated data about waste resources, current waste management, waste-to-energy utilization, and its potential in the region based on published research papers and policy reports. It was found that the major waste-to-energy technologies in the region are incineration, landfills with gas capture, and anaerobic digestion. The total quantity of the waste-to-energy capacity from landfill biogas plants, incineration plants, and other waste-to-energy practices in the region accounts for over 323 MW at present and is expected to grow to double its current size by 2022. Meanwhile, by 2030, the realizable generation potential from renewable municipal waste in six Southeast Asian countries (Indonesia, Malaysia, Philippines, Singapore, Thailand, and Vietnam) amounts to 17.26 terawatt-hours (TWh). The study also specifies the requirements and considerations for the selection of waste-to-energy technologies, as well as the dimensions related to the development of the technologies. Additionally, four major aspects—technical, financial, environmental, and social and political—regarding the challenges and opportunities for the development of these technologies are considered. The challenges and opportunities related to the development of waste-to-energy in the region reveal how to overcome the drawbacks and to grasp the benefits at present and in the near future. Finally, the study is concluded with suggestions for the selection of the technologies in the region. Full article

(This article belongs to the Special Issue Thermal Utilization of Fuels)

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