In the paper the reburning process has been characterised. A dependence of NOx in flue gas content decreasing efficiency on some parameters has been pointed. During experiment the reburning process has been controlled with pulse disturbation of reburning fuel injection. An increasing of NOx reduction efficiency has been noticed, due to pulsations intensifying mixing process in reduction zone.

The article presents the results of experimental investigations of interactions between a deformable structure and a liquid. The investigations were performed on two prismatic tanks with elastically deformable top walls. During the investigations, different levels of tank filling with liquid were examined. The investigation of this phenomenon has direct reference to frequently recorded real events, such as collision of a tanker with another ship or a harbour berth, rapid braking of a road or rail tanker, etc. Recognition of this phenomenon is based on simultaneous measurements of the following parameters:

1. excited accelerations of the tank-liquid system,

2. elastic accelerations of top walls of the tank,

3. hydrodynamic pressures on the deformable top walls.

The article discusses issues related to the generation, use, and transboundary movement of waste labeled with the code 191210 according to the waste catalogue regardless of its origin (municipal, industrial or mixed). Data contained in voivodship reports related to waste management and information about transboundary shipments shared by the Chief Inspectorate of Environmental Protection were also used in the article. The imbalance in the amount of produced and energetically used alternative fuels in Poland in the years 2015 to 2017 has been confirmed. This affects the economy of the waste management sector involved in the production of alternative fuels. The oversupply causes the prices of alternative fuels to fall and increases the need for subsidies in the case of the recovery or disposal of alternative fuels of lower quality. In the near future one should expect a stabilization of the supply of combustible waste to the cement industry, which is now beginning to achieve its technological potential; this is due to a high degree of replacement of fossil fuels. One should also expect an increase in the demand for alternative fuels from the commercial power sector and heating sector. It has been shown that much more alternative fuel is imported than exported from Poland. The amount of imported alternative fuel in the market is relatively low compared to the amount of fuel produced in the country. This oversupply affects, although not significantly, the possibility of using domestic waste for energy recovery. The export of the alternative fuel produced in the country is a favorable phenomenon when there is no possibility of sale on the domestic market. It seems rational, especially in the case of exports from installations producing fuels in border provinces.

The paper investigates the possibility of utilisation of heat-recirculating systems for fuel conversions having low net thermal effect. The experimental part is conducted with an electrically heated heat exchanger. It is shown that heat-recirculating systems can operate under superadiabatic conditions. Their thermal characteristics are provided by means of the dependencies of heat recirculation ratio on process parameters. Further, the heat-recirculating catalytic combustion system is characterised via combustion bifurcation diagrams. The similarities and differences of both those heat-recirculating systems are qualitatively compared and explained. Bifurcation characteristics proves to be useful tools in concise description of practical complex heat-recirculating fuel conversion systems in energy generation.

The development of air transport affects elements of the aviation fuel market. In recent years an increase in both the number of passengers and the number of passenger operations has been observed. This phenomenon also concerns passengers and the number of operations served by Polish airports which translates into more and more fuel consumption in Poland. The authors of the study tried to approximate the characteristics of aviation fuels used in various types of aircrafts. The most important of them, from the perspective of the Polish aviation sector, include Jet. This type of fuel plays a key role in civil aviation. In the article, the enterprises operating in the analyzed sector were also reviewed. The empirical part of the article is devoted, in turn, to the analysis of changes in air passenger transport in Poland and changes in Jet fuel prices on the Polish fuel markets. The conducted research shows that the dynamics of changes in the number of passengers, as well as the number of passenger operations at Polish airports were characterized by an upward trend, and the increase in the number of passengers was driven not only by a larger number of available flights, but also by such factors as: increasing the capacity of aircraft and increasing the fill rate for seats. The authors have also attempted to examine the strength of dependence between the number of passengers deciding to use Polish airports and Jet fuel prices, which in recent years have undergone significant fluctuations. For this purpose, the value of Pearson’s linear correlation coefficient was used and the analyzed period covered the years 2011–2017. The data on passenger traffic used in the study came mainly from periodic reports prepared by the Civil Aviation Office (ULC).

