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Two-wheeled vehicles, due to their population, constitute a significant share of road vehicles in Europe. Therefore, this article presents an overview and analysis of the applicable legal regulations regarding two-wheeled vehicle engines in terms of toxic exhaust emission tests. For the correct interpretation of emission standards, the authors of this work made the necessary analysis of the categorization of two-wheeled vehicles based on Polish law and the criteria of European regulations. The presented analysis concerns not only the current regulations, but also their development trends over the years. These considerations are supplemented with a literature review, which includes the problems of the ecology, energy consumption and construction of the considered group of vehicles. The work presented in this article also concerns the assessment of the conditions for conducting tests on objects belonging to category L in laboratory conditions on chassis dynamometers. On this basis, considerations were made to evaluate the currently applicable WMTC (World Motorcycle Test Cycle) test by comparing it with the actual operation of two-wheeled vehicles. This resulted in the formulation of conclusions regarding the need to introduce procedures for testing pollutant emissions in road conditions in the approval process.

Owing to society’s growing ecological awareness, researchers and car manufacturers have increasingly been focusing on the adverse impact of transport on the environment. Many scientific publications have been published addressing the influence of a variety of factors on the exhaust emissions generated by vehicles and machinery. In this paper, the authors present an analysis of the exhaust emissions of components such as CO, THC, and NOx in relation to the type and condition of the road surface. The analysis was performed on a heavy-duty truck designed for carriage of timber. The investigations were carried out with the use of the PEMS equipment (portable emission measurement system) on bitumen-paved roads and unpaved forest access roads. The portable measurement system allowed for an accurate determination of the influence of the road conditions on the operating parameters of the vehicle powertrain and its exhaust emissions. Additionally, the authors present the influence of the type of road surface on the vehicle fuel consumption calculated based on the carbon balance method.

The subject of the article is proposed proprietary M toxicity indicator, which is based on the assumption that CO2 emissions are a measure of the correctness of the combustion process. For this purpose, gaseous exhaust compounds such as hydrocarbons, nitrogen oxides, carbon monoxide and carbon dioxide were measured and analyzed. The test object was a motorcycle, equipped with an gasoline engine with a displacement of 0.7 dm3 and a maximum power of 55 kW. The tests were carried out using the PEMS (Portable Emissions Measurement System) AxionR/S+. The exhaust emissions measurement was done in line with the WMTC (World Motorcycles Test Cycle) certification test, dedicated to vehicles in this category. The test consists of three parts, each of them lasts 600 seconds and has a different maximum speed value. The test was performed on a single-roller chassis dynamometer, designed for testing two-wheeled vehicles. The toxicity indicators and rotation speed results were presented as a function of time.

The nature and conditions of the execution of tests (open or duct flow) in terms of evaluating the flow rate generated by positive pressure ventilators (PPV) may affect the parameters of the drive unit recorded during testing. In this article, popular PPVs (conventional type—W1 and turbo type—W2) of about 4.2 kW were tested under open flow (Method A) and duct flow (Method B) conditions. During the tests, engine load values were recorded: torque, speed, horsepower and, using portable emissions measurement systems (PEMS), exhaust gas emissions: carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), nitrogen oxides (NOx) and fuel consumption. Depending on the method used to measure ventilator flow rates, drive units can have different drive power requirements (from 3.2% to 4.5%). Changes in drive unit operating conditions induced by the flow measurement method are observed in the results of fuel consumption (from 0.65% to 9.8%) and emissions of harmful exhaust compounds: CO2 up to 2.4%, CO up to 67%, HC up to 93.2% and NOx up to 37%. The drive units of turbo type fans (W2) are more susceptible to the influence of the test methods in terms of flow assessment, where they have higher emissions of harmful exhaust gases when tested by Method A. Flow measurement methods affect the oscillation of propulsion power, which contributes to disturbances in the control of the fuel–air mixture composition. The purpose of this article is to analyse the impact of testing methods for measuring the flow rate of positive pressure ventilators on the performance of the drive unit.

Road transport holds for the largest share in the freight transport sector in Europe. This work is carried out by heavy vehicles of various types. It is assumed that, in principle, transport should take place on the main road connections, such as motorways or national roads. Their share in the polish road infrastructure is not dominant. Rural and communal roads roads are the most prevalent. This fact formed the basis of the exhaust emissions and fuel consumption tests of heavy vehicles in real operating conditions. A set of vehicles (truck tractor with a semi-trailer) meeting the Euro V emission norm, transporting a load of 24,800 kg, was selected for the tests. The research was carried out on an non-urban route, the test route length was 22 km. A mobile Semtech DS instrument was used, which was used to measure the exhaust emissions. Based on the obtained results, the emission characteristics were determined in relation to the operating parameters of the vehicles drive system. Road emission, specific emission and fuel consumption values were also calculated.

