Preparation method of high-molecular-weight block polyether, silyl ether mixed defoaming agent and preparation method thereof

Abstract

The invention provides a silyl ether mixed defoaming agent. The silyl ether mixed defoaming agent comprises the following components in parts by weight: 24-40 parts of high molecular weight block polyether; 20-30 parts of polymer polyether modified polysiloxane; 10-30 parts of fatty alcohol; and 15-35 parts by weight of a cosolvent; wherein the high-molecular-weight block polyether is obtained bypolymerizing polyol and alkylene oxide; wherein the high-molecular silyl ether modified polysiloxane is prepared from high-molecular-weight block polyether modified polysiloxane. Compared with the prior art, the polyether chain segment with hydrophilicity is grafted to the polysiloxane chain segment with hydrophobicity, so that the formed silyl-ether copolymer has the advantages of two defoaming agents, namely silicon and ether; the high molecular polyether modified polysiloxane and the high molecular weight block polyether are compounded for use, so that the good defoaming effect of the highmolecular polyether modified polysiloxane and the good foam inhibition effect of the high molecular weight block polyether have a synergistic effect, the reduction of the foam amount is effectively ensured, and meanwhile, the fatty alcohol with high surface activity is matched, so that the improvement of the defoaming efficiency is promoted.

Description

technical field [0001] The invention belongs to the technical field of defoamers, and in particular relates to a preparation method of high molecular weight block polyether, a silicon ether mixed type defoamer and a preparation method thereof. Background technique [0002] Delayed coking is an oil refinery that thermally destroys heavy residual oil to produce light oil. Due to its low quality requirements for raw materials, low processing costs, and low investment, it has developed rapidly in my country. In the delayed coking unit, the oil and gas produced by the cracking of raw materials and the natural surfactant contained in the raw materials tend to generate foam layers in the coking tower, which reduces the processing capacity of the coking tower and reduces the utilization rate of equipment. [0003] In view of the harm of foam in delayed coking production, the method of injecting defoamer at the top of the tower is generally used to deal with it. The first-generation...

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Problems solved by technology

[0004] The defoamers currently used in delayed coking units mainly include silicone defoamers and non-silicon defoamers. Silicone defoamers have a high silicon content, which will affect the activity and service life of catalysts in downstream hydrogenation units , non-silicon-based defoamers are difficult to replace silicone-based defoamers in a short period of time due to their shortcomings such as poor high-temperature stability, poor defoaming ability, and high production costs

[0005] At present, the silicon content in the defoamer is generally positively correlated with the performance. When the silicon content is reduced, the defoaming effect is significantly reduced, the coke tower has a short coke generation time, and the switching time is short, resulting in waste of energy and personnel.

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