Search Results (133)

Biomass and other solid wastes create potential environmental and health hazards in our modern society. Conversion of the wastes into energy presents a promising avenue for sustainable energy generation. However, the feasibility of the approach is limited by the challenges in material handling because of the special properties of the materials. Despite their critical importance, the complexities of material handling often evade scrutiny until operational implementation. This paper highlights the challenges inherent in standard solid material-handling processes, preceded by a concise review of common solid waste typologies and their physical properties, particularly those related to biomass and biowastes. It delves into the complexities of material flow, storage, compaction, agglomeration, separation, transport, and hazard management. Specialised characterisation techniques essential for informed process design are also discussed to mitigate operational risks. In conclusion, this paper emphasises the necessity of a tailored framework before the establishment of any further conversion processes. Given the heterogeneous nature of biomaterials, material-handling equipment must demonstrate adaptability to accommodate the substantial variability in material properties in large-scale production. This approach aims to enhance feasibility and efficacy of any energy conversion initiatives by using biomass or other solid wastes, thereby advancing sustainable resource utilisation and environmental stewardship. Full article

Conventional methods for the synthesis of porous carbons are typically time- and energy-consuming and often contribute to the excessive accumulation of waste solvents. An alternative approach is to employ environmentally friendly procedures, such as mechanochemical synthesis, which holds great potential for large-scale production of advanced carbon-based materials in coming years. This review covers mechanochemical syntheses of highly porous carbons, with a particular focus on new adsorbents and catalysts that can be obtained from biomass. Mechanochemically assisted methods are well suited for producing highly porous carbons (e.g., ordered mesoporous carbons, hierarchical porous carbons, porous carbon fibers, and carbon–metal composites) from tannins, lignin, cellulose, coconut shells, nutshells, bamboo waste, dried flowers, and many other low-cost biomass wastes. Most mechanochemically prepared porous carbons are proposed for applications related to adsorption, catalysis, and energy storage. This review aims to offer researchers insights into the potential utilization of biowastes, facilitating the development of cost-effective strategies for the production of porous carbons that meet industrial demands. Full article

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

The amount of waste generated by society is constantly increasing. Consequently, there is a need to develop new and better methods of treating it. A significant part of municipal waste is biowaste, which can be treated as a source of valuable resources such as nutrients, organic matter, and energy. The present work aims to determine the properties of the tested household biowaste and the possibility of using it as feedstock in slow pyrolysis to obtain biochar. The slow pyrolysis process of the biowaste was carried out in an electrically heated Horizontal Tube Furnace (HTF) at temperatures of 400 °C, 500 °C, and 600 °C in a nitrogen atmosphere. The analysis showed that depending on the type and composition of the biowaste, its properties are different. All the biowaste tested has a high moisture content (between 63.51% and 81.53%), which means that the biowaste needs to be dried before the slow pyrolysis process. The characteristics of kitchen biowaste are similar to those of food waste studied by other researchers in different regions of the world. In addition, the properties of kitchen biowaste are similar to those of the typical biomasses used to produce biochar via slow pyrolysis, such as wood, almond shells, and rice husks. Both kinds of garden biowaste tested may have been contaminated (soil, rocks) during collection, which affected the high ash content of spring (17.75%) and autumn (43.83%) biowaste. This, in turn, affected all the properties of the garden biowaste, which differed significantly from both the literature data of other garden wastes and from the properties of typical biomass feedstocks used to produce biochar in slow pyrolysis. For all biowaste tested, it was shown that as the pyrolysis temperature increases, the yield of biochar decreases. The maximum mass yield of biochar for kitchen, spring garden, and autumn garden biowaste was 36.64%, 66.53%, and 66.99%, respectively. Comparing the characteristics of biowaste before slow pyrolysis, biochar obtained from kitchen biowaste had a high carbon content, fixed carbon, and a higher HHV. In contrast, biochar obtained from garden biowaste had a lower carbon content and a lower HHV. Full article

Spent automobile catalysts can be an important source of platinum for industry applications. Low-cost and simple technologies for platinum recovery from this source are sought, especially involving the application of green adsorbents. Honeycomb biowaste can be an excellent candidate for this purpose; n-hexane-treated honeycomb biowaste is therefore obtained for the first time. This material is characterized using several instrumental techniques, confirming the presence of O, N, and P heteroatoms on its surface and the complex morphology of its particles. The maximum static Pt(II)/Pt(IV) adsorption (46 mg/g and 60 mg/g, respectively) onto the n-hexane-extracted honeycomb biomass is reached at pH = 1.55 and a contact time of 50 h. The adsorption kinetics are best fitted to the pseudo-second-order model in both cases. The Langmuir model best described the Pt(II)/Pt(IV) adsorption isotherms on the studied material. Quantitative desorption of the Pt from the studied material is reached for 1 mol/L thiourea dissolved in HCl. The adsorption mechanism of Pt(IV) ions onto the obtained material is based mainly on the surface complexation reactions. The studied material is successfully applied for the first time for Pt(IV) removal from a spent automobile catalyst leachate. Full article

