Yanchao Zhu

Application studies of activated carbon derived from rice husks produced by chemical-thermal process—A review

The production of functional activated carbon materials starting from cheap natural precursors using environmentally friendly processes is a highly attractive subject in material chemistry today. Recently, much attention has been focused on the use of plant biomass to produce functional carbonaceous materials, encompassing economic, environmental and social issues. Besides the classical route to produce activated carbons from fossil materials, rice husk shows clear advantages in that it can generate a variety of cheap and sustainable carbonaceous materials with attractive nanostructure and functional patterns for a wide range of applications. From a comprehensive literature review, it was found that porous carbon that derived from rice husks, in addition to having wide availability, has fast kinetics and appreciable adsorption capacities too. Porous carbon materials also play a significant role in new applications such as catalytic supports, battery electrodes, capacitors, and gas storage. In this review, an extensive list of rice husks literature has been compiled. Conclusions have been drawn from the literature reviewed, and suggestions for future research are proposed.

A sustainable route for the preparation of activated carbon and silica from rice husk ash

An environmentally friendly and economically effective process to produce silica and activated carbon form rice husk ask simultaneously has been developed in this study. An extraction yield of silica of 72-98% was obtained and the particle size was 40-50 nm. The microstructures of the as-obtained silica powders were characterized by X-ray diffraction (XRD) and infrared spectra (IR). The surface area, iodine number and capacitance value of activated carbon could achieve 570 m(2)/g, 1708 mg/g, 180 F/g, respectively. In the whole synthetic procedure, the wastewater and the carbon dioxide were collected and reutilized. The recovery rate of sodium carbonate was achieved 92.25%. The process is inexpensive, sustainable, environmentally friendly and suitable for large-scale production.

Production of furfural from xylose at atmospheric pressure by dilute sulfuric acid and inorganic salts

In this paper, the dehydration of xylose to furfural was carried out under atmospheric pressure and at the boiling temperature of a biphasic mixture of toluene and an aqueous solution of xylose, with sulfuric acid as catalyst plus an inorganic salt (NaCl or FeCl(3)) as promoter. The best yield of furfural was 83% under the following conditions: 150 mL of toluene and 10 mL of aqueous solution of 10% xylose (w/w), 10% H(2)SO(4) (w/w), 2.4g NaCl , and heating for 5h. FeCl(3) as promoter was found to be more efficient than NaCl. The addition of DMSO to the aqueous phase in the absence of an inorganic salt was shown to improve the yield of furfural.

A new route for preparation of hydrochars from rice husk

In the present work, a green and sustainable route for preparation of hydrochars from sulfuric acid hydrolysis solution of rice husk under low temperature and atmospheric pressure was described. This route was achieved with the catalysis of sulfuric acid. The sphere-like carbon materials with regular size of about 500 nm were obtained at 95 degrees C for 6h when the acid concentration was 42% and 52%. The morphology of the hydrochars changed with sulfuric acid concentration increased. The surface of the materials contained a large number of functional groups. Furthermore, the localized graphitic nature of the materials was proved by X-ray diffraction pattern. High surface area porous carbons could be prepared from the hydrochars after activation, and they exhibited good electrochemical performance.

Effect of Surface Modification on the Dispersion, Thermal Stability and Crystallization Properties of PET/CaCO3 Nanocomposites

Abstract In order to improve the dispersion and increase the compatibility between CaCO3 nanoparticles and a polyethylene terephthalate (PET) matrix, hydrophobic calcium carbonate (CaCO3) nanoparticles were successfully prepared via a carbonization reaction with stearic acid (SA) as the modifying agent. PET/CaCO3 nanocomposites were prepared by further in situ polymerization of purified terephthalic acid (PTA), ethylene glycol (EG) and CaCO3 nanoparticles. The surface modification of CaCO3, the microstructure and the properties of nanocomposites were investigated by water contact angles measurements TEM, FTIR, XRD, SEM, TGA and DSC. SEM examination of the fractured surfaces of nanocomposites showed that CaCO3 modified by SA achieved well dispersed in the PET matrix. Moreover, compared to the nanocomposite filled with the blank CaCO3, the resulting nanocomposite filled with the modified CaCO3 exhibit a better thermal stability and a superior crystallization property.