The development of novel fuel dehydrating icing inhibitors

Repetto, Sonia L.

Abstract

Dissolved water is a normal component of jet fuel which is vapourised during combustion; however, free water is a contaminant that can starve engines, freeze to form ice crystals capable of blocking fuel feeds, support microbial growth, and contribute towards corrosion. Jet fuel may be protected from the potentially hazardous effects of free-water using biocides and corrosion/icing inhibitors. This investigation seeks to identify novel chemical approaches to the dual management of water contamination and ice formation in jet fuel. The strategy of using organic molecules as dehydrating agents remains a relatively neglected solution, perhaps because of the complexity of the physical organic chemistry involved in developing and refining these systems. This Thesis describes our systematic approach towards the development of jet fuel additives which are kinetically fast, selective, lipophilic water scavengers that produce, upon hydrolysis, a hydrophilic ice inhibitor [Fuel Dehydrating Icing Inhibitors (FDII)]. A qualitative and quantitative analysis of the factors influencing the rates of hydrolysis for carefully selected geminal ethers is presented. The mechanistic understanding of the hydrolysis reactions of five and six membered geminal ethers has been consolidated using a combined kinetic 1H NMR, isotopic labelling and computer assisted conformational analyses approach. For the first time, stereoelectronic arguments have been employed to rationalise the rates of hydrolysis of five membered ortho esters. A novel one-pot stereospecific O-acylative cleavage of epoxides is presented. It is anticipated that this new synthetic methodology would provide access to novel FDII in the future. Finally, logKOW calculations have been used to predict the partitioning behaviour of FDII, and thereby screen candidate molecules for future study. We believe that FDII represents a novel and versatile approach for protecting jet fuel against the effects of water contamination.

Citation

Repetto, S. L. The development of novel fuel dehydrating icing inhibitors. (Thesis). University of the West of England. Retrieved from https://uwe-repository.worktribe.com/output/7512199

• Thesis Type: Thesis
• Deposit Date: Jul 7, 2021
• Publicly Available Date: Jul 7, 2021
• Public URL: https://uwe-repository.worktribe.com/output/7512199
• Award Date: Dec 31, 2015