Most bioplastics are based on polysaccharides, which are either synthesized from a variously sourced monomer or extracted from some biomass waste. In many cases, some lignocellulosic fibers are then added to the obtained bioplastics to form biocomposites and extend their range of applications beyond packaging films and generically easily biodegradable materials. Plant-extracted tannins, which, as such, might also be building blocks for bioplastics, do nonetheless represent a useful complement in their production when added to polysaccharide-based plastics and biocomposites, since they offer other functions, such as bioadhesion, coloration, and biocidal effect. The variety of species used for tannin extraction and condensation is becoming very wide and is also connected with the local availability of amounts of bio-waste from other productions, such as from the food system. This work tries to summarize the evolution and recent developments in tannin extraction and their increasing centrality in the production of polysaccharide-based plastics, adhesives, and natural fiber composites. Full article

Avocado is a rich source of numerous nutrients, such as micro- and macroelements, essential unsaturated fatty acids, and vitamins essential for the correct functioning of the body. Consequently, its consumption has significantly increased in recent years. The primary edible part of the fruit is the flesh, while the seed is still considered biowaste. Currently, various methods for utilization of this biowaste are being explored, prompting the authors of this work to investigate the catalytic properties of ground avocado seeds. Dried, ground avocado seeds were used as the catalyst in the environmentally friendly oxidation of limonene with oxygen. The process was carried out in mild conditions, without the use of any solvent and at atmospheric pressure. The studies examined the influence of temperature (70–110 °C), the amount of the catalyst (0.5–5.0 wt%), and the reaction time (15–360 min). The analyses of the post-reaction mixtures were performed using the gas chromatography method (GC). The maximum value of the conversion of limonene obtained during the tests was 36 mol%. The main products of this process were as follows: 1,2-epoxylimonene, carveol, and perillyl alcohol. Also, the following compounds were determined in the post-reaction mixtures: carvone and 1,2-epoxylimonene diol. The studied process is interesting, taking into account both the management of waste in the form of avocado seeds and possible wide applications of limonene transformation products in medicine, cosmetics and the food industry. Given that limonene is now increasingly being extracted from waste orange peels, this is also a good way to manage the future naturally derived limonene and reduce the amount of waste orange peels. The presented studies fit perfectly with the goals of sustainable development and circular economy and may be the basis for the future development of “green technology” for obtaining value-added oxygenated derivatives of limonene. These studies show the use of waste biomass in the form of avocado seeds to obtain a green catalyst. In this context, our research presents an effective way of waste valorization. Full article

Organic wastes from households, private gardens, the maintenance of urban greenery, and active nature conservation measures are often difficult to manage. This lignocellulosic biomass may be suitable for anaerobic digestion (AD). However, the mono-digestion of plant material, such as waste from active conservation measures for wetlands, results in a low methane (CH₄) yield. The aim of this study was to assess the feasibility of using common reed silage for co-digestion with plant-based biowaste from households. The specific methane yield (SMY) was determined in biochemical methane potential (BMP) tests performed on biowaste, reed silage, and combinations of reed silage with 10%, 30%, 50%, 70%, and 90% of biowaste on a fresh weight basis. The lowest SMY was observed for the mono-digestion of reed silage (160.40 ± 4.09 NL kg_VS⁻¹), while biowaste had the highest CH₄ yield (284.03 ± 7.03 NL kg_VS⁻¹). The subsequent addition of biowaste enhanced CH₄ production from 158.57 ± 7.88 NL kg_VS⁻¹ (10% of biowaste) to 233.28 ± 11.91 NL kg_VS⁻¹ (90% of biowaste). A key advantage of biogas production is its role in reducing CO₂ emissions into the atmosphere, which result from the use of conventional fuels for energy generation. The avoided CO₂ emissions generated in electricity and heat production range between 378.62 kgCO₂ t_TS⁻¹ and 676.36 kgCO₂ t_TS⁻¹ depending on the reed silage-to-biowaste ratio used for biogas production. This study reveals that reed silage is not an optimal feedstock for biogas production, and its share in co-digestion with biowaste should not exceed 10% of the total input to the biogas plant. Full article

