Analysis of potassium release and combustion characteristics of paper sludge under fast heating conditions

The development of the paper-making industry has led to the production of a large amount of paper sludge, and the treatment of paper sludge has become an important environmental issue. Paper sludge is a typical biomass fuel with a certain content that can be utilized as green energy. Therefore, it is necessary to study the combustion characteristics of paper sludge. This paper investigated the feasibility of combustion utilization of paper sludge, simulated the condition of fast heating, and explored the combustion characteristics and potassium release of paper sludge. This study discussed the effects of changes in combustion atmosphere on the heating rate, mass loss, and potassium release of paper sludge. The combustion of paper sludge can be divided into three stages: ignition stage, volatile combustion stage and coke combustion stage. In addition, the study also analyzed the potassium release characteristics of paper sludge using emission spectroscopy technology. By comparing the original samples of paper sludge with water-washed paper sludge, some potassium storage forms in the paper sludge were obtained, and it was clarified that there is almost no water-soluble potassium in paper sludge. By comparing the total release of potassium elements, it was proved that most of them are stored in ash, making the recovery and utilization of potassium elements more convenient during the combustion process.