Search Results (21)

Gasification of municipal solid waste and other biogenic residues (e.g., biomass and biowaste) is increasingly recognized as a promising thermochemical pathway for converting non-recyclable fractions into valuable energy carriers, with applications in electricity generation, district heating, hydrogen production, and synthetic fuels. This paper provides a comprehensive analysis of major gasification technologies, including fixed bed, fluidized bed, entrained flow, plasma, supercritical water, microwave-assisted, high-temperature steam, and rotary kiln systems. Key aspects such as feedstock compatibility, operating parameters, technology readiness level, and integration within circular economy frameworks are critically evaluated. A comparative assessment of incineration and pyrolysis highlights the environmental and energetic advantages of gasification. The valorization pathways for main product (syngas) and by-products (syngas, ash, tar, and biochar) are also explored, emphasizing their reuse in environmental, agricultural, and industrial applications. Despite progress, large-scale adoption in Europe is constrained by economic, legislative, and technical barriers. Future research should prioritize scaling emerging systems, optimizing by-product recovery, and improving integration with carbon capture and circular energy infrastructures. Supported by recent European policy frameworks, gasification is positioned to play a key role in sustainable waste-to-energy strategies, biomass valorization, and the transition to a low-emission economy. Full article

Today, the global production of plastic packaging reaches a million tons annually, resulting in significant amounts of plastic waste in the environment, which causes serious pollution issues and negatively affects the health of all living beings. However, the recycling rate for plastic packaging waste in Europe currently remains limited (~38%). With this in mind, this study focuses on the collection, characterization, and recycling, through pyrolysis, of 23 random plastic samples collected from food and non-food packaging waste in Greece. The samples were analyzed using thermal characterization techniques, such as Differential Scanning Calorimetry (DSC) and Evolved Gas Analysis (EGA), in conjunction with FTIR spectroscopy to gather important information and identify the polymers present in each sample. Furthermore, the samples underwent pyrolysis, resulting in valuable products such as the monomers styrene or ethylene, along with other useful secondary compounds, including benzoic acid, depending on the polymer type of each sample. The most prevalent polymer identified was PE (35%), while the remaining samples consisted of PET (22%), PP (22%), and PS (17%); only one sample was a blend of PE/PP. DSC facilitated the identification of the polyethylene type (LDPE, HDPE, or LLDPE). Full article

Incineration remains Europe’s main practice for plastic packaging waste treatment, primarily due to the limitations of mechanical recycling technology. Consequently, research and development of more sustainable and flexible approaches are of high importance. Thermochemical conversion of polypropylene, polystyrene, and municipal plastic packaging mix via high-temperature flash pyrolysis (1000 °C/s) is studied in this research, focusing on the kinetics and yields of the devolatilisation stage. The primary stage results in the formation of volatile organic compounds considered intermediate products for carbon black production. The experiments were conducted in a pressurised wire mesh reactor, investigating the influence of temperature (600–1200 °C), residence time (0.5–10 s), and pressure (1–25 bar). The positive effect of temperature on the volatile yield was observed up to 2–5 s. The devolatilisation stage was completed within a maximum of 5 s at temperatures ranging from 800 to 1200 °C. The pressure was determined to be a kinetically limiting factor of the process to up to 800 °C, and the effect was not present at ≥1000 °C. Raman spectroscopy measurements revealed that pyrolytic carbon deposited on the post-experimental meshes is structurally similar to the industrially produced carbon black. The kinetic data and developed model can be further applied in the upscale reactor design. Full article

With a value of 400.3 Mt, the global plastics production increased in 2022 with a plus of 2.5 wt% compared to the previous years. Unfortunately, plastic waste is often disposed of inappropriately, causing environmental problems and an avoidable waste of resources. In 2019, the European Circular Economy Action Plan was issued to encourage plastic recycling. Nevertheless, at the end of 2022, post-consumer mechanically recycled plastics in Europe accounted only for 13.2 wt% of the European plastic production (58.8 Mt). Mechanical recycling fails to recycle mixed, partially degraded, or contaminated plastic waste. Then, there is an acute demand for new, efficient, and cost-effective recycling technologies to fill the gap left by mechanical recycling. Chemical recycling is considered a complementary alternative because it can process waste streams composed of heterogenous and difficult plastics. Currently in Europe, around 58.8 kt (0.1 wt%) of plastic production was obtained by chemically recycled plastics, but the road is marked. The Plastic Europe association announces that its members are going to produce 2.8 Mt of chemically recycled plastics by 2030. Mixed plastic waste is the main target, and pyrolysis and gasification, identified as the suitable technologies for its treatment, represent 80 wt% of the planned capacities. Full article

