Bing-Shun Huang

Catalytic upgrading of syngas from fluidized bed air gasification of sawdust.

This study was conducted to investigate the effects of various gasification temperatures in a fluidized bed gasifier on biomass-derived products and to evaluate the efficiency of syngas upgraded by a secondary catalytic reactor. The results indicated that biomass vaporization was clearly affected by gasification temperature, resulting in the obtained products having different composition ratios. Additionally, the hydrogen promotion ratios were found to be strongly dependent on the condensable products, indicating that the products were upgraded via the use of a catalyst in the secondary reactor. If biomass vaporized at suitable gasification temperatures can produce a large amount of condensable products, the products could be effectively upgraded for hydrogen production by the secondary catalytic reactor under very mild conditions (250°C). Overall, the process not only upgraded hydrogen production, but also degraded contaminants; therefore, its implementation should reduce the cost of operation and pollution control in the biomass-to-energy industry.

Sustainable hydrogen production from electroplating wastewater over a solar light responsive photocatalyst

An environmentally friendly and sustainable photocatalytic hydrogen production system was successfully developed using ethylenediaminetetraacetic acid (EDTA) found in the wastewater from electroplating plants as the photo-excited hole scavenger and a solar light responsive multi-junction material as the photocatalyst. Additionally, a facile method of metal removal was established to increase the photocatalytic hydrogen production efficiency. The influences of the metal concentration, pH of the electroplating wastewater, and the photocatalyst concentration on the efficacy of hydrogen production were studied in detail. The results show that before metal removal, the unchelated metal ions and/or the metal–EDTA chelates block the active sites of the photocatalyst, resulting in suppressed adsorptions of H+ ions and/or H2O, which results in negligible hydrogen production efficiency. Through the metal removal process developed in this study, most of the metals could be removed and most of the EDTA could be retained. The removal efficiencies of copper, nickel, and zinc ions were all higher than 90%, facilitating better reaction between the liberated EDTA molecules and the photo-excited holes, improved charge separation, and enhanced hydrogen production efficiency. The system showed economically optimal hydrogen production when the reaction pH was maintained at pH = 6 and the photocatalyst concentration was maintained at 2 g L−1 under simulated sunlight irradiation.

Photocatalytic conversion of ethylenediaminetetraacetic acid dissolved in real electroplating wastewater to hydrogen in a solar light-responsive system

A sustainable and multifunctional photocatalysis-based technology has been established herein for simultaneous hydrogen generation and oxidation of ethylenediaminetetraacetic acid (EDTA) in real electroplating wastewater. When the photocatalyst concentration was 4 g/L and electroplating wastewater pH was 6, optimal adsorptions of EDTA2-, H+, and H2O were observed, while hydrogen generation efficiency reached 305 µmol/(h g). Owing to EDTA oxidation and occupation of the active sites of the photocatalyst by Ni ions or Ni-EDTA chelates, the charge separation and adsorptions of H+ and H2O decreased, reducing hydrogen generation efficiency with time. The lower EDTA and Ni concentrations in treated wastewater showed that photocatalytic conversion of EDTA in real electroplating wastewater to enhance hydrogen generation efficiency can be a practical alternative energy production technology. This study provided a novel idea to enhance the value of electroplating wastewater, to build a hydrogen generation route with no consumption of a valuable resource, and to reduce EDTA and Ni concentrations in electroplating wastewater.

An effective method for controlling the nanoparticle size of anatase TiO 2

Uniform anatase-type titania (TiO2) nanoparticles were prepared by controlling gelation pH during the sol-gel process. Particle size of the anatase TiO2 was increased from ca. 7 to 23 nm with the pH increasing from 2 to 9. When pH value was 10, particle morphology showed spheroids and square shapes because of the formation of an anatase phase and hydrogen titanium oxide. Optimal preparation condition was at pH 2, with fine nanoparticles forming the anatase phase at ca. 10 nm. Results indicated that it was an effective method to control the crystallite size of anatase-type TiO2 by adjusting the pH values of sol during the sol-gel process.