CN112725045B

CN112725045B - Coal water slurry and preparation method thereof

Info

Publication number: CN112725045B
Application number: CN201911038189.2A
Authority: CN
Inventors: 王芳杰; 崔龙鹏; 王树青; 王大川
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2019-10-29
Filing date: 2019-10-29
Publication date: 2022-11-15
Anticipated expiration: 2039-10-29
Also published as: CN112725045A

Abstract

The invention relates to the field of waste recycling, and discloses coal water slurry and a preparation method thereof. The coal water slurry is prepared from the following raw materials: coal powder, a dispersing agent, BDO organic waste liquid and coal grinding water; the coal powder has an internal water content of 5-8%, a grindability index of 40-80, and an air-drying base ash content of 6-15%. In the preparation process of the coal water slurry, the organic waste liquid generated in the BDO production process is fully utilized, and the BDO organic waste liquid is changed into valuable; the prepared coal water slurry has excellent slurry forming property, can realize higher actual measurement concentration, has proper viscosity and stability, and has excellent fluidity.

Description

Coal water slurry and preparation method thereof

Technical Field

The invention relates to the field of waste recycling, in particular to coal water slurry and a preparation method thereof.

Background

The alkynal method is the mainstream method for producing 1, 4-Butanediol (BDO) by enterprises, and comprises the steps of firstly reacting formaldehyde and acetylene to generate 1, 4-butynediol, and then hydrogenating and saturating the 1, 4-butynediol under high pressure to generate 1, 4-butanediol. Wherein, the reaction of formaldehyde and acetylene needs to use sodium carbonate and sodium hydroxide to adjust the pH, and the 1, 4-butanediol solution with lower concentration obtained by the reaction is subjected to the rectification processes of concentration, desalination, low-boiling-point substance removal, high-boiling-point substance removal and the like to obtain the 1, 4-butanediol with higher purity. In order to avoid the influence on product quality caused by accumulation of impurities in the rectifying tower, part of materials need to be discharged and replaced from all the rectifying towers, the replaced materials are BDO organic waste liquid, the main components are tar and sodium salt, wherein the main components of the tar are 1, 4-butanediol, decenol and nonanediol.

The method for producing 1t BDO by using the alkynal method can generate 0.1t organic waste liquid, and the new environmental protection method requires enterprises to carry out harmless resource treatment on the BDO organic waste liquid. Most enterprises adopt incineration technology, but an incineration system cannot stably operate for a long period due to difficulty in discharging solid salt in the operation process. Some enterprises adopt distillation to recover a part of alcohol substances, but the technology consumes more energy, and a large amount of waste liquor remained after distillation cannot be thoroughly treated.

CN104197340A discloses an incineration treatment device and method for treating BDO and IPA waste liquid and waste gas, the device comprises an incineration boiler, a waste gas and waste liquid supply system, a fuel gas supply system, a combustion-supporting air supply system, a solid salt collecting system, a flue gas discharge system and the like, the method adopts an incineration boiler integrated device to carry out harmless treatment on waste gas and waste liquid generated by a BDO production device and an IPA production device, and a large amount of steam is generated as a byproduct, thereby realizing the recycling of heat energy in BDO organic waste liquid, but not effectively utilizing the chemical energy of the BDO organic waste liquid.

CN104262097A discloses a method for harmlessly treating BDO organic waste liquid, which comprises the steps of treating the BDO organic waste liquid to obtain an alcohol product and sodium nitrate, and fully applying tar with a high heat value.

CN106349018A discloses a method for producing BDO organic waste liquid by innocent treatment, which comprises the step of treating the BDO organic waste liquid to obtain BDO and sodium salt products, but the BDO waste liquid has large composition fluctuation, so that the product quality is not easy to control, and the influence on the continuous operation of the device is large.

Disclosure of Invention

Aiming at the problems of high treatment cost, incapability of effectively utilizing BDO organic waste liquid and the like in the prior art, the invention provides coal water slurry and a preparation method thereof. The coal water slurry is mixed with the BDO organic waste liquid, so that the coal water slurry has excellent slurrying performance and meets the use requirement of a gasification furnace, and the effective resource utilization of the BDO organic waste liquid is realized, so that the BDO organic waste liquid has the characteristic of low treatment cost.