The discovery of the Northern Copper Belt in SW Poland is a result of an extensive exploration project with a key role played by various science-related methods. The project relied on mapping the distribution of mineral zones in the entire Fore-Sudetic Monocline, a unit known for its occurrences of Cu-Ag orebodies. This approach involved the examination of historical drill cores from over 400 oil and gas holes in this area, with the collection of samples for laboratory analyses. A close relationship was confirmed between the distribution of orebodies and the transformation of organic matter. Rock-Eval pyrolysis was also performed on selected samples. The tests of rock specimens were accompanied by the reprocessing of historical gravimetric and seismic surveying results. Field magnetotelluric surveying was also performed in certain areas. This phase resulted in the identification of areas with a high probability of finding the best ore, allowing for the initiation of the drilling stage. So far, 37 exploratory boreholes have been drilled in those locations, nearly all of them with highly positive results. The Northern Copper Belt consists of three deposits, Nowa Sól, Mozów, and Sulmierzyce North, along with numerous prognostic areas distributed therebetween. The future production of copper, silver, and the accompanying valuable elements presents a chance to provide the whole of Europe with a new plentiful supply of those critical raw materials. Full article

This scientific paper provides an overview of the current state of pyrolysis in Europe, with a focus on mapping the key research areas and technologies employed. This research relied on search equations that centered on the utilization of biomass and plastics as primary feedstocks in pyrolysis, with a particular emphasis on biochar generation and different technologies applied. The results showed that both plastic and biomass pyrolysis can contribute to reducing waste and mitigating greenhouse gas emissions. However, plastic pyrolysis can release harmful pollutants due to the presence of chlorine and other additives in plastics, which requires sophisticated emission control systems to be implemented. The production of biochar from sewage sludge is identified as a promising approach for phosphorus recovery, which can subsequently be utilized as a valuable fertilizer in agricultural applications. The data from this study contribute to exploring future applications at pilot and industrial scales for pyrolysis, with a critical assessment of the use of feedstocks. Moreover, this work provides information about current companies that are already operating on a large scale with pyrolysis and a map of the principal countries in Europe engaged in pyrolysis research, correlating the characteristics of the pyrolysis processes investigated. Full article

The world is moving towards decarbonization policies in the energy and industrial sectors to bring down carbon dioxide release and reach net zero emissions. Technologies to capture CO₂ and use it as a feedstock to produce CO₂-based chemicals and biofuels via chemical or biochemical conversion pathways can potentially reduce the amount of CO₂ released. The paper serves the innovative scientific knowledge for CO₂ transformation via a biochemical pathway to microalgal biomass with its subsequent treatment to biofuels and bioproducts assuming milder climatic conditions (Central or Eastern Europe, Visegrad countries or climatically related world regions). The recent trends were critically reviewed for microalgal biorefinery to reach the sustainability of microalgal-based chemicals with added value, digestion, hydrothermal liquefaction, pyrolysis, and gasification of microalgal residues. Knowledge-based chemical process engineering analysis, systematic data synthesis, and critical technical evaluation of available life cycle assessment studies evaluated the sustainability of microalgal biorefinery pathways. The research showed that biological CO₂ fixation using water, seawater or wastewater to produce third-generation biomass is a promising alternative for bioethanol production via pretreatment, enzymatic hydrolysis, digestion, and distillation, and can be realized on a large scale in an economically viable and environmentally sound manner. Its best economically promising and sustainable pathway is perceived in producing microalgal-based nutraceuticals, bioactive medical products, and food products such as proteins, pigments, and vitamins. Machine learning methods for data mining, process control, process optimization, and geometrical configuration of reactors and bioreactors are the crucial research needs and challenges to implementing microalgal biorefinery in an operational environment. Full article

The main goal of the study was to assess the possibility of practical use of products of pyrolysis of refuse-derived fuel (RDF), i.e., pyrolysis gas, biochar and pyrolysis oil, as an alternative to standard fossil fuels. The subject matter of the paper reaches out to the challenges faced by the global economy, not only in the context of the energy crisis, but also in the context of the energy transformation currently beginning in Europe. The increase in fuel and energy prices prompts countries to look for alternative solutions to Russian minerals. At the same time, the growing amount of municipal waste forces the implementation of solutions based on energy recovery (the amount of municipal waste per EU inhabitant in 2021 is 530 kg). One such solution is pyrolysis of RDF, i.e., fuels produced from the over-sieve fraction of municipal waste. In Poland, insufficient processing capacity of thermal waste conversion plants has led to significant surpluses of RDF (1.2 million Mg of undeveloped RDF in Poland in 2021). RDF, due to their high calorific value, can be a valuable energy resource (16–18 MJ/k). This issue is analyzed in this study. Full article

