Removal Of Tar And Preparation Of High Quality Product Gas From Biomass Pyrolysis

As an important clean energy, biomass has the characteristics of large storage capacity and it is renewable energy, which can effectively reduce the dependence on fossil energy. There are many ways to use biomass, such as direct combustion as the most commom way, in which biomass pyrolysis is one of the most important and effective way to deal with biomass. But it will also produce biomass tar in the biomass pyrolysis process, biomass tar will block the pipeline when it liquefied in cryogenic equipment region, resulting in equipment damage and energy dissipation, moreover tar have a serious threat to the human body’s health and environment. The pyrolysis of biomass aims to eliminate the tar and to prepare the high quality product gas, how to eliminate the tar is the key point.We summarized the study of domestic and foreign scholars on biomass pyrolysis in recent years in this paper, comparing the advantages and disadvantages in tar removal, the pyrolysis process using catalytic to remove tar removal is the best effective treatment. The pyrolysis of biomass with catalyst can effectively reduce the yield of tar and improve the quality of product gas. The key technology is how to select the catalyst to remove the biomass tar, the catalyst’s activity and life are important standards when we select the catalyst.Using a new type of catalyst for the synthesis of high activity, long service life of the catalyst system design mainly using corn straw as raw material. First determine the biomass pyrolysis temperature, considering the economic and experimental point of view, determining the 600 ℃ as the temperature of biomass pyrolysis; secondly, the selection of filter, considering the absorption system of ash and mass balance, determining the molecular sieve as filler; going on series of pyrolysis experiment with catalyst of alkali metal loaded, comparing the removal of tar and the quality of product gas, selecting the active metal component of nickel, iron, lanthanum; making perovskite type LaNiO₃ catalyst as catalyst, the catalyst loading is 6wt%, catalytic temperature is 800 ℃,under the condition of the best catalytic effect, which can collect material accounted for before reaction straw quality percentage reached at 97.47%, reduce weight loss of 23.68%, the elimination rate of heavy tar reached at 78.77%, the product gas volume rises from 4.11L to 10.76L and significantly improve the product gas calorific value, the optimal calorific value of the product gas is 4359.27 kcal/m3, the life of the catalyst is 13.5h.Biomass pyrolysis is controlled with the factors of temperature, heating rate. Biomass pyrolysis is also related to the type and size of biomass. Biomass pyrolysis will be promoted with the reduction of particle size,40 mesh size of biomass has the best influence in pyrolysis of biomass; carrying on research of three kinds of biomass, draw the conclusion:going on the industrial analysis of different kinds of biomass. The degree of biomass pyrolysis is decided by the volatile, the ash content in biomass has a positive impact to biomass pyrolysis because of its constituents.