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An emulsifier or surfactant has to have a hydrophilic (water loving) or polar head and a lipophilic (fat loving) or non-polar tail. One end connects with water, the other with oil, and it brings the two things together. Cetyl alcohol, cetearyl alcohol, behenyl alcohol, stearic acid, beeswax, and other waxes only have lipophilic or oil loving parts. They cannot be used as an emulsifier because they lack the hydrophilic or water loving parts, which means they won't bring water and oil together.
Cetyl alcohol might not be an emulsifier, but it's a great thickener for our products. I like to use cetyl alcohol in my lotions to increase the viscosity and increase slip and glide. Stearic acid will increase the viscosity, but it offers a little more drag and thickness than cetyl alcohol. It's inexpensive - I think I pay about $4 a pound for it (about $8 a kilogram) - and it works well to moisturize without oils. I like to use it in my facial moisturizers to offer oil free moisturizing to my acne prone skin, and it's a lovely addition to a lotion bar to make it glide a little better.
If cetearyl alcohol interests you, take a look at this recipe for turning an oil into a whipped butter.