One of the greatest challenges humankind currently faces is global warming, mainly caused by greenhouse gas emissions. Here we have attempted to show how thermal conversion products, specifically from the pyrolysis of biomass wastes such as sewage sludge, can be used effectively and equivalently to sequester CO₂ in brownfield and degraded areas. Scenarios were devised that showed the significant potential for CO₂ sequestration in the form of biochar from sewage sludge deposited on degraded and brownfield areas. With the current amount of sludge production, such sludge could even be used in its entirety as a raw material in pyrolysis processes, where, in addition to the biochar, the heat necessary for drying the sludge could be generated and high-energy gas and liquid fractions could be obtained, which could be used to produce alternative fuels. It is therefore important to consider both the potential for CO₂ sequestration on degraded and brownfield sites and the potential for sludge disposal in Europe as viable options for reducing greenhouse gas emissions and promoting sustainable waste management practices. Full article

This research aims to develop a new strategy to valorize wasted COVID-19 masks based on chemical recycling by pyrolysis to convert them into useful products. First, surgical and filtering face piece masks, as defined in Europe by the EN 149 standard (FFP2), were thermally pyrolyzed at temperatures of 450, 500, and 550 °C, and the yields of valuable solid (biochar), liquid (biooil), and syngas products and their characteristics were determined. At low temperatures, biochar formation was favored over biooil and syngas production, while at high temperatures the syngas product yield was enhanced. The highest yield of biooil was found at a pyrolysis temperature of 500 °C, with both surgical and FFP2 masks achieving biooil yields of 59.08% and 58.86%, respectively. Then, the pyrolysis experiments were performed at 500 °C in a two-stage pyrolysis catalytic reactor using sepiolite as a catalyst. Sepiolite was characterized using nitrogen adsorption–desorption isotherms and Fourier-transform infrared spectroscopy. Results showed that the two-stage process increased the final yield of syngas product (43.89% against 39.52% for surgical masks and 50.53% against 39.41% for FFP2 masks). Furthermore, the composition of the biooils significantly changed, increasing the amount of 2,4-Dimethyl-1-heptene and other olefins, such as 3-Eicosene, (E)-, and 5-Eicosene, (E)-. Additionally, the methane and carbon dioxide content of the syngas product also increased in the two-stage experiments. Ultimately, the effect of sepiolite regeneration for its use in consecutive pyrolysis tests was examined. Characterization data showed that, the higher the use-regeneration of sepiolite, the higher the modification of textural properties, with mainly higher changes in its pore volume. The results indicated that the pyrolysis of face masks can be a good source of valuable products (especially from biooil and syngas products). Full article

Desalination is an opportunity to get fresh water for irrigation and for drinking. Reverse Osmosis (RO) for sea water desalination is a solution for the high demand for water in Atlantic islands. The most efficient process to get desalinated water is RO; however, it is necessary to study what to do with the RO membranes used at the end of their life. This paper confirms the possibility to recycle them. The main categories of recycling by thermal processing commonly used in the industry include incineration and pyrolysis to produce energy, gas and fuel. These processes can be applied to mixed plastic waste, such as the combination of materials used in the manufacture of RO membranes. Recycling RO elements from desalination plants is shown to be an opportunity and pioneering initiatives are already underway in Europe. Energy recovery, via incineration, is feasible nowadays and it is a possibility to recycle RO membranes. On the other hand, the recycling of RO elements, via the pyrolytic industry, for fuel production could be centralized in a new industry already planned in the Macaronesia area and all obsolete osmosis membranes could be sent there for recycling. Recycling RO membranes is a very important opportunity for the environment and economy of the zone. This is a new business in water treatments with membranes, very interesting for decreasing the residues and the carbon footprint. The importance of this work is applied to sea water membranes, brackish water ones, and also wastewater tertiaries RO elements at the end of their life. Full article

The wine industry is one of the most relevant socio-economic activities in Europe. However, this industry represents a growing problem with negative effects on the environment since it produces large quantities of residues that need appropriate valorization or management. From the perspective of biorefinery and circular economy, the winery residues show high potential to be used for the formulation of new products. Due to the substantial quantities of phenolic compounds, flavonoids, and anthocyanins with high antioxidant potential in their matrix, these residues can be exploited by extracting bioactive compounds before using the remaining biomass for energy purposes or for producing fertilizers. Currently, there is an emphasis on the use of new and greener technologies in order to recover bioactive molecules from solid and liquid winery residues. Once the bio compounds are recovered, the remaining residues can be used for the production of energy through bioprocesses (biogas, bioethanol, bio-oil), thermal processes (pyrolysis, gasification combustion), or biofertilizers (compost), according to the biorefinery concept. This review mainly focuses on the discussion of the feasibility of the application of the biorefinery concept for winery residues. The transition from the lab-scale to the industrial-scale of the different technologies is still lacking and urgent in this sector. Full article

