阅读说明：本技术 一种烧用高硫煤的催化脱硫治理方法 (Catalytic desulfurization treatment method for high-sulfur coal for combustion ) 是由 邱威胜 于 2021-08-19 设计创作，主要内容包括：本发明提供了一种烧用高硫煤的催化脱硫治理方法,依次包含高温燃中脱硫工序,中高温烟气脱硫工序和低温石灰石湿法脱硫工序。本发明通过一种综合治理的方式,在不影响出口超低排放值35 mg/m～(3)以下的情况下,可放宽对煤炭的使用标准,最高可以使用5%含硫煤。(The invention provides a catalytic desulfurization treatment method of high-sulfur coal for combustion, which sequentially comprises a high-temperature combustion middle desulfurization process, a middle-high temperature flue gas desulfurization process and a low-temperature limestone wet desulfurization process. The invention adopts a comprehensive treatment mode without influencing the ultralow discharge value of 35mg/m at the outlet 3 In the following cases, the standard of use of coal can be relaxed, and sulfur-containing coal can be used up to 5%.)

1. The catalytic desulfurization treatment method of high-sulfur coal for combustion is characterized by sequentially comprising a high-temperature combustion middle desulfurization process, a medium-high temperature flue gas desulfurization process and a low-temperature limestone wet desulfurization process.

2. The catalytic desulfurization treatment method for high-sulfur coal for combustion as set forth in claim 1, wherein the desulfurization step during high-temperature combustion comprises the following operations: spraying the high-temperature in-combustion desulfurization catalyst diluted by catalytic water on the surface of coal by a spraying device before the coal enters a coal mill.

3. The catalytic desulfurization treatment method for high-sulfur coal for combustion as claimed in claim 2, wherein the desulfurization catalyst in the high-temperature combustion accounts for 3 to 8 per mill of the total weight of coal carbon, and the composition of the desulfurization catalyst in the high-temperature combustion is as follows: 1% of cerium oxide, 1% of titanium oxide, 3% of ferric oxide, 5% of manganese boride, 5% of sodium oxide, 35% of calcium oxide and 50% of catalytic water.

4. The catalytic desulfurization treatment method for high-sulfur coal for combustion as claimed in claim 2, wherein the mass ratio of the desulfurization catalyst in high-temperature combustion to the catalytic water is 1: 5-10.

5. The catalytic desulfurization treatment method for the high-sulfur coal for combustion as claimed in claim 1, wherein the temperature range applicable to the middle-high temperature flue gas desulfurization process is 120-650 ℃, and the middle-high temperature flue gas desulfurization process comprises the following operations: the medium-high temperature flue gas desulfurizer is atomized in the flue gas.

6. The catalytic desulfurization treatment method of high-sulfur coal for combustion as claimed in claim 5, wherein the composition of the medium-high temperature flue gas desulfurization agent is as follows: 2.5% of cerium oxide, 2.5% of titanium oxide, 5% of manganese, 5% of ferric oxide, 10% of sodium carbonate, 5% of modified calcium sulfate, 5% of modified silicon dioxide and 65% of modified quicklime powder.

7. The catalytic desulfurization treatment method for high-sulfur coal for combustion as claimed in claim 6, wherein the preparation method of the modified silica and the modified quicklime powder comprises the following steps: adding catalytic water into silicon dioxide and quicklime powder with fineness of more than 200 meshes during mixing and grinding in a mixer.

8. The catalytic desulfurization treatment method for high-sulfur coal for burning as claimed in claim 1, wherein in the low-temperature limestone wet desulfurization process, catalytic water is selected to slurry limestone to form absorption slurry, and a low-temperature wet desulfurization catalyst is added into an absorption tower.

9. The catalytic desulfurization treatment method of high-sulfur coal for combustion as claimed in claim 8, wherein the low-temperature wet desulfurization catalyst comprises: 6.5 percent of quartz parent silicide salt, 2.5 percent of nano titanium oxide, 1 percent of nano manganese oxide, 50 percent of adipic acid, 20 percent of sodium diacetate and 20 percent of modified calcium oxide.

