DD268682A1 - METHOD FOR THE TREATMENT OF WAESS-RATED OIL SLIP - Google Patents

Abstract

The invention relates to a process for the treatment of aqueous oil sludge incurred in oil refineries and petrochemical plants in the form of stable emulsions. According to the invention, a preheated oil sludge in a pre-evaporator 2 and a stripping column 4 is treated by distillation and emulsion-splitting at a stripping steam treatment and bottom temperatures of 95-115C. The top products 13 and 14 are recycled as distillate 10 with a boiling range of 90-260C in the production process. The residue 12 is pumped in succession after the phase separation in water and oil phase in the residue template 7. Due to the almost complete utilization of the sludge ingredients, the process is economical and environmentally friendly. Fig. 1

Description

In order to increase the flexibility of the process and work up Ölschiämme UntRrschied'ichstei origin. If necessary, lime hydrate is added to the oil sludge in 10-20% by mass in a mixer.

This particularly applies to sludges which tend to foam during stripping in the stripping column.

The kalkhydrathaltiye residue is landfillable, or used for fertilizer production or could be burned.

The method can be realized with little technological effort. Also, the labor force is in operation

low rate of procedure. Due to the increased oil phase recirculation rate, the process is considered to be "economical and environmentally friendly".

embodiment

The invention will be explained in more detail with reference to two examples and a drawing:

example 1

An aqueous oil sludge having a composition of the following:

Water content 56 mass fractions in%

mechanical components 4.5 mass fractions in%

Salinity 336mg / l

and a density of 0.934 g / kg

is after separation of visible water and mechanical components and heating in the heat exchanger 15 and mixer 1 mixed by inserting steam 9 and heated to a temperature of 31 ⁰ C.

This homogenized oil sludge is fed to the pre-evaporator 2.

At a bottom temperature of the pre-evaporator 2 of 95 ^C C and the introduction of stripping steam, a top product 13 is driven off with a Siedebersich of 92-205 ⁰ C. The bottom product is passed through steam jet 3 and a sump product line in the stripping column 4. Here is obtained by further stripping be a bottom temperature of 115 ° C, a top product with a boiling range of 200 -:> 60 ^C C,

The Kopfpiodukte be condensed in the heat exchanger 15, separated from the water 11 in the separation vessel 6 and returned as a distillate 10 in the production process.

The bottom product of the stripping column 4 shows after a contact time with steam of 0.6 hours after cooling in the heat exchanger 5 in the residue template 7 a demulsification with an associated phase separation. The oil phase can be used with a water content of 0.5% by weight in both as heating oil component and as Einsntzprodukt for oil refineries.

The water phase can be fed to the wastewater treatment. The complete recirculation of the oil phase makes the process environmentally friendly and of high material economy.

Example 2

A ^1- aqueous oil sludge with foaming tendency during foaming treatment having the composition:

Water content 64.5. Mass shares in%

mechanical components 8.2 mass fractions in%

is treated as in Example 1.

After an addition of hydrated lime 16 of 12% by weight based on the amount used in mixer 1 ₍ foaming

in the pre-evaporator 2 and Abtreibskolonne 4 no longer occurred.

In this case, an identical yield of distillate 10 was achieved as in Example 1., The residue 12 is homogenized in the pumpable state before. By adsorbing the oil phase of hydrated lime, this residue is landfillable.

The residue shows after cooling an amorphous, granular structure. Due to the almost complete utilization of the sludge ingredients, the process is environmentally friendly and economical.

Claims (4)

1. A process for the treatment of aqueous sludges, characterized in that oil sludge (8) by a heat exchanger (5) and a mixer (1), optionally with lime hydrate (16) is heated to a temperature of 65-85 ⁰ C, the oil sludge (8) in the operated as stripping columns pre-evaporator (2) and stripping column (4) at bottom temperatures of 95- 115 ⁰ C is treated by distillation and Emulsionsspaitend and a distillate (10) with a boiling range of 90-260 ⁰ C in one Heat exchanger (15) condensed and a separation vessel (6) is deposited. 2. The method according to claim 1, characterized in that the contact time of the oil sludge (8) with the water vapor (9) in the mixer (1), pre-evaporator (2) and stripping column (4) is 0.1-1 hour, the accumulating residue (12) is burned or added to the feedstream of crude oil distillation in 1-2 parts by volume in%. 3. The method according to claim 1, characterized in that when foaming Ölschlämmen in the stripping column (4) lime hydrate (16) in 10-20 parts by mass in% in the mixer (1) is added and the resulting residue (12) organic fertilizers is added. For this 1 page drawing Field of application of the invention The invention relates to a process for the treatment of aqueous oil sludge incurred in oil refineries and petrochemical plants in the form of stable emulsions. Characteristics of the known state of the art The workup of oil sludges is due to their high water content and their emulsion formation associated with high technological effort. In most processes, therefore, a return of the oil phase is omitted in the production process by only a dewatering of the sludge is made to make it finally landfillable after a chemical treatment. In DE-AS 1645762 a device is described, with which the emulsion is destroyed by means of a filter consisting of polytetrafluoroethylene chips and to achieve a separation of the oil phase from the water phase in a multi-stage procedure. The expenditure on equipment is very high. The suitability of this method is only possible for sludges with a weak emulsion formation. Object of the invention The object of the invention is to provide an improved process for the treatment of aqueous oil sludges, which is characterized in particular by a gentle recovery of the hydrocarbons at their high Au-.beute yield. Due to the high recycling rate and the good quality of the hydrocarbons, the process is economical and environmentally friendly. Explanation of the toilet sens the invention The invention has for its object to develop a process for the treatment of aqueous oil sludge. In particular, a high recycling rate of the hydrocarbons into the production process should be achieved in high quality. The process should at the same time take place during a gentle process control of the recovery, an emulsion break. According to the invention, a treated or untreated oil sludge obtained in oil refineries and petrochemical plants, heated by heat transfer and a mixer with steam connection to 65-85 ° C and optionally mixed with hydrated lime. In a pre-evaporator and a stripping column, the oil sludge at temperatures of 95-115 ⁰ C with Stiippdampf is treated by distillation and Emulsionsspaitend. By exploiting the steam volatility of certain hydrocarbon fractions, the light hydrocarbon fractions of the oil sludge are recovered as distillates of high purity as a result of the boiling point reduction. This concerns the fractions of the Siedelage between 90 and 260 ° C. With a corresponding technical design, it is possible to meter top product of the pre-evaporator into the gasification fuel and the overhead product of the stripping column into the diesel fuel after the water has been separated off in a separation tank. At a contact time of the steam in the mixer, pre-evaporator and stripping column of 0.1-1 hour, a yield of the distillable fraction of hydrocarbons of at least 90% by volume is guaranteed. In addition, an emulsion cleavage of the residue is achieved in the residue template in compliance with this contact time. By the phase separation of the residue in water and oil phase almost complete recycling of the valuable ingredients of the oil sludge is ensured in the production process.