2017世界木材日研讨会——Closed-loop Recycling of Wood Preservative Systems
国际木文化学会 | 1422 view(s) | 2018/07/03
摘要：CCA-treated wood is first extracted in microwave reactor in the presence of acid solutions. the acid extracted CCA solution can then be easily drained off through a filter and separated from the CCA-wood. To this solution, precipitants or complex agents were added and the solution was agitated and then allowed to sedimentation. The sediment; which contains the Cr, Cu, and As; was then separated from the solution by centrifugation or filtration. By this process Cu, Cr, and As were removed by more than 99%, respectively. As the second step, the wood liquefaction reagents are added to the microwave reactor containing the CCA-free-wood and reacts at 120 – 150 0C to converts the spent wood to be used as bio-based raw materials for the preparation of polymer materials, such as polyurethanes and phenolic resins. As the third step, the CCA-bearing sediment were regenerated by adding concentrated inorganic acid such as sulfuric, nitric or phosphoric acid, and reused in the preservation industries of wood. Since the process uses relative low temperature, short reaction time, and relatively small amount of organic reagents, it is an effective and economically feasible technique for recycling of spent CCA-treated wood.