The acceleration of urbanization and industrialization has accelerated the speed of building renewal, followed by explosive growth in the quantity of construction and demolition waste (CDW). High-value reuse technolog...
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The acceleration of urbanization and industrialization has accelerated the speed of building renewal, followed by explosive growth in the quantity of construction and demolition waste (CDW). High-value reuse technology scheme for all components, including classification and deep processing, is a sustainable development direction of great significance to achieve maximum utilization of CDW. Recent advances in green and ecological regeneration approaches for CDW are systematically elaborated in this review, including reinforcement approaches for recycled aggregates and alkali activated technology for recycled powders. Firstly, the main components of CDW and their characteristics are summarized, and the environmental hazards of CDW are expounded. The resource utilization of CDW is indispensable from the perspective of environmental protection and low-carbon development. Furthermore, the CDW treatment process and regeneration approach are analyzed in detail. The application of CDW in recycled coarse aggregates, fine aggregates, and cementitious materials is sufficiently illustrated in this study. Representative mature and sustainable approaches are evaluated to explore the development prospects of the CDW treatment process in terms of economic feasibility, ecological protection, and technological reform. Finally, based on the comprehensive analysis of the technical advantages of CDW resource utilization, a sustainable, low-carbon, and full-component resource regeneration CDW recycling strategy containing pretreatment, deep treatment, and fine processing is proposed. The multi-process collaboration makes the resource utilization for CDW more systematic and sustainable. The process proposed in this study can provide valuable insights for future zero-waste utilization of CDW.
Lignin,an abundant aromatic polymer in nature,has received significant attention for its potential in the production of bio-oils and chemicals owing to increased resource availability and environmental *** hydrodeoxyg...
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Lignin,an abundant aromatic polymer in nature,has received significant attention for its potential in the production of bio-oils and chemicals owing to increased resource availability and environmental *** hydrodeoxygenation of guaiacol,a lignin-derived monomer,can produce cyclohexanol,a nylon precursor,in a carbon-negative and environmentally friendly *** study explored the porous properties and the effects of activation methods on the Ru-based catalyst supported by environmentally friendly and cost-effective *** selective cleavage of C_(ary)-O bonds was achieved under mild conditions(160°C,0.2 MPa H_(2),and 4 h),and alkali activation further improved the catalytic *** characterization methods revealedthat hydrothermal treatment and alkali activation relatively contributed to the excellent performance of the catalysts and influenced their porous structure and Ru dispersion.X-ray photoelectron spectroscopy results revealed an increased formation of metallic ruthenium,indicating the effective regulation of interaction between active sites and *** synergistic approach used in this study,involving the valorization of cellulose-derived hydrochar and the selective production of nylon precursors from lignin-derived guaiacol,indicated the comprehensive and sustainable utilization of biomass resources.
Many effective pretreatment methods (such as dilute acid, dilute alkali, ionic liquids, etc.) have been developed for lignocellulose upgrading, but several defaults of low working mass, high sugar loss and extra cost ...
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Many effective pretreatment methods (such as dilute acid, dilute alkali, ionic liquids, etc.) have been developed for lignocellulose upgrading, but several defaults of low working mass, high sugar loss and extra cost of solid-liquid separation and water washing hinder their large-scale applica- tion in industry. Besides, the valorization of lignin-rich residue from pretreated biomass after hy- drolysis or fermentation greatly contributes to the economy and sustainability of lignocellulosic biorefinery, which is usually underestimated. This study developed a densification pretreatment with binary chemicals (densifying lignocellulosic biomass with sulfuric acid (SA) and metal salt (MS) followed by autoclave treatment ((DLCA(SA-MS)), which was conducted under mild con- dition (121 ℃) with a biomass working mass as high as 400 kg/m^(3) . The DLCA(SA-MS) biomass achieved over 95% sugar retention, 90% enzymatic sugar conversion and a high concentration of fermentable sugar (212.3 g/L) with superior fermentability. Furthermore, bio-adsorbent de- rived from DLCA(SA-MS) biomass residue was highly adsorptive and suitable for dyeing wastew- ater treatment, providing a feasible and eco-friendly method for lignin-rich residue valorization. These findings indicated that DLCA(SA-MS) pretreatment enables the full-component utilization of biomass and boosts the economic viability of lignocellulosic biorefinery.
Effective fractionation of lignocelluosic biomass and subsequent valorization of all three major components under mild conditions were achieved. Pretreatment with acidified monophasic phenoxyethanol (EPH) efficiently ...
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Effective fractionation of lignocelluosic biomass and subsequent valorization of all three major components under mild conditions were achieved. Pretreatment with acidified monophasic phenoxyethanol (EPH) efficiently removed 92.6 % lignin and 80 % xylan from poplar at 110 degrees C in 60 min, yielding high-value EPH-xyloside, EPH-modified lignin (EPHL), and a solid residue nearly purely composed of carbohydrates. After removing the grafted acetyl groups using 1 % NaOH at 50 degrees C, the highest enzymatic digestibility reached 92.3 %. EPHL could be recovered in high yield and purity with an uncondensed structure, while xylose was converted to EPH-xyloside, a potential precursor in biomedical industries. Additionally, the acidified monophasic EPH solvent could effectively fractionate biomass from species other than hardwood, achieving over 70 % delignification from recalcitrant pinewood under the same mild conditions, demonstrating the high potential of monophasic EPH pretreatment. This work introduces an acidified monophasic phenoxyethanol (EPH) system with effective fractionation of lignocelluosic biomass under mild conditions. The pretreatment resulted in a cellulose rich residue with high enzymatic digestibility, EPH-modified lignin, and EPH-xyloside. image
Herein, acidic concentrated lithium bromide-water system was efficiently carried out to synthesize levulinic acid (LA) from raw lignocellulose by two-step treatment. Saccharification was processed in 1st step, and 80....
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Herein, acidic concentrated lithium bromide-water system was efficiently carried out to synthesize levulinic acid (LA) from raw lignocellulose by two-step treatment. Saccharification was processed in 1st step, and 80.96 wt% glucose and 85.60 wt% xylose were yielded based on their theoretical yield from poplar at 110 degrees C for 20 min. The hydmlysate after solid residual lignin (SRL) separation was converted into LA and furfural by thermal treatment (130 degrees C) in the 2nd step, where 67.0 wt% LA and 48.0 wt% furfural were yielded. The SRL in 1st step, with high hydrophobicity and uniform dispersity, was used to prepare lignin nanoparticles (LNPs), which showed tailored size (100-200 nm diameters) and morphology in solid or hollow structure with single hole. Additionally, the residue in 2nd step was suggested as biochar. So far, this study offered a simple pathway for utilization of raw lignocellulose in water system, resulting in high yields of LA and LNPs.
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