According to a first aspect of the present invention, there is provided a coal water slurry prepared from raw materials comprising: coal powder, a dispersing agent, BDO organic waste liquid and coal grinding water; wherein the coal powder has an internal water content of 5-8%, a grindability index of 40-80, and an air-drying base ash content of 6-15%; based on the total weight of the raw materials, the using amount of the coal dust is 55-62 wt%, the using amount of the dispersing agent is 0.1-0.5 wt%, the using amount of the BDO organic waste liquid is 1-5 wt%, and the using amount of the coal grinding water is 33-43 wt%.

According to a second aspect of the present invention, there is provided a process for preparing a coal-water slurry, the process comprising: and uniformly mixing the coal powder, the dispersing agent, the BDO organic waste liquid and the coal grinding water.

In the preparation process of the coal water slurry, the organic waste liquid generated in the BDO production process is fully utilized, and the BDO organic waste liquid is changed into valuable; the prepared coal water slurry has excellent slurry forming property, can realize higher actual measurement concentration, has proper viscosity and stability, has excellent fluidity and meets the use requirement of the coal water slurry of the gasification furnace.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

According to a first aspect of the present invention, there is provided a coal-water slurry, the coal-water slurry being prepared from raw materials comprising: coal powder, a dispersing agent, BDO organic waste liquid and coal grinding water.

In the invention, the coal powder has the internal water content of 5-8%, the grindability index of 40-80 and the air drying base ash content of 6-15%, so that the slurry forming performance of the coal water slurry can be improved. The coal powder can be single coal meeting the use requirement, and can also be mixed coal obtained by blending more than two kinds of raw material coal.

Preferably, the calorific value of the air drying base cartridge of the pulverized coal is more than or equal to 25MJ/kg, and the flowing temperature of the coal ash is 1200-1350 ℃.

In the invention, the internal water content and the air drying base ash content of the coal are measured according to GB/T212; the grindability index is measured according to GB/T2565; the calorific value of the air drying base cartridge is measured according to GB/T213; the soot flow temperature was measured in accordance with GB/T219.

According to a preferred embodiment, the particle size distribution of the coal fines is: 1-5% of 8-14 mesh particles, 5-10% of 14-40 mesh particles, 20-40% of 40-200 mesh particles, and the balance of 200 mesh particles. The pulverized coal can be obtained by grinding and screening raw material coal.

In the invention, the BDO organic waste liquid refers to organic waste liquid generated in the BDO production process. The BDO organic waste liquid contains various alcohols, sodium salts, water and the like, wherein the alcohols comprise 1, 4-butanediol, butanol, methanol, propanol, propargyl alcohol, butynediol and the like, and the sodium salts comprise Na ₂ CO ₃ . For the present invention, preferably, the water content in the BDO organic waste liquid is from 5 to 20 wt%, more preferably from 10 to 15 wt%; the alcohol content is from 50 to 85% by weight, more preferably from 53 to 66% by weight; the sodium salt content is 10 to 30% by weight, more preferably 13 to 26% by weight. Further preferably, the content of 1, 4-butanediol in the BDO organic waste liquid is 23-28 wt%. In addition to water, alcohol and sodium salts, other major components of organic waste streams include furans and olefins.

In the invention, the alcohol in the BDO organic waste liquid plays a role of dispersing coal powder, the hydroxyl on the alcohol can be adsorbed on coal particles, and aggregation among the coal particles is prevented through the following functions: 1) The hydrophilicity of the coal particles is increased, and the wettability of the coal particles is improved; 2) The electronegativity of the surfaces of the coal particles is enhanced, so that the electrostatic repulsion between the coal particles is increased; 3) The structure of the hydroxyl group generates steric hindrance effect to prevent coal particles from agglomerating with each other. The alcoholic hydroxyl group can form a skeleton structure by bridging among coal particles through hydrogen bonds or covalent bonds, water is wrapped in gaps, so that the viscosity of the coal water slurry is moderately increased, the stability of the coal water slurry is favorably improved, and sodium salt in BDO organic waste liquid can be used as a pH regulator in the pulping process.

In the present invention, the dispersant may be a naphthalene sulfonate formaldehyde condensate and/or sodium lignosulfonate. Preferably, the dispersant is sodium lignosulfonate, so that the coal water slurry is more suitable for use requirements in the gasification furnace.

In the invention, the coal grinding water is a mixture of partial wastewater generated in the coal gasification process and mainly comprises slag water treatment system wastewater, slag basin black water, shift stripper condensate, methanol rectification wastewater and the like.

