Study On Thermogravimetric Analysis And Pyrolysis Kinetics Of Cellulose

Clean energy and renewable biomass energy utilization are attracting increasing attention due to the growing deplection of fossil energy and the associated environment problems. Biomass power plant is expected to be brought industrialization. However, at present domestic biomass production enterprises can profit only relying on state subsidevs policy. Through the expansion of types of raw materials, and efficient energy conversion technologies can reduce the cost of production, and promote the development of related business.In this paper, the meaning of use of biomass energy and pyrolysis were summarized, and then from TGA experiment, the kinetic statues quo of cellulose pyrolysis was discussed.One of the main components of biomass, cellulose, was selected to be the experimental samples. TGA of cellulose was firstly studied in TG equipment and then several groups of experiment of different heating rate were made to compare the treatment effect of different thermal analysis methods (single scan rate and multi scan rate), and sample size and heating procedure were also changed. Smooth handling was carried out for experiment data and lastly kinetic analysis was made in different representative methods.The experimental results show that the pyrolysis of cellulose in the TG curve performs a step. And the pyrolysis process is divided into four parts, namely decomposition and absorbtion of water, lower degree of polymerization, main pyrolysis and slow decomposition of remnants.The faster the heating rate, the more serious the thermal hysteresis. The impact of heating rate to the temperature of largest weightlessness point can be expressed using the equation T_p= 277.29 + 1.6286β. Experiments with different sizes of samples show that the pyrolysis characteristics of small size samples is decided by chemical reaction while large ones is controlled by multiple factors such as chemical reaction and heat transfer and proliferation. The DTA baseline drift is mainly related on the change of substantial specific heat capacity before and after pyrolysis (that is before and after chemical reaction). When DTA baseline drifts upward, it means that the specific heat capacity of product is samller than the sample, while downward, it means larger. The kinetic parameters derived by various kinetic methods have definite deviations, but they can be validated and supplemented from each other. According to different results, the pyrolysis reaction order of cellulose obtained is about 1 and the activation energy during main pyrolysis period is about 152.1 kJ/mol.