Production process of high-purity ethyl tert-butyl ether

Abstract

The invention provides a production process of high-purity ethyl tert-butyl ether. The production process comprises the following steps: (1) adding ethanol and isobutene into a fixed bed etherification reactor, and carrying out etherification, so as to obtain a crude product; (2) carrying out washing extraction on the crude product, so as to obtain a water phase solution and an oil phase solution; and (3) adding the water phase solution into an ethanol rectifying tower for rectification, returning an ethanol-enriched material obtained from the tower top, as a raw material, to the step (1), replacing washing water with an ethanol-deficient material obtained from the tower bottom, and circularly utilizing the ethanol-deficient material; adsorbing the oil phase solution by virtue of an adsorption tower to remove water and alcohol, adding the oil phase solution into the rectifying tower for rectification, returning the ethanol-enriched material obtained from the tower top, as the raw material, to the step (1), and obtaining high-purity ethyl tert-butyl ether from the tower bottom. The production process has the beneficial effects that the technological process is simple, the operation is flexible, the product purity is high, the utilization rates of ethanol and isobutene are high, after washing extraction, water can be recycled and reused, and the emission load of wastewater is low.

Description

technical field [0001] The invention belongs to the technical field of synthesis of ether compounds, and in particular relates to a production process of high-purity ethyl tert-butyl ether. Background technique [0002] The gasoline components of catalytic cracking (FCC) in my country generally have problems such as low octane number, high olefin and sulfur content. In recent years, environmental protection requirements have become more and more stringent, and the quality of gasoline tends to be unleaded, low aromatics, low vapor pressure, high octane number and high oxygen content. At present, the most common way to increase the octane number of gasoline without increasing the aromatics content is to add methyl tertiary butyl ether (Methyl Tertiary Butyl Ether) to gasoline. The English abbreviation of methyl tertiary butyl ether is MTBE. [0003] MTBE has a high octane number. After adding it, it can effectively increase the octane number of gasoline, increase the oxygen c...

AI Technical Summary

Problems solved by technology

When the catalytic rectification reactor is used, because the chemical balance is constantly broken during the reaction process, the conversion rate of isobutene is relatively higher, and the product purity is also higher. The purity of ETBE can generally reach more than 95%, but catalytic rectification exists in the reactor. Disadvantages such as complex structure and complex catalyst loading

The fixed bed technology has the advantages of simple structure and flexible operation, but limited by the reaction balance, the utilization rate of raw materials is not high, and the concentration of ETBE in the product is not high.

And because the product forms a multivariate azeotropic system, conventional rectification cannot obtain high-purity ETBE

As in the fixed bed process of US4440963, it adds 2-methylpentane to the raw material to break the azeotropy so as to obtain relatively pure ETBE, but the addition of the entrainer increases the load of rectification and reduces the etherification reaction Catalyst utilization in the tank

In addition, the process described in EP755911 is to add methanol as an entrainer after the etherification reaction. Methanol and isobutene are distilled from the top of the fractionation tower, while ethanol is mixed in ETBE and distilled from the bottom of the tower. The ethanol is not well recycled. , while ETBE purity is also affected

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