Production Factors Controlling the Physical Characteristics of Biochar Derived from Phytoremediation Willow for Agricultural Applications
Production Factors Controlling the Physical Characteristics of Biochar Derived from Phytoremediation Willow for Agricultural Applications
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DOI：
10.1007/s12155-013-9380-x
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发表时间：
2014-03
影响因子：
3.6
通讯作者：
A. Fletcher;Malcolm A. Smith;A. Heinemeyer;R. Lord;C. Ennis;E. Hodgson;K. Farrar
中科院分区：
文献类型：
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作者：
A. Fletcher;Malcolm A. Smith;A. Heinemeyer;R. Lord;C. Ennis;E. Hodgson;K. Farrar
柳树是一种主要的生物能源原料，可用于生物修复，最近已被用作制造农业应用的生物炭的生物质原料。在这里，我们详细研究了影响柳树炭特性的物理和化学因素，其中原料是生物修复的副产品，可能会将重金属等污染物转移到木材饲料中。在350-650°C的热处理温度（HTTs）下，在恒定的氩气流量下，设置为100或500 mL min - 1，通过热解生长在污染土地上的短旋枯枝柳树，进行多次处理，产生生物炭样品。分析了样品的屈服、元素分析和结构特征，包括表面积和孔径分布、表面功能和金属含量。所得炭均具有较高的固定碳含量，但表面特征不同，随着高温的增加，基本特征显著增加，这是由于表面氧部分的去除。结果表明，产生明确的介孔结构需要450°C的最低热解温度，这是促进氧气运输所必需的，HTT≥550°C产生的总表面积为170 m2g−1，更重要的是，有一个适合微生物定植的可观的外表面积。数据表明，选择和优化字符属性是可能的；然而，这些因素的相互作用可能意味着需要做出一些妥协。
Willow, a leading bioenergy feedstock, may be planted for bioremediation and has been used, more recently, as the biomass feedstock in the manufacture of biochar for agricultural applications. Here, we present a detailed study of the physical and chemical factors affecting willow char properties, where the feedstock is a by-product of bioremediation, potentially transferring pollutants such as heavy metals to the wood feed. Biochar samples were produced via pyrolysis of short-rotation coppice willow, grown on contaminated land, using several treatment times at heat treatment temperatures (HTTs) in the range 350–650 °C, under a constant flow of argon, set at either 100 or 500 mL min−1. The samples were analysed for yield, elemental analysis and structural characteristics, including surface area and pore size distribution, surface functionality and metal content. All chars obtained have high fixed carbon contents but vary in surface characteristics with a marked increase in basic character with increasing HTT, ascribed to the removal of surface oxygen moieties. Results indicate a minimum pyrolysis temperature of 450 °C is required to produce a defined mesoporous structure, as required to facilitate oxygen transport, HTT ≥ 550 °C produces total surface area of >170 m2g−1and, more importantly, an appreciable external surface area suitable for microbial colonisation. The data show that selection and optimisation of char properties is possible; however, the interplay of factors may mean some compromise is required.