Lubricating oil solvent dewaxing is an expensive petroleum refining process with high investment and operating costs. Therefore, countries are committed to finding suitable solvents, developing new crystallization equipment, improving filtration equipment, and improving solvent recovery processes and operating conditions to improve the technical level of solvent dewaxing. In addition, research into hydrodewaxing is ongoing.
In order for lubricating oil to maintain good fluidity under low temperature conditions, the wax that is easy to solidify must be removed. This process is called dewaxing. The dewaxing process not only reduces the freezing point of lubricating oil, but also obtains wax. The so-called waxes are those hydrocarbon compounds that become solid at room temperature (15°C). The main bodies are n-alkanes and cyclic hydrocarbons with long side chains. N-alkanes above C16 are solid at room temperature.
There are many methods of dewaxing. Currently, the commonly used methods are cold press dewaxing, solvent dewaxing and urea dewaxing.