• Energy Research

Continuous hydrogenolysis of 5-hydroxymethylfurfural to 2,5-dimethylfuran is successfully developed and demonstrated using alumina-supported nickel–iron alloy catalysts with in situ observation of the structural transformation.

This work aims to enhance the value of palm empty fruit bunches (EFBs), an abundant residue from the palm oil industry, as a precursor for the synthesis of luminescent carbon dots (CDs). The mechanism of fIuorimetric sensing using carbon dots for either enhancing or quenching photoluminescence properties when binding with analytes is useful for the detection of ultra-low amounts of analytes. This study revealed that EFB-derived CDs via hydrothermal synthesis exceptionally exhibited luminescence properties. In addition, surface modification for specific binding to a target molecule substantially augmented their PL characteristics. Among the different nitrogen and sulfur (N and S) doping agents used, including urea (U), sulfate (S), p-phenylenediamine (P), and sodium thiosulfate (TS), the results showed that PTS-CDs from the co-doping of p-phenylenediamine and sodium thiosulfate exhibited the highest PL properties. From this study on the fluorimetric sensing of several metal ions, PTS-CDs could effectively detect Fe3+ with the highest selectivity by fluorescence quenching to 79.1% at a limit of detection (LOD) of 0.1 µmol L−1. The PL quenching of PTS-CDs was linearly correlated with the wide range of Fe3+ concentration, ranging from 5 to 400 µmol L−1 (R2 = 0.9933).

Arsenic (As) removal by nano bimetallic Cu‐Fe synthesized by in‐situ (Cu‐Fe)IS and impregnation (Cu‐Fe)IM techniques was studied. Synthesized Cu‐Fe by both techniques provided smaller particles than NZVI particles. (Cu‐Fe)IM showed higher efficiency in As removal, compared to (Cu‐Fe)IS and pristine NZVI. Batch experiments were performed by varying percent Cu loading (0–30% by wt). As(III) was removed completely by 10 wt % Cu loading on NZVI under an IM technique. It also provided double removal rate compared to pristine NZVI. X‐ray absorption near edge structure analysis supported that a mixed phases of Cu2O and CuO in (Cu‐Fe)IM enhanced As removal toward co‐precipitating with iron species about 20% for both As(III) and As(V) removal. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1449–1457, 2017

AbstractThe catalytic conversion of sugars (glucose and fructose) to furan compounds (HMF and furfural) was studied under hot compressed water (HCW) conditions. The effect of catalyst types (homogeneous acid (H3PO4) and base (NaOH)), and starting materials (monosaccharide and cellulose) on furan yields was investigated. It was found that at 200°C, phosphoric acid showed great catalytic activity on the production yield of HMF from dehydration of the sugars, when compared with NaOH. Cellulose is composed of glucose units, and would first be hydrolyzed and then dehydrated to furans. The optimum condition for hydrolysis/dehydration was observed under the acid-catalyzed conditions with the reaction temperature of 230°C and reaction time of 5 minutes, at which the yields of sugar and furan compounds were achieved at 23.0 and 7.5%, respectively.

A highly stable rhenium-promoted copper catalyst catalyzes the hydrogenolysis of furfural, a platform chemical derived from sustainable bioresources, into the fuel-additive 2-methylfuran.

Abstract Lignocellulosic biomass; hemicellulose, has been recognized as one of the most important renewable bioresources for production of alternative biofuels and biochemicals. The successful utilization of biomass derived from agricultural feedstocks to replace petroleum and petrochemical products would strongly support the sustainable bio-economy and biorefinery industry around the world. C5 and C6 sugars produced by the deconstruction of lignocellulosic materials through hydrolysis processes can be further converted to key intermediate chemicals, including furfural, 5-hydroxymethylfurfural, furan and organic acids. Among these, furfural is considered as a promising biomass-derived platform which can be a key intermediate for producing a variety of C4 and C5 species, such as, furan, tetrahydrofuran, pentanediol, lactic acid, and levulinic acid. This review will show the catalytic processes, especially, heterogeneous catalysis, for converting furfural into value-added biochemicals and biofuels. The applications of these compounds are added as background information, and the research trends based on several publications and patents in the past decade are intensively analyzed.

Bone materials are mainly composed of an inorganic constituent called hydroxyapatite (HA). In the current study, mesoporous Zn2+/Ag+ doped hydroxyapatite nanoparticles (Zn-Ag doped HA) with high antibacterial activity were synthesized through ultrasonic coupled sol-gel techniques under calcination temperatures of 600 °C for 4 h and 1100 °C for 1 h. The variance in the molar ratio of Zn2+/Ag+ in Ca9.0Zn1.0−xAgx(PO4)6(OH)2 (x = 0.0, 0.25 to 1.0) and its effects on the chemical and physical properties of the powdered samples were investigated. The results show that the hexagonal framework of HA incorporated both the Zn2+ and Ag+ ions and the rhombohedral structure of β-TCP. The main functional groups of HA and Zn-Ag doped HA samples were hydroxyl and phosphate. All samples have mesoporous characteristics with a Type IV isotherm. The agar well diffusion process was used to examine antibacterial activity against E. coli, P. aeruginosa, S. aureus, B. cereus and B. subtilis. Effective antibacterial activity was displayed by Zn-Ag doped HA. Excellent antibacterial performance was shown by Ca9.0Zn0.75Ag0.25(PO4)6(OH)2 against all tested bacterial strains, except P. aeruginosa. This material showed inhibition zones ranging from 7 to 11 mm, implying that it is a suitable material with an antibacterial action for environmental applications, specifically for water purification.

Torrefaction is a promising biomass thermal conversion technology to produce biochar due to its ease of operation and mild operating conditions. In this study, cassava rhizome (CR) was torrified under various sweeping gas types (nitrogen (N2), carbon dioxide (CO2), mixture gas (N2 + CO2)) and flow rates (50, 150, 250 mL/min) at 200–300 °C for 30 min. The experimental results show that fuel properties of CR were remarkably upgraded after torrefaction. Sweeping gas has less effect on fuel properties of torrified CR than torrefaction temperature. Torrefaction under CO2 atmosphere produced the biochar with minimum ash content. Torrefaction at 300 °C under 50 mL/min CO2 was recommended as the promising condition to produce biochar replacing lignite coal. Thermal properties and chemical functional groups of the derived biochar suggested that torrefaction process removed mainly oxygen and hydrogen contents which could be achieved through decarbonization (DC), dehydrogenation (DH), and deoxygenation (DO) pathways. Economic feasibility revealed that the torrefaction of CR is cost-advantage under the proposed condition.