Biochar (BC) is often proposed as a tool for climate change mitigation, due to the expected long lifetime in the environment. However, BC’s stability can vary depending on feedstock type and the presence of labile carbon fractions. In this study, we verify the recent methods with new possible tools for biochar stability assessment on six different biochars derived from commonly available Europe biomass sources. Elemental composition (CHNO), dissolved organic carbon (DOC) and water-soluble carbonates content (WSC), volatile organic compounds (VOCs) composition, and mid-infrared spectra (MIR) were performed to estimate the persistence of biochars. Under similar conditions of pyrolysis, biochar properties can vary depending on a feedstock origin. Less aromatic structure and higher contents of labile carbon fractions (DOCs and WSC) in food waste biochars affected the lower stability, while biochars derived from high lignocellulose materials (straw, wood, and grass) were strongly carbonized, with persistent, aromatic structure. Labile carbon pool content (DOC, WSC) and spectral analysis can be useful tools for biochar stability assessment, giving similar information to the standard molar ratio method. Biochars obtained from agriculture and forestry management biomass should be considered as highly stable in soil and are appropriate for long-term carbon sequestration purposes. Full article

Reverse osmosis membranes could be reused in the same or another desalination plant by replacing the membranes in the dirtiest first positions with those in the least damaged last positions, also changing the best first stage membranes to the second and vice versa. The useful life of these membranes could be extended by chemical cleaning and giving them a second life in tertiary treatment plants, as well as reusing them in industrial processes where special reverse osmosis membranes are used and degrade rapidly, in processes with leachates from landfill waste, and also an interesting option is the oxidation of reverse osmosis elements to obtain nanofiltration, ultrafiltration or microfiltration membranes for the elimination of physical dirt. The main categories of recycling by thermal processing commonly used in the industry include incineration and pyrolysis to produce energy, gas and fuel. These processes can be applied to mixed plastic waste, such as the combination of materials used in the manufacture of reverse osmosis membranes. Recycling of reverse osmosis elements from desalination plants is shown to be an opportunity, and pioneering initiatives are already underway in Europe. Energy recovery via incineration is feasible but is not considered in line with the environmental, social and political problems it may generate. However, the recycling of reverse osmosis elements via the pyrolytic industry for fuel production can be centralized in a new industry already planned in the Macaronesia area, and all obsolete osmosis membranes can be sent there. This is a technically and economically viable business opportunity with a promising future in today’s recycling market, as discussed in the article. Full article

Among the sustainable ways of municipal solid waste management (MSW) is energy recovery, particularly into refuse derived fuel (RDF). However, the potential, application, and research of RDF in existing cases is not exhausted. Additional analysis of literature is needed to provide further insights into the area. The evolution of RDF research over the past 30 years is analyzed and presented in this paper. Using a statistical approach, a bibliometric analysis was conducted for research on RDF from the SCOPUS database to assess perspectives and trends and gain a better understanding of the scope of RDF research. The bibliometric analysis tools, co-citation, keyword occurrence, co-authorship, and bibliometric coupling network, were utilized in VOSviewer to map out keywords, collaborations, and citations. The result from the analysis indicated that scholarly works around RDF were largely written in English (92.7%). Journal articles were the most frequently occurring document type, representing 68.5% of the records, followed by conference papers (24.9%). Out of a total of 1184 documents analyzed, the number of publications rose steadily from 26 in 2003 to 102 in 2021. Most publications on RDF were in the subject area of Environmental Science (648), Energy (483), and Engineering (441). Waste Management, Fuel, Waste Research and Management, and the Journal of Cleaner Productions were the sources that contained most of the publications on RDF research. The contributions (number of publications) in the RDF research were largely from the US (176), Italy (97), Japan (90), Germany (86), China (79), and the UK (74), among others. Collaborations were notable between the US, Europe, and the Asian regions (China, India, and Thailand). Conspicuously missing were research contributions from the African region, comparatively, thus emphasizing the need for contributions from such perspectives. The keyword analysis result further showed studies were within knowledge areas of conversion processes, applications, and management. Thermochemical conversion pathways were highly applied to RDF and thus combustion/co-combustion/incineration (717), gasification (224), and pyrolysis (115). Additionally, research on RDF applications was mostly in the cement industry (150) and electricity generation (55). The time incident analysis outlined recent interest and emerging trends in optimization of valorization processes, towards a circular economy and sustainability. Cross-cutting areas of environmental focus (emissions) were observed along the years analyzed. There is a rising focus on indicators for commercialization, environmental impacts, and optimum production from the analysis. This is useful especially for the emerging regions/territory of research contributions. These discussions would potentially maximize the co-benefits of energy generation and eco-environment sustainability via cost benefits deployments suggested for future research. Analyzing the RDF research trends, these findings are useful for the future endeavor of researchers and developers. Full article