Punto de Fusión
Dear Dr. Vela,
What are synthetic waxes and what are the differences with paraffin wax?
Synthetic waxes are also hydrocarbon waxes, but they are obtained by synthesis. These types of waxes include Fischer Tropsh/GLT and Alpha Olefin waxes.
The physical properties of these waxes can be, and in many cases are, very similar to the physical properties of a petroleum paraffin wax. In many applications these waxes can replace a petroleum wax on a direct 1:1 basis. The main difference is how these waxes are produced.
Petroleum waxes are typically a by-product in the production of base oil, which main purpose is automotive lubricants. In a typical refinery producing Group I base oils, the oil fractions are de-waxed, and the by-product from this process is called slack wax, then depending on the refinery the slack wax is de-oiled to produce a refined paraffin wax.
In the case of synthetic waxes, the wax is NOT a by-product. The refineries that make these products are designed to produce wax from the start, particularly in the Fischer Tropsch/GTL process.
The Fischer Tropsch/ GTL process was invented in Germany during the second world war to produce fuels using carbon as a raw material. This process was adapted and perfected by Sasol in South Africa during the time of apartheid, also using carbon as its main raw material. Over the last 30 years the process has been adapted to use natural gas as a main feedstock, but over the last decade many other products, including methane gas from landfill trash.
The process converts the raw material into a liquid called syngas, using a special catalyst. From there the plant is designed to produce the desired products, so if the plant is designed to produce wax, it will always produce wax. These waxes are 100% linear hydrocarbon waxes just like paraffin wax, and in most cases are 100% compatible with paraffin wax applications.
Alpha Olefin wax is obtained by a chemical process, that fractionates ethylene oligomers. This process, only makes even number carbon fractions (2, 4…20, 22, etc.) Depending on the manufacturer many of the fraction with a carbon number above C 20 will be solid at room temperature and can have similar physical properties to a paraffin wax, and some can be adapted to be used in candles. Paraffin waxes typically used in candles have a carbon chains between C 24 and C 30; however, paraffin wax will have odd hydrocarbon chains and iso—paraffin content, which makes them different in some applications.
With the ongoing threat of petroleum paraffin wax going away due to changes in base oil technology, these waxes can be a possible long-term alternative. If you want to use these waxes, please consult with your preferred supplier, and do the appropriate and necessary testing to make sure that these products would fit in your process.