Phase behavior, density, viscosity, conductivity, pH, and surface tension were measured, and FTIR was performed for a series of mixtures of sugar (glucose, fructose, xylose, and sucrose), water, and choline chloride (ChCl) at specific molar ratios. These mixtures, called sugar-based natural deep eutectic solvents (NADESs), were investigated as a function of temperature. Contact angle measurements indicated that NADES exhibited slightly lower wettability but higher surface tension than water. Temperature was found to greatly impact density, viscosity, and conductivity. The optimum water molar ratio for lower viscosity was found at ratios higher than those reported in the literature, indicating that the NADES investigated may have industrial process applications.

Sustainable and renewable sources of liquid and solid fuels are essential to prevent fossil fuel use from damaging the environment. Secondary agricultural residues, which are already transported to food processing centers, have great potential to be converted into biofuels. The wastes from coffee roasting, sugar production, and rice milling have been investigated using hydrothermal carbonization (HTC) to produce aqueous products containing monosaccharides alongside solid biofuels. These sugar-laden liquid products were characterized after pretreating coffee silverskins, sugarcane bagasse, and rice husks with HTC. They were then concentrated using direct contact membrane distillation (DCMD), a low-energy process that can use waste heat from other biorefinery processes. The higher heating value of the solid products was also characterized by bomb calorimetry. The liquid products from HTC of these wastes from food production were found to contain varying concentrations of glucose, xylose, galactose, and arabinose. DCMD was capable of concentrating the liquid products up to three times their original concentrations. Little difference was found among the higher heating values of the solid products after 180 °C HTC pretreatment compared to 200 °C pretreatment. HTC of waste from food processing can provide solid biofuels and liquid products containing sugars that can be concentrated using DCMD.

Research background. Mayhaw jelly, made from mayhaw berries from the southern United States, is a popular food product that on processing produces a berry pomace waste. Little information is available in the literature about this waste or how to valorize it. This study investigated this food production waste and its possibilities for conversion to a biofuel. Experimental approach. Dried mayhaw berry wastes were characterized with fiber analysis using the US National Renewable Energy Laboratory methods. After drying and grinding, hydrothermal carbonization was applied to the mayhaw berry wastes, the mayhaw waste without seeds, and mayhaw waste seeds. Fourier transform infrared spectroscopy (FTIR) was performed on mayhaw berry wastes, mayhaw waste without seeds, and mayhaw waste seeds. Calorimetry revealed the fuel value of each component of the waste and of the dried mayhaw berry wastes without any component separated. Friability testing on pellets of the biomass investigated their durability. Results and conclusions. Fiber analysis indicated a high proportion of lignin compared to cellulose in the dried mayhaw waste. Hydrothermal carbonization did not enhance the fuel value of the seeds due to their tough outer coat that inhibited hydrothermal carbonization’s high ionic-product water penetration. Other mayhaw berry waste samples had enhanced fuel value after treatment at 180 or 250 °C for 5 min, with a higher fuel value attained for 250 °C treatment. After hydrothermal carbonization, the wastes were easily pelletized into durable pellets. Fourier transform infrared spectroscopy characterization indicated raw seeds had high lignin content, as did the hydrothermal carbonization-treated mayhaw berry wastes. Novelty and scientific contribution. Hydrothermal carbonization is a process not previously applied to mayhaw berry wastes. This study fills in the gaps of this waste biomass’ potential to become a biofuel.

The development of each nation is evaluated by its infrastructure, and each nation is competing with the others in infrastructure advancement, especially in the construction of roadways, since they play a vital role in the economic and social development of the nation. The conventional materials used for road construction are concrete and asphalt, which pose significant environmental challenges. This research gives insight into the potential of fly ash (FA) and corn stover (CS) in synthesizing geopolymer, as an alternative material for the construction of roads. This study examines the impact of three FA and CS mixture percentages and the particle size of CS on the compressive strength and porosity of geopolymer. The results indicate that incorporating larger amounts of CS in fly ash-based geopolymer may decrease the compressive strength of the geopolymer. Smaller CS particle sizes also tend to lead to lower compressive strength. Porosity of the geopolymer tended to increase with the incorporation of higher percentages of CS, particularly for smaller corn stover sizes. As a fine aggregate replacement for geopolymer, CS incorporation has the potential to reduce mined aggregate obtained from a process that harms the environment.

Seafood waste is often landfilled and/or discarded into water, raising microbiological pollution and environment policy concerns. Repurposing this low-cost biomass collected at point-source processing centers can help reduce greenhouse gas emissions and support industrial progress in developing economies. Safe alternative methods to utilize seafood waste were investigated. Hydrothermal carbonization-enriched shrimp shell waste was converted into higher-value products, such as sprayable fertilizer and dry biochar fertilizer pellets. Environment friendly sprayable fertilizer from shrimp and crab shell waste as an inexpensive carbon fixer is a potential solution. An average spray coverage area of 0.12 m² from only 300 mL of 1:10 shrimp shell waste to water mixture is reported. Characterization using N:P:K ratios from elemental analysis showed crustacean shell waste to comprise long-term organic carbon fixers in the soil with minor mineral enrichment, demonstrating potential for long-term soil care. Additionally, hydrothermally carbonized mineral rich shrimp shell and untreated crab shell waste were pelletized to test their friability and feasibility in transportation. Such a bio-investigation to promote economic goals for sustainability can improve biomass waste handling locally.

Adequate water supplies are crucial for missions to the Moon, since water is essential for astronauts’ health. Ionic liquids (ILs) have been investigated for processing metal oxides, the main components of lunar regolith, to separate oxygen and metals. The IL must be diluted in the process. Recycling this diluted IL post-processing is important to reduce the materials required in resupply missions. In addition, water will be needed in lunar greenhouses for growing food and aiding in sustaining a habitable environment. Direct contact membrane distillation (DCMD) is a new technology for water purification that was examined in this study for its feasibility to concentrate IL. Hydrophobic membranes composed of polytetrafluoroethylene (PTFE) and polyvinylidene (PVDF) were found to hold promise in separating solutes from water to concentrate a diluted IL solution and to recover water. A bench-scale DCMD system was employed to test this method at temperatures of 50 °C, 65 °C, and 80 °C. Hence, the benefits and limitations of DCMD with PTFE and PVDF membranes were explored for the aqueous IL 1-ethyl-3 methylimidazolium hydrogen sulfate for DCMD performed at different temperatures.