Activated carbon/titanium dioxide (AC/TiO2) nanohybrids were synthesized by a hydrothermal technique using various weight percent of commercial AC and were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA). The synthesized nanohybrids were applied to photodegradation of Reactive Red-35 (RR-35) dye in aqueous solution using sunlight. Due to the synergistic effect of adsorption and photodegradation activity, AC/TiO2 nanohybrids were more efficient in treating the aqueous dye solution than that of AC and TiO2. The maximum (95%) RR-35 dye removal from the water was obtained with 20 wt% AC/TiO2 within 30 min at natural pH of 5.6. The possible photodegradation mechanism of RR-35 dye with AC/TiO2 was discussed from the scavenger test. Moreover, AC/TiO2 was found to be suitable for long-term repeated applications through recyclability experiments. Therefore, AC/TiO2 nanohybrid is a promising photocatalyst for treating azo dyes especially RR-35 from water.
Polyethylene furanoate (PEF) is a biobased plastic, similar to synthetic polyethylene terephthalate (PET), which is produced from the platform chemical 2,5‐hydroxymethylfurfural (HMF). Much of the literature surrounding PEF is focused on unit processes, with little regard for their sustainability and economic viability. In this comprehensive critical review, the entire process of PEF production, from the feedstock to polymerization and upstream applications, is critically examined. Identification of individual pathways capable of producing PEF efficiently and with favorable properties while considering economic viability and environmental sustainability are presented. For each unit operation, recent technological developments are summarized, and recommendations are made based on process efficiency. The collection of the findings from both life cycle assessments (LCA) and techno‐economic analyses (TEA) facilitated the identification of pathways with the greatest potential for environmental sustainability and economic viability of PEF production.
The overwhelming demand for lithium-ion batteries necessitates a sustainable and environment-friendly production of graphite anode materials. Catalytic graphitization of pyrolysis oil is promising for mass-scale production of biographite.
11 June 2021 in Reaction Kinetics, Mechanisms and Catalysis
The worldwide demand for graphite, as the main anode material for Li-ion batteries, is expected to double by 2028 since it supports the use of electricity, including transient renewable sources, for energy storage, sustainable mobility, and automation. However, the dependence on non-renewable and external resources jeopardizes the world supply chain. This study explores the technical and economic performance of transforming lignocellulosic biomass into biographite and fuel-grade hydrocarbons through pyrolysis bio-oil upgrading. According to simulation results, the total power demand for the biorefinery reached 10,784 kWh per tonne of biographite, of which 36 % can be supplied by the heat integration network and power plant. Sensitivity and risk analyses were conducted to evaluate the economics, with process yields identified as the most relevant indicators to the minimum selling price (MSP). The analysis revealed a promising cost-competitive range for biographite MSP against fossil-based graphite (medium quality synthetic graphite Chinese market price ∼$4.2/kg). Case D, which includes biofuels as a byproduct, presents the best metrics, reaching a MSP of $3.3/kg of anode-grade biographite with a profit margin of 27 %. While including biofuels in the product slate provides the best economic performance, the uncertainty associated with the big capital investment makes its risk 13 % higher to attain an IRR >20 % than the case in which biographite is produced as a standalone product. Overall, this study demonstrates that integrated biorefineries can produce a cost-competitive bio-based anode material for Li-ion batteries.
Advanced engineering of naturally occurring materials opens new doors in nanoscience and nanotechnology for the separation and/or removal of environmental hazards. Here, a series of nanocomposites containing kaolinite and chitosan varying in the range of 20 to 80% (w/w) kaolinite were used for the adsorptive removal of a reactive textile dye, Remazol Red, from an aqueous solution. Batch experiments were carried out to investigate the effects of pH, contact time, and initial dye concentration on the adsorption capacity. Nanocomposites containing 80% kaolinite (w/w) and 20% chitosan (w/w), i.e., NK80C20, showed an equilibrium adsorption capacity of 371.8 mg/g at pH 2.5, which was 5.2 times higher than that of commercial activated charcoal. Moreover, NK80C20 was regenerated instantly up to 99.9% at pH 10. Therefore, NK80C20 can be effectively utilized as a potential adsorbent for the separation of Remazol Red and homologous azo dyes from industrial effluents. We expect that the findings from this study will play a vital role in environmental research leading to advanced applications in water purification.