Quality Improvement of Pyrolysis Char Derived From Various Kind of Solid Waste for Recycling

本研究以工业废弃物等不同来源的16种炭为实验材料。为了使用炭作为燃料，应降低氯含量以避免腐蚀。用溶解度表征了生活垃圾炭中氯的溶解度。CO2鼓泡可以将氯降低到水泥窑可接受的水平。粉碎对非水溶性氯的溶解是无效的。灰分含量是另一个应该降低的分数，用于炭的燃料使用。富灰分（r<125 um）采用浮沉分离、泡沫浮选和油团聚等方法。因此，较低的可燃回收率可以获得高热值的优质炭。对于生活垃圾衍生的焦炭，采用泡沫浮选或油团聚法可达到目标质量水平（20000kj /kg热值和30%灰分）。EDX/SEM分析结果表明，即使经过1 h的碾磨，炭颗粒也没有分离成单一物质，即使在炭质量不足以用作燃料的情况下，也可以将炭化作为填埋前的热预处理方法。在间歇浸出和柱式浸出试验中，炭化处理均可显著降低可溶性有机碳含量。炭化渣中重金属的释放量减少，但其释放量随好氧/厌氧条件的变化而变化，并且取决于炭化渣在表面或孔隙结构上的物理吸附。

In this study, sixteen kinds of char obtained from various sources including industrial waste were used for experiments. In order to use char as fuel, chlorine level should be reduced to avoid corrosion. Chlorine in char derived from MSW was characterized in terms of solubility. CO2 bubbling could reduce chorine to acceptable level for cement kiln use. Pulverization was proven to be ineffective in the dissolution of non water-soluble chlorine.Ash content is another fraction which should be lowered for fuel use of char. Ash rich fraction (r<125 um) was subjected to float-sink separation, froth flotation, and oil agglomeration methods. As a result, a lower combustible recovery rate was resulted to get a good quality of char with high heating values. For MSW-derived char, the targeted quality level (20000 kJ/kg heating value and 30% ash content) was attained using froth floatation or oil agglomeration. Results of the EDX/SEM analysis indicated that char particles were not segregated to single substances even after being milled for 1 h.Even in the case that char quality is not good enough for fuel use, carbonization was considered as a thermal pretreatment method before landfilling. Soluble organic carbon levels were fairly decreased by carbonization both in batch and column leaching tests. The release amount of heavy metals from carbonization residue decreased but its extent could be varied with the aerobic/or anaerobic condition, and which relys on the physical adsorption onto the surface or pore structure of carbonization residue.