PROCESS AND APPARATUS FOR CONTINUOUS EXTRACTING HYDROCARBONS FROM MEDIUM/LOW-RANK COAL BY INDIRECT HEATING STEPWISE PYROLYSIS

摘要

The present invention relates to a process for continuous extracting hydrocarbons from medium/low-rank coal by indirect heating stepwise pyrolysis. The process comprises the following steps: the medium/low rank-coal after compression molding is fed into a drying preheating section for drying preheating; then is fed into a pyrolysis section for more than three stages gradient temperature-elevating pyrolysis by indirect heating mode, and the hydrocarbon gases produced in each stage are collected continuously and respectively; , the obtained solid product after pyrolysis is successively fed into a stuffy coke section, a coke quenching section and a pull coke section for treatment, the obtained low temperature coke is discharged through a sealed coke discharging section. The present invention also relates to an apparatus for continuous extracting hydrocarbons from medium/low-rank coal by indirect heating stepwise pyrolysis. The process and apparatus provided by the present invention completely solve the problems of polluted gases emissions and high noise pollution at source; stepwise pyrolysis and stepwise discharge according to different temperatures ensure that valuable hydrocarbon compounds in the coal gas are prevented from the secondary cracking ; around 90% sensible heat of the coke is recycled by the coke dry quenching, and energy consumption is reduced by around 80% in comparison with the conventional coke dry quenching process.