Study On Conversion Of Lignin To Lah By Catalytic Pyrolysis

In this paper, a powder -particle fluidized bed developed by our group was used to investigate lignin pyrolysis. A fluidized bed ,which is a simulated thermolysis reactor, was made for the research on the effect of its operating conditions on pyrolysis characteristics. The effect of operating condition i.e. velocity of flow, height of bed and kinds of particles on fluidized status was determined to obtain the optimum operating condition of the fluidized bed and provide the necessary foundation experimental data for pyrolysis experiments.In the stream of N₂, TGA was used to study the pyrolysis characteristics of four kinds of lignin. Two kinds of methods, Kissinger and Ozawa were used to determine the kinetics parameters of pyrolysis of Kraft lignin.Experiments on the catalytic pyrolysis of the lignin sulfonate were conduced by using a new type of powder-particle fluidized bed to improve the yield of the light aromatic hydrocarbon, i.e. benzene, toluene, xylene and naphthalene (BTXN). The effect of catalyst species, fluidizing gases and pyrolysis temperature on the yield of the BTXN were investigated. According to the results, the contents of sulfur is high in the lignin sulfonate ,and the volatile matter is effected by the temperature. In the case of the inert media silica sand, the yield and the distribution of the pyrolysis products were almost unchanged under the different kind of atmosphere. In the case of the catalyst C0M0-B with hydrogen atmosphere, the intermediate BTXN yield reached 2.52%(mass), daf, 3.3 times as much as that in the case of silica sand. Therefore, in order to obtain valuable BTXN as an intermediate in the pyrolysis as much as possible, it is crucial to select high sulfur resistance and hydrogenization activity catalyst.