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Co-combustion of biomass-based fuels and fossil fuels in power plant boilers, utility boilers, and process furnaces is a widely acknowledged means of efficient heat and power production, offering higher power production than comparable systems with sole biomass combustion. This, in combination with CO2 and other greenhouse gases abatement and low specific cost of system retrofit to co-combustion, counts among the tangible advantages of co-combustion application. Technical and operational issues regarding the accelerated fouling, slagging, and corrosion risk, as well as optimal combustion air distribution impact on produced greenhouse gases emissions and ash properties, belong to intensely researched topics nowadays in parallel with the combustion aggregates design optimization, the advanced feed pretreatment techniques, and the co-combustion life cycle assessment. This review addresses the said topics in a systematic manner, starting with feed availability, its pretreatment, fuel properties and combustor types, followed by operational issues, greenhouse gases, and other harmful emissions trends, as well as ash properties and utilization. The body of relevant literature sources is table-wise classified according to numerous criteria pertaining to individual paper sections, providing a concise and complex insight into the research methods, analyzed systems, and obtained results. Recent advances achieved in individual studies and the discovered synergies between co-combusted fuels types and their shares in blended fuel are summed up and discussed. Actual research challenges and prospects are briefly touched on as well.
Miroslav Variny; Augustín Varga; Miroslav Rimár; Ján Janošovský; Ján Kizek; Ladislav Lukáč; Gustáv Jablonský; Otto Mierka. Advances in Biomass Co-Combustion with Fossil Fuels in the European Context: A Review. Processes 2021, 9, 100 .
AMA StyleMiroslav Variny, Augustín Varga, Miroslav Rimár, Ján Janošovský, Ján Kizek, Ladislav Lukáč, Gustáv Jablonský, Otto Mierka. Advances in Biomass Co-Combustion with Fossil Fuels in the European Context: A Review. Processes. 2021; 9 (1):100.
Chicago/Turabian StyleMiroslav Variny; Augustín Varga; Miroslav Rimár; Ján Janošovský; Ján Kizek; Ladislav Lukáč; Gustáv Jablonský; Otto Mierka. 2021. "Advances in Biomass Co-Combustion with Fossil Fuels in the European Context: A Review." Processes 9, no. 1: 100.
Air infiltration into the combustion chambers of industrial furnaces is an unwanted phenomenon causing loss of thermal efficiency, fuel consumption increase, and the subsequent increase in operating costs. In this study, a novel design for a rotary tilting furnace door with improved construction features is proposed and tested experimentally in a laboratory-scale furnace, aimed at air infiltration rate reduction by decreasing the gap width between the static furnace door and the rotating body. Temperatures in the combustion chamber and oxygen content in the dry flue gas were measured to document changes in the combustion process with the varying gap width. Volumetric flow values of infiltrating air calculated based on measured data agree well with results of numerical simulations performed in ANSYS and with the reference calculation procedure used in relevant literature. An achievable air infiltration reduction of up to 50% translates into fuel savings of around 1.79 to 12% of total natural gas consumption of the laboratory-scale furnace. The average natural gas consumption increase of around 1.6% due to air infiltration into industrial-scale furnaces can thus likewise be halved, representing fuel savings of almost 0.3 m3 per ton of charge.
Róbert Dzurňák; Augustin Varga; Gustáv Jablonský; Miroslav Variny; Réne Atyafi; Ladislav Lukáč; Marcel Pástor; Ján Kizek. Influence of Air Infiltration on Combustion Process Changes in a Rotary Tilting Furnace. Processes 2020, 8, 1292 .
AMA StyleRóbert Dzurňák, Augustin Varga, Gustáv Jablonský, Miroslav Variny, Réne Atyafi, Ladislav Lukáč, Marcel Pástor, Ján Kizek. Influence of Air Infiltration on Combustion Process Changes in a Rotary Tilting Furnace. Processes. 2020; 8 (10):1292.
Chicago/Turabian StyleRóbert Dzurňák; Augustin Varga; Gustáv Jablonský; Miroslav Variny; Réne Atyafi; Ladislav Lukáč; Marcel Pástor; Ján Kizek. 2020. "Influence of Air Infiltration on Combustion Process Changes in a Rotary Tilting Furnace." Processes 8, no. 10: 1292.
