Dispersant material for mitigating crude oil fouling of process equipment and method for using same

Abstract

An improved dispersant material for mitigating crude oil fouling comprises a reaction product of a polyamine and a polyisobutylene succinyl anhydride made with a polyisobutylene having a vinylidene double bond content of at least 50%. The reaction product has an active nitrogen atom content of at least about 2% by weight. The reaction product is prepared by thermally reacting the polyisobutylene with maleic anhydride to produce said polyisobutylene succinyl anhydride and thereafter reacting the polyisobutylene succinyl anhydride with a polyamine having 5 to 7 active nitrogen atoms.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] None BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to dispersant materials useful for mitigating and / or inhibiting fouling of equipment used for handling and / or treating liquid hydrocarbons such as crude oil and the like, and particularly to improved antifoulant materials based on a reaction product of a hydrocarbon long chain such as polyisobutylene (PIB), a bridging agent such as maleic anhydride and a substance having a polar group such as a polyamine (PAM). Such products are sometimes referred to generically as PIBSA-PAMs. The invention also relates to methodology useful for mitigating the fouling tendencies of crude oils and the like which includes the addition of an improved fouling mitigating and / or inhibiting dispersant material thereto. Furthermore, the invention relates to improved crude oil compositions wherein fouling tendencies have been mitigated by the presence therein o...

AI Technical Summary

Benefits of technology

[0014] A principal object of the invention is to provide an improved dispersant material for inhibiting and / or mitigating crude oil fouling of process equipment. In particular it is an object of the invention to provide an improved dispersant having a chemical makeup which facilitates the incorporation therein of an increased number of polar sites capable of chelating with undesirable carbonaceous materials contained in crude oils and the like. Furthermore, it is an object of the invention to provide an improved high quality PIBSA-PAM material which is produced from a clean, high quality PIBSA made using a PIB having a significant concentration of vinylidene double bonds. In the sense of the invention, a clean PIBSA is one which is relatively clear, has a light color and contains essentially no char or chlorine.

[0017] In another important aspect, the invention provides a method for mitigating crude oil fouling of chemical process equipment which includes providing a dispersant material comprising a reaction product of a polyamine and a polyisobutylene succinyl anhydride made with a polyisobutylene having a vinylidene double bond content of at least 50%, said reaction product having an active nitrogen atom content of at least about 2% by weight; and dispersing the dispersant material in a crude oil wherein fouling properties are to be mitigated.

Problems solved by technology

However, when crude oils, and particularly those that are deficient in aromatics and / or resins, are subjected to the high temperatures needed for processing, the asphaltenes and other undesirable carbonaceous materials become incompatible with the liquid phase and tend to flocculate and / or precipitate so as to deposit and accumulate on hot metal internal surfaces of processing equipment.

This accumulation of undesirable carbonaceous materials on the internal surfaces of process equipment is often referred to as “fouling.” And fouling often causes serious operational problems such as reduced heat transfer efficiency and increased pressure drop characteristics.

In fact, in some cases fouling is of sufficient magnitude to totally block flow through the equipment.

Moreover, fouling often may be the cause of increased metal corrosion.

Needless to say, the fouling of process equipment such as heat exchangers and / or furnace tubes, for example, is a costly problem in refineries and petrochemical plants and the like, since the fouled equipment must be dismantled, cleaned and reassembled.

Such cleaning operations are not only tedious and costly, but result in a large amount of “downtime” during which the units are not functioning.

Accordingly, the undesirable carbonaceous materials are kept in suspension and not allowed to flocculate out for accumulation on the internal surfaces of the process equipment.

The PIBSA products are generally of low quality with high color and considerable char.

As a consequence of these things, the efficiency of the conventional dispersants for purposes of inhibiting and / or mitigating fouling is limited.

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