LV13465B - Equipment for neitralization of sulphuric acid tar - Google Patents

Abstract

This invention is related to the neutralization of dangerous sulphuric acid tar that is residual product of oil chemical refining. Its objective is to increase the economic efficiency of processing. The equipment offered (fig.1) comprises: a storage for acid tar (tar basin) with an upper layer of water 1; layer 2 of flowing tar that can be used as fuel; pseudo-solid layer of tar 3 in not-flowing condition; layer 4 where the acid tar is mixed with soil (the last two layers can not be used as fuel and their purification is technologically complicated and not economically beneficial); tank 5 for neutralization of acid tar; tank 6 with a neutralizing substance. The walls of tank 5 and its bottom being exposed to acid and alkali can be covered with an epoxy resin to improve acid and alkali resistance. The tank 5 is connected to the tar layers by connecting pipe 8 and valve that is installed in chamber 7. The connecting pipe 8 might be extended by a flexible hose, which allows taking tar from different storage layers. The sections 5 and 6 are located at the pumping facility where the pumps 9 and 10 are installed for supply of neutralizing substance and removal of used neutralizing medium and refined tar 10. The perforated pipes 11 are installed in the lower parts of the mixing sections 5 and 6, by which the compressed air 12 or, if needed, water steam are supplied. Supply of neutralizing medium from tank 6 to tank 5 is carried out through the pipeline valve 14. The neutralization method of sulphuric acid tar comprises forced feed of tar from the tar storage to the neutralizing tank 5, supply of neutralizing medium thereto, as well as mixing of compound until tar is neutralized and refined. The alkali water solution of the neutralizing medium, such as caustic soda, is prepared in a separate tank and transferred into the second section by gravity.

Description

The plant is concerned with the treatment of petroleum waste (sulfuric tar) in the petrochemical industry resulting from the production of various types of petroleum oils and from chemical contamination.

Sulfur tar pitch neutralization plants [1] are known which, when mixed with tar pitch and lime, produce a dry granulated material which is subsequently burned in a special furnace for destruction. In this case, the tar pitch is lost as a fuel.

Equipment [2] consisting of a sulfuric acid tar collector, a mobile metal container for neutralization and for the storage of a neutralizing agent (raw lime) is known. The sulfuric tar pitch is forced from the collector to the mobile tank and neutralized there.

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These known devices have the following shortcomings:

- metal tanks deteriorate rapidly due to acid exposure;

- the collector quickly deteriorates due to acid (the collector costing $ 32000 becomes invalid within 6 months);

- chemical impurities and metals remain tar, which prevents their use as a fuel;

- high economic costs are required.

The proposed solution addresses these shortcomings. This involves creating a receptacle for the neutralization of sulfuric tar as a two-compartment tank and installing it so that its surface is flush with water covering the sulfuric tar, with one of the sections connected by a short pipe to the layer of sulfuric tar, with a bypass valve, the second section having a neutralizing agent, perforated pipes located in the lower part of the tank. In addition, the solution involves the preparation of a neutralizing agent such as an aqueous solution of caustic soda in a single container, which is poured into the second section by self-flow, followed by the addition of a sulfuric tar sludge from the collector.

The proposed apparatus for neutralizing sulfuric tar is shown in Figure 1. It includes a collector (a lake of tar) with a surface water layer 1, a flowable tarry layer 2 that can be used as fuel), a non-pseudosurface layer 3 and a sulfuric tar and soil mixture layer 4 (the last two layers are not interesting as fuel technologically difficult and economically disadvantageous); a tank for the neutralization of sulfuric tar 5 and a tank for the neutralizing agent 6. The walls and bottom of the tank may be covered with epoxy resin for protection against acid and alkali. The section 5 is connected to the tar layer by means of a conduit 8 and a valve mounted in the switching chamber 7. conduit 8 may be extended by attaching to it a flexible hose allowing the tar to be taken from different sectors of the collector. Sections 5 and 6 include a pump house where pumps 9 and 10 are provided for delivering neutralizing agent 9 and for pumping contaminated water to rinse and neutralize medium, as well as the neutralized and purified tar 10. For mixing, the lower part of sections 5 and 6 is provided with perforated conduits 2 for supplying compressed air 12 or steam 13, if necessary, for the passage of neutralizing medium from section 6 to section 5 through a bypass valve 14.