Nitrogen oxides (NOx) from combustion contribute significantly to atmospheric pollution. An experimental setup was employed to investigate the application of three primary denitrification methods, i.e., reburning (staged combustion), overfiring air (OFA), and flue-gas recirculation (FGR), individually and in combination, combusting natural gas (NG) and propane–butane gas (PBG). Fuel heat inputs of 16 and 18 kW and air excess coefficients of 1.1 and 1.2, respectively, were tested. The highest individual denitrification efficiency of up to 74% was obtained for FGR, followed by reburning and OFA. A denitrification efficiency between 8.9% (reburning + OFA) and 72% (reburning + OFA + FGR) with NG combustion was observed. Using a 20% FGR rate yielded denitrification efficiency of 74% for NG and 65% for PBG and also led to a significant decrease in carbon monoxide (CO) emissions, so this can be recommended as the most efficient denitrification and de-CO method in small-scale furnaces. Reburning alone led to a sharp, more than 12-fold increase in CO emissions compared to the amount without any other method application. The presented results and the difference between our experimental data and the literature data acquired in some other studies indicate the need for further research.
Ladislav Lukáč; Miroslav Rimár; Miroslav Variny; Ján Kizek; Peter Lukáč; Gustáv Jablonský; Ján Janošovský; Marcel Fedák. Experimental Investigation of Primary De-NOx Methods Application Effects on NOx and CO Emissions from a Small-Scale Furnace. Processes 2020, 8, 940 .
AMA StyleLadislav Lukáč, Miroslav Rimár, Miroslav Variny, Ján Kizek, Peter Lukáč, Gustáv Jablonský, Ján Janošovský, Marcel Fedák. Experimental Investigation of Primary De-NOx Methods Application Effects on NOx and CO Emissions from a Small-Scale Furnace. Processes. 2020; 8 (8):940.
Chicago/Turabian StyleLadislav Lukáč; Miroslav Rimár; Miroslav Variny; Ján Kizek; Peter Lukáč; Gustáv Jablonský; Ján Janošovský; Marcel Fedák. 2020. "Experimental Investigation of Primary De-NOx Methods Application Effects on NOx and CO Emissions from a Small-Scale Furnace." Processes 8, no. 8: 940.
The performance of an adsorptive heat-moisture regenerator based on a silica gel–sodium sulphate composite adsorbent was studied. The correlation between the adsorbent composition and structural characteristics of the laboratory-scale device was investigated. An algorithm for the calculation of the efficiency factors of the adsorptive regenerator was further developed. The suggested algorithm calculates the operational parameters, including the temperatures, humidities and volumetric flows of internal and external air, and estimates the regenerator’s performance via temperature and moisture efficiency factors, total adsorption and time needed to achieve maximum adsorption, air pressure loss and fan power input. The validity of the calculation results obtained using the proposed algorithm was confirmed experimentally. Temperature efficiency factor, air pressure loss and fan power consumption are crucial parameters for the estimation of the optimal operating regime of an adsorptive heat-moisture regenerator. The correlation between meteorological conditions and efficiency factors was assessed and applied in a simulation of residential house-scale air conditioning unit operation. Maximal values of temperature efficiency factor were found at internal and external air temperatures of 15 to 20 °C and −5 to 0 °C, respectively. Moisture efficiency factors were observed to reach their maximum at the absolute humidities of external and internal air of 4.0 to 5.0 g/m3 and 2.75 to 3.0 g/m3, respectively. The fan power consumption of the adsorptive heat-moisture regenerator was found to be comparable to or even lower than that of commercial air conditioning units used in comparably voluminous interiors.
Elena Belyanovskaya; Miroslav Rimár; Roman Lytovchenko; Miroslav Variny; Kostyantyn Sukhyy; Oleksandr Yeromin; Mikhailo Sykhyy; Elena Prokopenko; Irina Sukha; Mikhailo Gubinskyi; Ján Kizek. Performance of an Adsorptive Heat-Moisture Regenerator Based on Silica Gel–Sodium Sulphate. Sustainability 2020, 12, 5611 .
