Abstract:
The invention provides a process for the selective hydrogenation of glycolaldehyde in a process stream comprising glycolaldehyde and one or more monosaccharide in a solvent, said process comprising contacting the process stream with hydrogen in the presence of a hydrogenation catalyst composition at a temperature of no more than 150°C and for a residence time of no more than 90 minutes.
Abstract:
Structural health monitoring (SHM) is essential but can be expensive to perform. In an embodiment, a method includes sensing vibrations at a plurality of locations of a structure by a plurality of time-synchronized sensors. The method further includes determining a first set of dependencies of all sensors of the time-synchronized sensors at a first sample time to any sensors of a second sample time, and determining a second set of dependencies of all sensors of the time-synchronized sensors at the second sample time to any sensors of a third sample time. The second sample time is later than the first sample time, and the third sample time is later than the second sample time. The method then determines whether the structure has changed if the first set of dependencies is different from the second set of dependencies. Therefore, automated SHM can ensure safety at a lower cost to building owners.
Abstract:
The invention provides a process for the recovery of C 3 -C 6 carboxylic acid from a vaporous aqueous stream, comprising providing a vaporous aqueous stream comprising C 3 -C 6 carboxylic acid, contacting said vaporous aqueous stream comprising C 3 -C 6 carboxylic acid with an absorbing solvent in an absorption unit, to produce a first stream comprising absorbing solvent and C 3 -C 6 carboxylic acid and a second stream comprising water vapour, feeding said first stream comprising absorbing solvent and C 3 -C 6 carboxylic acid to a solvent recovery unit, to produce a third stream comprising C 3 -C 6 carboxylic acid and a fourth stream comprising absorbing solvent, and optionally recycling at least a portion of the fourth stream comprising absorbing solvent to the absorption unit, wherein the absorbing solvent is an oxygen-containing organic compound having (i) a Hansen solubility parameter distance R a with respect to C 3 -C 6 carboxylic acid as determined at 25°C of 15 MPa 1/2 or less, preferably 12 MPa 1/2 or less, more preferably 10 MPa 1/2 or less; (ii) a 1-octanol/water partition coefficient logP OW as determined at 25 °C and pH 7 of at least 0, preferably at least 0.5, more preferably at least 1.0, even more preferably at least 1.5, yet even more preferably at least 2.0, most preferably at least 3.0; and (iii) a boiling point at atmospheric pressure that is at least 5 °C higher, preferably at least 10 °C higher, more preferably at least 20 °C higher than the boiling point of the C 3 -C 6 carboxylic acid.
Abstract:
The invention provides a process for the recovery of a acetic acid from a vaporous aqueous stream, comprising providing a vaporous aqueous stream comprising acetic acid, contacting said vaporous aqueous stream comprising acetic acid with an absorbing solvent in an absorption unit, to produce a first stream comprising absorbing solvent and acetic acid and a second stream comprising water vapour, feeding said first stream comprising absorbing solvent and acetic acid to a solvent recovery unit, to produce a third stream comprising acetic acid and a fourth stream comprising absorbing solvent, and optionally recycling at least a portion of the fourth stream comprising absorbing solvent to the absorption unit, wherein the absorbing solvent is an oxygen-containing organic compound having (i) a Hansen solubility parameter distance Ra with respect to acetic acid as determined at 25 °C of 15 MPa 1/2 or less, preferably 12 MPa 1/2 or less, more preferably 10 MPa 1/2 or less; (ii) a 1-octanol/water partition coefficient logP OW as determined at 25 °C and pH 7 of at least 0, preferably at least 0.5, more preferably at least 1.0, even more preferably at least 1.5, yet even more preferably at least 2.0, most preferably at least 3.0; and (iii) a boiling point at atmospheric pressure that is at least 5 °C higher, preferably at least 10 °C higher, more preferably at least 20 °C higher than the boiling point of acetic acid.
