Oil dewaxing plants.

Oil product dewaxing is removal of wax and ceresin from oil products (diesel fuels, oils) resulting in improvement of their quality, in particular, in reduction of their setting point. Dewaxing is carried out by the following methods: crystallization of the above components from oil product solution, e.g. oil crystallization in ligroin at chilling; selective dissolution of oil products in solvent that doesn’t dissolve wax and ceresin; wax capability to form carbamide complex (carbamide dewaxing) and microbiological method are also applied. Produced wax and ceresin are used as valuable raw materials in various industries.

Dewaxing diagram
Dewaxing diagram

Oil product dewaxing flow diagram with use of solvents:
  1. raw material heater;
  2. regenerative heat exchanger;
  3. cooler;
  4. intermediate tank;
  5. drum filter with tray;
  6. 7. apparatus for solvent distillation from filtrate and wax cake;

Viscous products are dewaxed by easily boiling solvents that dissolve wax badly, but dissolve well other components of basic oil products. Solvents generally contain methyl ethyl ketone or acetone with toluol (sometimes with benzol), dichloroethane with dichloromethane, higher ketones, liquid propane.

Process flow diagram (see fig.) includes oil product dilution; blend chilling (by means of liquefied ammonia, propane or ethane); filtration of formed suspension via drum filters. Resultant filtrate consists of solution of dewaxed product and wax cake containing solvent that is further removed by distillation and recycled. Solvent to raw material volumetric ratio depends on the type and viscosity of oil products and can range from 2 to 5.

Dewaxing unit

In order to dewax low-viscosity fuels and oils, the latter are mixed with aqueous or alcoholic carbamide solution that forms clatharate complexes with normal waxes (carbamide dewaxing). Reduction of medium viscosity and improvement of mass exchange is achieved by adding a solvent (isooctane, gasoline, dichloromethane) to the composition; activating agents (lower aliphatic alcohol, ketone, chlororganic compound etc.) are added to accelerate complexing. Clathrate is separated by sedimentation, filtration, centrifugation etc. Microbiological dewaxing of oil fuels can be defined as selective oxidizing of normal waxes by some microorganisms. The process is carried out in aqueous medium by air agitation. Dewaxed product is separated by filtration or sedimentation. Catalytic dewaxing is required to reduce the setting point of oil products. The process utilizes hydrogen treating of oil products over special catalyst at the temperature of 360-420 °Ń, at the pressure of 4-8 MPa and at the volume feed of raw material of 0.5-4 1/h. Wax and ceresin produced by dewaxing are purified and are applied as valuable raw materials in petrochemical and other industries.

We offer dewaxers based on the customers' enquiries.
Our delivery program includes the units for operation at low ambient temperatures (up to -50°C).

With the enquiries and for any further questions, please, contact us. We are ready to answer all your questions in the shortest possible time.