Agricultural tractors are highly fuel-consuming and soil/air polluting machines; thus, the introduction of new sustainable technologies, such as hybridization, can be very impactful for the development of electric hybrid agricultural tractors. These vehicles combine the classic internal combustion engine with an electric machine. This paper reports the modeling and simulation, conducted using a simulation software typically used for on-road vehicles, of a two-wheel-drive agricultural tractor in three different configurations: the conventional one, and the series and parallel electric-hybrid powertrains. The simulated task is the trailing of a “big square baler” during the process of straw wrapping and baling. The evaluation and the comparison of the fuel consumption, CO₂ emissions and the depth of discharge of the different configurations have been carried out to determine if it is possible to downsize the ICE while maintaining the same performance levels. This study highlights the fact that both the fuel consumption and the CO₂ emissions of series and parallel electric-hybrid agricultural tractors are ten times lower and five times lower than those of a traditional tractor, respectively. Furthermore, the presence of an electric machine allows a more precise speed profile tracking. This study points out that the hybridization of agricultural tractor powertrains is one of the most promising approaches for reducing pollutant emissions and fuel consumption.

The conventional open ponding system employed for palm oil mill agro-effluent (POME) treatment fails to lower the levels of organic pollutants to the mandatory standard discharge limits. In this work, carbon doped black TiO₂ (CB-TiO₂) and carbon-nitrogen co-doped black TiO₂ (CNB-TiO₂) were synthesized via glycerol assisted sol-gel techniques and employed for the remediation of treated palm oil mill effluent (TPOME). Both the samples were anatase phase, with a crystallite size of 11.09–22.18 nm, lower bandgap of 2.06–2.63 eV, superior visible light absorption ability, and a high surface area of 239.99–347.26 m²/g. The performance of CNB-TiO₂ was higher (51.48%) compared to only (45.72%) CB-TiO₂. Thus, the CNB-TiO₂ is employed in sonophotocatalytic reactions. Sonophotocatalytic process based on CNB-TiO₂, assisted by hydrogen peroxide (H₂O₂), and operated at an ultrasonication (US) frequency of 30 kHz and 40 W power under visible light irradiation proved to be the most efficient for chemical oxygen demand (COD) removal. More than 90% of COD was removed within 60 min of sonophotocatalytic reaction, producing the effluent with the COD concentration well below the stipulated permissible limit of 50 mg/L. The electrical energy required per order of magnitude was estimated to be only 177.59 kWh/m³, indicating extreme viability of the proposed process for the remediation of TPOME.

High-velocity oxy-fuel (HVOF) thermally sprayed Cr₃C₂-NiCr coatings have been shown to be effective in shielding important machinery and equipment components from wear in harsh, high-temperature conditions. In this investigation, the HVOF thermal spray coating technique was used to deposit Cr₃C₂-NiCr powder with 10% Co particles onto ductile cast iron. The effect of the Co particles on the mechanical, tribological, and microstructure characteristics of a Cr₃C₂-NiCr/ductile cast iron system was investigated. The microstructure analysis employed various techniques, including light microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). Scratch tests were applied to analyze the coating quality and adhesion. The coatings created using the HVOF spray method with Cr₃C₂-NiCr powders mixed with Co particles exhibited a dense structure containing large Co particles, partially melted, and very fine Cr₃C₂ particles embedded into the NiCr alloy matrix. Additionally, they possessed high hardness and excellent adhesion to the substrate. The results of bending strength tests were also presented, together with information on the coating’s microhardness and fracture toughness. These included an analysis of the cracks and delamination in the Cr₃C₂-NiCr/ductile cast iron system. It was observed that the addition of Co particles significantly increased the resistance to cracking and wear behavior in the studied system.

Agricultural tractors are high fuel-consuming and polluting machines, thus the introduction of new sustainable technologies, as hybridization, can be very impactful for the development of electric hybrid agricultural tractors. These vehicles combine the classic internal combustion engine with an electric machine, to reduce the environmental impact and improve the efficiency. This paper reports the modeling and the simulation conducted, using a simulation software typically used for on-road vehicles, of a two wheel-drive agricultural tractor in three different configurations: the conventional one, the series and the parallel electric hybrid powertrain. The simulated task is the trailing of a big square baler during the process of straw wrapping and baling. The evaluation and the comparison of the fuel consumption, CO2 emissions and the depth of discharge of the different configurations has been carried out to determine if it is possible to downsize the ICE, maintaining the same performances. This study points out that the hybridization of agricultural tractors powertrains is one of the most promising approaches to reduce pollutant emissions and fuel consumption.

The evaluation of direct energy inputs and the assessment of the carbon footprint of an agricultural tractor during the execution of an agricultural operation is a complex task. Methodological approaches such as field surveys and life cycle assessments can provide unreliable and non-repeatable results. This study exploits the use of numerical simulation to assess the fuel consumption of two agricultural tractors and their CO₂ emissions during the execution of pesticide treatment and milling. The digital models of the Landini REX 4-120 GB and the Fendt 942 Vario were developed, starting from experimental data acquired during field tests in which the power required at the power take-off (PTO) by the respective operating machine was measured. Two custom working cycles, simulating the two agricultural operations, have been defined and simulated. The estimated fuel consumption was 7.8 L∙ha⁻¹ and 23.2 L∙ha⁻¹, respectively, for the Landini REX 4-120 GB during pesticide treatment and for the Fendt 942 Vario during milling. The corresponding direct energy inputs required for the two agricultural operations were equal to 300.3 MJ∙ha⁻¹ and 893.2 MJ∙ha⁻¹, respectively. The estimated carbon footprint was 26.5 kg_CO2∙ha⁻¹ and 68.4 kg_CO2∙ha⁻¹ for pesticide treatment and for milling, respectively. Moreover, considering the operational efficiency of the systems, an analysis of the available mechanical work supplied by the fuel was conducted.

One of the solutions contributing to the development of energy independence is the utilization of biogas as an alternative fuel for agricultural tractors. Biogas is recognized as a renewable energy source, and its usage aids in the reduction in greenhouse gas emissions on a global scale. The reuse of this material/waste exemplifies the concept of a circular economy. Several models of agricultural tractors designed explicitly for biogas utilization or adaptable for its use are available in the market. This study aimed to evaluate the energy-ecological parameters of the MP tractor (T6.180 Methane Power) powered by Compressed Natural Gas (CNG) in comparison to its structurally identical counterpart fueled by Diesel (T6.180 Electro Command). Based on the Air–Fuel Ratio (AFR) coefficients for diesel and methane, as well as values of air excess ratios (λ) and the proportions of CO and CO₂ emissions determined for various engine load states, the mass emission of selected exhaust components for the examined tractors was estimated. This research highlights that biogas-powered tractors hold the potential to contribute to the sustainable development of agriculture through the reduction in greenhouse gas emissions, improvement in farm energy autonomy, and optimal resource utilization, closely aligned with the principles of a circular economy.