Desulfurizer for cement kiln line and its preparation method and application
By using composite desulfurizers with polyacrylamide and other components in cement kiln lines, the shortcomings of dry and ammonia desulfurization technology are solved, efficient and stable SO2 removal is achieved, flue gas fluctuations and wastewater discharge are reduced, and desulfurization is improved. Rate and efficiency.
Patent Information
- Application Number
- CN202411216946.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-02
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2044-09-02
AI Technical Summary
In the flue gas desulfurization technology of the existing cement kiln lines, dry desulfurization leads to increased resistance of the fan, increased power consumption, and reduced thermal efficiency, and cannot stably meet emission standards. Ammonia desulfurization has safety hazards and high operating costs, and the by-product recycling is complex. , resulting in excessive SO2 emissions and smog problems.
Polyacrylamide, sodium humate, methyldiethanolamine, triethanolamine, triethylenetetramine, sodium bicarbonate, and sodium hexametaphosphate are used as desulfurizers, as high-temperature resistant dispersants, adsorbents and catalysts, and directly in dry cement Added to the second-level suspension preheater of the kiln to solid sulfur into cement clinker, improve desulfurization efficiency and reduce fluctuations.
It has achieved efficient desulfurization, reduced SO2 emissions, reduced wastewater emissions, less investment, simple equipment, improved desulfurization rate and efficiency, strong stability, and avoided flue gas drag and haze problems.
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of cement production admixtures, and in particular to a desulfurizer for a cement kiln line and a preparation method and application thereof. Background Art
[0002] Environmental protection requirements for industrial pollution emissions are becoming increasingly stringent, and the requirements for SO2 removal technology for cement and other enterprises are also gradually increasing. The treatment of harmful components SO2 in high-temperature flue gas is mainly concentrated on flue gas desulfurization. Flue gas desulfurization technologies mainly include wet, semi-dry and dry methods: wet flue gas desulfurization technology uses liquid absorbents such as water or alkaline solutions (or desulfurization liquids) to remove SO2, dry / semi-dry flue gas desulfurization technology uses powdered or granular absorbents, adsorbents or catalysts to remove SO2, and the circulation and discharge are dry. The wet limestone-gypsum desulfurization process is the most widely used process in industrial production at home and abroad. At present, the flue gas desulfurization technologies used in the cement industry include wet, dry and semi-dry methods. The wet desulfurization technology is mainly introduced by the coal-fired power industry, while the dry desulfurization technology mainly uses the characteristics of cement production technology to reduce SO2 emissions.
[0003] Among the existing desulfurization technologies, calcium-based desulfurization technology and ammonia desulfurization technology are widely used. Calcium-based dry desulfurization makes full use of the characteristics of the new dry cement process. The system process and operation and maintenance are simple, and the investment and operation costs are low. However, dry desulfurization leads to increased fan resistance, increased power consumption, and reduced thermal efficiency. Its desulfurization rate is slow and the efficiency is low. It cannot stably meet the existing emission standards and is only suitable for cement production lines with low SO2 emissions. The ammonia desulfurization technology has strong adaptability to flue gas fluctuations, fast desulfurization rate, high and stable efficiency (>98%), and by-products can be used as fertilizers. There are no processes such as powder making and pulping, and there are no wastewater and waste residue treatment processes. The process flow is short, the equipment is small, and the maintenance and overhaul volume is small. However, ammonia water has high biological toxicity and is easy to volatilize. There are safety hazards in transportation and use, resulting in excessive ammonia emissions, serious equipment corrosion, and high operating costs. In addition, the recovery process of the desulfurization product (NH4)2SO4 is complicated. When the recovery is incomplete, the flue gas is seriously dragged white, and the escaped (NH4)2SO4 aerogel is more likely to cause haze. Summary of the invention
[0004] In order to solve the problems existing in the prior art, the present invention provides a desulfurizer for a cement kiln line, which adopts polyacrylamide, sodium humate, methyldiethanolamine, triethanolamine, triethylenetetramine, sodium bicarbonate and sodium hexametaphosphate as effective ingredients, which are directly added in the secondary suspension preheater of a dry cement kiln to fix sulfur in cement clinker. The desulfurizer has the characteristics of high desulfurization efficiency, small fluctuation of flue gas, mature on-site process, low investment, no wastewater discharge, etc.