Emissions from the road transport sector are a major contributor to the climate change. Commonly used heavy vehicles powered by diesel engines emit toxic and harmful compounds that adversely affect the environment. For this reason, increasingly newer Euro emission standards are being introduced. Therefore, the emission performance of heavy-duty vehicles used in the transportation processes of diverse loads was investigated. The first research object was a set of vehicles equipped with a crane used for loading and unloading timber. The measurements were carried out in a specially designed research test reflecting the way the vehicle is used. It consisted of the drive to the loading site, the transport of timber to the destination and the processes of loading and unloading timber. The test route included driving on both unpaved forest roads and asphalt roads. The second research object was a set of vehicles used in long-distance road transport. The research route characterizing the traffic of vehicles from the cited group was selected here. There were three stages of the route–urban, extra-urban and highway. The whole trip was carried out with a load of 24,800 kg. The testing equipment consisted of SEMTECH DS and AVL Micro Soot Sensor devices belonging to the PEMS (Portable Emission Measurement System) group. Based on the obtained results, the influence of the operating conditions on the exhaust emissions and fuel consumption was determined.

The article presents selected problems concerning tests of toxic exhaust emissions from engines of vehicles, mobile devices, engines used in gardening and construction works. For this group of engines, this type of testing is carried out primarily in laboratory conditions, however, variable load conditions during actual operation justify efforts to determine the level of emissions in real operating conditions. Research in real operating conditions for different engine categories becomes increasingly more standard, in this aspect, it is necessary to verify the state of knowledge and methodology in the aspect of testing engines of machines and mobile devices. The research performed by the authors was the first of this type using PEMS equipment, hence some conclusions and observations can be made from the obtained results. At present, the type approval procedures for the engine group in question do not account for emissions tests in real operating conditions, while also missing any description of a standardized research methodology. In addition, the engine group in question is not really suitable for testing in real conditions. An introduction to research aimed at developing an exhaust emission test methodology in real operating conditions of mobile device engines was included in the article.

The subject of this article is a comparative analysis of exhaust emissions for: HC (hydrocarbons), CO (carbon monoxide), CO2 (car-bon dioxide), NOx (nitrogen oxides) from a passenger vehicle and a motorcycle in laboratory conditions on a dynamometer station. The first vehicle category was represented by a compression-ignition engine with a displacement volume of 1.3 dm3 and a power of 66 kW. The exhaust aftertreatment system included a catalytic converter and a particulate filter. The second category was a motorcycle, equipped with an engine with a displacement of 0.7 dm3 and a maximum power of 55 kW. The two-wheeled vehicle was equipped with a three-way catalytic converter. Speeds were modeled on the European type approval test – NEDC (New European Driving Cycle). In order to conduct a comparative analysis of exhaust emissions and fuel consumption from vehicles of different categories, the obtained results were presented in the form of emissions converted into passenger-kilometers (g/pkm). The research used modern equipment belonging to the PEMS (Portable Emissions Measurement Systems) group of devices. The analyzes carried out enable the decision mak-ing on which vehicles have a greater environmental impact due to their exhaust emissions, taking into account the distance and the number of passengers carried.

City buses are one of the main means of public transport in cities. As they move in a limited and densely populated area and are intensively exploited, it is particularly important that they are environmentally friendly. There are many ways to reduce emissions from city buses, including the use of hybrid propulsion. Another way is to use low-emission fuels. This article presents the results of the emission tests of an 18 m articulated city bus with a serial hybrid drive fuelled comparatively by conventional diesel fuel and oxygenated fuel containing 10% v/v of triethylene glycol dimethyl ether (TEGDME). The emission tests were carried out during the actual operation of the bus on a route in Poznań (Poland) and over the SORT cycles. The obtained test results were compared also with the results obtained for a conventional bus. The reduction in emissions of some exhaust components was found when the hybrid bus was fuelled with oxygenated fuel during its actual operation on the bus route. There was a reduction in CO emissions by ~50% and NOx emissions by ~10%. Almost identical levels of PM and HC emissions and smoke opacity were observed for both fuels. In the SORT cycles, the differences in the emissions obtained for both types of fuel were small. In general, for the hybrid bus, a lower influence of oxygenated fuel on emissions was recorded than for the conventional bus.

