Development of Renewable Energy Sources in the European Union in the Context of Sustainable Development Policy

Development of Oil Industry in Poland in the Context of the European Union

Oil industry is developing well in Poland. This study aimed to examine the development of the Polish oil industry after joining the European Union. The following questions were asked: What were the changes in the consumption of vegetable oils in Poland after EU enlargement in 2004? How did the production of vegetable oil change in Poland after EU enlargement in 2004? And has the liquidity of the Polish oil industry changed after EU enlargement in 2004? First, the changes in the oil industry were evaluated. This research proved the development of the fat industry. We used the regression model to analyze the impact of chosen factors on the economic situation of the oil industry in Poland. Rapeseed is the main source of oil for the edible oil and biodiesel industry. High prices of rapeseed increased the sown area of rapeseed. The production of crude rapeseed oil changed from 520.1 thousand tons in 2005 to 1440 thousand tons in 2023. Biofuels made from rapeseed oils are called first generation. Poland's production of refined rapeseed oil changed from 386.5 thousand tons in 2005 to 541 thousand tons in 2023. These numbers confirm the development of edible oil and biofuel production. The gross profit increased from PLN 133 mln in 2005 to PLN 443.8 mln in 2023. The net profit of the fat industry increased from PLN 110 mln in 2005 to PLN 381.6 mln in 2023. The oil industry is characterized by high investment, which reached the level of PLN 232.9 mln in 2023. The investment rate in 2023 was PLN 1.96 %. The changes observed in the rapeseed market after Poland joined the EU affected the performance of vegetable oil and biofuel producers. The regression analysis proved the hypothesis that the monthly consumption of rapeseed oil is the main factor influencing the oil industry situation in Poland. The oil industry is important to the development of the whole economy. Particular attention should be paid to current liquidity, which is why a constant supply of money from sold oil and biodiesel is needed to cover costs.

Investigation of Hybrid Electrodes of Polyaniline and Reduced Graphene Oxide with Bio-Waste-Derived Activated Carbon for Supercapacitor Applications

Graphene-based materials have been widely studied in the field of supercapacitors. However, their electrochemical properties and applications are still restricted by the susceptibility of graphene-based materials to curling and agglomeration during production. This study introduces a facile method for synthesizing reduced graphene oxide (rGO) nanosheets and activated carbon based on olive stones (OS) with polyaniline (PAni) surface decoration for the development of supercapacitors. Several advanced techniques were used to examine the structural properties of the samples. The obtained PAni@OS-rGO (1:1) electrode exhibits a high electrochemical capacity of 582.6 F·g-1 at a current density of 0.1 A·g-1, and an energy density of 26.82 Wh·kg-1; thus, it demonstrates potential for efficacious energy storage. In addition, this electrode material exhibits remarkable cycling stability, retaining over 90.07% capacitance loss after 3000 cycles, indicating a promising long cycle life. Overall, this research highlights the potential of biomass-derived OS in the presence of PAni and rGO to advance the development of high-performance supercapacitors.

Potential of acetic acid to restore methane production in anaerobic reactors critically intoxicated by ammonia as evidenced by metabolic and microbial monitoring

BACKGROUND

Biogas and biomethane production from the on-farm anaerobic digestion (AD) of animal manure and agri-food wastes could play a key role in transforming Europe's energy system by mitigating its dependence on fossil fuels and tackling the climate crisis. Although ammonia is essential for microbial growth, it inhibits the AD process if present in high concentrations, especially under its free form, thus leading to economic losses. In this study, which includes both metabolic and microbial monitoring, we tested a strategy to restore substrate conversion to methane in AD reactors facing critical free ammonia intoxication.

RESULTS

The AD process of three mesophilic semi-continuous 100L reactors critically intoxicated by free ammonia (> 3.5 g_N L-1; inhibited hydrolysis and heterotrophic acetogenesis; interrupted methanogenesis) was restored by applying a strategy that included reducing pH using acetic acid, washing out total ammonia with water, re-inoculation with active microbial flora and progressively re-introducing sugar beet pulp as a feed substrate. After 5 weeks, two reactors restarted to hydrolyse the pulp and produced CH4 from the methylotrophic methanogenesis pathway. The acetoclastic pathway remained inhibited due to the transient dominance of a strictly methylotrophic methanogen (Candidatus Methanoplasma genus) to the detriment of Methanosarcina. Concomitantly, the third reactor, in which Methanosarcina remained dominant, produced CH4 from the acetoclastic pathway but faced hydrolysis inhibition. After 11 weeks, the hydrolysis, the acetoclastic pathway and possibly the hydrogenotrophic pathway were functional in all reactors. The methylotrophic pathway was no longer favoured. Although syntrophic propionate oxidation remained suboptimal, the final pulp to CH4 conversion ratio (0.41 ± 0.10 LN_CH4 g_VS-1) was analogous to the pulp biochemical methane potential (0.38 ± 0.03 LN_CH4 g_VS-1).

CONCLUSIONS

Despite an extreme free ammonia intoxication, the proposed process recovery strategy allowed CH4 production to be restored in three intoxicated reactors within 8 weeks, a period during which re-inoculation appeared to be crucial to sustain the process. Introducing acetic acid allowed substantial CH4 production during the recovery period. Furthermore, the initial pH reduction promoted ammonium capture in the slurry, which could allow the field application of the effluents produced by full-scale digesters recovering from ammonia intoxication.

The Development of Renewable Energy Sources in the European Union in the Light of the European Green Deal

Climate and energy policies are the key areas of the European Union’s development aspirations in the international arena. The European Green Deal sets ambitious new goals in this respect, emphasizing clean energy. The development of the energy sector, relying chiefly on renewable sources, is one of the conditions for the EU to transition to energies that do not produce waste that pollutes or is otherwise harmful to the Earth and human health. This paper assesses the development of renewable sources of energy in the EU and identifies challenges to the realization of the EU’s energy priorities. An analysis of renewable sources of energy in the EU in 2012 and 2020 is the prime method. The generation of primary energy from renewable sources, the share of energy from renewable sources in the final energy consumption, the structure of energy generation from renewable sources, and the share of energy from renewable sources in the energy used by the transport sector are discussed. Secondary data are employed, made available by Eurostat and Statistics Poland. To reach the objective of the study, Z. Hellwig’s taxonomic method is applied to assess the development of renewable energy sources (RES). Cluster analysis (Ward’s agglomerative clustering method) is additionally used for separation of objects and member states that are similar with regard to the phenomenon reviewed. Particular attention is paid to the challenges that societies and economies face in view of the assumptions of the EU’s new Green Deal, which envisages a balancing of CO2 emissions and absorption. This analysis discovers varied progress on the development of RES in the member states, posing a threat to the European community’s aspirations.