In this paper, the hydropyrolysis of a low-rank coal in a swept fixed bed (SFB) reactor was carried out by fixing the hydrogen pressure (40 kg/cm(2)), the hydrogen flow (2 L/min), and the residence time (10 min) at increasing temperatures (400, 500, and 600 degrees C). In addition, the coal bed height (h, 1.5h, 2h, 2.5h, and 3h) was modified by increasing the coal loading weight of the fixed bed. This is the first time that the influence of the coal bed height on the distribution and characteristics of the hydroconversion products has been analyzed. In all of the experiments carried out, regardless of the hydropyrolysis temperature, the percentages of tars and char directly depend on the coal bed height. It is also demonstrated that there is not only a quantitative dependence, but that also the height of the coal bed is very important and plays an important role in the nature of the conversion products from hydropyrolysis.