Low emission has a significant impact on air quality in Poland. Low sources are found which lead to high concentrations of pollutants in the area inhabited by humans. The effects of low emissions on health and life in the polluted areas (Małopolska, Silesia) are conducive to radical decisions regarding the quality of solid fuels and their combustion facilities. At present, local anti-smuggling laws have been introduced in the two provinces banning the burning of the most emitting fuels such as mules, flotoconcentrates and lignite. Regional EU-funded programs for the use of renewable energy sources (RES) and energy efficiency improvement will transition to the implementation phase of the approved projects as of 2017. This is expected to significantly reduce energy consumption for heating buildings and replacing old boilers and automatic furnaces with low-emission heating devices. In the case of households, proving that the residential building has adequate energy efficiency characteristics is necessary in order to receive co-financing for replacing an old solid fuel boiler with a new low-emission boiler,. The paper will present the current situation on the regulation of the fuel market in the household and small–scale consumer sector and the proposal for changes to the law on monitoring and control of solid fuel quality. Another important issue will be significant changes in heating up to 500 kW, proposed by the Ministry of Development in October 2016. The proposed regulation precedes the implementation of the Ecodesign Directive, which will come into effect as of 2022 for room heaters and heating furnaces up to 500 kW for solid fuels. All these actions will help reduce low emissions and improve energy efficiency.

The uncertainty in the supply of crude oil, increasing the number of vehicles and rising air pollution, especially in urban areas, has prompted us to look for alternative fuels. It is understood that using Compressed Natural Gas (CNG) in IC engines could be a mid-term solution to these problems. It is well established that CNG has better combustion characteristics and low emissions compared to conventional gasoline and diesel fuel. In the present study, an experiment was conducted to evaluate the engine performance and exhaust emissions using various percentages of CNG in dual fuel mode. CNG was mixed in the intake manifold’s air stream, and diesel was injected after the compression of the CNG air mixture. This paper presents experimental results of 40%,60%, and 80% CNG in the air stream. Engine performance and emissions are presented and discussed at a speed of 1200 rpm to 1500 rpm in steps of 50 rpm. The results of the experiments showed that adding CNG to diesel engines in dual-fuel combustion significantly impacted performance and emissions. Compared to single diesel fuel combustion, dual fuel combustion increases brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) at all CNG energy shares and engine speeds. Carbon monoxide (CO) and hydrocarbon (HC) emissions were increased, while nitrogen oxide (NOX) and smoke opacity were decreased in dual fuel combustion compared to single diesel fuel.

In the recent times, lot of research work carried out in the field of fuel cells explicitly divulges that it has the potential to be an ultimate power source in upcoming years. The fuel cell has more storing capacity, which enables to use in heavy power applications. In these applications, power conditioning is more vital to regulate the output voltage. Hence, we need a dc-dc converter to provide a constant regulated output voltage for such high-power system. Currently, many new converters were designed and implemented as per the requirement. This paper has made comparative study on several topologies of the quadratic high gain dc-dc converter and the applications where these topologies can be used when the fuel cell is given as a source. Also, we have compared various parameters of all the converters considered and generated the results with steady-state and dynamic study. In this article, we briefed the types of analysis carried on the dc-dc converter to study its performance. Moreover, various application of fuel cell is presented and discussed. This paper will be a handbook to the researchers who start to work on high gain dc-dc converter topologies with quadratic boost converter as a base. This article will also guide the engineers to concentrate on the fuel cell components where it needs to be explored for optimizing its operation.

The paper presents methodology for calculating optimal drive torques which ensure reduced or minimal fuel consumption and emission of toxic components of exhaust gas during acceleration of a car. Data for fuel consumption and toxic emission in dynamic conditions (for a run with changeable speed) are obtained using experimental measurements during typical drive tests. A dynamic optimization problem for calculating a drive torque has been formulated using dynamic characteristics and a simple mat hematical model a vehicle when travelling in a straight line. The optimization problem has been solved for a drive with petrol and LPG. Results of numerical calculations followed by conclusions are presented.

