Why and how dewaxing of lube oils is done?
The main purpose of dewaxing is to remove hydrocarbons that solidify readily (i.e., wax) for making lubricating oil base stock with low pour points (-9 to 14°F).
Which of the following solvent is used for dewaxing?
The two principal solvents used in solvent dewaxing units are methyl ethyl ketone (MEK) and propane. Although the majority of dewaxing units in the U.S. refineries use MEK), some advantages of using propane as a solvent compared to MEK include the following [2]:
What is MEK dewaxing?
MEK (Methyl Ethyl Ketone) dewaxing is a complex process process for physically removing wax, by crystallisation and (rotary vacuum) filtration. A rotary vacuum filter consists of a hollow drum that sits in a vat, which is covered by a sealed hood and is maintained at a slightly positive pressure.
What does Dewax mean?
to remove wax from
Definition of dewax : to remove wax from specifically : to remove paraffin wax from (oil) usually by chilling, pressing, or treating with a solvent.
What is dewaxing in batik?
The dewaxing method in adire making simply means melting the wax off the fabric. Artisan using wax resist and a stamp to create designs on fabric.
What is oil made of chemically?
Crude oil is a mixture of comparatively volatile liquid hydrocarbons (compounds composed mainly of hydrogen and carbon), though it also contains some nitrogen, sulfur, and oxygen. Those elements form a large variety of complex molecular structures, some of which cannot be readily identified.
How is dewaxing of a lubricant oil done by solvent refining?
In solvent dewaxing the oil feed is diluted with solvent to lower the viscosity, chilled until the wax is crystallized, and then filtered to remove the wax. Solvents used for the process include propane and mixtures of methyl ethyl ketone (MEK) with methyl isobutyl ketone or MEK with toluene.
What is dewaxing of concentrates?
Dewaxing, similar to winterization, removes unnecessary fats and waxes from the end product. Dewaxing dissolves the crude extract in butane, usually, under sub-zero temperatures. Most often, this can occur within a closed-loop system through an inline dewaxing element.
What is the chemical process for dewaxing Lube?
The isodewaxing process and a version of the ExxonMobil process called MSDW (Mobil selective dewaxing) are also used for dewaxing lube feedstocks. Processes using shape-selective catalysts deliver products with a much better viscosity index than noncatalytic processes that use solvents for dewaxing (44).
What is a dewaxed oil?
Dewaxing is a separation process that takes advantage of deasphalted oil (DAO) and heavy vacuum gas oil (HVGO) from the vacuum distillation tower as feedstocks in producing lubricating oil base stock and, to some extent, distillate fuels such as gasoline.
What is the temperature of dewax Lube?
The process concept can also be applied to dewax lube feedstock (Mobil lube dewaxing, MLDW), although it would then be operated at lower temperature (260–360 °C), because of the relatively small concentrations of poison in the lube feedstock (218).
What are the by-products of dewaxing?
Note that wax (long-chain paraffins) obtained in dewaxing is a marketable by-product. Lubricating oil base stock is the principal product of interest. The main purpose of dewaxing is to remove hydrocarbons that solidify readily (i.e., wax) for making lubricating oil base stock with low pour points (-9 to 14°F).