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The Design Problem
Published in Martyn S. Ray, Martin G. Sneesby, Chemical Engineering Design Project, 2020
Martyn S. Ray, Martin G. Sneesby
Phthalic anhydride is an intermediate petrochemical used for the manufacture of plasticisers (especially for PVC), alkyd resins, polyesters and dyestuffs. It is traded in either molten form (requiring heated tankers) or as a white powder (‘flake’). Ortho-xylene (or o-xylene) is the primary raw material although naphthalene has been used widely in the past. The manufacture of phthalic anhydride consumes almost all o-xylene produced so that sourcing a suitable supply of high purity o-xylene is a critical consideration in the early stages of the feasibility study. Fixed bed and fluidised bed reactors are both viable alternatives as both can produce high yields by using appropriate specific catalysts. Care must be taken in the process handling stages as explosive mixtures form easily between phthalic anhydride dust and air, and spontaneous reaction occurs with many organic compounds including skin tissue.
Chemicals from Aromatic Hydrocarbons
Published in James G. Speight, Handbook of Petrochemical Processes, 2019
The main use for phthalic anhydride is for producing plasticizers by reactions with C4 to C10 alcohols. The most important polyvinyl chloride plasticizer is formed by the reaction of 2-ethylhexanol (produced via butyraldehyde, Chapter 8) and phthalic anhydride:
Electron paramagnetic resonance study of the paramagnetic center in gamma-irradiated tetrahydrophthalic anhydride single crystal
Published in Radiation Effects and Defects in Solids, 2020
Acid anhydrides are formed from the dehydration reaction of two carboxylic acid groups. Anhydrides are highly reactive toward nucleophiles and are able to acylate a number of the important functional groups of proteins and other macromolecules (20). Acid anhydrides are used in a variety of chemical processes but particularly in epoxy resins. Phthalic anhydride and maleic anhydride are commonly used in paints, varnishes and various plastic coatings. Acid anhydrides are also used as plasticizers for PVC and other plastics, especially where temperature stability is required, as for example in coatings for wires and cables (21).