Continuous concentration purification method for desulfurization by-product magnesium sulfate solution

A desulfurization by-product, magnesium sulfate technology, applied in the direction of magnesium sulfate, chemical instruments and methods, separation methods, etc., can solve the problems of long time, secondary pollution, high investment and operation costs, etc., to achieve increased oxidation speed and conversion rate, Reduce the cost of desulfurization and realize the effect of resource utilization

Inactive Publication Date: 2014-08-20
EAST CHINA UNIV OF SCI & TECH +1
View PDF2 Cites 14 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The existing process has many advantages and can meet the requirements of environmental protection, but the disadvantages are high investment and operating costs, low value of desulfurization by-products such as calcium sulfate, and even secondary pollution problems
[0006] Therefore, in the conventional magnesium oxide desulfurization process, there are disadvantages such as long time for magnesium sulfite to be oxidized to magnesium sulfate, high power consumption, low concentration of magnesium sulfate solution, and high energy consumption for concentration.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Continuous concentration purification method for desulfurization by-product magnesium sulfate solution

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] Flue gas condition: 170000Nm 3 / h, SO 2 Concentration 1200mg / Nm 3 , temperature 150°C. The concentration of magnesium oxide slurry is 10%, and the volume is 87m 3 .

[0033] The flue gas enters the desulfurization tower (the desulfurization tower is a spray tower), and the absorption liquid is sprayed into the tower from the upper part. Catalyst is added to the absorption liquid, and the flow rate of the absorption liquid is 1500t / h. SO in the flue gas exiting the top of the tower 2 The content is 30mg / Nm 3 , The desulfurization rate is 97.5%. After desulfurization, the flue gas enters the chimney from the top of the tower after being demistered by the demister. After 20h, a solution containing 25% magnesium sulfate was obtained. Take out a part of the absorption liquid, after evaporation, concentration and cooling, magnesium sulfate crystallizes out, and after filtration and drying, magnesium sulfate heptahydrate is obtained, with a content of 99.5%.

[0034]

Embodiment 2

[0036] Flue gas condition: 6500Nm 3 / h, SO 2 Concentration 2286mg / Nm 3 ), the temperature is 140°C. The concentration of magnesium oxide slurry is 10%, the volume is 3.0m 3

[0037] The flue gas enters the desulfurization tower (the desulfurization tower is a spray tower). The absorption liquid is sprayed into the tower from the upper part, and the catalyst is added to the absorption liquid. The flow rate of the absorption liquid is 10t / h. SO in the flue gas exiting the top of the tower 2 The content is 40mg / Nm 3 , the desulfurization rate is 98.2%. After desulfurization, the flue gas enters the chimney from the top of the tower after being demistered by the demister. After 47h, a solution containing 23.6% magnesium sulfate was obtained. Take out a part of the absorption liquid, after evaporation, concentration and cooling, magnesium sulfate crystallizes out, and after filtration and drying, magnesium sulfate heptahydrate is obtained.

[0038]

Embodiment 3

[0040] Flue gas condition: 45000Nm 3 / h, SO 2 Concentration 914mg / Nm 3 , temperature 160°C. The concentration of magnesium oxide slurry is 15%, the volume is 7m 3 .

[0041] The flue gas enters the desulfurization tower (the desulfurization tower is a spray tower), and the absorption liquid is sprayed into the tower from the upper part. Catalyst is added to the absorption liquid, and the flow rate of the absorption liquid is 30t / h. SO in the flue gas exiting the top of the tower 2 The content is 20mg / Nm 3 , the desulfurization rate is 97.8%. After desulfurization, the flue gas enters the chimney from the top of the tower after being demistered by the demister. After 21 hours, a solution containing 22.6% magnesium sulfate was obtained. Take out a part of the absorption liquid, and undergo conventional crystallization separation to obtain magnesium sulfate heptahydrate with a content of 99.4%.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention relates to a resource treatment technology of flue gas pollutants, and aims to provide a continuous concentration purification method for a magnesium oxide desulfurization by-product magnesium sulfate solution. The method is as below: leading out part of magnesium sulfate solution from a desulfurization circulation absorption liquid, adding a filter aid and filtering; returning the filtered solution to a desulfurization tower, vaporizing water in diluted magnesium sulfate solution by using the adiabatic evaporation of high temperature flue gas, so as to concentrate the magnesium sulfate solution; when the concentration of magnesium sulfate reaches above 20-25%, subjecting a part of the magnesium sulfate solution to conventional cooling crystallization or evaporation crystallization; and separating to obtain magnesium sulfate heptahydrate with purity above 99%. The method realizes the resource of sulfur element and reduces the cost of magnesium oxide desulfurization process.

Description

technical field [0001] The invention relates to the technical field of environmental protection, in particular to a continuous concentration and purification method based on an oxidative desulfurization by-product-magnesium sulfate solution. Background technique [0002] my country is a big coal-burning country, and coal accounts for 75% of the total primary energy consumption. The massive consumption of energy has caused serious air pollution, the most prominent of which is SO 2 and NO x Acid rain hazards from emissions, and NO x Ozone layer depletion and photochemical smog. According to the "First National Pollution Source Survey Bulletin" published by the Ministry of Environmental Protection on February 6, 2010, in 2007, my country's sulfur dioxide emissions were 23.20 million tons, smoke and dust 11.6664 million tons, and nitrogen oxides 17.977 million tons. The task is daunting. At present, my country's total sulfur dioxide emissions rank first in the world, and t...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): B01D53/73B01D53/80B01D53/50C01F5/40
Inventor 方云进江建军邹建倪琼汤涛殷志祥黄骅沈达范大鸿沙骁周澄李强郭叶书姚承宗褚红娟朱建华
Owner EAST CHINA UNIV OF SCI & TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products