TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The pulverized combustible solid biomass material comprises lignin powder. The ratio is 3 parts/wt. of glycerol and up to 5 parts/wt. of lignin powder for obtaining the slurry that upon heating to 90 degrees C has low viscosity. The ratio is 1 parts/wt. of glycerol and at least 1 parts/wt. of lignin powder. The pulverized combustible solid biomass material comprises pulverized vegetable solid biomass material, including sawdust, powder or dust of wood. The ratio is 1 parts/wt. of glycerol and up to 1 parts/wt. of pulverized vegetable solid biomass material; or 9 parts/wt. of glycerol and up to 1 parts/wt. of pulverized wood for obtaining a slurry that is pumpable at room temperature; 10 parts/wt. of glycerol and up to 3 parts/wt. of pulverized vegetable peat for obtaining a slurry that is pumpable at room temperature. The pulverized combustible solid biomass material comprises both lignin and powder, dust, sawdust or other pulverized vegetable solid biomass material, preferably wood, and/or powder of carbon from vegetable material. The pulverized combustible solid bio mass material comprises carbon from vegetable solid bio mass material. The glycerol included in the slurry is a byproduct from production of biodiesel fuel or soap, fatty acids, fatty alcohols or alkyl esters. The lignin powder has a water content of 30 wt.%. The pulverized wood has water content of 10-20 wt.% for obtaining slurry that is pumpable at room temperature. Preferred Method: The method comprises adding some water to the glycerol or the slurry to make the slurry less viscous. The glycerol is heated to a temperature of 90 degrees C, and the formed slurry has a viscosity of at most 2000 mPas at 90 degrees C. The method comprises: mixing up to 5 (preferably at least 1) parts/wt. of lignin powder with 3 (preferably 1) parts/wt. of glycerol for obtaining a slurry that upon heating to 90 degrees C has low viscosity; mixing up to 1 parts/wt. of pulverized vegetable solid biomass material with 1 parts/wt. of glycerol; mixing up to 1 parts/wt. of pulverized wood with 9 parts/wt. of glycerol; and mixing up to 5 parts/wt. of lignin powder with 3 parts/wt. of glycerol for obtaining a slurry that is pumpable at room temperature. The glycerol, to which pulverized combustible solid biomass material is added, is a byproduct from production of biodiesel fuel or soap, fatty acids, fatty alcohols or alkyl esters. EXAMPLE - None given.