The properties of petroleum coke

Petroleum coke is a product obtained by distilling crude oil to separate light and heavy oil, and then thermally cracking the heavy oil. From the appearance, the coke is black lumps of irregular shape and size (or Particles), with metallic luster, coke particles have a porous structure, the main element is carbon, accounting for more than 80wt%, and the rest are hydrogen, oxygen, nitrogen, sulfur and metal elements. Petroleum coke has its unique physical, chemical and mechanical properties. It is the non-volatile carbon of the heating part. The indicators of volatile matter and mineral impurities (sulfur, metal compounds, water, ash, etc.) determine the chemical properties of coke. The Franli factory took advantage of its high calorific value to create suitable products.

Classification of petroleum coke

According to different proceeding ways and properties, we can divide petroleum coke into types, as following:

The form of petroleum coke varies with the process, operating conditions and feed properties. Petroleum coke produced from petroleum coke factories is called green coke, which contains some volatile components of uncarbonized hydrocarbons. Green coke can be used as fuel-grade petroleum coke. If it is used as an anode for aluminum smelting or electrodes for steelmaking need to be calcined at high temperature to complete carbonization and reduce volatile matter to a minimum.

The appearance of the coke produced by most petroleum coke factories is dark brown porous solid irregular block, and this kind of coke is also called sponge coke. The second type of petroleum coke with better quality is called needle coke and sponge coke. It is more suitable for electrodes because of its lower electrical resistance and thermal expansion coefficient. Sometimes another kind of hard petroleum coke is also produced, which is called shot coke. This kind of coke is shaped like a bullet, has a small surface area and is not easy to coke, so it has few uses.

Detailed explanation is displayed one by one.

1. Needle coke: It has obvious true-like structure and fiber texture, and is mainly used as high-power and ultra-high-power graphite electrodes in steelmaking.

2. Sponge coke: high sulfur content, high moisture content, rough surface, high price.

3. Shot coke or spherical coke: the shape is spherical, the diameter is 0.6~30mm, and the moisture content is low because of the smooth surface. It is generally produced from high-sulfur and high-asphaltene residual oil, and can only be used for power generation, cement and other industrial fuels.

4. Powder coke: produced by runoff coking process, its particles (diameter 0.1~0.4mm) have high volatile content and high thermal expansion coefficient, so they cannot be directly used in electrode preparation and carbon industry.

Environmental protection strategy of petroleum coke

(1) The process of low-temperature raw meal separation to the kiln tail smoke chamber is adopted to quickly combine and condense the SO2 gas and cold raw material in the flue gas to prevent crusting.

(2) Optimize the design so that the structure of the decomposition furnace, burner and smoke chamber conforms to the combustion characteristics of petroleum coke.

(3) Pay attention to the characteristics of raw materials and production operations, select raw materials that meet the requirements of K^+ and Na^+ content, and control the fineness of petroleum coke powder and primary air volume.

Petroleum coke as a fuel is not only economically feasible, but also technically feasible. When the price of fuel coal is higher and the price of petroleum coke is low, it is more ideal to use it as the firing fuel. When using petroleum coke as firing fuel, environmental protection can be achieved by adjusting the sulfur content, and the firing and grinding systems can be adjusted and optimized accordingly, which can perfectly apply low-cost petroleum coke to the cement manufacturing industry.