In the invention, based on the total weight of the raw materials, the using amount of the coal powder is 55-62 wt%, the using amount of the dispersing agent is 0.1-0.5 wt%, the using amount of the BDO organic waste liquid is 1-5 wt%, and the using amount of the coal grinding water is 33-43 wt%.

Preferably, the total weight of the raw materials is taken as a reference, the using amount of the coal dust is 58-62 wt%, the using amount of the dispersing agent is 0.1-0.3 wt%, the using amount of the BDO organic waste liquid is 1-3 wt%, and the using amount of the coal grinding water is 36-40 wt%.

Preferably, the coal water slurry has a concentration of not less than 60 wt% and a viscosity of 780 to 920mPa · s.

According to a second aspect of the present invention, there is provided a method of preparing said coal-water slurry, the method comprising: and uniformly mixing the coal powder, the dispersing agent, the BDO organic waste liquid and the coal grinding water.

According to the method of the present invention, the pulverized coal is obtained by grinding and sieving raw material coal, and the grinding can be performed in a ball mill.

According to a specific embodiment, the method for preparing the coal water slurry comprises the following steps:

(1) Uniformly stirring the coal dust, the dispersing agent and coal grinding water to obtain a mixed solution;

(2) And uniformly stirring the mixed solution and the BDO organic waste liquid to obtain the coal water slurry.

Preferably, in the step (1), the stirring speed is 800-1000rpm, and the stirring time is 8-10 minutes. In the step (2), the stirring speed is 900-1100rpm, and the stirring time is 2-3 minutes. More preferably, the stirring speed of step (2) is greater than the stirring speed of step (1). Considering the operation flow of the gasification unit of the factory, the mixed liquid and the BDO organic waste liquid are respectively stored in the storage tank, the specific embodiment is easy to realize the preparation of the coal water slurry in the actual operation of the factory and is easier to operate.

The present invention will be described in detail below by way of examples.

In the following examples and comparative examples,

sodium lignosulfonate is purchased from XingGuang Baoyi chemical company, yixing city, jiangsu province, and has a brand number of XGC-99-II.

The naphthalenesulfonate formaldehyde condensate was purchased from Shaoxing Shangyu Zhejiang province chemical Co., ltd.

The slurry forming property of the coal water slurry is measured according to GB/T18856, and specifically comprises the measurement of measured concentration, apparent viscosity and stability.

The fluidity of the coal water slurry was measured in accordance with the following two methods. One is visual, divided into four grades, a being continuous flow, B being semi-continuous flow, C being discontinuous flow, D being no flow. Another method is to use t ₅₀ To express the fluidity of the coal water slurry: 100mL of coal water slurry is put into a funnel with the diameter of 90mm, the length of 165mm and the inner diameter of an outlet of 9mm, the outlet of the funnel is received by a measuring cylinder, timing is started from the dropping of the coal water slurry, and the time used when the volume of the coal water slurry in the measuring cylinder is 50mL is recorded as t ₅₀ ，t ₅₀ The smaller the size, the better the fluidity of the coal-water slurry.

The following examples are provided to illustrate the coal slurries of the present invention and the process for their preparation. All parts mentioned refer to parts by weight.

Example 1

(1) Starting materials

The raw material coal is silver second coal, the internal water content is 7.29 percent, the heat productivity of the air drying base cartridge is 27.51MJ/kg, the grindability index HGI =47, the air drying base ash content is 6.35 percent, and the flowing temperature of the coal ash is 1346 ℃;

grading and granularity of coal powder: 8-14 mesh particles account for 2%,14-40 mesh particles account for 8%,40-200 mesh particles account for 30%, and the balance is particles below 200 meshes.

BDO organic waste liquid: water content 14.50 wt%, alcohol content 65.03 wt%, sodium salt content 13.61 wt%; and the content of 1, 4-butanediol in the waste liquid was 23.55% by weight.

(2) Preparation of coal water slurry

60 parts of coal powder, 0.2 part of sodium lignosulfonate and 38.8 parts of coal grinding water are added into a container and stirred at 1000rpm for 8min, then 1 part of BDO organic waste liquid is added and stirred at 1100rpm for 2min, and the coal water slurry is prepared. The properties of the coal water slurry are shown in table 1.

Example 2

Coal water slurry was prepared according to the method of example 1 except that the amounts of the pulverized coal, sodium lignosulfonate, coal grinding water and BDO organic waste liquid were 60 parts, 0.2 part, 37.8 parts and 2 parts, respectively, to prepare coal water slurry. The properties of the coal water slurry are shown in table 1.

