The torrefaction of municipal solid waste is one of the solutions related to the Waste to Carbon concept, where high-quality fuel—carbonized refuse-derived fuel (CRDF)—is produced. An identified potential problem is the emission of volatile organic compounds (VOCs) during CRDF storage. Kinetic emission parameters have not yet been determined. It was also shown that CRDF can be pelletized for energy densification and reduced volume during storage and transportation. Thus, our working hypothesis was that structural modification (via pelletization) might mitigate VOC emissions and influence emission kinetics during CRDF storage. Two scenarios of CRDF structural modification on VOC emission kinetics were tested, (i) pelletization and (ii) pelletization with 10% binder addition and compared to ground (loose) CRDF (control). VOC emissions from simulated sealed CRDF storage were measured with headspace solid-phase microextraction and gas chromatography–mass spectrometry. It was found that total VOC emissions from stored CRDF follow the first-order kinetic model for both ground and pelletized material, while individual VOC emissions may deviate from this model. Pelletization significantly decreased (63%~86%) the maximum total VOC emission potential from stored CDRF. Research on improved sustainable CRDF storage is warranted. This could involve VOC emission mechanisms and environmental-risk management.
Capsaicin is known as an oily extract of paprika that is characterized by pungent taste and bioactivity. It also may cause irritation to the mouth and stomach which is why is so important to immobilize capsaicin on a carrier to prevent it. The usage of alginate oligomers, which has an antioxidant potential compared to alginate, is of benefit because it may be used in the immobilization of bioactive substances that are fragile to oxidation. The purpose of this study was to use sodium alginate oligomers as a coating material in the encapsulation process of paprika oleoresin. Alginate oligomers were produced by chemical degradation with hydrogen peroxide. The characteristics of the samples were obtained by measuring the viscosity, the contact angle of the surface, and the surface tension of solutions. The obtained solution of alginate oligomers served as the carrier material for the immobilization of capsaicin. Capsules were prepared by ionic gelation using a calcium chloride solution as a crosslinking agent. In this way, capsules without and with the core (capsaicin) were prepared and their ability to scavenge free radicals (DPPH) and iron-reducing properties (FRAP) were determined. The stability of the capsules was examined by thermal decomposition and under conditions of the gastric and small intestine, and capsaicin content was detected using high-performance liquid chromatography. It was found that alginate oligomers could be used in the encapsulation of bioactive compounds and the efficiency was above 80%. Capsule production from alginate oligomers affected their thermal stability. The use of alginate derivatives as a carrier increased the antioxidant properties of the finished product, as well as its ability to reduce iron ions. The use of alginate oligomers as a coating material prevented the active substance from being released too early in the conditions of the small intestine, prolonged the stability of the capsules, and supported their durability in gastric conditions.
Brewers' spent grain (BSG) contains bioactive compounds. It was hypothesized that heating treatments using conventional water bath heating (CWH) on brewers' spent grain (BSG) would modify the functionality, chemical constituents and antioxidant activities of BSG. Different temperatures and time exposures (80, 90 and 100 °C at 15, 30 and 60 min) were applied on fresh undried BSG. CWH at 80 °C increased the amount of flavan-3-ols, while 100 °C at 30 and 60 min improved the ABTS (2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulfonic acid) value. CWH significantly declined saturated fatty acid and enhanced the poly-unsaturated fatty acid. Moreover, CWH discharged pungent, floral, spice and mushroom odor perceptions and formed fruity, sweet and pleasant odor perceptions, as well as essential-oil-related compounds. Additionally, CWH improved water-holding and oil-holding capacities. In conclusion, CWH as a low-cost treatment improved the functionality, fatty acid composition and aromatic profile of BSG.