The subject of this article is the identification of engine exhaust emissions of two-wheel vehicles under laboratory conditions. For this purpose, analysis of road and time emission of gaseous compounds: HC, CO, CO2, NOx from a motorcycle equipped with an engine with a displacement volume of 0.7 dm3 and a maximum power of 55 kW was made. The tests were performed on a dynamometer station designed for testing two-wheel vehicles. The speed characteristic was taken from the European type approval test WMTC, consisting of three parts. Each of these parts lasted 600 seconds and was characterized by a different maximum vehicle speed value. The mobile AXION R/S apparatus part of the PEMS device group was used in the research. What is more, the exhaust emissions results were referred to the values listed by the exhaust emission standard met by the tested vehicle (Euro 4 standard). Laboratory tests presented in the article are only intended as a basis for further research, which includes exhaust emission tests from two-wheel vehicles in real operating conditions.

The paper presents the investigations of exhaust emissions under actual operation of two rail vehicles: a track geometry vehicle and a clearance vehicle. The environmental assessment of this type of objects is difficult due to the necessity of adapting the measurement equipment and meeting the safety requirements during the tests (particularly regarding the distance from the overhead electrical lines). The authors have proposed and developed a unique research methodology, based on which a detailed exhaust emissions analysis (CO, HC, NOx, and PM) was carried out. The complex assessment included the unit and on-track exhaust emissions. In the analyses, the authors also included the operating conditions of the powertrains of the tested machinery. The obtained environmental indexes were referred to the homologation standards, according to which the vehicles were approved for operation. Due to the nature of operation of the tested vehicles, the authors carried out a comprehensive environmental assessment in the daily and annual approach as well as in the aspect of their operation as combined vehicles, which is a novel approach to the assessment of the environmental performance of this type of objects.

The projected increase in the availability of gaseous fuels by growing popularity of household natural gas (NG) filling stations and the increase in the production of gaseous biogas-derived fuels is conducive to an increase in the use of NG fuel. Currently, natural gas in various forms (compressed natural gas (CNG), liquefied natural gas (LNG)) is popular in maritime, rail and road transport. A new direction of natural gas application may be non-road mobile machines powered by a small spark-ignition engine (SI). The use of these engines in the wood chippers can cause the reduction of machine costs and emissions of harmful exhaust gases. In addition, plant material chippers intended for composting in bio-gas plants can be driven by the gas they are used to produce. The biogas can be purified to bio-methane to meet natural gas quality standards. The article presents the design of the natural gas supply system, which is an upgrade of the Lifan GX 390 combustion engine spark ignition engine (Four-stroke, OHV (over head valve) with a maximum power of 9.56 kW), which is a common representative of small gasoline engines. The engine is mounted in a cylindrical chipper designed for shredding branches with a maximum diameter of up to 100 mm, which is a typical machine used for cleaning work in urban areas. The engine powered by CNG and traditionally gasoline has been tested in real working conditions, when shredding cherry plum (Prunus cerasifera Ehrh. Beitr. Naturk. 4:17. 1789 (Gartenkalender4:189–204. 1784)). Their diameter was ca. 80 mm, 3-metere-long, and humidity content ca. 25%. The systems were tested under the same actual operating conditions, the average power generated by the drives during shredding is about 0.69 kW. Based on the recorded results, it was found that the CNG-fuelled engine was characterized by nitrogen oxides (NOx) emissions higher by 45%. The other effects of CNG were a reduction in carbon dioxide (CO2), carbon monoxide (CO) and hydrocarbon (HC) emissions of about 81%, 26% and 57%, respectively. Additionally, the use of CNG reduced fuel consumption by 31% and hourly estimated machine operating costs resulting from fuel costs by 53% (for average fuel price in Poland: gasoline: 0.99 EUR/L and CNG: 0.71 EUR/m3 on 08 November 2020). The modernization performed by the authors ensured the work of the drive unit during shredding, closer to the value of stoichiometric mixtures. The average (AVG) value of the air fuel ratio (AFR) for CNG was enriched by 1.2% (AVG AFR was 17), while for the gasoline engine the mixture was more enriched by 4.8% (AVG AFR was 14). The operation of spark-ignition (SI) combustion engines is most advantageous when burning stoichiometric mixtures due to the cooperation with exhaust aftertreatment systems (e.g., three-function catalytic converter). A system powered by CNG may be beneficial in systems adapting to operating conditions, used in low-power shredding machines, whose problem is increased HC emissions, and CNG combustion may reduce them. The developed system does not exceed the emission standards applicable in the European Union. For CO emissions expressed in g/kWh, it was about 95% lower than the permissible value, and HC + NOx emissions were 85% lower. This suggests that the use of the fuel in question may contribute to tightening up the permissible emission regulations for non-road machinery.

