FR2788278A1 - Production of white oils and cracking bases from used lubricated oils by desulfuration, dechlorination, demetallization, distillation and catalytic hydrogenation - Google Patents

Abstract

The production of white oils and cracking bases from used lubricated oils is carried out by desulfuration, dechlorination, demetallization, distillation and catalytic hydrogenation.

Description

-1 -

  PROCESS FOR PRODUCING WHITE OILS AND BASES

  CRACKABLE FROM USED LUBRICATING OILS

  The present invention relates to a process which makes it possible to manufacture a white oil as well as the development of a crackable base for supplying

catalytic crackers.

  Used lubricating oils come mainly from the draining operation of automobile engines. These used oils are extremely toxic and a law requires their collection and disposal in

  approved centers throughout Europe.

  Used oil, also known as engine drain oil, is made up of additives to which there is added soiling due to engine operation at operating temperatures (+ 300 C). In fact, this oil contains volatile constituents (water, petrol, diesel), desk oil-soluble compounds formed by oxidation, (resins, metallic soap, additives of viscosity index, organo-metallic compounds), compounds insoluble in oils (carbon particles, atmospheric dust, metals, metal oxides, lead oxides kept in suspension by detergents added to oils), additives containing a metal,

  dispersant additives, ashless additives, antioxidant and anti additives

  corrosives, metals from pipes or fittings (iron, copper, lead), bearings (silver, cadmium), fuels (tetrastyle lead,

among others).

  -2- The list of products mentioned is not exhaustive but given for

  example. Descriptions are provided for illustrative purposes but not

  limiting. The oil deteriorates and becomes colored by oxidizing action in engines, by the formation of colored varnishes and by the action of sulfur. The removal of heavy metals, metalloids, complex products, tars, colloidal residues and other content in used engine oils is currently carried out by the combined action of heat, sulfuric acid, bleaching earth, filtration,

centrifugation, distillation.

  Another method of removing heavy metals, metalloids, complex products, tars and the like contained in waste oils, consists in the use of complexing agents in order to extract the heavy metals and the metalloid and to supplement this. purification by action

centrifugation.

  The lubricating oils currently available on the market have evolved considerably since the manufacturers add to the base oil and to common additives a fraction of between 5 and 10% of synthetic oil (generally polyalphaolefins) as well as oil with very high viscosity index in variable proportion according to the desired quality of the oil (between 5 and

  %), as well as thickeners (at least 5% of polymers).

  These increasingly elaborate additives which are being added to the base oil today have generated problems which have totally disrupted the regeneration systems hitherto employed by the oil recycling industry. In addition, these new additives prevent the use of

  high-performance techniques of the membrane type, because they plug it.

  Indeed, the presence of polymers in used oils has generated

  very complex problems at the bottom of the distillation columns.

  In particular problems of solidification as well as problems of solidification in the heat exchangers. Regenerators have attempted to solve these problems by increasing the distillation temperature. This increase in distillation temperature at the bottom of the column (around 375 ° C.) generated cracking phenomena giving a strong odor to the oil after distillation. This strong odor resulting in a significant discount on the sale price of the regenerated oil. These cracking phenomena also generate a coloration of the oils imposing an extensive bleaching treatment on bleaching earths, resulting in a significant additional cost of the production price. I) e more that did not solve the problems of

  solidification and solidification in the distillation column.

  I. studies carried out by environmental authorities have demonstrated the presence of aromatic polymorphonuclear compounds in waste oils. These aromatic products are considered carcinogenic by the Authorities, the majority of European countries impose their reduction with the final objective

  in the short term their elimination in lubricating oils.

  The drop in the price of basic lubricating oil makes recycling of

this one much less attractive.

  -4- Given the investments involved and the low financial return obtained in the regeneration of oils, it is important to

  implements a process allowing better recycling of this recycling.

  The disclosure of the invention and the claims solves this problem

  economic. The present invention relates to a treatment for producing a white oil as well as a crackable base which can be used to feed a catalytic cracker as well as the production of base oil for lubrication. When the drain oils are collected and they arrive at a collection and processing center, the average analytical characteristic of these oils is as follows: -5-

  ANALYSIS OF USED LUBRICATING OILS

  Density Kg / I 0.905 - 0.930 Viscosity at 40 C cSt 40 - 140 Composition (vol.%) Water Vol% 5 - 15 Light Vol% 1 - 04 Diesel Vol% 10 - 15 Lubricating oil Vol% 55 - 75 Asphalted Vol% 10 - 15 Nitrogen Wt% 0.03 Sulfur Wt% 0.1 - 0.6 Chlorine ppm 600-1500 Ash Wt% 0.5 - 1.5 Flash point C 50 70

METALS

  BA ppm 10 - 20 Ca ppm 700 - 900 Pb ppm 1000 - 1800 Zn ppm 650 - 750 20.P ppm 650 - 750 B1 ppm 15-20 Mg ppm 250 - 350 Na ppm 120 - 300 Si ppm 100 200 To be able to produce recyclable and distillable products, all sulfur and chlorine products must be eliminated, all metals, water, light (volatile) products and ashes. The technical characteristics of the base oil for lubrication impose strict limits on heavy and chlorine metals and on color indices. It is imperative to distil at a temperature below 260 ° C. to avoid the coloring of the base oil and the production of aromatic polymers in order to obtain a marketable product. The technical characteristics of the base for feeding a cracker

  catalytic requires a completely dechlorinated product (less than one ppm).