AMA StyleElena Belyanovskaya, Miroslav Rimár, Roman Lytovchenko, Miroslav Variny, Kostyantyn Sukhyy, Oleksandr Yeromin, Mikhailo Sykhyy, Elena Prokopenko, Irina Sukha, Mikhailo Gubinskyi, Ján Kizek. Performance of an Adsorptive Heat-Moisture Regenerator Based on Silica Gel–Sodium Sulphate. Sustainability. 2020; 12 (14):5611.
Chicago/Turabian StyleElena Belyanovskaya; Miroslav Rimár; Roman Lytovchenko; Miroslav Variny; Kostyantyn Sukhyy; Oleksandr Yeromin; Mikhailo Sykhyy; Elena Prokopenko; Irina Sukha; Mikhailo Gubinskyi; Ján Kizek. 2020. "Performance of an Adsorptive Heat-Moisture Regenerator Based on Silica Gel–Sodium Sulphate." Sustainability 12, no. 14: 5611.
Alkylate produced by catalyzed reaction of isobutane and olefin-rich streams is a desired component for gasoline blending. Fractionation of the alkylation reactor effluent is energy demanding due to the presence of close boiling point components and solutions cutting its energy intensity; expenses associated with this process are investigated intensely nowadays. This paper presents a novel conceptual design and techno-economic analysis of alkylation reaction effluent fractionation revamp to reach a cut in energy costs of the fractionation process without the need to revamp the rectification columns themselves, providing thus an alternative approach to a more sustainable alkylation process. Two cases are considered—A. additional steam turbine installation or B. combustion engine-driven heat pump-assisted rectification. Mathematical modeling of the considered system and its revamp is applied using the “frozen technology” approach. Real system operation features and seasonal variations are included considering the refinery’s combined heat and power (CHP) unit operation and CO2 emissions balance both internal and external to the refinery. Case A yields an expectable yearly benefit (saved energy minus additionally consumed energy minus CO2 emissions increase; expressed in financial terms) of €110–140 thousand, net present value (NPV) of −€18 to €272 thousand and produces 3.3 GWh/year of electric energy. Case B delivers a benefit of €900–1200 thousand, NPV of −€293 to €2823 thousand while producing 33 GWh/year of electricity. Both cases exhibit analogous simple payback periods (8–10 years). Marginal electric efficiency of Case B (78.3%) documents the energy integration level in this case, exploiting the system and CHP unit operation synergies. CHP unit summer operation mode and steam network restrictions significantly affect the seasonal benefit of Case B. CO2 emissions increase in both cases, Case A and Case B, considering the refinery level. However, including external CO2 emissions leads to emissions decrease in both cases of up to 26 kton/year (Case B.) The presented results document the viability of the proposed concepts comparable to the traditional (reference) solution of a high performance (COP = 8) heat pump while their performance sensitivity stresses the need for complex techno-economic assessment.
Miroslav Variny; Patrik Furda; Ladislav Švistun; Miroslav Rimár; Ján Kizek; Norbert Kováč; Peter Illés; Ján Janošovský; Jakub Váhovský; Otto Mierka. Novel Concept of Cogeneration-Integrated Heat Pump-Assisted Fractionation of Alkylation Reactor Effluent for Increased Power Production and Overall CO2 Emissions Decrease. Processes 2020, 8, 183 .
AMA StyleMiroslav Variny, Patrik Furda, Ladislav Švistun, Miroslav Rimár, Ján Kizek, Norbert Kováč, Peter Illés, Ján Janošovský, Jakub Váhovský, Otto Mierka. Novel Concept of Cogeneration-Integrated Heat Pump-Assisted Fractionation of Alkylation Reactor Effluent for Increased Power Production and Overall CO2 Emissions Decrease. Processes. 2020; 8 (2):183.
Chicago/Turabian StyleMiroslav Variny; Patrik Furda; Ladislav Švistun; Miroslav Rimár; Ján Kizek; Norbert Kováč; Peter Illés; Ján Janošovský; Jakub Váhovský; Otto Mierka. 2020. "Novel Concept of Cogeneration-Integrated Heat Pump-Assisted Fractionation of Alkylation Reactor Effluent for Increased Power Production and Overall CO2 Emissions Decrease." Processes 8, no. 2: 183.
