Electricity was produced by catalytic oxidation of carbon monoxide (CO) by using gold catalysts at room temperature. The observed rates are faster than conventional processes operating at 500 kelvin or higher for the conversion of CO with water to produce hydrogen and carbon dioxide through the water-gas shift (WGS). By eliminating the WGS reaction, we remove the need to transport and vaporize liquid water in the production of energy for portable applications. This process can use CO-containing gas streams from the catalytic reforming of hydrocarbons to produce an aqueous solution of reduced polyoxometalate compounds that can be used to generate power. The reduced polyoxometalate can be reoxidized in fuel cells that contain simple carbon anodes.

A novel approach has been developed in order to use Kraft lignin as a renewable resource for the production of chemicals. The concept is based on the use of polyoxometalates as reversible oxidants and on the use of radical scavengers, which prevent lignin fragments from repolymerizing. The oxidation of Kraft lignin, which is a potential source of functionalized phenols, by H3PMo12O40 in water yields a relatively small amount of monomeric species detected by GC-MS. The addition of methanol to the reaction resulted in an increase in the yield of monomeric products by a factor of up to 15. Vanillin and methyl vanillate are the main products obtained, in a maximum yield of 5 wt % based on dry Kraft lignin. Methanol plays a decisive role in the prevention of repolymerization by reducing lignin-lignin condensation reactions. Furthermore, it is proposed that methanol generates small amounts of .CH3 and CH3O. radicals through the acid-catalyzed formation of dimethyl ether which couple with lignin fragments.

In this work, a process for producing vanillin and methyl vanillate from an industrial kraft lignin by oxidation in aqueous methanol at acidic pH is proposed. A series of consecutive runs, comprising the steps of kraft lignin oxidation, monomer extraction, and filtration of residual lignin, were conducted. The depolymerization of kraft lignin (1 g per run) was carried out in a stirred batch reactor with 80 vol % methanol/water as the solvent, with H 3 PMo 12 O 40 as a homogeneous catalyst, and with 10 bar of oxygen initially present. The monomeric products were recovered from the process by extraction with chloroform and quantified by gas chromatography/mass spectrometry (GC/MS). Residual kraft lignin was recovered from the reaction medium by filtration. After extraction and filtration, the reaction medium, containing the homogeneous catalyst, was reused in the next run. The sum of all quantified products (gas phase, extract, and solids), as well as the amount of consumed oxygen, reached constant levels after five runs, and no indications of catalyst deactivation were found. Extracted products containing vanillin (3.5 wt %) and methyl vanillate (3.5 wt %) were recovered with a yield of 65 wt %. The extracted products were further analyzed by size exclusion chromatography (SEC) and Fourier transform infrared (FTIR) spectroscopy regarding their average molecular weight and functional group contents.

In this paper, the extraction of vanillin dissolved in water with a suitable organic phase using microstructured devices made of PDMS is discussed. Two flow patterns, segmented and stratified flow, were compared. LIF and l-PIV measurements showed a laminar profile for stratified flow; whereas for segmented flow, vortices in the slug end were detected. Additionally, for the stratified flow regime, the influence of the channel width and therefore the surface-to-volume ratio was investigated. A decrease of the channel cross-sectional area results in a significant enhancement of mass transfer for the stratified flow regime. A further increase in mass transfer was obtained using segmented flow instead of stratified flow. However, stratified flow may be favored due to the ease of implementation of phase separation on the chip.

As one of the three main components in woody biomass, lignin is an abundant but underused renewable raw material and carbon source. Owing to its aromatic structure and large availability as a by-product of pulping, its conversion into chemicals is highly attractive. In the present work, the oxidation of a softwood kraft lignin in acidic media was investigated in the presence of a homogeneous catalyst. The objective was to find a cheap but efficient catalyst for the depolymerization of kraft lignin into aromatic monomers. Different transition metal salts were screened and compared to phosphomolybdic acid, which was investigated in previous studies, and to experiments in sulfuric acid without additional catalyst. Vanillin and methyl vanillate were the main monomeric products detected by gas chromatography/mass spectrometry but their formation was only slightly increased by using transition metal salts (up to 6.28 wt% yield). However, the presence of iron or copper chloride resulted in fast formation kinetics and significant amounts of other monomeric products. In addition, an efficient fragmentation of the lignin molecule from a weight-average molecular weight of 3500 g mol -1 down to 500 g mol -1 was observed by sizeexclusion chromatography. The enhanced incorporation of oxygen into the reaction products in the presence of those catalysts was proven by Fourier transform infrared spectroscopy and the influence of the catalyst concentration was studied.