[0005] Specifically, the desulfurizer for cement kiln line of the present invention is composed of the following raw materials in parts by weight: 5-8 parts of polyacrylamide, 5-8 parts of sodium humate, 10-12 parts of methyldiethanolamine, 3-5 parts of triethanolamine, 2-3 parts of triethylenetetramine, 5-8 parts of sodium bicarbonate, and 3-5 parts of sodium hexametaphosphate.
[0006] The raw materials of the desulfurizer of the present invention can be divided into a high temperature resistant dispersant, an adsorbent and a catalyst according to the mechanism of action. Among them, polyacrylamide and sodium humate are used together as a high temperature resistant dispersant, which can enhance the full mixing of the components of the desulfurizer with the cement raw material, and the adsorbent and the catalyst are wrapped on the surface of the cement raw material particles, so that the desulfurization effect can be better exerted at high temperature; methyldiethanolamine, triethanolamine, triethylenetetramine and sodium bicarbonate are used together as adsorbents, which can react with sulfur dioxide generated in the raw material, and form sulfate after being adsorbed on the surface of the raw material particles and fixed. The research of the present invention shows that the adsorbent compounded by the above four components has a synergistic effect, can efficiently adsorb sulfur dioxide gas, realize the fixation of sulfur dioxide, and the adsorbent can also promote the absorption of sulfur dioxide by carbonate or metal oxide in the raw material particles; sodium hexametaphosphate is mainly used as a catalyst, which can form polyphosphate at high temperature, and the polyphosphate ionic liquid at high temperature can absorb sulfur dioxide and calcium ions, and is also beneficial to the decomposition of calcium carbonate in the raw material sintering process, promotes the high temperature melting effect of the solid phase reaction process, and reduces the re-decomposition rate of sulfur-containing minerals.
[0007] Preferably, the desulfurizer for cement kiln line of the present invention is composed of the following raw materials in parts by weight: 6 parts of polyacrylamide, 7 parts of sodium humate, 10 parts of methyldiethanolamine, 4 parts of triethanolamine, 3 parts of triethylenetetramine, 7 parts of sodium bicarbonate, and 3 parts of sodium hexametaphosphate.
[0008] Preferably, the desulfurizer for cement kiln line of the present invention is composed of the following raw materials in parts by weight: 8 parts of polyacrylamide, 6 parts of sodium humate, 11 parts of methyldiethanolamine, 3 parts of triethanolamine, 3 parts of triethylenetetramine, 8 parts of sodium bicarbonate, and 4 parts of sodium hexametaphosphate.
[0009] Preferably, the desulfurizer for cement kiln line of the present invention is composed of the following raw materials in parts by weight: 5 parts of polyacrylamide, 8 parts of sodium humate, 12 parts of methyldiethanolamine, 3 parts of triethanolamine, 2 parts of triethylenetetramine, 6 parts of sodium bicarbonate, and 5 parts of sodium hexametaphosphate.
[0010] Preferably, the purity of all raw materials in the present invention is industrial purity or chemical purity.
[0011] The present invention also relates to a method for preparing the above-mentioned desulfurizer for cement kiln line, which specifically comprises the following steps:
[0012] 1) Weigh each raw material by weight,
[0013] 2) Mix all the raw materials evenly and package.
[0014] The present invention also relates to the application of the above-mentioned desulfurizing agent for cement kiln line in dry cement kiln desulfurization.
[0015] Preferably, the dry process cement kiln uses a suspension preheater to preheat the raw material.
[0016] Preferably, the desulfurizing agent of the present invention is added at the cyclone of the secondary suspension preheater.
[0017] Preferably, the amount of desulfurizer added is 0.03-0.3% of the raw meal mass, which can be adjusted according to the sulfur content of the raw meal and the residual sulfur requirements of the flue gas.
[0018] Preferably, the desulfurizing agent of the present invention is used in an environment temperature of 300-600°C.