Leaded and unleaded petrol samples as well as diesel oil samples were analysed lo determine Cd. Cr. Cu, Ni, Pb, Zn and As concentrations. In order lo obtain low detection limits new method of samples preparation was used. The fuel samples were dissolved in hydroraffinate which was the crude oil fraction obtained as a result of atmospheric distillation in the range of I 50---250°C. The obtained data on the metal concentrations in the investigated fuels allow determining the following emission factors of traffic fuels consumption processes [mg/kg fuel]: leaded and unleaded petrol - Cr - 0,5; Cu - 0,3; Ni - 0.5; Pb - 50 (leaded): Pb - 5 (unleaded); diesel fuel - Cd - 0,05: Cu - 0,3: Ni - 0.5. It was found in the investigations that traffic fuels consumption is not the source of Zn and As emission. The same refers to Cd emission in case of leaded and unleaded petrol consumption. On the basis of the identified emission factors Pb emission from traffic in Poland for years 1980---1999 as well as Cd, Cr, Cu and Ni emission for I 999 were assessed. The following emission in 1999 was determined as a result of the assessment [Mg]: Cd - 0,3: Cr - 2,9: Cu - 3,5 and Ni - 5,9. Emission of Pbu, was 237.6 Mg and Pb1.,w 79,2 Mg. These emissions were also compared with the total metal emissions in Poland.

Results of the investigation of thermal degradation of polyolefins in the laboratory-scale set-up reactors are presented in the paper. Melting and cracking processes were carried out in two different types of reactors at the temperature of 390-420°C. This article presents the results obtained for conversion of polyolefin waste in a reactor with a stirrer. Next, they were compared with the results obtained for the process carried out in a reactor with a molten metal bed, which was described in a previous publication. For both processes, the final product consisted of a gaseous (2-16 % mass) and a liquid (84-98 % mass) part. No solid product was produced. The light, "gasoline" fraction of the liquid hydrocarbons mixture (C4-C10) made up over 50% of the liquid product. The overall (vapor) product may be used for electricity generation and the liquid product for fuel production.

It has been found that the vegetable oils are promising substitute, because of their properties are similar to those of diesel fuel and they are renewable and can be easily produced. However, drawbacks associated with crude vegetable oils are high viscosity, low volatility call for low heat rejection combustion chamber, with its significance characteristics of higher operating temperature, maximum heat release, and ability to handle lower calorific value (CV) fuel etc. Experiments were carried out to evaluate the performance of an engine consisting of different low heat rejection (LHR) combustion chambers such as ceramic coated cylinder head-LHR-1, air gap insulated piston with superni (an alloy of nickel) crown and air gap insulated liner with superni insert - LHR-2; and ceramic coated cylinder head, air gap insulated piston and air gap insulated liner - LHR-3 with normal temperature condition of crude rice bran oil (CRBO) with varied injector opening pressure. Performance parameters (brake thermal efficiency, brake specific energy consumption, exhaust gas temperature, coolant load, and volumetric efficiency) and exhaust emissions [smoke levels and oxides of nitrogen [NOx]] were determined at various values of brake mean effective pressure of the engine. Combustion characteristics [peak pressure, time of occurrence of peak pressure, maximum rate of pressure rise] were determined at full load operation of the engine.

Conventional engine (CE) showed compatible performance and LHR combustion chambers showed improved performance at recommended injection timing of 27°bTDC and recommend injector opening pressure of 190 bar with CRBO operation, when compared with CE with pure diesel operation. Peak brake thermal efficiencyincreased relatively by 7%, brake specific energy consumption at full load operation decreased relatively by 3.5%, smoke levels at full load decreased relatively by 11% and NOx levels increased relatively by 58% with LHR-3 combustion chamber with CRBO at an injector opening pressure of 190 bar when compared with pure diesel operation on CE.

The dynamics of economic development determines the need to develop technologies for waste recycling especially the acquisition of condensed fuels for the needs of the local diversification of energy sources. In a short time, Poland will probably lack its own produced electricity. To apply the process of diversification of energy sources, by developing methods of generating energy from waste, it becomes crucial to protect the environment. The use of cogeneration technology based on fuels derived from waste, in particular concentrated oil and gas fuels, is becoming more common and provides the basis for securing the energy supply in the preferred diversification process. Plastic waste processing in the controlled depolymerization process, which is the reverse of the polymerization process for hydrocarbon recovery – uses petroleum derivatives its production. At present, the greatest interest arises in the material recovery of plastics and rubber in the process of anaerobic thermal decomposition (thermolysis/pyrolysis), which is used on an industrial scale and consists in the degradation of polymer bonds into low molecular weight. The imperative of a modern economy is to obtain energy from fuels from waste treatment, including hazardous waste, preferably in the cogeneration process. The fuel obtained from waste may be used to obtain thermal or electric energy in order to diversify energy sources. The article presents innovative Polish technologies of obtaining fuel in processes of anaerobic thermal decomposition mainly of elastomeric and polymeric waste (including hazardous ones) for direct application in power generators of various power.

