System and method for treating low-rank coal

Abstract

The invention discloses a system and method for processing low-rank coal. The system includes: a fast pyrolysis device with a pyrolysis gas outlet, and a particle dust removal unit is arranged at the pyrolysis gas outlet; a dust collector with a pyrolysis gas outlet. Gas inlet, dust particle outlet and dedusted gas outlet; desulfurization and decarbonization device, with dedusted gas inlet and purified gas outlet; heating device, with purified gas inlet and heated gas outlet; gas-based shaft furnace, gas-based vertical The furnace has a reducing gas inlet, a cooling gas inlet, an oxidized pellet inlet, a furnace top gas outlet, a reduced pellet outlet and a heat exchanged gas outlet, and the reducing gas inlet is connected with the heated gas outlet. The system can effectively use the pyrolysis gas obtained from the pyrolysis of low-rank coal as reducing gas for the gas-based shaft furnace, and at the same time by-produce semi-coke, which significantly improves resource utilization and reduces CO2 emissions, and the process is short and water-intensive. Low consumption and low investment.

Description

technical field [0001] The invention belongs to the technical field of metallurgy and chemical industry, in particular, the invention relates to a system and method for processing low-rank coal. Background technique [0002] The structural characteristics of coal itself determine that low-rank coal has high volatile content and strong activity. Due to high moisture and oxygen content and low calorific value, the direct utilization (combustion or gasification) efficiency is low, and the economic value is far inferior to high-rank coal. Therefore, The low-rank coal developed and utilized on a large scale must be processed and upgraded before it can be used for domestic production. One of the most scientific and commonly used processing methods is pyrolysis, also known as "dry distillation" or "thermal decomposition". Pyrolysis refers to a series of physical changes and chemical reactions that occur when coal is continuously heated to a higher temperature in the absence of air...

AI Technical Summary

Problems solved by technology

Limited by natural gas resources, the gas-based direct reduction metallurgy process is costly and unsuitable for China's national conditions, while the traditional coal-to-gas process suffers from high equipment investment, high cost, high water consumption, large environmental load, immature technology, and investment Disadvantages such as low return rate hinder the development of gas-based direct reduction in China

In addition, in the current pyrolysis reactor, the pyrolysis oil gas stays in the reactor for a long time, and the secondary reaction of oil gas is severe, which affects the quality of pyrolysis oil gas

The pyrolysis reactor uses lump coal as raw material, which is costly

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