Mushroom production in Poland is an important and dynamically developing element of diverse agriculture. Mushroom spent compost (MSC) is major waste generated during production, i.e., MSC: mushrooms is ~5:1. To date, the main use of MSC is soil application as organic fertilizer. To date, several methods of MSC treatment have been researched and developed including production of compost, bioethanol, biogas, enzyme lactase, xylo-saccharides, and hydrogen. Torrefaction may be considered a novel approach for biomass valorization. Thus, we are pioneering the potential use of MSC valorization via torrefaction. We explored valorizing the waste biomass of MSC via thermal treatment – torrefaction (‘roasting’) to produce biochar with improved fuel properties. Here for the first time, we examined and summarized the MSC torrefaction thermogravimetric analyses, fuel properties data of raw biomass of MSC and biochars generated from MSC via torrefaction. The effects of torrefaction temperature (200~300 °C), process time (20~60 min), on fuel properties of the resulting biochars were summarized. The dataset contains results of thermogravimetric analysis (TGA) as well as proximate analyses of MSC and generated biochars. The presented data are useful in determining MSC torrefaction reaction kinetics, activation energy and to further techno-economical modeling of the feasibility of MSC valorization via torrefaction. MSC torrefaction could be exploited as part of valorization resulting from a synergy between an intensive mushroom production with the efficient production of high-quality renewable fuel.
The quantity of biodegradable plastics is increasing steadily and taking a larger share in the residual waste stream. As the calorific value of biodegradable plastic is almost two-fold lower than that of conventional ones, its increasing quantity decreases the overall calorific value of municipal solid waste and refuse-derived fuel which is used as feedstock for cement and incineration plants. For that reason, in this work, the torrefaction of biodegradable waste, polylactic acid (PLA), and paper was performed for carbonized solid fuel (CSF) production. In this work, we determined the process yields, fuel properties, process kinetics, theoretical energy, and mass balance. We show that the calorific value of PLA cannot be improved by torrefaction, and that the process cannot be self-sufficient, while the calorific value of paper can be improved up to 10% by the same process. Moreover, the thermogravimetric analysis revealed that PLA decomposes in one stage at ~290–400 °C with a maximum peak at 367 °C, following a 0.42 reaction order with the activation energy of 160.05 kJ·(mol·K)−1.
The lysimeter experiment was conducted at the laboratory scale. Different water and leachate dilutions (0%, 25%, 50%, 100% of leachate) were supplied to the lysimeters to achieve the variation in pollutants concentration. The measure of leachate disposal effectiveness was the amount of evaporated leachate solution in evapotranspiration and transpiration. Analysis of evaporation dynamics and the impact of the plants on the leachate disposal effectiveness were determined. Correlation between biomass increase, transpiration and leachate concentration was observed. The highest evapotranspiration was obtained in the lysimeter with leachate concentration 25% and was on the level of 2.3 mm/day and for transpiration, 2.21 mm/day. The lowest values of evapotranspiration (0.55 mm/day) and transpiration (0.39 mm/day) were observed in the lysimeters supplied only by concentrated leachate. The highest leachate treatment efficiency 0.78 mm leachate/day was achieved in lysimeter K3-50% leachate concentration. There was an increase in transpiration participation in evapotranspiration in time. In the lysimeters supplied by the solutions with leachate concentrations, 25% and 50% transpiration participation in evapotranspiration ranged from 80% to 90%, in case of concentrated leachate from 60% to 70%. Evapotranspiration in all lysimeters was 3, 5-14 times higher than evaporation. It seems to be the result of plant impact on evaporation and confirms the possibility of this method being used for leachate treatment. Willows in lysimeter (K3-50% of leachate) had the most effective physiological fit to landfill leachate treatment.
This study evaluates the compatibility and innovative applications of unmodified vegetable oils, including rapeseed, sunflower, linseed, castor, and used cooking oils, in the production of sustainable polymeric materials, particularly polyurethane adhesives. Fatty acid composition was characterized using GC-MS, functional groups were identified by FTIR, and physicochemical properties, such as hydroxyl value, acid value, viscosity, and density, were measured using conventional analytical techniques. The results highlight significant differences in the properties of the oils, influencing their suitability for specific industrial applications. Castor oil, with its high ricinoleic acid content and hydroxyl value, was identified as the most suitable option for bio-based polyols and polyurethane production. Compatibility tests confirmed that unmodified oils can be effectively blended with polyols, ensuring stability and homogeneity without chemical modification. This approach simplifies production, reduces reliance on petrochemical feedstocks, and advances the development of environmentally friendly polyurethane adhesives. Future research will focus on optimizing formulations and assessing the long-term performance of adhesives incorporating unmodified vegetable oils.
