The Experimental Study On The Catalytic Pyrolysis Of The Bamboo

Energy sources and industrial raw in chemical industry are mostly originated from fossil resources. Many environmental problems, such as the energy crisis and the inevitable increasing of the CO2 net concentration in atmosphere, result from the vast use of fossil resources. So it is necessary to exploit new renewable energy sources and raw materials for chemical industry. Biomass energy is paid much more attention than before because of many advantages such as the large quantity, low effect to environment and the regeneration ability. This article selects bamboo as the sample to study from two ways. One is the study of the pyrolysis and catalytic pyrolysis of the bamboo in TG equipment (ZPY–2P) at different heating rates, different pressures and different catalysts under the temperature range of 50～700℃and N2 atmosphere. The other is the study of the reaction kinetics of the bamboo with two different methods. The remarkable conclusions are drawn as follows:1. TG results demonstrate that the pyrolysis process of bamboo can be considered as a two-step reaction, which is consisted of four phases: the dehydrating phase, the pre-charring phase, the charring phase and the calcining phase. The decomposition of hemicellulose is at the pre-charring phase and the decomposition of cellulose and lignin are at the charring phase. The faster the heating rate is, the later the reactive temperature on TG will be. And the volatile of pyrolysis production will be reduced along with the increasing of the gauge pressure. Compared with the bamboo before and after dryness, we can conclude that the dryness temperature of the bamboo should not be more than 200℃.2. Before and after the bamboo is dried, the curves of TG are almost alike. The main differences are: the curve of TG of the fresh bamboo has a distinct weight-loss process at the dehydrating phase; the initial temperature of pyrolysis and the largest temperature of DTG of the fresh bamboo are higher than the dried sample; the curve of TG of the fresh bamboo moves to the left as a whole.3. The reaction at the dehydrating phase is much more violent after adding catalysts, which make the rate of weight-loss increase. At the pre-charring phase and the charring phase, the catalysts enter into the sample as the form of ions and destroy the inner structure of the bamboo. Especially the process from the pre-charring phase to the charring phase becomes much more fluent after adding acidic catalyst and alkaline catalyst, which make the pyrolysis happen much easier.4. The weight-loss rate of the sample becomes large after adding Ca+; K+ restrains the separation of the volatile from the hemicellulose, cellulose and lignin; Fe3+ makes the reaction at the dehydrating phase complex and catalyzes the decomposition of the lignin at the calcining phase; the temperatures of every phase move ahead after adding HCl and it makes the decomposition of the hemicellulose and cellulose easier; The weight-loss rate of the bamboo at the dehydrating phase is the largest after adding NaOH than other catalysts.5. The reaction order of the bamboo pyrolysis is about 1.5, and the activation energy of the whole pyrolysis process is 283.47kJ/mol approximately.