DESIGN FEATURES OF THE EXPERIMENTAL UNIT AND NUMERICAL STUDIES OF BAGASSE THERMOCHEMICAL PROCESSING PART 2. ANALYSIS OF THE PYROLYSIS PROCESS IN A FIXED BED APPARATUS

• Дата: 2024
• Автори: Rohman , B., Kobzar , S. G.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: Institute of Renewable Energy National Academy of Sciences of Ukraine 2024
• Теми: fixed bed; biomass; Bagasse; thermal conductivity; pyrolysis; steam-air gasification; conductive; radiation; heat transfer; gas; temperature
• Онлайн доступ: https://ve.org.ua/index.php/journal/article/view/481
• Назва журналу: Vidnovluvana energetika

Using the biomass pyrolysis model built in the first part of the work, the Bagasse and Wood Birch thermolysis process was investigated. Different variants of bed heating were considered by: a) electric heating of the outer and inner surfaces of the pyrolyzer; b) electric heating of the outer surface and heating of the inner surface of the pyrolyzer with combustion products; c) electric heating of the outer surface of the pyrolyzer and combined heating of the inner surface: in the first 20 s electric heating is used, further − thermal energy of combustion products with a temperature of 1300 °С. It is shown that: a) for fast pyrolysis it is necessary at the initial moments of time τ = 0−1 s to bring to the outer and inner walls of the pyrolyzer large heat fluxes: qw+ = 203.2 and qw− = 187.16 kJ/(s·m2), respectively. The dependences qw(τ) necessary for regulating the temperatures of the pyrolyzer walls were obtained; b) at the outlet from the Bagasse pellet bed the following gas composition at a temperature of 736 °С (on dry mass) is obtained: CO2 = 12,1 %; CO = 44,70 %; H2 = 17,2 %; C1,16H4 = 24,95 % (70 % CH4 + 30 % C2H4); C6H6,2O0,2 = 0,712 % і N2 = 0,3 % with a caloric value of 19185 kJ/nm3; c) at temperature 850°С the gas composition: CO2 = 7,13 %; CO = 51,4 %; H2 = 15,6 %; C1,16H4 = 23,71 %; C6H6,2O0,2 = 2,2 % satisfactorily agrees with the experimental data Zanzi R., obtained at temperature 850 °С: CO2 = 9 %; CO = 56,2 %; H2 = 15,70 %; CH4 = 12 % і C2H4 = 6,9 %; d) the main problem of Bagasse fast pyrolysis organizing, is a narrow intertube gap of 35 mm, where the bed is located; e) to expand the gap to 75 mm keeping high heating bed rates, it is necessary to use recirculation of pyrolysis gases with temperature 800 °С.