As the raw material transition from fossil to renewable feedstock progresses, the demand for biogenic raw materials for industrial purposes will increase. This applies above all to the energy and chemical sectors. However, the capacities for biogenic energy and carbon sources to be provided by agriculture and forestry are limited. This review examines the contribution that biogenic raw materials and CO₂ from biogenic sources can make to sustainable chemical production in the EU. It analyses statistical data from the EU and studies from the chemical industry. First priority needs to be given to edible biomass for the sector of nutrition. When it comes to the industrial use of biomass, sectors should be prioritised that cannot do without carbon-supplying raw materials. This is particularly the case in the field of organic chemistry. This review focuses on bio-based organic chemical products and gives an outlook on the future of chemical production in Europe based on primary, secondary, and tertiary biomass and CO₂ from biogenic sources. Finally, two new indicators for economically and ecologically sustainable industrial use of biomass are proposed. Both indicators can support the determination of the sustainability status of the sustainable integration of agriculture, forestry, residual, and biowaste management in bioeconomic value networks. Full article

The annually wasted amount of food has surpassed 1 billion metric tons. Food waste is considered as an important source for the recovery of bioactive compounds, such as carotenoids. There is a demand for antioxidants, nutraceuticals and natural colorants in various industries and carotenoids are one of the commonly used compounds that fit this description. Pumpkin and spinach waste, whose combined amount is over 2 million metric tons, contains bioactive compounds and these wasted foods could be utilized for the recovery of carotenoids. Carotenoids are hydrophobic molecules; therefore, commercial extraction processes often use highly non-polar solvents, and these are rarely environmentally friendly. The aim of this research was to develop effective extraction processes for carotenoids from pumpkin and spinach using environmentally friendly green chemicals. A series of deep eutectic solvents (DESs) composed with L-menthol and carboxylic aliphatic acids were made for the extraction of carotenoids from pumpkin (Cucurbita moschata) and spinach (Spinacia oleracea) via mechanical mixing–assisted extraction (MMAE) and homogenization-assisted extraction (HAE). Response surface methodology (RSM) and analysis of variance (ANOVA) were used to analyze the data and optimization. The DESs composed from L-menthol and propionic acid had the best effect on the extraction of total carotenoid content (TCC) (represented as β-carotene) from pumpkin and spinach via solutions with 1:2 and 1:4 molar ratios, respectively. The yield of carotenoid extraction is expressed in μg-β-carotene/g of pumpkin or spinach. Under the calculated optimum conditions, the yields are estimated to be 11.528 μg-β-carotene/g-pumpkin for the MMAE method, 8.966 μg-β-carotene/g-pumpkin for the HAE method, 16.924 μg-β-carotene/g-spinach for the MMAE method and 18.870 μg-β-carotene/g-spinach for the HAE method. Full article

Bioresources have been gaining popularity due to their abundance, renewability, and recyclability. Nevertheless, given their diverse composition and complex hierarchical structures, these bio-based sources must be carefully processed to effectively extract valuable raw polymeric materials suitable for producing man-made organic fibres. This review will first highlight the most relevant bio-based sources, with a particular focus on promising unconventional biomass sources (terrestrial vegetables, aquatic vegetables, fungi, and insects), as well as agroforestry and industrial biowaste (food, paper/wood, and textile). For each source, typical applications and the biopolymers usually extracted will also be outlined. Furthermore, acknowledging the challenging lignocellulosic structure and composition of these sources, an overview of conventional and emerging pre-treatments and extraction methods, namely physical, chemical, physicochemical, and biological methodologies, will also be presented. Additionally, this review aims to explore the applications of the compounds obtained in the production of man-made organic fibres (MMOFs). A brief description of their evolution and their distinct properties will be described, as well as the most prominent commercial MMOFs currently available. Ultimately, this review concludes with future perspectives concerning the pursuit of greener and sustainable polymeric sources, as well as effective extraction processes. The potential and main challenges of implementing these sources in the production of alternative man-made organic fibres for diverse applications will also be highlighted. Full article

