CN1644650A - Combined process for dry distillation of coal and production of carbon black by plasma cracking - Google Patents

Abstract

The combined process of coal dry distillation and plasma cracking to produce carbon black according to the invention belongs to the field of coal chemical industry, plasma chemical industry and carbon black production, and is characterized in that coal generates coke and semi-coke through the dry distillation process, and dry distillation containing a large amount of carbon-containing volatile substances The dry distillation gas containing volatile carbon-containing substances directly enters the plasma reactor, and reacts with the plasma to generate carbon black and hydrogen and other products, forming a combined process of coal dry distillation and plasma cracking to produce carbon black. The invention solves the problems of low utilization rate of energy in the existing process and shortage of raw materials for producing carbon black. The combination process has the characteristics of high energy utilization efficiency, short process, saving equipment investment, low production cost, significant economic benefits, and little environmental pollution.

Description

Combination Process of Coal Dry Distillation and Plasma Cracking to Produce Carbon Black

technical field

The invention relates to a combined process for producing carbon black by coal dry distillation and plasma cracking, which relates to a combined process for producing carbon black by coal dry distillation and plasma cracking, and belongs to the fields of coal chemical industry, plasma chemical industry and carbon black production.

technical background

Carbon black and the main products of coal dry distillation (including metallurgical coke, foundry coke, ferroalloy coke, gas and coal tar) are indispensable chemical raw materials in the modern national economy and play an extremely important role in many basic industrial sectors.

Carbon black raw material oil is divided into three categories according to the source: one is clarified oil (DC), which is produced when gasoline is produced by fluid catalytic cracking (FCC) of gas oil; the other is ethylene tar (ET), which is naphtha and gas oil Produced in the process of steam cracking to produce ethylene; the third is coal tar and its fractions (CT), including creosote oil and anthracene oil, etc., which are produced in the process of coal conversion. The carbon black oil in Europe and the United States is mainly DC, especially in the United States, more than 95% is DC. my country is mainly coal tar and ethylene tar.

my country's carbon black consumption in 2003 exceeded 1 million tons, which exceeded the forecast for 2005 and was close to the level of demand in 2010. The demand for carbon black in rubber and other industries is strong, and carbon black is in short supply. my country's apparent consumption of ethylene in 2003 reached more than 6 million tons, and the estimated total ethylene tar produced should be 1.5 to 2 million tons. In fact, 30% to 50% of all ethylene tar can be used for carbon black production, and the rest All used as fuel, the shortage of ethylene tar is a real problem. Last year, my country's coke output was more than 160 million tons, and the available coal tar was estimated to be 3.5 million tons. In fact, a considerable part of the tar was burned with the retort gas before it was cooled and precipitated from the retort gas, which wastes resources and pollutes the environment. , In addition, some coal tar is used to produce naphthalene and other chemical products, and the coal tar actually used to produce carbon black is also in short supply.

Due to the above reasons, carbon black raw material oil has long been a seller's market, and the main cost of carbon black production is raw material oil, which accounts for 70% to 80% of the total cost of carbon black. It can be said that whoever has the raw materials will be invincible in the production of carbon black. On the other hand, the reasonable utilization rate of coal dry distillation gas is seriously insufficient, and a large amount of dry distillation gas is wasted.

The traditional manufacturing process of carbon black includes furnace method, tank method, thermal cracking method, and plasma cracking method. Although the new carbon black production process has good quality and low pollution, it has the problems of higher power consumption and lower thermal efficiency than conventional processes.

In the coal dry distillation process, the dry distillation gas derived from the dry distillation chamber contains CO, H ₂ , CH ₄ , and volatile carbon-containing substances. After cooling and processing, coal gas and coal tar are obtained; in the carbon black production process, the coal tar is first Preheating, and then into the carbon black reaction furnace, the reaction occurs to generate carbon black. In this process, the retort gas is first cooled and then heated, and the energy is repeatedly wasted, and cooling and heating equipment are required at the same time. The volatile carbon-containing substances in the retort gas are prone to secondary reactions during the cooling and heating process to form tar residue and hard carbon, resulting in waste of resources and environmental pollution.

