Design The Pyrolysis Zone Of Compound Reactor For Oxygen-Heating Calcium Carbide Production

China's energy production structure and consumption structure will inevitably be dominated by coal for a long time,because of the lack of petroleum.Calcium carbide,known as "the mother of organic chemical industry" is one of the important traditional coal chemical products.Although our country in the last century in 50s established calcium carbide industry,the long-term used of electric-heating method to produce calcium carbide,making the energy utilization rate is low.For this reason,the research on the production technology of oxygen-heating calcium carbide production was carried out in Beijing University of Chemical Technology in 2007.In this paper,the pyrolysis behavior of composite particles in the pyrolysis zone of the composite reactor was studied.In this paper,the pyrolysis behavior of solids is studied from three scales.The first scale is reaction kinetics.At this scale,derived from the mathematical relationships between the Stieltjes integral,Stieltjes integral and Pade approximant,new Pade approximants to the normal and generalized temperature integrals are obtained,and an error analysis and comparison of the proposed approximations along with some other ones of high precision is performed,showing that they are accurate enough and applicable in non-isothermal kinetic analysis.what's more,In this paper,a unified method for the inversion of the model parameters of the distributed activation energy model under three different heating conditions,linear temperature rising,parabolic temperature rising and exponential temperature rising via translating the distributed activation energy model into Fermi integral.The particle size,which is based on the first scale as a sub model,is studied next.At this scale,a one-dimensional unsteady pyrolysis model of spherical particles is established and validated,confirmed that the composite particles are homogeneous structure with calcium hydroxide.In the aspect of the influence of heat source on the pyrolysis process,The endothermic action of calcium hydroxide is greater than that of the bituminous coal,and the endothermic effect of evaporation can be ignored;In the aspect of the control step of pyrolysis process,the effect of intermal thermal resistance is greater than that of external thermal resistance,and the effect of extermal thermal resistance is greater than that of the reaction kinetics.At last,the bed size,which is based on the second scale as a sub model,is studied.The pyrolysis model was established for one-dimensional gas-solid countercurrent contact of moving bed.Estimated that the gas energy flow rate is not less than 3 MJ s-1.The critical height of the pyrolysis zone is determined by the energy flow rate required for solid phase pyrolysis and the energy flow rate providing form gas phase.Increasing the energy flow rate of the gas phase can reduce the critical height of the pyrolysis zone,but it can also Increase equipment and operating expenses.Comprehensive consideration is needed to minimize the total cost.