Abstract:

The rapid pyrolysis of 3 different ranks of coals, including lignite from Inner Mongolia, bituminous from Shenfu coalfield，and anthracite from Guizhou, has been carried out in a high-frequency furnace which could sharply reduce the secondary reactions.The pyrolysis temperatures were ranged from 600℃ to 1200℃ with an interval of 100℃.The effects of coal rank and temperature on the yields of char, char-C， and pyrolysis gas, as well as the percentages of H₂, CO, CH₄，and CO₂ in the pyrolysis gas produced from the primary stage of pyrolysis were investigated.Results show that both of the yields of char and char-C increase, while the yield of pyrolysis gas decreases as the coal rank increases.The yields of char and char-C decrease, and the yield of pyrolysis gas increases with the increasing temperature.The char-C yield of lignite can reach a level lower than 50% at the temperature of 1200℃.H₂ and CO are the main components of the pyrolysis gas, while the contents of CH₄ and CO₂ are much lower.As the temperature increases, the contents of H₂ and CO increase, and the contents of CH₄ and CO₂ decrease.The contents of H₂+CO in pyrolysis gas increase with the increasing temperature.The H₂+CO contents from 3 coals are all higher than 90% at the temperature of 1200℃.The H₂/CO ratio of pyrolysis gas also increases as the temperature increases.Both the H₂+CO contents and H₂/CO ratio in pyrolysis gas from 3 coals are in the order of anthracite>lignite>bituminous.The low heating values of pyrolysis gas from all the 3 coals are higher than 11 MJ·m^-3.As the pyrolysis temperature increases, the low heating values of pyrolysis gas of bituminous and anthracite decrease, while the heating values of pyrolysis gas of lignite have a peak value at the temperature about 1000℃.

Key words: 煤, 快速热解, 焦, 热解气, 热值

摘要：

利用能有效避免二次转化反应的高频炉热解装置对3种不同变质程度的煤进行了600～1200℃条件下的快速热解，考察了在煤热解最初阶段焦产率、焦-C产率、热解气产率、热解气4种主要组分H₂、CO、CH₄和CO₂的比例以及热解气热值随煤阶和热解温度的变化规律。结果表明，焦的产率和焦-C的产率均随煤阶的升高而升高，热解气的产率随煤阶的升高而降低；热解温度的提高能显著降低煤焦和焦-C的产率并提高热解气的产率。热解气组分以H₂煤, 快速热解, 焦, 热解气, 热值