Chemical Engineering & Technology
© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Every month, the Editors select two papers referring to current discussions in the scientific, public and economic communities and in view of the potential for further developments. The papers are freely accessible for one month.
Catalytic Tar Removal from Syngas
February 09, 2017
Transformation of biomass into fuels and chemicals is becoming more and more important in order to stop global warming and diversify energy sources. Gasification is the most efficient method for converting biomass via syngas into sustainable fuels. During this process, a number of by-products, e.g., tar, alkali metals, and ash, are formed. Especially tar causes operational problems in further applications, such as plugging lines and filters by forming coke and condensing on cold parts or catalyst deactivation during conversion of bio-syngas to chemical products. Therefore, tar has to be removed before downstream processing. T. B. Dörr et al. used Mo/V/W-mixed oxides for the catalytic oxidation of tar without affecting the syngas components. They investigated the reactivity of different tar model compounds, namely, benzene, naphthalene, toluene, and phenol. Since benzene was the least active component, this compound was used as tar representative for comparison of the catalytic performance of the mixed oxides with pure V2O5, WO3, and MoO3 catalysts. The oxidation activity of V2O5 was considerably higher than for Mo/V/W-mixed oxides but V2O5 also showed higher values for the undesired conversion of syngas. WO3 and MoO3 were inert.
T. B. Dörr, S. Schmidt, A. Drochner, H. Vogel
Catalytic Tar Removal from Bio-Syngas via Oxidation on Metal Oxide Catalysts
Chem. Eng. Technol. 2017, 40 (2), 351–358.
Toxicological Investigation of Resin-Embedded Nanoparticles
February 09, 2017
Nanoparticles (NPs) are applied, e.g., in medicine as well as in textile, cosmetics, and food industry, to improve the properties of various products. NP coatings in particular have gained importance in recent years. With such coatings super-hydrophobic or selfcleaning surfaces can be achieved. However, nanomaterials might pose environmental and toxicological risks. Therefore, careful risk management is required when applying nanocomposites in sanitary facilities. F. Sambale et al. investigated the whole process chain from particle dispersion to coating characterization for NP hydrophobic resin coatings and identified correlations between the formulation parameters and coating properties (wettability, roughness, hardness, and toxicity). The toxicological properties of alumina NPs and composites with a polyester resin were studied by determining their impact on lung and liver cancer cells. It was found that octylsilane-modified alumina NPs could improve hydrophobicity and mechanical properties of the product and that alumina NPs in aqueous solutions are nontoxic whereas nanocomposites decreased the cell viability depending on the applied particle size and concentration of alumina NPs in the nanocomposites.
F. Sambale, J. Hesselbach, B. Finke, C. Schilde, F. Stahl, D. Bahnemann, T. Scheper, A. Kwade
Surface and Mechanical Properties of Nanoparticulate Resin Coatings and Their Toxicological Characterization
Chem. Eng. Technol. 2017, 40 (2), 376–384.