ACS Sustainable Resource Management最新文献

This work provides a method to transform sodium lignosulfonate into sulfonated carbon materials through chemical activation using magnesium salt as a template instead of using conventional sulfonation agents, such as concentrated sulfuric acid or chlorosulfonic acid. Several magnesium salts, including magnesium nitrate, magnesium chloride, magnesium acetate, and magnesium citrate, are employed as activating templates for comparison, and magnesium nitrate turns out with the most abundant sulfonic acid group density of 1.35 mmol/g and highest specific surface area of 512 m²/g. Especially, the effect of magnesium salts during carbonization process on the structure evolution is explored using tandem thermogravimetric-mass spectrometry and reveals that magnesium nitrate prevents sulfur loss in the form of SO₂, SO₃, or H₂S during carbonization, thus exhibiting the most abundant sulfonic acid group. These sulfonated carbon materials are tested in the alkylation reaction of furfural and 2-methylfuran to produce a C15 precursor of biodiesel, where the conversion of furfural and selectivity for 5,5-(furan-2-ylmethylene)bis(2-methylfuran) reach 90.2% and 87.2% at 70 °C for 6 h, respectively. This investigation underscores the efficient utilization of sulfonic acid functional groups inherent in sodium lignosulfonate to produce sulfonated carbon materials without the introduction of an exterior sulfur source and opens avenues for a broader application of lignosulfonates.

Activated carbon (AC) from nutshells has the potential to be an economically attractive product. This study developed ACs from almond and walnut shells and compared their performance against two commercial ACs (Calgon Carbon Filtersorb 400 and Kuraray YP50) in adsorbing methylene blue (MB) at various concentrations. Activated carbons were generated from nutshell biochar using 2 levels of activation to investigate the effect of activation residence time on material properties including pore development and MB adsorption. Raw nutshells, nutshell biochars, and nutshell ACs were characterized using elemental (CHNSO) analysis, proximate analysis, thermogravimetric analysis, activation kinetics, Fourier transform infrared (FTIR), scanning electron microscopy (SEM), MB adsorption testing, Brunauer-Emmett-Teller (BET) surface area and pore size distribution, and linear regression analysis on incremental pore volume and methylene blue adsorption capacity. Results demonstrated that almond and walnut shells can be used to make activated carbon that has a similar or better methylene blue adsorption performance than the tested commercial carbons. Almond shell, walnut shell, and YP50 and Filtersorb 400 activated carbons showed MB adsorption capacities of 440, 358, 487, and 310 mg g^–1, respectively. Physical activation using carbon dioxide led to enhanced micropore development, and specifically, greater volume of pores with widths between 8-18 Å led to higher MB adsorption capacity. Activated carbon manufactured from nutshells shows significant potential for wastewater applications as well as other applications requiring microporous carbon.

In current state of the art, we report a solitary pot green tactic for the synthesis of task-specific CuI nanoparticles (NPs) encapsulated by eco-healthy low value biomass (LVBM) meglumine. The synthesized meglumine encapsulated CuI NPs (Meg-Cu) material was characterized by using various analytical tools, and it was found that CuI NPs (with <100 nm size) were encapsulated by meglumine molecules interacting with −NHMe and −OH functionalities of meglumine. Meg-Cu was utilized marvelously as a catalyst for the creation of 1,2,3-triazole scaffolds. The established protocol allowed the synthesis of 1,2,3-triazoles via both two- and three-component routes. Moreover, the protocol was efficiently used for the synthesis of 1,2,3-triazoles initiated from anilines via in-situ generation of aromatic azides. The catalyst was successfully recycled up to three times without a loss of catalytic activity. The structural integrity of the spent catalyst was investigated by FT-IR and TGA analysis. The present protocol embraces features like a short reaction time, wide substrate scope, environment-friendly reaction conditions, and good to excellent yields.

Even though current research on bio-based poly(ester-ether) elastomers (TPEEs) has expanded to include applications, only odd TPEEs with outstanding melting temperatures have been reported thus far. This is due to certain features, like desirable elastic properties and high melting temperature, which are still challenging to obtain without the utilization of petroleum-based monomers. In order to prepare bio-based TPEE with both high thermal resistance and elastic recovery, furan-based poly(1,4-cyclohexanedimethylene furandicarboxylate)-poly(tetramethylene glycol) multiblock copolymers (PCFTMG^2k) were synthesized in this work. These copolymers had weight fractions of soft segments PTMG (ω_PTMG) ranging from 30 to 80% while maintaining M_n of the soft segments at 2 kg/mol. Indeed, while PTMG segments are found to delay substantially the crystallization of the PCF within the copolymers, the results show that TPEEs with both elastic properties and high melting temperatures can be successfully prepared by introducing soft segments with relatively good crystallization ability and controlling the content of soft segments. Moreover, the crystallization behavior of the copolymers was investigated, from which it was found that the copolymers transformed from a non-cocrystallization state to an isodimorphic state as the content of soft segments increased. More importantly, PCFTMG^2k-80, containing 80 wt % of the PTMG segment, showed a shape recovery rate as high as 84.9% during the first cyclic test at 200% strain and T_m up to 198°C at a high PTMG concentration, which is higher than those of almost all the TPA-based TPEEs. This PCFTMG^2k bio-based TPEE will occupy an important position in the future market of high melting temperature thermoplastic elastomers.

Methanol is a potential alternate liquid transportation fuel. Conventional processes for methanol production from methane are energy-intensive. Microbial conversion of methane to methanol (Biological Gas-To-Liquid process) is a potential eco-friendly alternative. In this study, we have reported the intensification of methane fermentation to methanol (24 h batch mode) by Methylotuvimicrobium buryatense 5GB1C using 33 kHz sonication. The fermentation process was optimized for the sonication treatment time and duty cycle. A maximum titer of 20 mM (127.5 mg methanol/g dry cell weight biomass) was obtained in a 10 h sonication treatment at a 10% duty cycle, which was ∼57% higher than in control experiments. A mechanistic study of this result using pmoA gene expression (measured using qRT-PCR) and total protein analysis (sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)) revealed that the overexpression of the pmoA gene (therefore, pmoCAB operon) led to the overexpression of the particulate methane monooxygenase (pMMO) enzyme in the metabolic pathway of M. buryatense resulting in the production of pMMO in higher quantities than that in control experiments. The ultimate manifestation of these phenomena was faster enzyme kinetics and high methanol yield.