  The technical characteristics of a Neutral Solvent that can serve as a basis for the production of a white oil by catalytic hydrogenation requires

  almost complete demetalization (total heavy metals less than 5 ppm).

  To obtain all these characteristics, the following procedure will be carried out: In a first phase, the drain oil will be desulphured to make the drain oil will be stored in a tank equipped with a heating coil. When introducing the drain oil into this tank, a secondary amine will be added in stoichiometric proportion of the sulfur to be eliminated. This secondary amine will combine with sulfur and sulfur products. The separation will be done by decantation at moderate temperature around C and we will obtain a desulfurized oil phase and an aqueous phase containing the sulfur compounds and which will be separated from the oil phase.

  A second phase will then be implemented. Demetalization.

  That is to say the extraction of metallic compounds (of heavy metals type).

  To make a heavy metal sequestrant in the aqueous phase and in

  stoichiometric proportion will be mixed with the oil by homogenization.

  To achieve this homogenization, a homogenizer similar to that used in the dairy industry to homogenize milk will be used and which will be specially adapted for this use. The sequestrant used will be of the sodium type in order to combine with part of the chlorinated compounds. The separation of demetalized oil and heavy metals as well as of the aqueous phase will be done by centrifugation. Desulfurized oil, demetalized and

  partially dechlorinated will be stored in an intermediate tank.

  The next step will consist in extracting the light and volatile phases from the oil by passing through a flash column at approximately 140 ° C. at atmospheric pressure. The next step will consist in extracting the diesel fuel from the oil by passing it through a distillation column at a temperature of approximately 190 ° C. and a partial vacuum in this operation the rest of the chlorinated compounds will be eliminated by the fact that the distillation conditions (temperature pressure) lead to its extraction. The asphaltene type compounds as well as the polymers will be eliminated in the following stage by a fractionation type distillation carried out under a very high vacuum (less than a torr) and at a temperature of approximately 250 C. The distillation column which will be ideally a thin film evaporator will be constructed and operated in such a way that two sections are obtained. The first cut will be Neutral Solvent 150 lubricating oil and the second cut from the bottom of the column will be a

  mixture of Neutral Solvent 300 of asphaltenes and polymers.

  The Neutral Solvent 150 cut can be sold as such as a lubricating base oil or as a crackable base for the supply of catalytic crackers or undergo an additional treatment to extract it.

  aromatic type polymers.

  - 8- The section at the bottom of the column will undergo hot centrifugation in order to separate the Neutral Solvent 300 from the asphaltenic and other compounds. The centrifuge used for separation will be a horizontal type decanter specially adapted for hot work and constructed of materials capable of resisting the erosion generated by carbonaceous articulations

asphaltic type.

  Neutral Solvent 300 will then undergo catalytic type hydrogenation to produce white oils with characteristics

market techniques.

-9- 2788278

Claims (11)

  1) Process for the production of white oil, base oil for lubrication and crackable base for feeding a catalytic cracker, characterized in that the oil is purified to allow catalytic hydrogenation   necessary for the production of white oil.   2) Method according to claim 1, characterized in that a used lubricating oil.   3) Method according to claim 2, characterized in that one uses a   secondary amine in stoichiometric proportion of the sulfur to be eliminated.   4) Method according to claim 3, characterized in that one operates a demetalization using a sequestrant of heavy metals in phase   aqueuse mixed with oil by homogenization.   ) Method according to claim 4, characterized in that an extraction of the light and volatile aqueous phases is carried out by passage through a   flash column at about 140 C at atmospheric pressure.   6) Method according to claim 5, characterized in that one operates an extraction of diesel in a distillation column at a temperature of  C and a partial vacuum.   7) Method according to claim 6, characterized in that the rest of the chlorinated compounds will be eliminated by the fact that the distillation conditions   (temperature pressure) lead to the extraction of the remaining chlorine.   8) Process according to claim 7, characterized in that the compounds of the asphaltenes and polymers type and Neutral Solvent 300 will be separated from the   Neutral Solvent 150 by distillation.   9) Method according to claim 8, characterized in that the distillation will be carried out under a very high vacuum (less than a torr) and a temperature of 250 C.   10) Method according to claim 9, characterized in that the distillation cut of Neutral Solvent 150 will be a base oil for lubrication   or a base for the supply of catalytic crackers.   11) Process according to claim 10, characterized in that the distillation cut containing the asphaltenes, the polymers and the Neutral Solvent 300   will undergo mechanical separation to extract the Neutral Solvent 300.   12) Method according to claim 11, characterized in that the Neutral Solvent 300 will undergo a catalytic type hydrogenation in order to produce a white oil