Research progress of petrochemical sludge treatment technology
Abstract: the petrochemical industry is a highly polluting industry. After refining the crude oil through chemical technology, it will discharge the emulsified sludge with high water content from the sewage treatment system and the building objects. This sludge is difficult to settle naturally. If it is not treated, it will cause severe environmental pollution after the direct discharge, and on the other hand it will be polluted. The oil substance contained in the mud has caused waste.
Key words: progress and analysis of petrochemical sludge treatment technology
First, the production of sludge in the processing of crude oil
In the process of crude oil processing, in addition to producing oil products, it also produces large amounts of chemicals and crude oil residues, collectively known as sludge. According to the general process of crude oil processing, crude oil can produce a certain amount of sediment, oil separation and sediment, a certain amount of dregs and biological silt, such as sand washing liquid treatment car and washing fluid treatment vehicle, and some filter decoration as well as some kinds of catalysis. Compared with the sediment and scum, the oily sludge produced in the oil separation tank of the refinery and chemical sewage treatment field, which is our common sediment, is large in quantity, high in water content and difficult to dehydrate, which is the main object of sludge treatment in the petrochemical industry.
In addition, the dross from flotation cell is also one of the main petroleum processing wastes. It is mainly composed of suspended particles and emulsified oil, which is produced by using flocculants in the refining process. The emulsified oil in such sewage is very high and is difficult to clean by conventional methods. Petroleum itself is an organic matter. After extraction, a certain amount of biological residues will be generated. These residues mainly exist in the form of sludge and scum. It is highly smelly in the sink tank, and has high moisture content and is hard to dehydrate.

Two. Progress in the technology of sludge treatment in petrochemical industry
According to the use of processing equipment and treatment methods, as well as the different processing objects, the more popular methods of treatment of petrochemical sludge at home and abroad are coking, extraction and incineration, as well as the fixation and biological methods.
1. Coking treatment
The coking reaction treatment is a more advanced technology for the treatment of petroleum sludge. Because of the limitation of the material of the treatment equipment, it is still in the laboratory R & D stage at home, and a stable alloy material is urgently needed as the reactor of the equipment. The principle of the coking method is to decompose the crude oil residue in the oil sludge by decomposition device and decompose it into relatively stable petroleum coke and light oil, so as to realize the recycling of resources and the protection of the environment.
2, extraction treatment
Extraction method, mainly using propane three ethylamine, reformer oil and supercritical liquid agent as extraction liquid, using multistage separation extraction technology and advanced supercritical fluid extraction technology to extract oil residue from sludge. The extraction method is widely applied in foreign petrochemical industry. Its operation technology is relatively complex and the cycle is long, but the treatment of sludge is more thorough. It is generally used to extract the sludge of biological residue and the sediment with high content of organic matter. In China, the application of extraction method is still in the further promotion stage.
3. The fixation method
From the point of view of environmental protection, petrochemical researchers use a popular method to treat sludge, namely solidification. Curing methods are popular in foreign countries and are usually used to deal with dangerous chemicals or toxic substances in order to reduce their environmental hazards. The use of curing technology to treat oil sludge can reduce the erosion and influence of harmful ingredients and toxic organic matter to the natural environment to a great extent, and protect the groundwater. Domestic scholars believe that the treatment of oil sludge will not have a negative effect on the soil. The trace crude oil transferred from the self purification of soil can be decomposed by the microorganism in the soil, and the new assimilative formula studied by scholars not only achieves the purpose of curing the oil and sediment, but also makes the incineration of the solidified substance do not affect the combustion efficiency. Rate.
4, incineration treatment
Various types of oil sludge are incinerated in a specially designed combustion boiler using the flammability of the oil itself. This sludge treatment technology has been widely used in most of our refineries, and scholars in western developed countries are also very recognised by the technology of incineration. Although this sludge treatment technology is more practical, but the incineration is large, there is two pollution to the water, air and the environment, the key point is that the recovery of oil residue is not realized, and the waste of resources is caused. In order to overcome the defects of the incineration method, technicians have developed and designed a special density circulating fluidized combustion boiler, which has reduced the cost of incineration to a certain extent, and played a role in protecting the environment.
5, biodecomposition method
The application of biological treatment methods is more popular. It is divided into two main categories. One is to add specific nutrients (N, P, S, etc.) into the oily sludge to promote the microorganism in the sludge to reproduce continuously in the soil, so that the sludge is degraded in stages. The results of practical tests showed that the microbial degradation rate of oil residue in sludge can reach 20%-70%. The two is to add petroleum hydrocarbon degrading bacteria to oily sludge and use the surface active microorganism produced by metabolism to treat the sludge. This method can remove the harmful substances in the oil residue, and can also degrade the harmful substances such as aromatic hydrocarbons in the sludge.
In addition to the above treatment technology, sludge profile control technology, cold defrosting technology and foam flotation technology, hydrolysis technology and electric demulsification technology are well used in domestic and foreign oil fields. In this kind of sludge treatment, the collocation of the sludge and the formation of the sludge and the activity characteristics of the molecules of the sludge are effectively used, and the efficient additives or the physical properties of the sludge are used to freeze the sludge. But these technologies require relatively high additives and technology, and are still in the stage of further research and development and application.