10. The catalytic desulfurization treatment method for high-sulfur coal fired according to any one of claims 2, 5 and 8, characterized in that the catalytic water is water treated by an energy-saving device for water cracking of an ultra-energy boiler.

Technical Field

The invention relates to the technical field of coal desulfurization, in particular to a catalytic desulfurization treatment method for high-sulfur coal for combustion.

Background

In order to meet the environmental protection requirements of the existing power plants, steel plants, cement plants and the like, a desulfurization system is modified into the standard of ultralow emission (35 mg/m)³Below) that the sulfur content of coal at the inlet is not more than that of coal at the outlet, and the emission value of sulfur dioxide at the outlet is required to reach 35mg/m³In the following, 90% or more of plants are concerned about not meeting the environmental requirements, and coal with a low sulfur content is selected for burning. In addition, after the equipment is operated for many years, the desulfurization equipment system is old, the system operation efficiency is poor, and the problems of corrosion or faults and the like are caused by related equipment, so that the desulfurization system is urgently needed to apply a novel desulfurization optimization scheme to solve the situation that the efficiency of the desulfurization system is not good in the future.

In addition, because most factories on the market choose to burn the coal with low sulfur content, the price of the low-sulfur coal is high, a large amount of high-sulfur coal is stored in a warehouse and can not be effectively utilized, the amount of the future low-sulfur coal is inevitably and slowly reduced, under the condition that the low-sulfur coal is not enough, a large amount of high-sulfur coal is inevitably used, the high-sulfur coal can cause the increase of the sulfur content at an inlet, because the desulfurization capacity of a normal desulfurization system is fixed, the coal with higher sulfur content is selected for burning, and the environmental protection requirement can not be met. In view of such demands, many technologies for treating high-sulfur coal, such as ultrasonic pretreatment, chemical pretreatment, application of catalyst during combustion, application of synergist after combustion, etc., are developed in the market, and these technologies have high cost and poor application efficiency, and cause serious environmental pollution and a large amount of waste water. Therefore, it is necessary to develop a desulfurization technique for high-sulfur coal, which is easy to operate, low in cost, effective and free from environmental pollution.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the defects of the prior art, the invention aims to provide a desulfurization treatment method which is simple to operate, low in cost and high in desulfurization efficiency aiming at less high-sulfur coal.

The technical scheme of the invention is as follows:

in order to achieve the purpose, the invention provides a catalytic desulfurization treatment method of high-sulfur coal for combustion, which sequentially comprises a high-temperature combustion middle desulfurization process, a middle-high temperature flue gas desulfurization process and a low-temperature limestone wet desulfurization process.

Further, the desulfurization process in the high-temperature combustion includes the following operations: spraying the high-temperature in-combustion desulfurization catalyst diluted by catalytic water on the surface of coal by a spraying device before the coal enters a coal mill.

Specifically, the mass ratio of the desulfurization catalyst to the catalytic water in the high-temperature combustion is 1: 5-10.

The action principle of the desulfurization process in the high-temperature combustion of the invention is as follows: the sulfur and oxygen molecules in coal react in the presence of a desulfurization catalyst in a similar way to the adsorption on the surface of a gas-solid phase. According to the principle of surface adsorption reaction, firstly, after oxygen molecules are adsorbed by the surface of a desulfurization catalyst, double bonds of the oxygen molecules can be broken due to the static electricity and catalysis of positive centers of the desulfurization catalyst and a catalytic water material, and partial sulfur is prevented from reacting with oxygen at high temperature.

Further, the desulfurization catalyst in the high-temperature combustion accounts for 3-8 per mill of the total weight of the coal; further, the composition of the desulfurization catalyst in high-temperature combustion is as follows: 1% of cerium oxide, 1% of titanium oxide, 3% of ferric oxide, 5% of manganese boride, 5% of sodium oxide, 35% of calcium oxide and 50% of catalytic water.

