Experimental Study On The Dynamic Characteristics And Emission And Capture Of HCl From Co-Combustion Of Sewage Sludge And Bituminous Coal

China is facing more and more pressure of the disposal of sewage sludge undercontinuous development of urbanization. There are many advantages for the incineration ofsewage sludge such as short distance transportation, little hazardous products, fast disposalspeed, no sterilization before incineration. Heat produced during the incineration can alsobe used for power and steam generation. At present, incineration for sewage sludge hasbeen used in some economically developed areas of China. Co-cumbustion of sewagesludge and coal is one of the approached for sludge incineration. It not only solves theproblem of sewage sludge’s combustion instability, but also takes use of sewage sludge togenerate electricity and heat for citizens. Thus, more and more attentions have been drawntowards this approach in many countries.The routine analysis told that sewage sludge had high volatile content and ash content,and low carbon content and calorific value. Clinkering property of sewage sludge was bad,but the improvement of it seemed to come when co-combustion of sewage sludge andbituminous coal by ST（℃） comparison.The grindability of mixture of sewage sludge andbituminous coal was found to decrease with increasing of blending rate of sewage sludge inthe mixture, and the average diameter/size of sewage sludge particles was much bigger thanbituminous coal, which was close to bituminous coal when sewage sludge mixing withbituminous coal.After the thermogravimetric experiments of sewage sludge, bituminous coal and theirmixture, we found: when the blending rate of sewage sludge in the mixture is more than50%, the mixture samples had two peak values in DTG curve, and the ignition/burnout andcomprehensive-burn characteristics of bituminous coal were improved when mixing withsewage sludge. Furthermore, after the mechanical equations and the corresponding kineticsparameter during the low/high temperature combustion periods were calculated through theCoats-Redfern integral method, the results showed that the sewage sludge, bituminous coaland their mixture burning were controlled by chemical reaction rate in the low temperaturecombustion period, which were controlled by the diffusion reaction rate in the high temperature combustion period, and the activation energy of mixing samples was found todecrease with increasing of blending rate of sewage sludge in the mixture.In this study, the emission of HCl from co-combustion sewage sludge and coal wasinvestigated under different heating rates, temperature, blending ratio and also atmosphere.For the removal of HCl, CaCO₃was used as additive at different temperature and ratio. Thegaseous HCl was real-time measured by GASMET DX400. The emission of HCl was foundto increase with increasing of blending rate of sewage sludge, while conversion rate ofClâ†'HCl decreased; The increasing of temperature helps to enhance the con-version rate ofClâ†'HCl, but it was negligible above600℃; The increasing of oxygen concentration in thecarrier gas could decreasing the conversion rate of Clâ†'HCl by oxidizing HCl into Cl2partially; The higher heating rate was found to result in an intensive releasing of HCl; HClremoval increases with the increasing of Ca/（S+0.5Cl）, and the optimum temperature forHCl removal is700℃when Ca/（S+0.5Cl） is2.