Method for replenishing fuel with high-temperature flue gas in upgrading low-rank coal

摘要

A method for replenishing fuel with high-temperature flue gas in upgrading low-rank coal comprises the following steps: 1) high-temperature oxygen-containing flue gas generated from low-rank coal briquette combustion is dedusted before, acting as an oxidant and replenishing heat source, mixing with low calorific value gas generated in upgrading low-rank coal for combustion, wherein low calorific value gas is completely combusted, and the flue gas and low calorific value gas are mixed by heat supplying ratio of 1:4; 2) hot oxygen-poor gas with oxygen content of less than 1% is generated by the combustion; 3) hot oxygen-poor gas, as a heat source, is circulated for upgrading low-rank coal through low-temperature coking. The method can lower production cost and save resources, and is environmental friendly.