Study Of The Briquetting Pyrolysis Technology For Low Rank Pulverized Coal In Microwave Field

After being added direct coal liquefaction residue, coking coal and other binders,formed coke was successfully prepared in this paper with the low rank pulverized coalin Sun Jiacha, northern part of Shaanxi province as the main raw coal, meanwhile theeffects of briquetting pressure, microwave power, particle size, pyrolysis time andcondensing temperature.etc on microwave briquetting pyrolysis process were mainlyinvestigated.In the conventional pyrolysis, the optimum proportions of liquefaction residue,coking coal and cellulose were10%,10%and0.5%respectively, which can be adoptedto prepare for briquette coal (formed coke) with relatively high compression strength.The briquette with compression and immersion strength of5710N/Ball and3125N/Ball and the formed coke with compression strength of3900N/Ball can be obtainedunder the briquetting optimal technological conditions as the briquetting pressure,pyrolysis time, briquetting water content and particle size were60kN,700℃,14%and<0.3mm separately.In the microwave pyrolysis, formed coke with compression strength of3750N/Ball can be obtained under the briquetting optimal technological conditions as thebriquetting pressure, briquetting water content and particle size, microwave power andcondensing temperature were60kN,14%,<0.3mm,720W and25℃separately. Theresults showed that compression strength of briquette coal (formed coke) and theformed coke yield increased, however the tar and gas yield decreased along with theincrease of briquetting pressure. As the microwave power increased, formed coke andtar yield decreased, while compression strength of briquette coal (formed coke) and gas yield increased. Tar yield ascended from15.6%at25℃to19.3%at0℃and gas yielddescended gradually as the condensing temperature decreased, which had no influenceon the compression strength of briquette coal (formed coke).