Comparative example 1

Coal water slurry was prepared according to the method of example 1 except that BDO organic waste liquid was not used and the amount of the coal-grinding water was increased to 39.8 parts to obtain coal water slurry. The properties of the coal water slurry are shown in table 1.

Example 3

(1) Raw materials

Blending coal by the mass ratio of the inner Mongolia coal to the silver second coal of 1: 3 to obtain mixed coal with the internal water content of 6.10%, the heat productivity of an air-drying base cartridge of 28.42MJ/kg, the grindability index HGI =48, the air-drying base ash content of 6.33% and the flow temperature of coal ash of 1302 ℃.

Coal powder grading particle size: 8-14 mesh particles account for 2%,14-40 mesh particles account for 8%,40-200 mesh particles account for 30%, and the balance is particles below 200 meshes.

BDO organic waste liquid: water content 10.29 wt%, alcohol content 53.22 wt%, sodium salt content 25.95 wt%; and the 1, 4-butanediol content in the waste liquid was 26.74% by weight.

(2) Preparation of coal water slurry

60 parts of coal powder, 0.2 part of sodium lignosulfonate and 38.8 parts of coal grinding water are added into a container and stirred at 800rpm for 10min, then 1 part of BDO organic waste liquid is added and stirred at 900rpm for 3min, and the coal water slurry is prepared. The properties of the coal water slurry are shown in table 1.

Example 4

Coal water slurry was prepared according to the method of example 3, except that the amounts of pulverized coal, sodium lignosulfonate, ground coal, and BDO organic waste liquid were 60 parts, 0.2 parts, 37.8 parts, and 2 parts, respectively, to prepare coal water slurry. The properties of the coal water slurry are shown in table 1.

Comparative example 2

Coal water slurry was prepared according to the method of example 3 except that BDO organic waste liquid was not used and the amount of coal-grinding water was increased to 39.8 parts to prepare coal water slurry. The properties of the coal water slurry are shown in table 1.

Example 5

(1) Starting materials

Blending the inner Mongolia coal and the Yangyi coal according to the mass ratio of 1: 3 to obtain the mixed coal with the internal water content of 5.41 percent, the calorific value of an air-drying base cartridge of 25.64MJ/kg, the grindability index HGI =62, the air-drying base ash content of 14.37 percent and the flowing temperature of coal ash of 1305 ℃.

(2) Preparation of coal water slurry

60 parts of coal powder, 0.2 part of sodium lignosulfonate and 38.8 parts of coal grinding water are added into a container and stirred at 1000rpm for 8min, and then 1 part of BDO organic waste liquid is added and stirred at 1100rpm for 2min to prepare the coal water slurry. The properties of the coal water slurry are shown in table 1.

Example 6

Coal water slurry was prepared according to the method of example 5 except that the amounts of pulverized coal, sodium lignosulfonate, ground coal, and BDO organic waste liquid were 60 parts, 0.2 parts, 37.8 parts, and 2 parts, respectively, to prepare coal water slurry. The properties of the coal water slurry are shown in table 1.

Comparative example 3

Coal water slurry was prepared according to the method of example 5 except that BDO organic waste liquid was not used and the amount of the coal-grinding water was increased to 39.8 parts to obtain coal water slurry. The properties of the coal water slurry are shown in table 1.

Comparative example 4

Coal water slurry was prepared according to the method of example 5 except that the amounts of the pulverized coal, sodium lignosulfonate, coal grinding water and BDO organic waste liquid were 60 parts, 0.2 part, 33.8 parts and 6 parts, respectively, to prepare coal water slurry. The properties of the coal water slurry are shown in table 1.

Example 7

(1) Starting materials

The same as in example 5.

(2) Preparation of coal water slurry

62 parts of coal powder, 0.2 part of sodium lignosulfonate and 32.8 parts of coal grinding water are added into a container and stirred for 8min at 1000rpm, and then 5 parts of BDO organic waste liquid is added and stirred for 2min at 1100rpm continuously to prepare the coal water slurry. The properties of the coal water slurry are shown in table 1.

Example 8

(1) Raw materials

The same as in example 5.

(2) Preparation of coal water slurry

Adding 55 parts of coal powder, 0.1 part of sodium lignosulfonate and 39.9 parts of coal grinding water into a container, stirring for 8min at 1000rpm, adding 5 parts of BDO organic waste liquid, and continuously stirring for 2min at 1100rpm to prepare the coal water slurry. The properties of the coal water slurry are shown in table 1.