The expected demand for hard coal intended for the households will progressively be decreasing. This is directly related to the introduced anti-smog resolutions, as well as the growing level of environmental awareness. However, it should be noted, that the use of the modern home heating boilers will result in an increase in the demand for medium coal sizes. The shortfall of this type of coal is already observed on the market. Therefore, its import is necessary. One of the solutions to increase the supply of the medium coal sizes is the production of coal briquettes. Moreover, their use will consequently lead to reduced emissions.

The paper presents a comparison of emissions from the combustion of coal briquettes and hard coal in home heating boilers. The briquettes were characterized by significantly lower emissions than hard coal (by 52% on average). The particulate matter emissions were lower by 70%. This may significantly contribute to improving air quality in Poland and in addition, limit the occurrence of smog. The possibility of further emission reduction by using low-emission fuels as briquette components was presented. The average relative emission reduction compared to hard coal for the analyzed fuels was estimated as follows: 62% for coal char, 57% for coke, 51% for charcoal/biocarbon, 49% for anthracite, 45% for torrefied biomass, and 33% for peat.

Furthermore, the issue of the mercury content in the analyzed fuels was discussed. The lowest mercury content was found in biomass fuels, in particular biomass after thermal treatment (torrefied biomass, biocarbon, and charcoal). Fuels produced from hard coal in the pyrolysis process (coal char and coke) were characterized by very low mercury content as well.

At present, electromobility is a very dynamically developing segment and at the same time has many unknowns that enterprises that want to develop this area in their structures have to face. This article aims is to show the difficulties of electromobility development from the perspective of Polish energy groups which are closely related to this area, especially considering the obligations imposed on energy companies by the legislator. The electrification of transport has become a reality and in order to use its potential to develop new services or implement innovations and new technologies, it is necessary to identify development barriers and prepare a response plan. The authors of the article decided to show the formal and legal implications for the development of electromobility in Poland in first order, and then examine the development strategies of Polish energy groups in terms of electromobility and indicate explored areas related to it. The next section focuses on identifying the main barriers to the implementation of business models, classifying them according to the following factors: economic, operational, technical, social and legal. This presentation of the problem allows for an in-depth recognition of the issue and realizing that in order to achieve the goals set by the Legislator, close cooperation of all stakeholders is necessary both at the national and local level, while engaging energy groups, financial companies, electric vehicle manufacturers, and above all local government units in these activities.

Current practice of waste generation and management in Ukraine has led to an increase in the area of landfills and a loss of the beneficial potential of waste. Today, territorial communities in Ukraine have received enormous new powers within the framework of decentralization, in particular, waste management is now under their jurisdiction. In order to implement the National Waste Management Strategy in Ukraine 2030 and the National Waste Management Plan 2030, communities need to activate the areas of effective disposal of household solid waste (HSW), and for this purpose it is necessary to take into account European norms and standards in this area, as well as share successful Ukrainian and foreign experience. The aim of the study is to analyze a successful case of waste management of a separate community in Ukraine (Illintsi United Territorial Community) as an example for other communities, as well as to develop guidelines for bioenergy recycling of waste in the community under the study with the production of RDF fuel and biogas in order to provide energy resources and improve the condition of the environment. To achieve this goal, there were used the following methods: monographic, deductive, inductive, analysis and synthesis, economic analysis, graphic and tabular, statistical, as well as the case-study method. The conducted research confirmed the growth of waste generation volumes in Ukraine and their limited beneficial use. The developed recommendations on the improvement of the household solid waste management based on the successful case of Illintsi Territorial Community and proposals for organizing the production of RDF fuel and biogas can become a strong basis for the development of communities on the basis of sustainability.