This study of process heat source change in industrial conditions has been developed to aid engineers and energy managers with working towards sustainable production. It allows for an objective assessment from energetic, environmental, and economic points of view, thereby filling the gap in the systematic approach to this problem. This novel site-wide approach substantially broadens the traditional approach, which is based mostly on “cheaper” and “cleaner” process heat sources’ application and only takes into account local changes, while neglecting the synergic effect on the whole facility’s operations. The mathematical model employed assesses the performance change of all the affected refinery parts. The four proposed aromatic splitting process layouts, serving as a case study, indicate feasible heat and condensate conservation possibilities. Although the estimated investment needed for the most viable layout is over €4.5 million, its implementation could generate benefits of €0.5–1.5 million/year, depending on the fuel and energy prices as well as on the carbon dioxide emissions cost. Its economics is most sensitive to the steam to refinery fuel gas cost ratio, as a 10% change alters the resulting benefit by more than €0.5 million. The pollutant emissions generated in the external power production process contribute significantly to the total emissions balance.
Miroslav Variny; Dominika Jediná; Ján Kizek; Peter Illés; Ladislav Lukáč; Ján Janošovský; Marián Lesný. An Investigation of the Techno-Economic and Environmental Aspects of Process Heat Source Change in a Refinery. Processes 2019, 7, 776 .
AMA StyleMiroslav Variny, Dominika Jediná, Ján Kizek, Peter Illés, Ladislav Lukáč, Ján Janošovský, Marián Lesný. An Investigation of the Techno-Economic and Environmental Aspects of Process Heat Source Change in a Refinery. Processes. 2019; 7 (11):776.
Chicago/Turabian StyleMiroslav Variny; Dominika Jediná; Ján Kizek; Peter Illés; Ladislav Lukáč; Ján Janošovský; Marián Lesný. 2019. "An Investigation of the Techno-Economic and Environmental Aspects of Process Heat Source Change in a Refinery." Processes 7, no. 11: 776.
The paper presents the results of the optimisation of burner nozzle diameters during the combustion of natural gas under the conditions of increasing oxygen concentrations in the oxidizer in aluminium melting processes in drum rotary furnaces. The optimisation of outlet nozzle diameters was performed employing the method of experimental measurements, the results of which can be used for aluminium melting in hearth furnaces. The measurements were carried out using an experimental upstream burner with 13.5 kW input power. The monitored oxygen concentrations in the oxidizer ranged from 21% to 50%. The measurements were performed and evaluated in two variations of the burner configuration (geometry). In the first study, the impact of the enriched oxidizer on the melting of aluminium ingots was evaluated with the defined diameter of the air nozzle, which resulted in a reduction of the aluminium charge melting time by 50% at 45.16% oxygen concentration in the oxidizer, thus achieving savings in the consumption of fuel used for melting. In the second study, the diameter was optimised depending on the combustion rate of the natural gas and oxidizer mixture. The optimisation of the nozzle parameters resulted in the reduction of the charge melting time by 23.66%, while the same 25% enriched oxidizer was used. With the rise of the enrichment level to 35%, further reduction by approximately 12% was observed. The measurement results prove considerable influence of the parameter (geometry) optimisation of the outlet nozzles and oxidizer enrichment. Appropriately selected parameters of the burner can contribute to achieving comparable results at a lower enrichment of the oxidizer. The obtained results demonstrate the intensification of the heat transfer in the current thermal aggregates. The research conclusions confirm that oxygen-enhanced combustion and modification of existing burners reduces the specific energy consumption on the process and reduces CO2 emissions.
Róbert Dzurňák; Augustín Varga; Ján Kizek; Gustáv Jablonský; Ladislav Lukáč. Influence of Burner Nozzle Parameters Analysis on the Aluminium Melting Process. Applied Sciences 2019, 9, 1614 .
AMA StyleRóbert Dzurňák, Augustín Varga, Ján Kizek, Gustáv Jablonský, Ladislav Lukáč. Influence of Burner Nozzle Parameters Analysis on the Aluminium Melting Process. Applied Sciences. 2019; 9 (8):1614.