Example 9

Coal water slurry was prepared according to the method of example 5 except that sodium lignosulfonate was replaced with a naphthalene sulfonate formaldehyde condensate of equal mass to prepare coal water slurry. The properties of the coal water slurry are shown in table 1.

Comparative example 5

Coal water slurry was prepared according to the method of example 5, except that the coal powder used was a mixed coal obtained by blending a ovine first coal and a silver second coal in a mass ratio of 3: 1, the mixed coal had an internal water content of 10.03%, an air-drying base cartridge calorific value of 23.78MJ/kg, a grindability index HGI =65, an air-drying base ash content of 21.35%, and a coal ash flow temperature of 1100 ℃.

The properties of the coal water slurry are shown in table 1.

TABLE 1

By combining the data in table 1, comparing examples 1-9 with comparative examples 1-3, it can be seen that the coal water slurry prepared by the method of the present invention can obtain a higher actual measurement viscosity under the condition of the same amount of coal powder, and the coal water slurry has higher fluidity and stability, and can meet the standard requirements of coal water slurry for gasification. In addition, comparing example 5 with comparative example 4, it can be seen that too high a dosage of BDO organic waste liquid can result in too high viscosity of coal water slurry and poor fluidity and stability. Comparing example 5 with comparative example 5, it can be seen that the introduction of the pulverized coal of the present invention into coal-water slurry can improve the fluidity of coal-water slurry.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. The coal water slurry is characterized by being prepared from the following raw materials: coal powder, a dispersing agent, BDO organic waste liquid and coal grinding water; wherein the coal powder has an internal water content of 5-8%, a grindability index of 40-80, and an air-drying base ash content of 6-15%;

based on the total weight of the raw materials, the using amount of the coal dust is 55-62 wt%, the using amount of the dispersing agent is 0.1-0.5 wt%, the using amount of the BDO organic waste liquid is 1-5 wt%, and the using amount of the coal grinding water is 33-43 wt%;

the alcohol content of the BDO organic waste liquid is 50-85 wt%.

2. The coal water slurry according to claim 1, wherein the water content of the BDO organic waste liquid is 5 to 20 weight percent, and the sodium salt content is 10 to 30 weight percent.

3. The coal-water slurry of claim 2, wherein the content of 1, 4-butanediol in the BDO organic waste liquid is 23-28 percent by weight.

4. The coal-water slurry according to claim 1, wherein the coal dust is used in an amount of 58-62 wt%, the dispersant is used in an amount of 0.1-0.3 wt%, the BDO organic waste liquid is used in an amount of 1-3 wt%, and the coal-grinding water is used in an amount of 36-40 wt%, based on the total weight of the raw materials.

5. The coal water slurry according to any one of claims 1 to 4, wherein the dispersant is sodium lignosulfonate.

6. The coal water slurry according to claim 1, wherein the calorific value of the air drying base cartridge of the pulverized coal is more than or equal to 25MJ/kg, and the flow temperature of the coal ash is 1200-1350 ℃.

7. The coal-water slurry according to claim 1 or 6, wherein the particle size distribution of the coal fines is: 1-5% of 8-14 mesh particles, 5-10% of 14-40 mesh particles, 20-40% of 40-200 mesh particles, and the balance particles below 200 mesh.

8. The coal-water slurry according to any one of claims 1 to 4 and 6, having a concentration of not less than 60% by weight and an apparent viscosity of 780 to 920 mPa-s.

9. The coal-water slurry according to claim 5, wherein the concentration of the coal-water slurry is not less than 60% by weight, and the apparent viscosity is 780 to 920 mPa-s.

10. The coal-water slurry according to claim 7, wherein the concentration of the coal-water slurry is not less than 60% by weight, and the apparent viscosity is 780 to 920 mPa-s.

11. A process for the preparation of a coal water slurry according to any one of claims 1 to 10, which process comprises: and uniformly mixing the coal powder, the dispersing agent, the BDO organic waste liquid and the coal grinding water.

12. The method according to claim 11, wherein the method comprises the steps of:

(1) Uniformly stirring the coal powder, the dispersing agent and the coal grinding water to obtain a mixed solution;

13. The method according to claim 12, wherein in the step (1), the stirring speed is 800-1000rpm, and the stirring time is 8-10 minutes; in the step (2), the stirring speed is 900-1100rpm, and the stirring time is 2-3 minutes.