The desulfurization process in the catalytic high-temperature combustion can remove 5-20% of sulfur dioxide gas.

Further, the temperature range applicable to the middle-high temperature flue gas desulfurization process is 120-650 ℃, and the method specifically comprises the following operations: the medium-high temperature flue gas desulfurizer is atomized in the flue gas.

Furthermore, the medium-high temperature flue gas desulfurizer can be used before and after a dust remover; the atomization process can be carried out by an automatic powder injection system; the specific dosage of the medium-high temperature flue gas desulfurizer can be varied from 1 ton to 20 tons per hour according to the design of the sulfur content of coal.

Further, the medium-high temperature flue gas desulfurizer comprises the following components: 2.5% of cerium oxide, 2.5% of titanium oxide, 5% of manganese, 5% of ferric oxide, 10% of sodium carbonate, 5% of modified calcium sulfate, 5% of modified silicon dioxide and 65% of modified quicklime powder.

Further, the preparation method of the modified silicon dioxide and the modified quicklime powder comprises the following steps: silicon dioxide with the fineness of more than 200 meshes and quicklime powder are mixed and ground in a mixer, and catalytic water with a certain proportion is added. The mixed modified silicon dioxide and modified quicklime powder have high catalytic activity equal to that of the quartz silicide, and can generate higher desulfurization activity at the temperature of over 120 ℃.

Under the action of the medium-high temperature flue gas desulfurizer, more than 30-60% of sulfur dioxide gas in the medium-high temperature flue gas can be captured.

Furthermore, in the low-temperature limestone wet desulphurization process, catalytic water is selected to prepare slurry for limestone to form absorption slurry, and a low-temperature wet desulphurization catalyst is added into the absorption tower.

The catalytic water is water treated by the water cracking energy-saving device of the super-energy boiler, and specifically, the catalytic water has the working principle that: the water molecules of the water splitting energy-saving device of the ultra-energy boiler release internal energy under the action of the energy field, the movement speed of the water molecules is increased, and the activity is greatly enhanced; the electrostatic attraction in the water cluster is weakened or relieved instantly under the action of the self-excitation energy field, and the polarization action of the crossed magnetic field inhibits the recombination of the small clusters, so that the water cluster flowing through the energy saver is finally dispersed into a plurality of high-activity small molecule clusters or even single molecules. Due to the structural change in the liquid, the viscosity of the liquid is reduced, the fluidity of the liquid is improved, and the energy consumption is obviously reduced in the vaporization process, namely the recessive endothermic energy of the water vapor is reduced, and the vapor yield is improved. After the boiler water passes through the self-excitation energy field, the activity of the boiler water is greatly enhanced, the dissolving capacity is also obviously improved, and the boiler water can promote calcium and magnesium ions in the water not to generate hard CaCO any more₃And MgCO₃Deposit on the tube wall, but generate soluble Ca (HCO)₃)₂And Mg (HCO)₃)₂In addition, the catalytic water also has certain positive charge ions, can react with sulfur dioxide more quickly when entering the desulfurizing tower, and the absorption efficiency is obviously improved.

Further, the low-temperature wet desulphurization catalyst comprises the following components: 6.5 percent of quartz parent silicification salt, 2.5 percent of nano titanium oxide, 1 percent of nano manganese oxide, 50 percent of adipic acid, 20 percent of sodium diacetate and 20 percent of modified calcium oxide.

Further, the addition amount of the low-temperature wet desulphurization catalyst is 1000 ppm.

The invention has the beneficial effects that:

the invention combines the high-temperature flue gas desulfurization process with the medium-high temperature flue gas desulfurization process and the low-temperature limestone wet desulfurization process, mainly combines the catalytic water catalysis technology and the desulfurization catalyst, and realizes the comprehensive treatment without influencing the ultralow emission value of 35mg/m at the outlet³In the following cases, the standard of use of coal can be relaxed, and sulfur-containing coal can be used up to 5%.