Chicago/Turabian StyleRóbert Dzurňák; Augustín Varga; Ján Kizek; Gustáv Jablonský; Ladislav Lukáč. 2019. "Influence of Burner Nozzle Parameters Analysis on the Aluminium Melting Process." Applied Sciences 9, no. 8: 1614.
A study on natural gas saving and emissions decrease in the public health care sector is presented. The analyzed hospital complex belongs to the largest ones in Slovakia and uses both hot water and water steam for heating purposes. Visual steam system inspection revealed serious inefficiencies, including steam venting, missing pipelines insulation and obsolete steam sources with dysfunctional blow-down system. Defined experiment with stepwise steam appliances shutdown enabled quantification of excess natural gas consumption due to these inefficiencies. Measures proposed for the solution of this state are inexpensive, with a short payback period. The expected natural gas savings amount up to 3200 MWh/year, which represents roughly 50% of the total natural gas consumption in the hospital complex.
Otto Mierka; Miroslav Variny; Ingrida Skalíková; Peter Sámel; Jan Kizek; Róbert Súth; Karol Nagy. Natural Gas Saving And Emissions Decrease In Public Health Care Sector – A Case Study. Civil and Environmental Engineering Reports 2019, 29, 102 -118.
AMA StyleOtto Mierka, Miroslav Variny, Ingrida Skalíková, Peter Sámel, Jan Kizek, Róbert Súth, Karol Nagy. Natural Gas Saving And Emissions Decrease In Public Health Care Sector – A Case Study. Civil and Environmental Engineering Reports. 2019; 29 (1):102-118.
Chicago/Turabian StyleOtto Mierka; Miroslav Variny; Ingrida Skalíková; Peter Sámel; Jan Kizek; Róbert Súth; Karol Nagy. 2019. "Natural Gas Saving And Emissions Decrease In Public Health Care Sector – A Case Study." Civil and Environmental Engineering Reports 29, no. 1: 102-118.
The aim of the present article is to present the achieved results on the experimental combustion aggregate. In the experimental measurement, the increased of the oxygen concentration in the oxidizing agent in the combustion of natural gas has been used. The results presented in this article are focused to achieve the thermal efficiency of the device, which is expressed by useful heat of the combustion aggregate. Part of the article is the analysis of the heating heat exchanger based on heat flow by convection and radiation and CFD mode of heat exchanger
Róbert Dzurňák; Gustáv Jablonský; Augustín Varga; Ján Kizek; Marcel Pástor; Ladislav Lukáč. Impact of oxygen enhanced combustion of natural gas on thermal efficiency of combustion aggregate. MATEC Web of Conferences 2018, 168, 07016 .
AMA StyleRóbert Dzurňák, Gustáv Jablonský, Augustín Varga, Ján Kizek, Marcel Pástor, Ladislav Lukáč. Impact of oxygen enhanced combustion of natural gas on thermal efficiency of combustion aggregate. MATEC Web of Conferences. 2018; 168 ():07016.
Chicago/Turabian StyleRóbert Dzurňák; Gustáv Jablonský; Augustín Varga; Ján Kizek; Marcel Pástor; Ladislav Lukáč. 2018. "Impact of oxygen enhanced combustion of natural gas on thermal efficiency of combustion aggregate." MATEC Web of Conferences 168, no. : 07016.
Róbert Dzurňák; Ján Kizek; Gustáv Jablonský. Influence of oxygen on heat transfer by convection in the experimental device. 36TH MEETING OF DEPARTMENTS OF FLUID MECHANICS AND THERMODYNAMICS 2017, 1889, 20007 .
AMA StyleRóbert Dzurňák, Ján Kizek, Gustáv Jablonský. Influence of oxygen on heat transfer by convection in the experimental device. 36TH MEETING OF DEPARTMENTS OF FLUID MECHANICS AND THERMODYNAMICS. 2017; 1889 ():20007.
Chicago/Turabian StyleRóbert Dzurňák; Ján Kizek; Gustáv Jablonský. 2017. "Influence of oxygen on heat transfer by convection in the experimental device." 36TH MEETING OF DEPARTMENTS OF FLUID MECHANICS AND THERMODYNAMICS 1889, no. : 20007.