Deep eutectic solvents (DES) represent an innovative and environmentally friendly approach for chitin isolation. Chitin is a natural nitrogenous polysaccharide, characterized by its abundance of amino and hydroxyl groups. The hydrogen bond network in DES can disrupt the crystalline structure of chitin, facilitating its isolation from bioresources by dissolving or degrading other components. DES are known for their low cost, natural chemical constituents, and recyclability. Natural deep eutectic solvents (NADES), a subclass of DES made from natural compounds, offer higher biocompatibility, biodegradability, and the lowest biotoxicity, making them highly promising for the production of eco-friendly chitin products. This review summarized studies on chitin isolation by DES, including reviews of biomass resources, isolation conditions (raw materials, DES compositions, solid–liquid ratios, temperature, and time), and the physicochemical properties of chitin products. Consequently, we have concluded that tailoring an appropriate DES-based process on the specific composition of the raw material can notably improve isolation efficiency. Acidic DES are particularly effective for extracting chitin from materials with high mineral content, such as crustacean bio-waste; for instance, the choline chloride-lactic acid DES achieved purity levels comparable to those of commercial chemical methods. By contrast, alkaline DES are better suited for chitin isolation from protein-rich sources, such as squid pens. DES facilitate calcium carbonate removal through H⁺ ion release and leverage unique hydrogen bonding interactions for efficient deproteination. Among these, potassium carbonate-glycerol DES have demonstrated optimal efficacy. Nonetheless, further comprehensive research is essential to evaluate the environmental impact, economic feasibility, and safety of DES application in chitin production. Full article

Expanding green areas in cities results in growth in green waste generation. This study presents the findings of an investigation into green waste from selective collection in a large Central European city (Warsaw, Poland), which can be identified as a valuable biomass resource. The research objective was to identify the properties of garden waste from single-family housing to determine valorization opportunities, emphasizing the utilization of GW as a source of energy. The research yielded several findings, including a notable degree of variability in fuel properties, including moisture content (CV = 30%), lower heating value (CV = 14.3%), and ash content (CV = 62.7/56.2%). The moisture content suggests composting, while the fertilizing properties indicate suitability for anaerobic digestion. The instability of the fuel properties, coupled with the elevated levels of chlorine, sulfur, and moisture, constrains the use of garden waste in thermal processes and alternative fuel production. Pyrolysis could be a viable approach for green waste feedstock, offering value-added products depending on the processing conditions and pre-treatment. Nevertheless, implementing a selective collection system is a critical condition for the optimal utilization of bio-waste, facilitating the quality and property control of green and food waste. This is essential for their effective processing, including energy recovery, thereby contributing to the efficient valorization of biomass. Full article

Exploring high-performance carbon anodes that are low-cost and easily accessible is the key to the commercialization of sodium-ion batteries. Producing carbon materials from bio by-products is an intriguing strategy for sodium-ion battery anode manufacture and for high-value utilization of biomass. Herein, a novel hard carbon (PPHC) was prepared via a facile pyrolysis process followed by acid treatment using biowaste pomegranate peel as the precursor. The morphology and structure of the PPHC were influenced by the carbonization temperature, as evidenced by physicochemical characterization. The PPHC pyrolyzed at 1100 °C showed expanded interlayer spacing and appropriate oxygen group content. When used as a sodium ion battery anode, the PPHC-1100 demonstrated a reversible capacity of up to 330 mAh g⁻¹, maintaining 174 mAh g⁻¹ at an increased current rate of 1 C. After 200 cycles at 0.5 C, the capacity delivered by PPHC-1100 was 175 mAh g⁻¹. The electrochemical behavior of PPHC electrodes was investigated, revealing that the PPHC-1100 possessed increased capacitive-controlled energy storage and improved ion transport properties, which explained its excellent electrochemical performance. This work underscores the feasibility of high-performance sodium-ion battery anodes derived from biowaste and provides insights into the sodium storage process in biomass-derived hard carbon. Full article

Industrial and domestic human activities have a significant impact on the environment, contributing, among other things, to the increased pollution of natural waters. The spread of heavy metals is particularly dangerous to the health and life of living organisms due to the high accumulation potential of, among others, Cr (VI), Zn (II), Cu (II), Cd (II), Fe (II), and Ni (II). In order to remove, concentrate, and/or recover ions of these metals, various physical and/or chemical methods are commonly used. In this study, spent coffee grounds (SCGs) efficiently removed copper ions from simulated aqueous solutions, especially at low metal ion concentrations. Without additional modification, coffee grounds performed comparably to traditional adsorbents like activated carbon or ion exchangers. It was found that used ground coffee grounds effectively removed Cu (II) ions at a wide range of concentrations, with the highest efficiency (over 85%) obtained for dilute solutions. On the other hand, regeneration tests performed using a 10% hydrochloric acid solution successfully restored the coffee residue adsorbent, achieving a desorption efficiency of about 35%. This method concentrated the solution and facilitated efficient metal recovery by minimizing acid usage. The sorbent used is an innovative, cheap, and easy-to-use material with high sorption capabilities. Full article