A new route to polyhydric alcohols

Parker, Gemma M. (2009) A new route to polyhydric alcohols. PhD thesis, University of Glasgow.

Abstract

Pentaerythritol is an important industrial chemical for use in paints and coatings, primarily, but also in fuels, explosives, medicine and polymers. The current process for this material is over 50 years old and is a multi-step process involving 3 homogeneous aldolizations and a crossed Cannizzaro reaction, generating 1.5 tonnes of waste for every 4 tonnes of product. This is also very energy inefficient. We are currently developing a radically different concept, shown below. This will deliver an integrated heterogeneous catalytic process with no waste and a high energy and materials efficiency.

Methanol/ Dehydrogenation Base Hydrog
Ethanol Catalyst Catalyst Catalyst

Pentaerythritol

The initial step, CH3OH HCHO + H2, will involve the use of Ag/SiO2 catalysts. This will be in the absence of O2, which differs from the current oxidative dehydrogenation process used to produce HCHO, i.e. a direct dehydrogenation. This step has been optimised by investigation of different surface properties to determine how surface area and dispersion will affect the overall adsorption and consequently the methanol/ethanol conversion and product yields. Deactivation of these catalysts has also been touched on by use of in-situ temperature programmed oxidation’s. Base catalysis involving an aldol type reaction of 2 aldehydes, HCHO and CH3CHO, will give the methylolated aldehyde intermediate.

This will then undergo a final hydrogenation to the desired product. Any unreacted aldehydes will, therefore, be hydrogenated back to starting materials and consequently recycled.
It will be attempted to couple all three reactions to explore how the catalysts perform when used in succession.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Additional Information: Due to copyright restrictions the full text of this thesis cannot be made available online. Access to the printed version is available.
• Keywords: Dehydrogenation, methanol, ethanol, polyols, polyhydric alcohol, formaldehyde, acetaldehyde, hydrogen, heterogeneous catalysis, Ag, silver, silica, supported catalysts, copper, alumina, micro reactor, decomposition
• Subjects: Q Science > QD Chemistry; T Technology > TP Chemical technology
• Colleges/Schools: College of Science and Engineering > School of Chemistry
• Supervisor's Name: Jackson, Prof. S. David
• Date of Award: 2009
• Depositing User: Dr Gemma Parker
• Unique ID: glathesis:2009-620
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 07 Apr 2009
• Last Modified: 10 Dec 2012 13:20
• URI: https://theses.gla.ac.uk/id/eprint/620