Plastics are one of the most widely used materials, and, in most cases, they are designed to have long life spans. Since plastic and packaging waste pollute the environment for many years, their disposal is of great importance for the environment and human health. In this paper, a system was developed to store liquid fuel from plastic and organic waste mixes without solidification, which then can be used as fuel in motor vehicles and construction machinery. For this purpose, polyethylene terephthalate (PET), polyvinyl chloride (PVC), and organic wastes and clay, zeolite, and MCS23-code materials (50% magnetite- %25 calcium oxide- %25 sodium chloride) were heated in a closed medium at temperatures ranging from 300 to400 oC and subsequently re-condensed. The study conducted twenty tests, involving various types and rates of plastic and organic materials, as well as different rates of catalysts. Among these tests, the highest liquid fuel yield (67.47%) was achieved in Test 9, where 50% PVC-50% PET waste, 75 g of clinoptilolite, and 500 g of MCS23 waste were collectively used. Notably, Test 12 exhibited the highest density value (79.8 kg/m3), while the best viscosity value (2.794 mm2/s) was observed in Test 2. Across all samples, flash point values were found to be below 40oC. The most favorable yield point value was recorded in Test 2 (-6oC). The samples displayed ash content within the range of 0 to0.01% (m/m)] and combustion heat values of 35.000> J/g which fall within the standard range. The incorporation of MCS23 with clinoptilolite additives is believed to have a significant impact on obtaining high-yield products with improved fuel properties.

Nuclear power was one of the factors underpinning the post-war success of the Euro-Atlantic region. The world is now in great need of a similar step forward

Nowadays, one of the biggest challenges faced by EU countries is the pursuit of zero-emission economies. Certainly, it is crucial to determine the role of fossil fuels in the energy transformation. In light of the European Green Deal, EU countries should cease the consumption of hydrocarbons, i.e. coal, crude oil and natural gas, by 2050. Nevertheless, there are significant differences regarding the possibility of decarbonizing the energy sectors of the different EU Member States. For many years, Romania has been successively implementing an energy transformation, the main goal of which is the significant reduction of fossil fuels in the energy mix. Just a few years ago, one of the most important energy resources was coal, which is to be eliminated within the next decade. However, a much greater challenge is the reduction and subsequent abandonment of natural gas and crude oil. The key task facing Romania is to ensure energy security, which is why decarbonization will be strongly coupled with the country’s economic and political capabilities. The exclusion of fossil fuels in power engineering means that there is a need to develop alternative generation capacities, in particular in nuclear, wind and solar energy. This article presents the current condition of the energy sector in Romania, with a particular emphasis on the role of fossil fuels in its transformation. An analysis of documents and field research shows that there will be a dynamic decarbonization in the coming years, which will result in a significant reduction in the consumption of fossil fuels. The priority of Romania’s energy policy is to achieve a zero-emission economy, but ensuring stability and security in the energy sector will be of key importance in this process.

Fuel tanks are designed with regard to standard loads and operating conditions. The investigations of the paper show the impact of such factors as tank corrosion and other means on variation of stress fields and deformation of the underground horizontal tank shell. Introduction of probabilistic methods allows for structural reliability assessment. While the computational time of the entire tank FEM model is high the preliminary analysis is restricted to structural part only. The analysis makes it possible to optimize the structure with regard to construction costs.

The advancement of contemporary internal combustion engine technologies necessitates not only design enhancements but also the exploration of alternative fuels or fuel catalysts. These endeavors are integral to curbing the emission of hazardous substances in exhaust gases. Most contemporary catalyst additives are of complex chemical origins, introduced into the fuel during the fuel preparation stage. Nonetheless, none of these additives yield a significant reduction in fuel consumption. The research endeavors to develop the fuel system of a primary marine diesel engine to facilitate the incorporation of pure hydrogen additives into diesel fuel. Notably, this study introduces a pioneering approach, employing compressed gaseous hydrogen up to 5 MPa as an additive to the principal diesel fuel. This method obviates the need for extensive modifications to the ship engine fuel equipment and is adaptable to modern marine power plants. With the introduction of modest quantities of hydrogen into the primary fuel, observable shifts in the behavior of the fuel equipment become apparent, aligning with the calculations outlined in the methodology. The innovative outcomes of the experimental study affirm that the mass consumption of hydrogen is contingent upon the hydrogen supply pressure, the settings of the fuel equipment, and the structural attributes of the fuel delivery system. The modulation of engine load exerts a particularly pronounced influence on the mass admixture of hydrogen. The proportion of mass addition of hydrogen in relation to the pressure of supply (ranging from 4–12 MPa) adheres to a geometric progression (within the range of 0.04–0.1%). The application of this technology allows for a reduction in the specific fuel consumption of the engine by 2–5%, contingent upon the type of fuel system in use, and concurrently permits an augmentation in engine power by up to 5%. The resultant economic benefits are estimated at 1.5–4.2% of the total fuel expenses. This technology is applicable across marine, automotive, tractor, and stationary diesel engines. Its implementation necessitates no intricate modifications to the engine design, and its utilization demands no specialized skills. It is worth noting that, in addition to hydrogen, other combustible gases can be employed.