Abstract:
The invention provides a process for the recovery of C 3 -C 6 carboxylic acid from a liquid or vaporous aqueous stream, comprising providing a liquid or vaporous aqueous stream comprising C 3 -C 6 carboxylic acid, contacting said aqueous stream comprising C 3 -C 6 carboxylic acid with an extractive solvent in an extractive distillation unit, to produce a first stream comprising extractive solvent and C 3 -C 6 carboxylic acid and a second stream comprising water, feeding said first stream comprising extractive solvent and C 3 -C 6 carboxylic acid to a solvent recovery unit, to produce a third stream comprising C 3 -C 6 carboxylic acid and a fourth stream comprising extractive solvent, optionally subjecting the second stream comprising water to a condensation step to allow liquid-liquid separation of entrained extractive solvent and water and optionally recycling at least part of said entrained extractive solvent to the extractive distillation unit, and optionally recycling at least a portion of the fourth stream comprising extractive solvent to the extractive distillation unit, wherein the extractive solvent is an oxygen-containing organic compound having (i) a Hansen solubility parameter distance R a with respect to the carboxylic acid as determined at 25 °C of 15 MPa 1/2 or less, preferably 12 MPa 1/2 or less, more preferably 10 MPa 1/2 or less; (ii) a 1-octanol/water partition coefficient logP OW as determined at 25 °C and pH 7 of at least 0, preferably at least 0.5, more preferably at least 1.0, even more preferably at least 1.5, yet even more preferably at least 2.0, most preferably at least 3.0; and (iii) a boiling point at atmospheric pressure that is at least 5 °C higher, preferably at least 10 °C higher, more preferably at least 20 °C higher than the boiling point of the C 3 -C 6 carboxylic acid.
Abstract:
A process for producing polycarbonate comprising: a) contacting a dialkyl carbonate with a dihydroxy compound in an oligomerization zone in the presence of an oligomerization catalyst under oligomerization conditions to form a first intermediate; and b) contacting the first intermediate with a diaryl carbonate in a polymerization zone in the presence of a polymerization catalyst under polymerization conditions to produce the polycarbonate wherein the molar ratio of dihydroxy compound to dialkyl carbonate in the oligomerization zone is at least 2:1.
Abstract:
A conductivity measurement apparatus for measuring the conductivity of a non-aqueous sample. The conductivity measurement apparatus includes a conductivity cell which contains the sample and which is disposed within a heater block which can control the temperature of the sample and a pressure vessel which can control the surrounding pressure for the conductivity cell. A probe senses conductivity of the sample as a voltage is applied across the sample.
Abstract:
Methods and systems for utilizing renewable energy, including nuclear, hydroelectric, wind, geothermal, and solar, to power electrochemical conversion of carbon dioxide to various reduced compounds including methanol and/or glycols, which can be condensed to form drop-in fuel compounds. A method may include providing a divided electrochemical cell comprising an anode compartment, a cathode, and an electrolyte; providing an aqueous solution of a reducible sugar and an alkali metal salt as electrolyte into the cathode compartment; providing electrical energy from an energy source selected from the group consisting of nuclear, hydroelectric, wind, geothermal, and solar power to the electrochemical cell to reduce said sugar to a polyhydric alcohol; and contacting the polyhydric alcohol with a solid acid condensation catalyst.
Abstract:
Methods and systems for utilizing renewable energy, including nuclear, hydroelectric, wind, geothermal, and solar, to power electrochemical conversion of carbon dioxide to various reduced compounds including methanol and/or glycols, which can be condensed to form drop-in fuel compounds. A method may include providing a divided electrochemical cell comprising an anode compartment, a cathode compartment, and an electrolyte; providing carbon dioxide to the cathode compartment; providing electrical energy from an energy source selected from the group consisting of nuclear, hydroelectric, wind, geothermal, and solar power to the electrochemical cell to reduce the carbon dioxide to at least a carboxylic acid or carboxylic acid intermediate; contacting the carboxylic acid or carboxylic acid intermediate with hydrogen to form a reaction product comprising a polyol and contacting the polyol with a solid acid condensation catalyst.