Contents of the invention

The purpose of the combined process of coal dry distillation and plasma cracking to produce carbon black of the present invention is: to solve the shortage of raw materials for carbon black production at present, the low utilization rate of coal dry distillation gas; the problem of low energy utilization efficiency of coal dry distillation process and plasma cracking process for producing carbon black, Also provided is a combined process for producing carbon black by combining coal dry distillation and plasma cracking.

The combined process of coal dry distillation and plasma cracking to produce carbon black in the present invention is characterized in that: coal is dry-distilled to generate coke and semi-coke products, and at the same time, dry distillation gas containing volatile carbon-containing substances is directly entered into the plasma reactor, and generated by the interaction with the plasma Carbon black, hydrogen and other by-products are essentially a process that combines coal dry distillation to produce semi-coke, coke process and plasma cracking process to produce carbon black.

A combined process of coal dry distillation and plasma cracking to produce carbon black, the process includes the following specific steps:

I. Put peat or lignite or bituminous coal or their mixture into the retort system, the coal is heated at 500-900°C in the retort system, and a pyrolysis-based reaction occurs to generate coke, semi-coke and other low-volatile carbon-containing solid substances and Retort gas containing volatile carbonaceous substances;

II. The dry distillation gas containing volatile carbon-containing substances enters the plasma reactor, the dry distillation gas containing volatile carbon-containing substances interacts with the plasma, the temperature of the system rises to 1500 ° C ~ 3000 ° C, the reaction is carried out under normal pressure, and the dry distillation gas Cracked into carbon black and hydrogen-rich gas. Depending on the working gas of the plasma generator used is H ₂ , Ar, O ₂ , N ₂ , H ₂ O, air and other gases, the products include carbon black and hydrogen, and a small amount of CO, N ₂ , CO ₂ , C _n H _m , NH ₃ and other gases;

III. Carbon black and hydrogen-rich gas enter the separation system, and the mixture of carbon black and gas is separated, and the carbon black is collected, granulated and packaged to become a product. The gas mixture can be processed as follows: (1) directly used as fuel gas, reducing gas, and synthesis gas; (2) gas-fired power generation supply plasma system and the entire process system; (3) further separation of H ₂ , C ₂ H ₂ from the mixed gas And other gas as product gas.

The plasma used in the process of producing carbon black by plasma cracking is generated by a gas discharge method.

The present invention can obtain the following advantages and positive effects by implementing the above technical solutions:

1. The heat of coal dry distillation gas is fully utilized, which greatly improves the energy utilization efficiency of the two processes of coal dry distillation and plasma cracking to carbon black. The comprehensive energy consumption is lower than the traditional oil furnace method, contact method, pyrolysis cracking method and plasma cracking carbon black production process; 2. Shorten the two sets of technological processes and save some equipment investment; 3. Open up for the utilization of retort gas 4. Broaden the source of raw materials for carbon black production, greatly reducing the production cost of carbon black, with remarkable economic benefits; 5. The yield of carbon black is high, up to 90%, saving raw materials; 6. Plasma heating Power, plasma generator working gas and other parameters are very simple to adjust, and one or more characteristics of carbon black can be controlled separately to produce carbon black materials suitable for various purposes; 7. Reduce the production process of coal dry distillation and carbon black 8. The by-products hydrogen and acetylene have high economic value.