The article presents the results of tests of the application of magnetic fuel activators, which improve the efficiency of metallurgical furnaces and positively affect the ecological aspects of their work. Energy indicators for metallurgical furnaces during operation before and after installation of magnetic fuel activators as well as the results of composition and concentration of emitted pollutants are included in the paper. The magnetic activation of liquid and gaseous fuels modifies their structure. As a result of the activation, the fuel mixture is selectively saturated with oxygen in the zone of free fuel flow. The combustion conditions were close to optimal, which is confirmed by the reduction of pollutants in the exhaust gases. Fuel saving in the combustion process is also a measurable economic effect. The tests included ovens of several types: pusher furnace, one and two chamber furnaces and a furnace with a rotary shaft. Several-month measurement cycles were carried out on each of them. The experiments consisted in the analysis of gas and heat consumption per month in individual furnaces before and after the use of magnetic fuel activators. The effectiveness of using activators was determined on the basis of the results of the tests carried out. As a result of a twelve-month test cycle on the pusher type furnace, a 36% reduction in gas consumption and a 22% reduction in heat consumption were achieved. After a seventeen-month measurement cycle on chamber furnaces, a 35% reduction in gas consumption and 6% in heat consumption were achieved. The tests on furnaces with a rotary shaft lasted fourteen months and showed a reduction in gas consumption by 8%. An improvement in the composition of fumes in the furnace atmosphere was achieved in all units with magnetic activators installed, as well as a reduction in the emission of harmful pollutants into the atmosphere from the installation.

The environment is the greatest good for the people. Everyone wants to breath air of the best possible quality, whether living in the city center of a metropolis or in a rural area. Air polluted with very fine particles contribute to the negative effect on people’s health and the whole environment. A significant part of air dust pollution comes from the so-called low emissions sources which include: non-standard furnaces, fireplaces, low-efficiency outdated boilers and local heat sources. Since the beginning of Polish Mining Group’s existence, the company actively participates and supports many activities, the aim of which is to improve the air quality by producing and supplying high quality coal for the residential sector. The company has undertaken pro-ecological activities towards creating a new, pro-ecological strategy as well as product offer. The production of an ecological coal assortment is systematically developing but new coal products are also being launched on the market. One of the company’s priorities is the production of thermal coal for the residential sector. Many organizational and technological changes have been made In that area (e.g. the establishmsnt of the Eco-Fuels Production Plant) to ensure a suitable level of production of the highest quality thermal coal.

Diesel generator engines operate in wide load modes; therefore, it is necessary to change the percentage of the mixture of diesel and biodiesel fuel depending on the operating mode of the engine; this ensures its technical performance at the required level in all operating modes, including starting and stopping the engine. This article describes an algorithm for the operation of a diesel generator and an algorithm for determining the composition of the fuel mixture. During the study, the ratio between the components of the mixture changed, taking into account the load modes of operation of the diesel generator, indicators of fuel supply and the formulation of the fuel mixture to ensure optimal values of technical and economic indicators. To assess the efficiency of the flow of working processes in a diesel cylinder, their duration was selected, which is estimated by the duration of the processes of fuel injection, evaporation and combustion. Using the dynamic regulation of the composition of the diesel and biodiesel fuel, the total fuel consumption increased by 5.9%, but the cost of purchasing the fuel is reduced by 10% (at prices as of November 2021) and by 14.6% (based on prices as of the beginning of 2022) compared to engine operation with diesel fuel. This confirms the expediency of using the dynamic adjustment of the composition of the fuel mixture. In addition, even higher economic indicators can be achieved by using an autonomous power plant with a diesel power capacity higher than the generator capacity.