Optimized heat exchange network of low-temperature methanol washing system

Abstract

The invention discloses an optimized heat exchange network of a low-temperature methanol washing system. The heat exchange network comprises an H2S concentration tower and a multi-stage centrifugal pump, wherein the H2S concentration tower is connected with an H2S concentration tower bottom methanol filter through the multi-stage centrifugal pump, the H2S concentration tower bottom methanol filter is connected with a methanol cold energy recovery heat exchanger through a pipeline, the methanol cold energy recovery heat exchanger is connected with a methanol regeneration tower inlet / outlet heat exchanger through a pipeline, the methanol regeneration tower inlet / outlet heat exchanger is connected with a methanol regeneration tower and a circulating water heat exchanger, the circulating water heat exchanger is connected with a methanol storage tank, and the methanol storage tank is connected to the methanol cold energy recovery heat exchanger through the multi-stage centrifugal pump. The heat exchange network has the characteristics of small number of equipped heat exchangers, low operation cost and high energy recovery rate, and is an optimal process scheme obtained after comprehensive design and comparison.

Description

technical field [0001] The invention relates to the technical field of low-temperature methanol washing technology, in particular to an optimized heat exchange network of a low-temperature methanol washing system. Background technique [0002] The low-temperature methanol washing process uses the mechanism that the solubility of solutes in solvents changes with temperature, and separates materials through physical methods. It is usually used to remove inorganic sulfur, CO2 and other acid gases in various types of gas. Since methanol needs to be cooled to -60°C through heat exchange, the design of the heat exchange network in this system, including cooling recovery, is extremely important for system energy saving and prolonging the service life of the device. At present, in the step-by-step cooling process of methanol, after the methanol in the lean methanol tank is raised by the centrifugal pump, it generally needs to pass through the circulating water heat exchanger, the re...

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Problems solved by technology

Due to the high pressure of methanol (8MPa~9MPa), the low pressure of circulating water (0.4MPa~0.5MPa), and the large pressure difference between the inside and outside of the heat exchanger tube bundle, it is required that the heat exchanger has a high resistance to pressure difference, and a small amount of H2S dissolved in methanol Such acid gas corrosion can easily cause the circulating water heat exchanger to leak, and the circulating water will be polluted in both directions, which will affect the process operation of the whole plant and cause the production equipment to stop production

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