Detailed ways

Embodiment 1

The mixed coal of gas fat coal, fat coal, coking coal and lean coal is added into the carbonization chamber, and the heat required for coal carbonization is generated by burning in the fire channel, which is introduced from the furnace wall. Fuel for heating the flue is provided by the gas phase by-products of the plasma carbon black production system. The coal material is dried and cracked in the retort chamber to generate semi-coke and coke, and the retort gas containing volatile carbon-containing substances is precipitated. The retort gas is sent into the plasma carbon black reactor, and interacts with the plasma containing highly active particles. The temperature of the system rises to 1800°C, and the retort gas is instantly cracked to generate by-products such as carbon black and hydrogen. The flue gas with carbon black is sprayed with water at the bottom of the reactor to cool down, and the carbon black is collected by a cyclone separator and a bag filter. The collected carbon black is transported, screened, granulated and then packaged. Part of the hydrogen-rich gas separated by the bag filter is supplied to the dry distillation process for heating; part of the power generation is used for the plasma system and the entire process system; part of the hydrogen-rich gas is separated to obtain pure hydrogen, acetylene and other products, and a small amount of hydrogen is used as the working gas of the plasma generator .

Embodiment 2

Lignite and solid heat carrier (hot semi-coke) are mixed in the dry distillation reactor, the coal material is heated rapidly, rapid cracking occurs, and dry distillation and precipitation are completed in the rear section of the dry distillation reactor. The solid heat carrier is sent into the riser to be heated by the co-current flow of hot flue gas, then enters the cyclone separator, the flue gas is discharged, and the semi-coke enters the semi-coke tank. Part of the semi-coke is used as a product; part of the semi-coke is returned to the dry distillation reactor for recycling. The retort gas containing volatile carbon-containing substances is sent to the plasma cracking process system. In the plasma cracking reactor, part of the plasma is formed to form plasma. The average temperature of the reactor rises to 2800°C, and the volatile carbon-containing substances are cracked instantly to form carbon black. And hydrogen-rich by-products, high-temperature soot-containing flue gas is preheated in the heat exchanger to heat the air and hydrogen-rich gas required by the carbonization process, and then the soot-containing flue gas is cooled by quenching water, and the carbon black is captured by the filter bag , the carbon black enters the powdered carbon black storage tank, then wet granulation, product packaging. Part of the hydrogen-rich gas is used for heating in the dry distillation process, and part of the power is used for the plasma system and the entire process system. Or part of the hydrogen-rich gas is separated to obtain pure hydrogen, acetylene and other products.

Claims (2)

1. A combination process of coal dry distillation and plasma cracking to prepare carbon black, characterized in that coal generates coke and semi-coke products through dry distillation, and simultaneously generates dry distillation gas containing volatile carbon-containing substances and directly enters the plasma reactor, and is combined with the plasma The generation of carbon black, hydrogen and other by-products is essentially a process that combines coal dry distillation to produce semi-coke, coke process and plasma cracking process to produce carbon black. The specific process steps are: I. Put peat or lignite or bituminous coal or their mixture into the retort system, the coal is heated at 500-900°C in the retort system, and a pyrolysis-based reaction occurs to generate coke, semi-coke and other low-volatile carbon-containing solid substances and Retort gas containing volatile carbonaceous substances; II. The dry distillation gas containing volatile carbon-containing substances enters the plasma reactor, and the dry distillation gas containing volatile carbon-containing substances interacts with the plasma, and the temperature of the system rises to 1500 ° C ~ 3000 ° C. The reaction is carried out under normal pressure, and the dry distillation gas Cracked into carbon black and hydrogen-rich gas. Depending on the working gas of the plasma generator used is H ₂ , Ar, O ₂ , N ₂ , H ₂ O, air and other gases, the products include carbon black and hydrogen, and a small amount of CO, N ₂ , CO ₂ , C _n H _m , NH ₃ and other gases; III. Carbon black and hydrogen-rich gas enter the separation system, and the mixture of carbon black and gas is separated, and the carbon black is collected, granulated and packaged to become a product. The gas mixture can be processed as follows: (1) directly used as fuel gas, reducing gas, and synthesis gas; (2) gas-fired power generation supply plasma system and the entire process system; (3) further separation of H ₂ , C ₂ H ₂ from the mixed gas And other gas as product gas. 2. The combined process of coal dry distillation and plasma cracking for producing carbon black according to claim 1, characterized in that the plasma used in the process for producing carbon black by plasma cracking is generated by a gas discharge method.