Method and device for preparing reagent hydrochloric acid

Abstract

The invention discloses a method and a device for preparing a reagent hydrochloric acid. The method comprises the following steps: chlorine and hydrogen are sent into a graphite synthesis furnace, synthesized hydrogen chloride gas is sent into a hydrogen chloride cooler and is cooled, the cooled hydrogen chloride gas enters an I-stage falling film absorption tower, and is absorbed by dilute hydrochloric acid, from an II-stage falling film absorption tower, in the I-stage falling film absorption tower to form reagent grade hydrochloric acid, the hydrogen chloride gas discharged from the I-stagefalling film absorption tower enters the II-stage falling film absorption tower, and is absorbed by ultrapure water in the II-stage falling film absorption tower to form dilute hydrochloric acid, andthe hydrogen chloride gas discharged from the II-stage falling film absorption tower enters a tail gas absorption tower, and is absorbed by the pure water in the tail gas absorption tower to form dilute hydrochloric acid for cycle use. The method has the advantages of simple production process, low investment, small occupied area, high production efficiency, high utilization rate of raw materials, high product quality, low energy consumption, low production cost, no discharge of wastewater or waste gas, convenience in maintenance and control, simplicity in operation, and realization of continuous and stable large-scale production.

Description

technical field [0001] The invention belongs to the field of chemical production, and in particular relates to a method for preparing reagent hydrochloric acid and a device thereof. Background technique [0002] In the prior art, there are two methods for producing reagent grade hydrochloric acid, including a one-step method and a two-step method. One-step technical solution: synthesize hydrogen chloride gas from chlorine and hydrogen in a synthesis furnace, and perform impurity removal reaction after cooling (using one or more reducing substances to react with impurities in hydrogen chloride gas), and the hydrogen chloride gas after removal of impurities The reagent hydrochloric acid is obtained through the absorption of the three-stage absorption device, and the unabsorbed tail gas is absorbed into dilute hydrochloric acid by the hydraulic jet pump. Its main disadvantages are: the liquid after removal of impurities pollutes the environment and is difficult to handle; the ...

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Problems solved by technology

Its main disadvantages are: the liquid after removal of impurities pollutes the environment and is difficult to handle; the absorption process is long and the product quality is unstable; the utilization rate of hydrogen chloride is low and the amount of dilute acid is large

Its main disadvantages are: complex process, many control points; more devices, large floor area, high investment; low production efficiency, low utilization rate of hydrogen chloride gas, and a part of hydrogen chloride gas cannot be separated. The utilization rate is low; the operation labor intensity is high; the maintenance work is difficult and dangerous; it needs to consume a lot of heat to evaporate hydrochloric acid to produce relatively pure hydrogen chloride gas, which consumes a lot of energy; the evaporated hydrogen chloride gas is easy to cause environmental pollution and absorb It will also produce acidic wastewater, which will cause certain harm to the environment; it does not have the ability of continuous large-scale production

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