Biofuels: Part II. Thermogravimetric research of dry decomposition

The article presents results of thermogravimetric measurements of the pyrolysis of dry biomass materials such as: grains and oats and triticale straw, energy plants called cukrosorgo. The initial phase of dry decomposition visible on the DTG curve is evaporation of moisture. The process of evaporation for the studied types of agro biomass occurred at temperatures of 65.9 °C (triticale straw) to 82 °C (oat grain). The next stage of the process concerned major transformations that for the studied cases were conducted in temperatures of 200–400 °C, and the maximum speed of transformations (the second peak is visible in the DTG graph) refers to the temperature range from 299.1 °C (oat grain) to 323.9 °C (triticale straw). The last phase of the process is characterized by the absence of mass loss, which in the case of dry biomass distribution determines the conditions of carbonizate formation. The calorific values of formed process gases ranged from 4,884 to 6,302 kJ/Nm 3 . Gases of such calorific values are defined as low calorific, despite the fact they can be successfully used for energy purposes, this is for burning in boilers and gas turbines. Carbonizates are characterized with high-calorific values from 24,100 to 27,900 kJ/kg. This type of high-calorific fuels is recommended to be burnt in the boiler furnaces in a mix with fuels with a lower calorific value such as pulverized coal or wet biomass. In these processes, the combustible gas is obtained, which can be burned in power boilers and gas turbines.