This work deals with the study of chemical stability and the general behavior of hydrophobic glassy polymers with an excess of free volume fraction, such as poly[1-(trimethylsylil)-1-propyne] (PTMSP), poly[1-(trimethylgermil)-1-propyne] (PTMGP) and poly[4-methyl-2-pentyne] (PMP). The dense membranes based on these polymers have been tested at conditions which are typical for the regeneration of CO2 absorbent liquids (e.g. CCS). As expected, these membrane materials initially showed a decline of the gas permeability (N2, O2 and CO2) at 100°C, which is mainly attributed to the relaxation of the free volume structure. The transport parameters then leveled off and a slight decreasing of the gas transport parameters in time was observed. In contrast to previous published data, no chemical degradation of those polymers, in particular the absence of CO and C-O groups, was detected by FTIR spectroscopy, even after exposure to air at 150°C. In addition, long-term contact with different kinds of physical and chemical absorbent liquids at 100°C did not lead to changes in the chemical structure and macroscopic properties of those polymers. It was shown that absorption liquids like water or alkanolamines can be regenerated by pressure and temperature swing (Δpm=40bar, T=100°C) in gas-liquid contactors based on PTMSP, PTMGP and PMP.@en

Syngas is an important intermediate in the chemical process industry. It is used for the production of hydrocarbons, acetic acid, oxo-alcohols, and other chemicals. Depending on the target product and stoichiometry of the reaction, an optimum (molar) ratio between hydrogen and carbon monoxide (H2:CO) in the syngas is required. Different technologies are available to control the H2:CO molar ratio in the syngas. The combination of steam reforming of methane (SRM) and the water-gas shift (WGS) reaction is the most established approach for syngas production. In this work, to adjust the H2:CO ratio, we have considered formic acid (FA) as a source for both hydrogen and carbon monoxide. Using thermochemical equilibrium calculations, we show that the syngas composition can be controlled by cofeeding formic acid into the SRM process. The H2:CO molar ratio can be adjusted to a value between one and three by adjusting the concentration of FA in the reaction feed. At steam reforming conditions, typically above 900 K, FA can decompose to water and carbon monoxide and/or to hydrogen and carbon dioxide. Our results show that cofeeding FA into the SRM process can adjust the H2:CO molar ratio in a single step. This can potentially be an alternative to the WGS process.@en

This paper describes a number of developments leading to sustainable catalytic and multi-phase reactors. For this purpose, traditional solvents are replaced by clean solvent alternatives such as supercritical fluids and aqueous surfactant systems, and processes are intensified using membrane reactors and contacting reactants at a molecular level.@en