5 kinds of carbon black production processes

 

Coal tar, ethylene tar, anthracene oil, natural gas, blast furnace gas, etc.

 

 

The production process of carbon black includes furnace method, spray method, lamp smoke method, groove method, drum method, gas mixing method, thermal cracking method, acetylene method and plasma method, among which furnace method, spray method, lamp smoke method and groove method , Drum method, mixed gas method are incomplete combustion method, thermal cracking method, acetylene method and plasma method are thermal cracking method. At present, lamp smoke carbon black is mainly used as paint colorant, drum method and mixed gas method carbon black is mainly used for pigment carbon black for paint and ink, acetylene carbon black is mainly used for dry battery production, and other production processes are in the production of rubber Use carbon black in the application.

 

 

 

The furnace method is in the reaction furnace, the raw material hydrocarbons (liquid hydrocarbons, gaseous hydrocarbons or their mixtures) form a closed turbulent flow system with an appropriate amount of air. Part of the raw material hydrocarbons are combusted with air to generate high temperatures to crack another part of the raw material hydrocarbons to produce carbon black, and then suspended The carbon black in the flue gas is cooled, filtered, collected, and granulated into a finished carbon black method. Among them, the manufacturing method using gaseous hydrocarbons (natural gas or coalbed methane) as the main raw material is called the gas furnace method (the main product is soft carbon black), and liquid hydrocarbons (aromatic heavy oil, including catalytic cracking clarified oil, ethylene tar, coal tar) The manufacturing method in which distillate, etc.) is the main raw material is called the oil furnace method.

 

The oil furnace method has become the main carbon black manufacturing method due to its characteristics such as multiple process adjustment methods, high heat utilization rate, low energy consumption and low cost. Compared with the oil furnace method, the gas furnace method consumes more raw materials and comprehensive energy consumption. After the price increase of natural gas, its main products have been replaced by the oil furnace method products. However, in areas where natural gas is cheap, the production of gas furnace carbon black is still advantageous, and gas furnace carbon black is still used in many rubber products. At present, the annual output of gas furnace carbon black in my country is 30,000 to 40,000 tons.

 

 

The feedstock oil of the spray method is sprayed from the upstream end of the reactor with a mechanical atomizing nozzle. This manufacturing method was developed by the former Soviet Union. Spray carbon black has the characteristics of large particles, extremely high structure, medium filling rubber strength and small permanent deformation. It is especially suitable for rubber sealing products. At present, the annual output of spray carbon black in my country is several thousand tons.

 

 

The trough method is in a naturally ventilated fire room, where natural gas or coalbed methane is incompletely combusted with air through thousands of porcelain burners to form a fish-tailed diffusion flame, which is in contact with the slow reciprocating channel steel through the flame reduction layer.The carbon black produced by cracking is deposited on the surface of the channel steel, and then the carbon black is scraped into the funnel by the scraper on the funnel, and the carbon black is output through the screw conveyor and granulated to make the finished carbon black. Channel carbon black has excellent reinforcement properties, and is especially suitable for NR. It has been widely used in the rubber industry. However, due to the serious environmental pollution caused by the price increase of raw gas and production, its production was basically stopped in the 1970s. However, channel carbon black is the only type of rubber carbon black that can be used in contact with food, and it is currently produced in a factory in Armenia.

 

 

Thermal cracking is a discontinuous carbon black manufacturing method. Each production line is equipped with two reactors lined with refractory materials. During production, natural gas and air are first introduced into a reactor and burned. After the reactor reaches a certain temperature, the introduction of air is stopped, so that the natural gas is thermally cracked to produce carbon black under the condition of isolating air. When the cracking reaction is carried out in this reactor, the other reactor starts to burn. Each reaction furnace is burned and heated after the cracking reaction has been completed and the temperature has dropped to a certain level, thus circulating production. The produced carbon black is cooled together with the flue gas, and then the collected carbon black is granulated.

 

Thermal cracking carbon black is the carbon black variety with the largest particles and the lowest structure. Thermal carbon black filled rubber has low tensile properties, but has high elasticity, low hardness and heat generation, low conductivity, and thermal carbon black has a large filling volume. It is suitable for sleeper pads and other requirements that require high elasticity, Rubber products with low heat generation and good insulation properties. In addition, thermal cracking carbon black has high carbon content and high purity, and can be used in the production of cemented carbide and carbon products.

 

 

The plasma method is a method in which a plasma generator is used to heat a reaction furnace to reach an extremely high temperature to crack the raw material hydrocarbons (gaseous hydrocarbons, liquid hydrocarbons or solid hydrocarbons) to continuously produce carbon black. This method has the following advantages:

 

·No need to heat the reactor with raw materials and fuels, the utilization rate of raw hydrocarbons is high, and oil with low aromatic content can be used, which can alleviate the shortage of fuels and raw materials.

 

·The hydrogen produced by cracking can be used as a chemical raw material or a clean fuel for automobiles.

 

·No harmful waste gas such as carbon monoxide, carbon dioxide, sulfur dioxide, nitrogen monoxide and nitrogen dioxide is produced and discharged, which is conducive to environmental protection.

 

·The pyrolysis reaction produces less tail gas, which can reduce the investment and operating costs of the carbon black collection system.

 

·The reachable temperature of the reactor is high and the range is wide, which is conducive to the diversification of products.

 

However, the atmosphere and product properties of the plasma method to generate carbon black are quite different from the conventional method, and this method is still in the research and development stage. At present, it has developed a nitrogen adsorption specific surface area of ​​52×103～9O×1O3m2·kg-1, a DBP absorption value of 90×10-5～250×10-5m3·kg-1, no pores on the surface, and physical properties of the filling compound Plasma carbon black close to conventional carbon black. The plasma method may become the main method of carbon black production.