Songmei Zhang

Direct conversion of cellulose to 1-(furan-2-yl)-2-hydroxyethanone in zinc chloride solution under microwave irradiation

Conversion of cellulose to 1-(furan-2-yl)-2-hydroxyethanone has been demonstrated in concentrated zinc chloride solution under microwave irradiation. Compared with the conventional oil-bath heating mode, microwave irradiation significantly reduced the reaction time and increased the yield of 1-(furan-2-yl)-2-hydroxyethanone. A typical degradation reaction with cellulose produced 1-(furan-2-yl)-2-hydroxyethanone in 12.0% molar yield in ZnCl(2) solution (ZnCl(2)-H(2)O ratio=2.25:1, w/w) with microwave irradiation at 600 W for 5 minutes at 135°C.

Electrocatalytic degradation of rice straw lignin in alkaline solution through oxidation on a Ti/SnO2–Sb2O3/α-PbO2/β-PbO2 anode and reduction on an iron or tin doped titanium cathode

A novel procedure for selective production of biomass-based compounds by electrochemical conversion has been developed in this work. At ambient pressure and mild temperature, rice straw lignin dissolved in sodium hydroxide solution was directly electro-oxidized on the surface of a Ti/SnO2–Sb2O3/α-PbO2/β-PbO2 anode, and subsequently, electro-reduction by the electro-generated chemisorbed hydrogen on the titanium-based (iron or tin doped titanium) cathodes proceeded. The electro-catalysis could effectively break the chemical linkages among phenylpropyl units in rice straw lignin, and more than 16 kinds of aromatic compounds containing phenols, aromatic hydrocarbon, aromatic ester, aromatic ketone, aromatic acid and aromatic aldehyde (e.g. guaiacol, syringol, dihydroeugenol, vanillin, p-coumaric acid, ferulic acid, etc.) were generated and identified utilizing GC-MS measurement. The operation conditions for the enhancement of the product yield including the current density, lignin concentration, temperature and reaction time were optimized. The results indicate that the properties of the cathode materials, current density and reaction time play important roles in the electrocatalytic hydrogenation of rice straw lignin.

Preparation and Characterization of a Humate Surfactant with Hydroxymethylation and Esterification Modification of Lignite

Abstract In this paper, a humate surfactant based on humic substances which were derived from lignite by modification of hydroxymethylation and esterification methods respectively was prepared. Determined by surface tension method, the cmc (critical micelle concentration) of the humate surfactant is 1.534 g/L and the corresponding surface tension is 48.8 mN/m. The optimum conditions of the modified processes are as follows: hydroxymethylation modification at pH 10.5, reaction temperature 90°C, reaction time of 60 min, dosage of stock (formaldehyde/lignite/g g−1) 10:10, and the amount of reacted paraformaldehyde was 6.23 mmol/g lignite. The esterification modification was carried but at 70°C, reaction time 10 h, dosage of 6.0 mmol n-decanoyl chloride/g lignite. The conversion rate of n-decanoyl chloride was 95%.