RU2097526C1 - Method of processing crude oil sludge - Google Patents

Abstract

FIELD: oil and gas production. SUBSTANCE: method consists in changing aggregational state of crude oil sludge from ductile-elastic to liquid one, adding solvent until content of solid particles in mixture attains a value as high as 35 wt % under continuously blowing mixture with hot nitrogen. Implementation of the method would allow utilizing crude oil sludge accumulated at oil field and warehouses with no damage to environment and clearing production areas used to store sludge. In addition, remaining solids with hydrocarbon content less than 6% can be used for bituminous pavements. EFFECT: improved environmental safety and enlarged building bitumen resource. 1 dwg

Description

 The invention relates to the oil and gas industry and can be used in the processing of bitumen, oil residue, sludge and other materials contaminated with petroleum hydrocarbons.

 Known for the comprehensive utilization of oil sludge, including the collection of oil sludge, the selection of water from it and mixing with fuel oil and subsequent combustion ("Research and use of the product of the processing of heavy oil residues" Collection of scientific papers. BashNIINP. Issue 29.-M. TsNIITEneftekhim, 1990. 156).

 The main disadvantage of this method is that the hydrocarbons that make up the sludge emit a large amount of combustion products during combustion, most of which are toxic, polluting the atmosphere.

 Closest to the proposed method is the processing of oil sludge, including changing its state of aggregation from a viscoplastic to liquid by heating and subsequent separation into components by filtration (sludge processing catalog Alfa Laval Oil Limitted Alfa Tower Great West Road GB BRENTFORD MIDDX TW8 9BT, s .8). In this case, heating is carried out several times, in front of each separation filter.

 The disadvantage of this method is that, in spite of heating, solid particles do not give away a tight and adhering layer of hydrocarbons, moreover, hydrocarbons that are poorly liquefied at elevated temperatures remain together with solid particles, increasing the amount of non-processed hydrocarbons in the residue and thereby increasing its mass. In addition, the method requires high energy costs for multiple heating of oil sludge in front of each of the filters.

 The objective of the invention is to improve the quality of purification of oil sludge and reduce its energy consumption.

 The problem is solved by the described method of processing oil sludge, including changing its state of aggregation from a viscoplastic to liquid by heating and subsequent separation into component components, new is that when heated, an additional solvent is introduced into the oil sludge to the content of solid particles in the mixture not more than 35 wt. with continuous barbation with hot nitrogen.

 Studies of patent and scientific and technical literature have shown that such a combination of essential features is new and has not been used before, this, in turn, allows us to conclude that the technical solution meets the criterion of "novelty."

 The drawing shows a flow chart of the implementation of the proposed method.

 The diagram shows an oil sludge barn 1 connected by line 2 to a slurry pump 3 (NP 100), the discharge of which by line 4 is connected to the input of the mixer 5. Another input of the mixer 5 by line 6 is connected to the discharge of the centrifugal pump 7 (CNS 38/60), whose input line 8 is connected to the boulite drive 9. The mixer 5, lines 6 and 8, bores the drive 9 are thermally insulated and equipped with internal channels (not shown in the drawing), into which overheated steam from boiler room 12 enters through lines 10 and 11, to return which serves as a line 13. The output of the mixer 5 line 14 connections ene to the input 15 of the centrifugal pump (CNS-60/98), which vykid line 16 connected to the divider 17 (hydrocyclone-demulsifier). The last line 18 is connected to the accumulator 19 of mechanical impurities, the line 20 with a drill 9, and the line 21 serves to discharge wastewater. During operation, half of the bulit storage tank 9 is filled with solvent (distillate or another light oil fraction can be used as solvent), and the other half with nitrogen, and the intake device of line 8 is placed in such a way that both solvent and nitrogen are sucked in. To eliminate possible losses, the entire cleaning system is sealed.

Cleaning according to the described scheme is as follows. The mixer 5 and bouts of the accumulator 9 are pre-filled with a solvent, approximately 2/3 of the volume, the remaining parts are filled with nitrogen. Then, overheated steam is supplied via lines 10 and 11 from boiler room 12 to the internal channels of the mixer 5, lines 6 and 8, and the sludge from the storage tank 9. After warming up to a working temperature of 80 ^o C, the pump 7 is turned on, while hot solvent is sucked in half with nitrogen from the sulit drive 9, are mixed in the pump and enter the bottom nozzles of the mixer 5. Upon exit from the nozzles, nitrogen is released from the solvent and floats in small bubbles, while the solvent boils with nitrogen. Simultaneously with the pump 7, a slurry pump 3 is turned on, which feeds the sludge from the barn 1 to the upper part of the mixer 5. The sludge is fed through the nozzles in small portions uniformly over the entire area of the mixer 5, the amount of sludge supplied is calculated so that the ratio of the volume of sludge to the solvent is about 1 to 3, but did not exceed the content of solid particles in the resulting mixture of more than 35 wt. at a higher solids content, the cleaning process does not occur. The most optimal solids content in the working mixture is 20 wt. Once in a solvent boiling with nitrogen, the state of aggregation of the sludge changes from pasty to liquid, its structure is destroyed, the enveloping solid particles of the hydrocarbon dissolve, and the solid particles are washed off. At the same time, nitrogen suppresses the active centers of solid particles; its bubbles, adhering to them, increase the buoyancy of these particles. Next, the resulting mixture is pumped into the separator 17 by a pump 15, in which it is separated into its constituent components: nitrogen, solvent, and solid particles, the nitrogen and solvent being fed into the boolite storage tank 9 for reuse in the cleaning cycle, and the solid particles into the storage tank of mechanical impurities 19 , and the water obtained as a result of purification to the wastewater line 21. It should be noted that part of the smallest solid particles, together with solvents and nitrogen, enter the boulite storage tank 9, where it settles. Bulit drive 9 is cleaned as necessary.

 The application of the invention will allow to utilize the oil sludge accumulated in the oil fields and in commodity parks without harming the environment, and free up the production areas used for storing sludge. In addition, the remaining mechanical impurities in which the percentage of hydrocarbons does not exceed 6% are used for paving.

Claims (1)

 A method of processing oil sludge, including changing its state of aggregation from viscoplastic to liquid by heating and subsequent separation into components, characterized in that when heating the oil, the solvent is additionally introduced into the oil sludge to contain no more than 35 wt. with continuous barbation with hot nitrogen.