Development of Bioenergy from Chromium-Copper-Arsenate (CCA) Treated Wood Wastes

利用铬铜砷酸盐 (CCA) 处理的木材废料开发生物能源

基本信息

批准号：
13680576
负责人：
HATA Toshimitsu
金额：
$ 2.3万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13680576/
关键词：
chromium copper arsenate bio-oil charcoal pulse current sintering bioenergy

项目摘要

Disposal of woods treated with chromated copper arsenate (CCA) preservatives has become a serious problem in the world. Environmentally benign disposal technologies have to be developed. We have tried to find pyrolysis conditions for CCA treated wood in order to maximize the retention of arsenic in wood charcoal along with a high oil yield. In 2002, a CCA treated sample given an extra heat treatment at 450℃ for 10 min was thoroughly investigated in order to establish the details of the reaction in which arsenic is captured in the pyrolysis residue prior to volatilization. Composition and structure of the metal compounds in the pyrolysis residue were examined by transmission electron microscopy. Alarge number of particles were found of variable diameter between 10 and 100 nm. The smaller ones were mostly spherical, sometimes faceted. The larger ones were lumpy. CCA compounds and their reaction products like Cr_2As_4O_<12> and As_2O_3 were identified in conventional TEM by Selected Area Electron Diffraction. In high resolution, the nanoparticles exhibited lattice fringes as indication of their mono crystalline character, fitting, e.g. the d_<210> = 0.204 nm of Cr. The volatility of arsenic during pyrolysis of CCA treated wood was measured by XRF (X-Ray Fluorescence) analysis at temperatures up to 500℃ and at times up to one hour. Weight change and arsenic content of the pyrolysis residue were measured after dissolution in HMO_3. More than 20 % of arsenic was already lost at 300℃, which may have been caused mainly by the volanlization of the unreacted arsenic compound after reduction of As(V) in As_2O_5 to As(III) in As_2O_3. Arsenic is probably released as As_4O_6, which is very difficult to capture and toxic. By an additional heat treatment this reduction can be prevented and the dry separation of the metals may be allowed

用镀铬砷（CCA）蜜饯处理木材已成为世界上一个严重的问题。必须开发环境良性处置技术。我们试图找到CCA处理过的木材的热解条件，以最大程度地将砷在木炭中保留，并具有高油脂产量。在2002年，对经CCA处理的样品进行了450分钟的额外热处理10分钟进行了彻底研究，以确定在挥发前在热解退休中捕获砷的反应细节。通过透射电子显微镜检查热解退休中金属化合物的组成和结构。发现直径在10到100 nm之间的颗粒数量。较小的大部分是球形的，有时是面对的。较大的是块状。 CCA化合物及其反应产物（例如CR_2AS_4O_ <12>和AS_2O_3）通过选定的区域电子衍射在常规TEM中鉴定出来。在高分辨率中，纳米颗粒暴露了晶格条，表示其单晶体特征，例如，例如D_ <210> = Cr的0.204 nm。通过XRF（X射线荧光）分析，在高达500℃的温度和有时最多一个小时的温度下，通过XRF（X射线荧光）分析测量了砷在CCA处理过的木材中的挥发性。在HMO_3中溶解后测量了热解住房的重量变化和砷含量。超过20％的砷已经在300°丢失了，这可能主要是由于AS_2O_5中的AS（v）降低AS（v）在AS_2O_3中的AS（V）后，未反应的砷化合物引起的。砷可能被释放为as_4o_6，这很难捕获和有毒。通过额外的热处理，可以预防这种减少，并且可以允许金属的干分离