Thermogravimetric Experimental Study on Combustion Performance of Co-firing of Sludge, Coal and Biomass in Micro-oxygen-rich Environment

摘要

In order to study the combustion characteristics of sludge, coal, biomass and the mixed sample in micro-oxygen-rich environment (simulating micro-oxygen-rich environment with 30%O_2/70%CO_2), thermogravimetric analysis method is used in the paper. The experimental results show that under the micro-oxygen-rich environment, sludge has low ignition temperature, the average burning rate, burnout rate and flammability index, so combustion performance of sludge alone is poor and the weightlessness is more obvious in 200 ～ 600°C. But after mixing coal or biomass, combustion performance of sludge is improved. We use comprehensive application of flammability index and burnout characteristics index to determine the best mixing ratio is about 65% of sludge and coal, about 45% of sludge and biomass. Comprehensive combustion characteristic index may not be suitable for determining combustion performance of the sludge and its samples by comparison to S under the optimum mixing ratio of the sample and there are some errors. Biomass activation energy is the largest, the activation energy of sludge minimal. But the activation energy of the mixed sample doesn't change regularly with the increase of sludge mixing proportion. So there is a deviation that we determine the mixing characteristics by a simple comparison of the activation energy of the samples. This paper provides a theoretical and data support for the selection and calculation of combustion parameters of mixed sludge and resource utilization of sludge.