[0019] The desulfurizer of the present invention is in liquid form and is a composite desulfurizer composed of three parts: a high temperature resistant dispersant, an adsorbent and a catalyst. It is added at the cyclone of the secondary preheater and has a good desulfurization effect. The desulfurizer of the present invention is added to the cyclone through an atomizing nozzle, and then adsorbed onto the raw material in the form of small droplets (liquid beads), and moves with the raw material in the cyclone. The desulfurizer and the raw material react fully, and the sulfide escapes to become SO2 at 300-600°C and is captured, and participates in the solid phase reaction together with the raw material, and generates sulfoaluminate minerals with higher thermal stability under the action of the catalyst. This process can not only make sulfur dioxide from the escaping gas state to be fixed and converted into mature material with the raw material, but also promote the high temperature melting effect of the solid phase reaction process under the action of a trace catalyst, so as to induce the formation of solid solution and reduce the decomposition rate of sulfur-containing minerals. Ultimately, the sulfur cycle in the kiln is broken, allowing the solid sulfur clinker to be discharged from the kiln system. Under the synergistic effect of multiple desulfurizers, the desulfurization rate and efficiency are greatly improved, which does not affect the normal operation of the cement kiln and can also improve the quality of clinker burning. DETAILED DESCRIPTION
[0020] In order to prove the technical effect of the present invention, a desulfurizer was prepared and used in a 5000t / d cement production line. The raw material feed rate was 460t / h, the clinker standard coal consumption was 98kg / t, and it was added at C2 of the secondary suspension preheater. The addition amount was 0.08% of the raw material mass. The desulfurization effect was measured. Without using the desulfurizer, the SO2 emission of the production line was 230mg / Nm 3 .
[0021] Example 1
[0022] The desulfurizer is composed of the following raw materials in parts by weight: 6 parts of polyacrylamide, 7 parts of sodium humate, 10 parts of methyldiethanolamine, 4 parts of triethanolamine, 3 parts of triethylenetetramine, 7 parts of sodium bicarbonate and 3 parts of sodium hexametaphosphate.
[0023] After testing, the outlet temperature of the decomposition furnace is 890℃, the outlet temperature of C1 is 225℃, and the SO2 emission is 39.3mg / Nm 3 .
[0024] Example 2
[0025] The desulfurizer is composed of the following raw materials in parts by weight: 8 parts of polyacrylamide, 6 parts of sodium humate, 11 parts of methyldiethanolamine, 3 parts of triethanolamine, 3 parts of triethylenetetramine, 8 parts of sodium bicarbonate and 4 parts of sodium hexametaphosphate.
[0026] After testing, the outlet temperature of the decomposition furnace is 889℃, the outlet temperature of C1 is 223℃, and the SO2 emission is 32.5mg / Nm 3 .
[0027] Example 3
[0028] The desulfurizer is composed of the following raw materials in parts by weight: 5 parts of polyacrylamide, 8 parts of sodium humate, 12 parts of methyldiethanolamine, 3 parts of triethanolamine, 2 parts of triethylenetetramine, 6 parts of sodium bicarbonate and 5 parts of sodium hexametaphosphate.
[0029] After testing, the outlet temperature of the decomposition furnace is 891℃, the outlet temperature of C1 is 226℃, and the SO2 emission is 37.5mg / Nm 3 .
[0030] Comparative Example 1
[0031] The desulfurizer is composed of the following raw materials in parts by weight: 14 parts of polyacrylamide, 11 parts of methyldiethanolamine, 3 parts of triethanolamine, 3 parts of triethylenetetramine, 8 parts of sodium bicarbonate and 4 parts of sodium hexametaphosphate.
[0032] After testing, the outlet temperature of the decomposition furnace is 890℃, the outlet temperature of C1 is 225℃, and the SO2 emission is 86.2mg / Nm 3 .
[0033] Comparative Example 2
[0034] The desulfurizer is composed of the following raw materials in parts by weight: 8 parts of polyacrylamide, 6 parts of sodium humate, 8 parts of triethanolamine, 9 parts of triethylenetetramine, 8 parts of sodium bicarbonate and 4 parts of sodium hexametaphosphate.
