Multiphase reactions using solid foams

The present invention relates to a gas-liquid-solid (GLS) process comprising contacting reactants on a solid foam material, wherein the solid foam material has a surface to volume ratio of at least 250 m2/m3. This foam material may include a catalyst composition or a catalyst material may be supported on the foam material. The foam material proyides improved mass transfer and favourable hydrodynamic parameters when compared to conventional packings so that an enhanced contact between reactants and an improved reactor performance is achieved

Multiphase reactions using solid foams

The present invention relates to a gas-liquid-solid (GLS) process comprising contacting reactants on a solid foam material, wherein the solid foam material has a surface to volume ratio of at least 250 m2/m3. This foam material may include a catalyst composition or a catalyst material may be supported on the foam material. The foam material proyides improved mass transfer and favourable hydrodynamic parameters when compared to conventional packings so that an enhanced contact between reactants and an improved reactor performance is achieved

A complementary study approach unravels novel players in the pathoetiology of Hirschsprung disease

Hirschsprung disease (HSCR, OMIM 142623) involves congenital intestinal obstruction caused by dysfunction of neural crest cells and their progeny during enteric nervous system (ENS) development. HSCR is a multifactorial disorder; pathogenetic variants accounting for disease phenotype are identified only in a minority of cases, and the identification of novel disease-relevant genes remains challenging. In order to identify and to validate a potential disease-causing relevance of novel HSCR candidate genes, we established a complementary study approach, combining whole exome sequencing (WES) with transcriptome analysis of murine embryonic ENS-related tissues, literature and databas

Solid foam packings for multiphase reactors: Modelling of liquid holdup and mass transfer

In this paper, experimental and modeling results are presented of the liquid holdup and gas–liquid mass transfer characteristics of solid foam packings. Experiments were done in a semi-2D transparent bubble column with solid foam packings of aluminum in the range of 5–40 pores per inch (ppi). The relative permeability model described by Saez and Carbonell (1985) is used to describe the liquid holdup data for solid foam packings of 5, 20 and 40 ppi. The investigated system variables are the superficial gas and liquid velocities, using counter-current flow with maximum gas velocities and liquid velocities of 0.8 m s-1 and 0.03 m s-1, respectively. The relative permeability model is able to describe the liquid holdup in the low liquid holdup or trickle flow regime as well as in the high liquid holdup regime, which resembles flow in a packed bubble column. Gas-to-liquid mass transfer is modelled using the penetration theory. Mass transfer coefficients up to 6 s-1 are predicted; these high values are largely due to the high specific surface area of the solid foam packings

Imprinting: the Achilles heel of trio-based exome sequencing

Genetics of disease, diagnosis and treatmen

Hydrodynamics of gas-liquid counter-current flow in solid foam packings

Solid foam materials combine high voidage and high surface area. These two properties are advantageous for use in chemical reactors due to the low frictional pressure drop and relatively high surface area that may be used for catalyst deposition. Hydrodynamic parameters such as liquid holdup, pressure drop, and flow regimes similar to those for packed beds, have been obtained for the gas and liquid flows through these solid foam packings. The open-celled solid foam packings used were in the range of 5–40 pores per linear inch (ppi). The regimes studied are two high liquid holdup regimes and a low liquid holdup regime (trickle flow regime). Also the flooding points for counter-current flow have been determined. (7th International Conference on Gas-Liquid and Gas-Liquid-Solid Reactor Engineering

Gas-liquid mass transfer and axial dispersion in solid foam packings

The mass transfer coefficient and other hydrodynamic parameters are presented for a gas and liquid (air–water system) moving in a co-current upflow configuration through solid foam packings in the range of 10–40 pores per linear inch (ppi). Axial dispersion in the liquid has been excluded by observing that the liquid was in plug flow in the range of superficial liquid and gas velocities studied ( and ). Also entrance and exit effects have been taken into account by evaluating the gas–liquid mass transfer for two different lengths of foam packing. The average pore size of the solid foam (ppi number) does not influence the overall volumetric mass transfer coefficient. Increasing the gas and liquid velocities increases the gas–liquid mass transfer and the maximum mass transfer coefficient was found to be approximately . The results are correlated with the energy dissipation rate and compared with spherical particles

Influence of liquid viscosity and surface tension on the gas-liquid mass transfer coefficient for solid foam packings in co-current two-phase flow

The gas–liquid mass transfer coefficient and other hydrodynamic parameters such as liquid holdup and frictional pressure drop are presented for gas and liquid moving in co-current upflow and downflow through solid foam packings of 10 and of 40 pores per linear inch (ppi). The effect of increasing the liquid viscosity on the mass transfer coefficient in co-current upflowis quantified and correlated to the frictional pressure drop, a measure of the frictional energy dissipation: kLaGLeL(ScL/Scwater)^0.69 = 2.05 × 10-4 Pf^0.8 (mL^3 mP^-3 s^-1). The gas–liquid mass transfer coefficient in co-current downflowis correlated to the liquid velocity and the Schmidt number using the correlation proposed by Sherwood and Holloway [Sherwood, T. and Holloway, F., 1940, Performance of packed towers—liquid film data for several packings, Transactions of the American Institute of Chemical Engineers 36: 39–70]: kLaGL eLD-1 L = 3.7(uL??L??-1L )1.16(ScL)0.5 (mL mP-3). The results for the gas–liquid mass transfer coefficient in co-current upflowwere correlated with a similar equation, where the influence of the gas velocity is included, similar to the correlations for packed beds of spherical particles proposed in Fukushima and Kusaka [Fukushima, S. and Kusaka, K., 1979, Gas–liquid mass transfer and hydrodynamic flow region in packed columns with cocurrent upward flow, Journal of Chemical Engineering of Japan 12 (4): 296–301]: kLaGL eLD-1 L = 311u0.44 G (uL??L??-1 L )0.92(ScL)0.5 (mL mP-3). In this study the liquid Schmidt number dependency of the gas–liquid mass transfer coefficient points to the penetration theory describing the rate of mass transfer for gas–liquid flow through solid foam packings. © 2007 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved