Gasification of wood char and effects of intraparticle transport

Abstract Kinetic parameters for gasification of hybrid poplar spp. char have been measured. A differential reactor was used to obtain rate data for catalytic and non-catalytic reactions of small wood char particles (1–2 mm in size) at 100 kPa for temperatures in the range 400–700 °C, steam partial pressures between 45–100 kPa, and space velocities in the range 2.0–7.3 s −1 During pyrolysis of wood without the addition of either K 2 CO 3 or Na 2 CO 3 , the cellular structure of the wood was preserved. Additionally, this cellular structure remained intact during most of the gasification process. Addition of K 2 CO 3 and Na 2 CO 3 before pyrolysis caused a degradation of the regular cellular structure and an increase in the rate of gasification of the resulting char. Effectiveness factor calculations were made for particles of various sizes and results indicate that diffusion control of the gasification reaction becomes important for particles larger than 0.5 CM.