| Bio-energy as a clean, effective, and renewable energy, as well as the only renewable carbon source, has drawn the attention of whole world. The briquette technology and pyrolysis technology can be seen as simple but efficient pathways of utilization of biomass resources. Bio-char is the main solid product of pyrolysis process, it is a carbon rich material, and it can be used in many fields. In specific condition, the bio-char would react with the carbon dioxide, which would work on the carbon dioxide emission reduction.In this paper, the pine sawdust was chosen for the raw material, and the relevant basic researches on characteristics of molded biomass as well as molded bio-char were investigated.Firstly, considering the production’s quality of briquette and pyrolysis process, the chosen raw material should contain lower ash content and higher lignin content, and the pine sawdust was suitable. Cmpared with the molded biomass and raw material, there were no obvious changes in proximate analysis, ultimate analysis, and heating value, which means that the briquette process only conferred about physical changes. The preheated briquette would produce the molded biomass with higher density, compared to cold briquette. And the density of molded biomass were influenced by the temperature, pressure, particle size and mold shape.And then, the characteristics of molded bio-char produced from different pyrolysis factors were investigated. It can be seen from the experimental results, the pyrolysis factors had a dramatically effects on the characteristics of molded bio-chars. As the pyrolysis temperature increased from 400℃ to 700℃, the molded bio-char had an improvement in its heating value, fix carbon content, ash content, carbon content, and pore-structure development, as well as its aromatic degree and graphite degree. Its char yield rate, volatile content, oxygen, and hydrogen content were decreased as the pyrolysis temperature increased. At lower temperature (400℃), the heating rates would have a positive correlation with char yield rates. As the temperature increased (500～700℃), the char yield rates decreased obvious as the heating rates increased. Compared with the molded bio-char and pulverized bio-char, it can be concluded that the molded bio-char had a higher char yield rate, ash content, graphite degree, and its pore-structure were more organized, but the heating value of molded bio-char was lower.It can be seen from the kinetic study of pyrolysis of molded biomass, the thermal hysteresis appeared with the increasing of heating rates, and the reaction area gradually moved to the high temperature zone. Through the calculation, the G-B function were more suitable to the molded biomass pyrolysis process in this paper, and the activation energy is about 103～107 kJ/mol.In this paper, the characteristics of pyrolysis of molded biomass under CO2 atmosphere were investigated.It can be seen from the experimental results, the pyrolysis at 800℃ would have an obvious effects in the reduction of CO2. The lower temperature seemed not very efficient. Compared with different atmosphere, the CO2 atmosphere can make the devolatilization reaction in advance, such that the peaks of CO2, CO and CH4 releasing were in advance. But the CO2 seemed to restrain the releasing of CH4, which making the H2 content decreased. The molded bio-char produced from 800℃ and CO2 atmosphere had a higher pyrolysis degree. It had higher fixed carbon content, carbon content, higher heating value, and extremely lower sulfur and nitrogen contents, which means that the molded bio-char had the potential to be the substitution of solid fossil fuel. The mechanical strength of molded bio-char seemed good, thus it would have the potential to be used as the reducing agent in metallurgy.
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