With the increasing global emphasis on renewable energy, the generation of biomass fly ash is anticipated to rise substantially in the coming years. This trend highlights the urgent need for effective strategies to manage and utilize this byproduct sustainably. This study reviews and classifies selected types of biomass ashes, treating them as representative examples that illustrate the wide variability in chemical compositions and physical properties across different biomass sources. These include ashes derived from woody biomass, agricultural residues, animal-origin biomass, and sewage sludge. Biomass ashes exhibit significant heterogeneity compared to coal ashes, which makes understanding their chemical composition—particularly the major components such as calcium (Ca), silicon (Si), and phosphorus (P)—critical for identifying suitable industrial applications. Special categories of ashes with elevated heavy metals and chlorine (Cl) levels are also identified and discussed. This approach enables the identification of sustainable utilization pathways, ranging from traditional uses, such as agricultural fertilizers and construction materials, to emerging applications in advanced engineering materials. Additionally, this paper addresses the assessment and mitigation of potential risks related to hazardous metals in biomass ashes.

Acting in accordance with the requirements of the 2015 Paris Agreement, Poland, as well as other European Union countries, have committed to achieving climate neutrality by 2050. One of the solutions to reduce emissions of harmful substances into the environment is the implementation of large-scale hydrogen technologies. This article presents the cost of producing green hydrogen produced using an alkaline electrolyzer, with electricity supplied from a photovoltaic farm. The analysis was performed using the Monte Carlo method, and for baseline assumptions including an electricity price of 0.053 EUR/kWh, the cost of producing green hydrogen was 5.321 EUR/kgH₂. In addition, this article presents a sensitivity analysis showing the impact of the electricity price before and after the energy crisis and other variables on the cost of green hydrogen production. The large change occurring in electricity prices (from 0.035 EUR/kWh to 0.24 EUR/kWh) significantly affected the levelized cost of green hydrogen (LCOH), which could change by up to 14 EUR/kgH₂ in recent years. The results of the analysis showed that the parameters that successively have the greatest impact on the cost of green hydrogen production are the operating time of the plant and the unit capital expenditure. The development of green hydrogen production facilities, along with the scaling of technology in the future, can reduce the cost of its production.

Direct air capture (DAC) technology is increasingly recognized as a key tool in the pursuit of climate neutrality, enabling the removal of carbon dioxide directly from the atmosphere. Despite its potential, DAC remains in the early stages of development, with most installations limited to pilot or demonstration units. The main barriers to its widespread implementation include high energy demands and significant capture costs. This literature review addresses the most critical research directions related to the development of this technology, focusing on its challenges and prospects for deployment. Particular attention is given to studies aimed at developing new, cost-effective, and efficient sorbents that could significantly reduce the energy intensity and costs of the process. Alternative technologies, such as electrochemical and membrane-based processes, show promise but require further research to overcome limitations, such as sensitivity to oxygen presence or insufficient membrane selectivity. The economic feasibility of DAC remains uncertain, with current estimates subject to significant uncertainty. Governmental and regulatory support will be crucial for the technology’s success. Furthermore, the location of DAC installations should consider factors such as energy availability, options for carbon dioxide storage or utilization, and climatic conditions, which significantly affect process efficiency. This review highlights the necessity for continued research to overcome existing barriers and fully harness the potential of DAC technology.

The use of poultry litter (PL) as a sustainable fuel is gaining more attention due to its wide availability and carbon neutrality. However, this type of feedstock is rich in ash and typically contains a high concentration of chlorine (Cl) and alkali elements (Na, K). Therefore, it is likely to cause unwanted issues during combustion and co-combustion, such as chlorine-induced corrosion, ash deposition, and bed agglomeration. In this study, for the first time, the influence of aluminosilicate additives on the above problems of poultry litter was investigated. Three aluminosilicate minerals are under consideration: kaolin, halloysite, and bentonite. Their influence on the chemical composition and meting tendencies of two poultry litter ashes are determined. The investigated ashes, PL1 and PL2, are characterized by different chlorine contents of 6.38% and 0.42%, respectively. The results show that in the case of the chlorine-rich PL1 ash, the additives reduced the chlorine content by up to 45%, resulting in a 3.93% of chlorine in the case of halloysite, 3.48% in the case of kaolin, and 4.25% in the case of bentonite. The additives also positively influenced the shrinkage starting temperature and the deformation temperature of the PL1 ash.