Drawings

FIG. 1 is a schematic diagram of catalytic water catalytic cracking according to the present invention.

Detailed Description

The invention will be illustrated below with reference to specific embodiments. It should be noted that the following examples are illustrative of the present invention, and are not intended to limit the present invention. Other combinations and various modifications within the spirit or scope of the present invention may be made without departing from the spirit or scope of the present invention.

The invention uses a No. 2 unit of 660MW multiplied by 2 of a certain power plant to execute industrial experiments, wherein the catalytic water catalysis equipment is an ultra-energy boiler water cracking energy-saving device produced by the under-peak energy industry limited company.

The original design conditions of the power plant are as follows:

the flue gas desulfurization is designed according to the received checking coal with 1.8 percent of total sulfur, 300T/h of coal is burned per hour, the desulfurization efficiency is not lower than 99.36 percent, and the SO at the flue gas desulfurization inlet is ensured under the condition of 100 percent BMCR (Mass reduction reactor) working condition design coal flue gas quantity of the boiler₂Concentration 5500mg/Nm³(Standard, dry basis, 6% O)₂)，SO₂The removal rate is more than or equal to 99.36 percent. Flue gas desulfurization outlet SO₂The discharge concentration is less than or equal to 35mg/Nm³The smoke dust emission concentration is less than or equal to 5mg/Nm³(Standard, dry, 6% O)₂)。

Operating parameters of the desulfurization system: the main tower runs four slurry circulating pumps and two oxidation fans, and the slurry volume of the main tower is about 2400m³(ii) a The secondary tower runs two slurry circulating pumps and one oxidation fan, and the slurry volume of the secondary tower is about 1500m³. The average load of the operation index boiler is about 440MW to 640MW, and the inlet SO₂The concentration is about 5000-6000 mg/m³And outlet of clean flue gas O₂The content is 3-8%, the temperature of inlet smoke is about 115-120 ℃, the temperature of outlet smoke is 40-60 ℃, the pH value of the slurry is 5.2-5.5, and the density is about 1100-1200 kg/m³Export index of 35mg/m³The following.

Because the desulfurization system equipment operates for years, the inlet SO of the desulfurization system equipment cannot reach the designed value under the full-load operation₂The concentration is 5500mg/m³The requirement of (2) can only reach 88 percent of the original design value.

Relevant test criteria are as follows:

performance evaluation test specification of limestone-gypsum wet flue gas desulfurization device DL/T998-one-step 2016

Method for testing performance of coal-fired flue gas desulfurization equipment (GB/T21508-

Method for measuring particles in fixed pollution source and sampling gaseous pollutants (GB/T16157 one year 1996)

Examples 1-6 below are for boiler load of 600MW with inlet SO₂The concentration is 5600mg/m³And (3) evaluating the experimental conditions left and right:

examples 1 to 3

Spraying a high-temperature in-combustion desulfurization catalyst diluted by 5 times of catalytic water on the surface of coal by a spraying device before the coal enters a coal mill, wherein the high-temperature in-combustion desulfurization catalyst comprises the following components: 1% of cerium oxide, 1% of titanium oxide, 3% of ferric oxide, 5% of manganese boride, 5% of sodium oxide, 35% of calcium oxide and 50% of catalytic water. The adding amount of the desulfurization catalyst in the high-temperature combustion and SO before the flue gas enters the desulfurization tower after the desulfurization catalyst is applied₂The concentrations are given in table 1 below:

table 1:

examples 4 to 6

At the outlet of the boiler, a flue gas pipeline after SCR treatment is provided with a medium-high temperature desulfurization system, a high-temperature flue gas desulfurizer is atomized in the flue gas through an automatic powder injection injector, and the applied high-temperature flue gas desulfurizer is composed ofThe method comprises the following steps: 2.5% of cerium oxide, 2.5% of titanium oxide, 5% of manganese, 5% of ferric oxide, 10% of sodium carbonate, 5% of modified calcium sulfate, 5% of modified silicon dioxide and 65% of modified quicklime powder. The injection amount of the high-temperature flue gas desulfurizer and SO before the flue gas enters the desulfurizing tower after the high-temperature flue gas desulfurizer is applied₂The concentrations are given in table 2 below:

table 2:

examples 7 to 10

A catalytic water catalysis system is installed in a process water tank of a 2# unit desulfurization system, limestone is pulped through catalytic water to form absorption slurry, and 1000ppm of low-temperature wet desulfurization catalyst is added into a main tower and a secondary tower respectively, wherein the low-temperature wet desulfurization catalyst comprises the following components: 6.5 percent of quartz parent silicification salt, 2.5 percent of nano titanium oxide, 1 percent of nano manganese oxide, 50 percent of adipic acid, 20 percent of sodium diacetate and 20 percent of modified calcium oxide. Aiming at SO before flue gas enters a desulfurizing tower₂The concentration is 5600-6200 mg/m³Examples 7-10 examine the number of slurry circulation pumps that need to be started at different operating loads before and after application of the aqueous catalytic solution containing the low temperature wet desulfurization catalyst, and the SO at the outlet during high load and full load operation₂And (4) concentration.

Example 7

Operating load: 350 MW-450 MW

Before application: SO before flue gas enters a desulfurizing tower₂The concentration is about 5600mg/m³5-6 pumps are required to be operated;

after application: SO before flue gas enters a desulfurizing tower₂The concentration is about 5600mg/m³3-5 pumps are required to operate.

Example 8

Operating load: 450 MW-550 MW

Before application: SO before flue gas enters a desulfurizing tower₂The concentration is about 5600mg/m³6 pumps are needed to operate;

after application: SO before flue gas enters a desulfurizing tower₂The concentration is about 5600mg/m³4-5 pumps are required.

Example 9

Operating load: 600 MW-650 MW (high load)

Before application: SO before flue gas enters a desulfurizing tower₂The concentration is about 5600mg/m³6 pumps are required to be operated, wherein the pulp supply of a main tower is 100T/h, the pulp supply of a secondary tower is 100T/h, and SO is arranged at an outlet₂Concentration value is higher than 35mg/m on average³；

After application: SO before flue gas enters a desulfurizing tower₂The concentration is about 5600mg/m³5-6 pumps are required to be operated, wherein the pulp supply of the main tower is 70T/h, the pulp supply of the secondary tower is 50T/h, and SO is generated at an outlet₂Concentration values below 15mg/m on average³。

Example 10

Operating load: 660MW (full load)

Before application: SO before flue gas enters a desulfurizing tower₂The concentration is about 6200mg/m³6 pumps are required to be operated, wherein the pulp supply of a main tower is 100T/h, the pulp supply of a secondary tower is 100T/h, and SO is arranged at an outlet₂Concentration value is higher than 35mg/m on average³The risk of serious standard exceeding exists;

after application: SO before flue gas enters a desulfurizing tower₂The concentration is about 6200mg/m³～7100mg/m³6 pumps are required to be operated, wherein the pulp supply of the main tower is 100T/h, the pulp supply of the secondary tower is 80T/h, and SO is arranged at an outlet₂Concentration values averaged 20 mg/m³The following.

Through comprehensive evaluation of a western's-an thermal institute and a power plant of an on-site third-party detection unit, the low-temperature limestone wet desulphurization process is independently applied, SO that the SO at the inlet can be increased₂The concentration is about 1700mg/m³～2200mg/m³Safe operation and improved inlet SO₂The concentration is about 1500mg/m³And the sulfur content of the inlet coal can be increased by about 0.6 percent.

The results of the industrial tests show that the high-sulfur coal desulfurization optimization technical scheme of the invention does not influence the ultralow emission value of 35mg/m at the outlet³In the following cases, the standard of use of coal can be relaxed, and sulfur-containing coal can be used up to 5%.