Mass effect in coal hydropyrolysis: effect on the retention of the tar model compound (2,4-xylenol) on the char

The measurements of retention times of 2,4-xylenol, a representative constituent of volatile matter, on coal char prepared at different temperatures under H 2 pressure show that retention increases with the preparation temperature up to 750 °C and then decreases. Measures of Hg penetration show a similar development evolution of the 0.1–10 μm pore size fraction. Analyses of the eluted gas and condensates after cracking of 2,4 xylenol on chars prepared at different temperatures show that cracking is not only enhanced on char compared with inert solid, but is dependent on the porosity of the samples.