Chemistry of Lubricity of fuels

[Ronny07]

Hi i'm doing experiments using the HFRR.

What are the detailed chemistry components which affect the lubricity properties of fuels?

Am I wrong in going down the route about electronegativity?
such that the long carbon chain increases viscosity due to tangled long chains therefore the lubricity?

I would like to know which : unsaturated compounds/fatty acids or chemical structure effects the lubricity of fuels...such as diesel and biodiesel.

thanks

Charles

 

[25362]

Excerpts from the internet:

Deeply desulfurized diesel gas oil has poor lubricity for distributor type injection pumps of diesel engines that use the gas oil for lubrication of their moving parts.
Among the polar compounds in diesel gas oil, phenols and carboxylic acids had good effects on lubricity of diesel gas oil, but since these acidic compounds were reduced with desulfurization, the low sulfur diesel gas oil had poor lubricity. On further investigation, it was observed that catechols and naphthenic acids also had good effects on lubricity of diesel gas oil.

A wide variation in lubricity performance of bio-diesel from different vegetable oils and sources has been noticed. It was noticed that the variation in the lubricating performance of bio-diesel could be better linked to its residual acidity than to variation in fatty acid composition.

 

[chusker15]

You should start by looking at the interactive forces among the molecules (London, van der waal, hydrogen bonding). Viscosity is a strange property in that it doesn't always trend like you'd expect, especially among various types of molecules.

I think this book might have some of the answers that you're looking for:

http://www.amazon.com/Properties-Ga...=sr_1_1?ie=UTF8&s=books&qid=1208380436&sr=8-1

I'd dig it out, but I left it at home.

 

[davsy]

Do a web/ literature search on Dr Jon van Gerpen, he has done a lot of engine testing of both Diesel and Biodiesel. He was professor of mechanical engineering at Iowa State university but I believe he heads up research into Biodiesel at Idaho now.

I am sure he has published quite a few papers on Lubricity.