Description of equipment operation

Example 1. In section 6, an aqueous solution of alkali (neutralizer) is prepared, for example caustic soda. Thereafter, valve 14 is opened and the neutralizing solution flows into section 5 for neutralization of sulfuric tar. After administration of a certain amount of neutralizing agent (sulfuric acid tar differs in composition between the different collectors), the short-pipe valve 8 is opened. The sulfuric acid tar enters the section 5 by self-flow and thus immediately enters the neutralizing medium, which ensures uniform neutralization. After the addition of sulfuric tar, the supply of compressed air 12 is switched on to ensure agitation. If additional neutralizing agent is required, pump 9 is switched on. The actual pH is determined and calculated by the laboratory. The results are shown in Table 1.

Table 1

Concentration of solution NaOH,% 46 13th 8.3 5.7 Tar pH of tar neutralization 11th 9.2 8.4 7.8

After the mixture has been neutralized (within 12-24 hours), the water contaminated by pump 10 is sent to the treatment plant.

Example 2. In section 5, 20% pure water is introduced and a demulsifier, such as Poliflok SM01, is turned on pump 10 and the solution circulates in a closed loop for 30 minutes. During the circulation process, not only chemical neutralization of the neutralized tar is carried out, but also chemical impurities and elements are washed away from it. The tar purification level was determined as a result of laboratory studies reported in Table 2.

Table 2

Chem. element P Zn Pb Hg Cu Cr S,% Sulfur tar tar concentration in mg / kg 35.4 9.63 3788 13.9 41.3 5.5 2.5 Washed tarragon concentration in mg / kg 0.17 0.87 7.33 0.97 1.7 0.54 1.1

The neutralized and chemical-free tar tar pump is pumped to a tank truck and directed to the sector for the treatment of waste oil. Despite the slight excess of various chemical elements beyond the MPEs, their presence is not dangerous, as the waste petroleum product is added to the main fuel (heavy fuel oil) in the amount of 10 - 20% of the main fuel. In this way, the purified tar is used as fuel in boiler houses.

Compared to prototypes, the proposed solution is more economical because it offers the following advantages:

there is no need for a specially designed pumping and transporting facility for sulfuric tar, as the supply of sulfuric tar to the neutralization tank is effected by gravity;

- refined tar can be used as fuel.

Claims (4)

1. REMEDIATION OF WASTE DUMPS AND CONTAMINATED AREAS (E.G.ACID SLUDGE POOLS). www.baufeld.de 2. Death Lake, http://whiteworld.ruweb.info/ (prototype). Formula of the Invention 1. An apparatus for neutralizing sulfuric tar, comprising a reservoir containing sulfuric tar, a reservoir for neutralizing it and a neutralizing agent, characterized in that the neutralization tank is formed in a two-compartment and arranged so that its surface is flush with the sulfuric acid, one of the sections is connected via a short pipe to a layer of sulfuric tar, but the sections are interconnected by a pipe valve and the other section contains a neutralizing agent. 2. An arrangement according to claim 1, characterized in that perforated pipes are located in the lower part of the tank. 3. A process for neutralizing the sulfuric tar, which involves forcing the sulfuric tar from the storage tank, the addition of the neutralizing agent therein and mixing the mixture to the neutralization of the sulfuric tar, with the addition of which is poured into the second section of the self-flow path, whereupon the sulfuric acid tar from the reservoir is filled in the same flow path. 4. A process according to claim 3, characterized in that the mixing of the sulfuric tar and the neutralizing solution is effected by supplying compressed air.