Thermal aggregates are using burner which burns combustible mixture with an oxidizing agent, by adjustment of the burner nozzle we can achieve better conditions of combustion to intensify heat transfer at furnace space. The aim of the present paper was using a computer program Ansys Workbench to create a computer simulation which analyzes the impact of the nozzle on the shape of a flame thereby intensifies heat transfer in rotary drum furnaces and radiation heat transfer from the flue gas into the furnace space. Article contains analysis of the geometry of the burner for achieving temperature field in a rotary drum furnace using oxy-combustion and the practical results of computer simulations
Róbert Dzurňák; Ján Kizek; Gustáv Jablonský. Intensification of heat transfer by changing the burner nozzle. THE APPLICATION OF EXPERIMENTAL AND NUMERICAL METHODS IN FLUID MECHANICS AND ENERGY 2016: XX. Anniversary of International Scientific Conference 2016, 1745, 20006 .
AMA StyleRóbert Dzurňák, Ján Kizek, Gustáv Jablonský. Intensification of heat transfer by changing the burner nozzle. THE APPLICATION OF EXPERIMENTAL AND NUMERICAL METHODS IN FLUID MECHANICS AND ENERGY 2016: XX. Anniversary of International Scientific Conference. 2016; 1745 ():20006.
Chicago/Turabian StyleRóbert Dzurňák; Ján Kizek; Gustáv Jablonský. 2016. "Intensification of heat transfer by changing the burner nozzle." THE APPLICATION OF EXPERIMENTAL AND NUMERICAL METHODS IN FLUID MECHANICS AND ENERGY 2016: XX. Anniversary of International Scientific Conference 1745, no. : 20006.
The aim of the paper was to improve the economy of rolling mill production and to extend the control range of cooling capacity of the accelerated cooling unit by choosing the optimal dimensions of the cooling chamber. The object of research was the interstand cooling unite for accelerated cooling of the hot-rolled products of round section in the line of continuous rolling mill in order to reduce the machine time rolling or even eliminate completely the requirement for heat treatment of the hot-rolled products in heat-treatment furnaces. The influence of the design parameters of the cooling chamber on the expanding the control range, retaining a high cooling capacity of the chamber, was investigated by the numerical model based on the finite difference method. The diagrams presented in the paper allow determining the diameters of the cooling chamber, which provide a wide control range of the chamber cooling capacity and minimization of energy consumption of the electric water pump.
Vladimir L. Brovkin; Vladislav A. Kachal; Tatiana V. Doroshenko; Ladislav Lazic; Augustin Varga; Jan Kizek; Svetlana V. Brovkina. CAPACITY OF THE INTERSTAND COOLING UNIT IN HOT ROLLING PROCESS. Acta Metallurgica Slovaca 2014, 20, 381 -388.
AMA StyleVladimir L. Brovkin, Vladislav A. Kachal, Tatiana V. Doroshenko, Ladislav Lazic, Augustin Varga, Jan Kizek, Svetlana V. Brovkina. CAPACITY OF THE INTERSTAND COOLING UNIT IN HOT ROLLING PROCESS. Acta Metallurgica Slovaca. 2014; 20 (4):381-388.
Chicago/Turabian StyleVladimir L. Brovkin; Vladislav A. Kachal; Tatiana V. Doroshenko; Ladislav Lazic; Augustin Varga; Jan Kizek; Svetlana V. Brovkina. 2014. "CAPACITY OF THE INTERSTAND COOLING UNIT IN HOT ROLLING PROCESS." Acta Metallurgica Slovaca 20, no. 4: 381-388.
Ladislav Lukáč; Ján Kizek; Magdaléna Repášová; Stefan Kuna. Design of methodology for wood chips moisture estimation determined for gasification. EPJ Web of Conferences 2014, 67, 02069 .
AMA StyleLadislav Lukáč, Ján Kizek, Magdaléna Repášová, Stefan Kuna. Design of methodology for wood chips moisture estimation determined for gasification. EPJ Web of Conferences. 2014; 67 ():02069.
Chicago/Turabian StyleLadislav Lukáč; Ján Kizek; Magdaléna Repášová; Stefan Kuna. 2014. "Design of methodology for wood chips moisture estimation determined for gasification." EPJ Web of Conferences 67, no. : 02069.