[0035] After testing, the outlet temperature of the decomposition furnace is 891℃, the outlet temperature of C1 is 226℃, and the SO2 emission is 138.5mg / Nm 3 .
[0036] Comparative Example 3
[0037] The desulfurizer is composed of the following raw materials in parts by weight: 8 parts of polyacrylamide, 6 parts of sodium humate, 11 parts of methyldiethanolamine, 3 parts of triethanolamine, 8 parts of sodium bicarbonate and 4 parts of sodium hexametaphosphate.
[0038] After testing, the outlet temperature of the decomposition furnace is 890℃, the outlet temperature of C1 is 224℃, and the SO2 emission is 141.0mg / Nm 3 .
[0039] Comparative Example 4
[0040] The desulfurizer is composed of the following raw materials in parts by weight: 8 parts of polyacrylamide, 6 parts of sodium humate, 11 parts of methyldiethanolamine, 14 parts of triethanolamine, and 4 parts of sodium hexametaphosphate.
[0041] After testing, the outlet temperature of the decomposition furnace is 888℃, the outlet temperature of C1 is 225℃, and the SO2 emission is 157.6mg / Nm 3 .
[0042] Comparative Example 5
[0043] The desulfurizer is composed of the following raw materials in parts by weight: 8 parts of polyacrylamide, 6 parts of sodium humate, 11 parts of methyldiethanolamine, 3 parts of triethanolamine, 3 parts of triethylenetetramine, and 8 parts of sodium bicarbonate.
[0044] After testing, the outlet temperature of the decomposition furnace is 891℃, the outlet temperature of C1 is 225℃, and the SO2 emission is 142.7mg / Nm 3 .
[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A desulfurizer for cement kiln line, characterized in that: The invention is composed of the following raw materials in parts by weight: 5-8 parts of polyacrylamide, 5-8 parts of sodium humate, 10-12 parts of methyldiethanolamine, 3-5 parts of triethanolamine, 2-3 parts of triethylenetetramine, 5-8 parts of sodium bicarbonate and 3-5 parts of sodium hexametaphosphate. The desulfurizer is added at the cyclone of the secondary suspension preheater.
2. The desulfurizer for cement kiln line according to claim 1, characterized in that: The invention is composed of the following raw materials in parts by weight: 6 parts of polyacrylamide, 7 parts of sodium humate, 10 parts of methyldiethanolamine, 4 parts of triethanolamine, 3 parts of triethylenetetramine, 7 parts of sodium bicarbonate and 3 parts of sodium hexametaphosphate.
3. The desulfurizer for cement kiln line according to claim 1, characterized in that: The invention is composed of the following raw materials in parts by weight: 8 parts of polyacrylamide, 6 parts of sodium humate, 11 parts of methyldiethanolamine, 3 parts of triethanolamine, 3 parts of triethylenetetramine, 8 parts of sodium bicarbonate and 4 parts of sodium hexametaphosphate.
4. The desulfurizer for cement kiln line according to claim 1, characterized in that: The invention is composed of the following raw materials in parts by weight: 5 parts of polyacrylamide, 8 parts of sodium humate, 12 parts of methyldiethanolamine, 3 parts of triethanolamine, 2 parts of triethylenetetramine, 6 parts of sodium bicarbonate and 5 parts of sodium hexametaphosphate.
5. The desulfurizer for cement kiln line according to claim 1, characterized in that: The purity of raw materials is industrial pure or chemical pure.
6. The method for preparing a desulfurizer for a cement kiln line according to any one of claims 1 to 5, characterized in that: The steps include: 1) Weigh each raw material by weight, 2) Mix all the raw materials evenly and package.
7. Use of the desulfurizer for cement kiln line according to any one of claims 1 to 5 in dry cement kiln desulfurization.
8. The use according to claim 7, characterized in that: The dry process cement kiln adopts a suspension preheater to preheat the raw material.
9. The use according to claim 8, characterized in that: The desulfurizer is added at the cyclone of the secondary suspension preheater.
10. The use according to any one of claims 7 to 9, characterized in that: The operating environment temperature of the desulfurizer is 300-600℃.