At the beginning of the twenty-first century, one of the major challenges of humanity was to reduce the negative effects of civilization development. Besides the engines used in road vehicles there is a large group of engines for non-road applications. This group includes motor propelled vehicles not used on the road NRMM (Non-Road Mobile Machinery). Engines of these vehicles, among all of the non-road applications, are characterized by very specific working conditions that do not allow for them to be qualified for propulsion engines. The main problem with these vehicles is the particulate matter and nitrogen oxides emission. Rail vehicles operating conditions these requirements take by the similar way, as having a wide range of rolling stock markedly alters the environmental impact of these vehicles. Thus it becomes necessary to consider the issue of the method of evaluation of engine emissions in rail vehicles in terms of their actual operating conditions. Thus, efforts to assess the actual level of emissivity for rail vehicles and attempts to improve it are necessary and justified.

The paper describes the investigations of the physicochemical properties of biocoal, a solid fuel obtained following the carbonization of rice starch. The production of biocoal (carbonization) was completed at the temperature of 600 °C in the nitrogen atmosphere. As a result of the carbonization, amorphous carbon with high monodispersity was obtained, devoided of oxygen elements and was a very well developed BET specific surface—360 m2 g−1. The investigations of the technical parameters have confirmed a very high concentration of energy. The calorific value of 53.21 MJ kg−1 and the combustion heat of 54.92 MJ kg−1 are significantly higher than those of starch before carbonization (18.72 MJ kg−1 and 19.43 MJ kg−1, respectively) and these values for typical biomass fuels. These values are also greater than those of hard coal. Other advantageous features of the obtained fuel are low ash (0.84%) and moisture content. These features predispose this fuel for the application as an alternative to conventional fuels.

This paper discusses the determination of fuel consumption and exhaust gas emissions when shredding branches in urban areas. It aimed to determine the hourly emission of exhaust gases to the atmosphere during such work and to identify the designs that can reduce it. The research was carried out with a cylinder woodchipper driven by a low-power (9.5 kW) combustion engine. There were three configurations of the tested drive unit: The factory setting (A) with a carburettor fuel supply system, modernized by us to include an electronic injection system (B). This system (B) was expanded with an adaptation system patented by the authors (P. 423369), thus creating the third configuration (C). The research was carried out when shredding cherry plum (Prunus cerasifera Ehrh. Beitr. Naturk. 4:17. 1789 (Gartenkalender 4:189-204. 1784)) branches with a diameter of 80 mm, which presented a large load for the machine. The machine was operated by one experienced operator. The average operating conditions during the tests were as follows: Branch delivery frequency of about 4 min−1 and mass flow rate of about 0.72 t h−1. During the tests with the use of PEMS (portable emissions measurement system, here Axion RS from Global MRV), we analyzed the emissions of compounds, such as CO, CO2, HC, and NOx, and determined the fuel consumption based on the carbon balance. The research showed that the use of an injection system (B) reduced fuel consumption from 1.38 to 1.29 l h−1 (by 6.7%) when compared to the carburettor system (A). Modernization of the injection system (B) with an adaptive system (C) reduced fuel consumption from 1.38 to 0.91 l h−1 (by 34%) when compared to the carburettor system (A). An hour of shredding with a cylinder chopper emits the following amounts of flue gases: design A (HC 0.013 kg h−1; CO 0.24 kg h−1; CO2 2.91 kg h−1; NOx 0.0036 kg h−1), design B (HC 0.0061 kg h−1; CO 0.20 kg h−1; CO2 2.77 kg h−1; NOx 0.0038 kg h−1), and design C (HC 0.017 kg h−1; CO 0.22 kg h−1; CO2 1.79 kg h−1; NOx 0.0030 kg h−1). The adaptive system entails significant reductions in non-HC emissions, which indicates that the system needs to be improved with respect to fuel-air mixture control for its enrichment of the low-to-high-speed change. The admissible emission limits for harmful compounds in exhaust gas for the tested group of propulsion units are in accordance with the provisions in force in the European Union from 2019 for the tested propulsion units during operation, with a full CO load about 6100 g h−1 and HC + NOx about 80 g h−1. The tested propulsion units emitted significantly less pollution under real operating conditions (because they did not work under full load throughout the entire test sample).

This work determines the effect of the addition of various amounts of vanadium oxide on the work of a cell built from a hybrid VxOy-TiO2-rGO system in a lithium-ion cell. Moreover, a new method based on solvothermal chemistry is proposed for the creation of a new type of composite material combining reduced graphene, vanadium oxide and crystalline anatase. The satisfactory electrochemical properties of VxOy-TiO2-rGO hybrids can be attributed to the perfect matching of the morphology and structure of VxOy-TiO2 and rGO. In addition, it is also responsible for the partial transfer of electrons from rGO to VxOy-TiO2, which increases the synergistic interaction of the VxOy-TiO2-rGO hybrid to the reversible storage of lithium. In addition a full cell was created LiFePO4/VxOy-TiO2-rGO. The cell showed good cyclability while providing a capacity of 120 mAh g−1.