Auto-gasification of a biofuel
Auto-gasification of a biofuel
复制标题
生物燃料的自动气化
DOI：
10.1016/s0010-2180(02)00415-7
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发表时间：
2002
影响因子：
4.4
通讯作者：
E. Vakkilainen
中科院分区：
文献类型：
--
作者：
M. Järvinen;R. Zevenhoven;E. Vakkilainen
介绍了一种新的煤焦气化机理。对于热大颗粒（即Bi >.1），温度分布是不均匀的。由于颗粒中存在不同的温度状态，干燥、脱挥发（或热解）和焦炭反应的阶段可能重叠。在某一点上，颗粒的表面完全脱挥发，而颗粒的内部仍在经历干燥和脱挥发。当H2O和co2从颗粒中流出时，它们穿过焦炭的热表面层。如果温度足够高，炭可能会气化。这里用黑液作为燃料样品。它具有这种自动气化所需的性能；热大颗粒，高初始含水量和非常多孔和高活性的炭。详细的数值模拟表明，30 - 40%的焦炭可以在自动气化脱挥发的同时转化。颗粒越大，温度越高，气化的炭的比例越大。对于煤和泥炭，典型的颗粒尺寸太小，当在粉状燃料或流化床炉中燃烧时，这种机制无法发挥任何作用。对于燃烧的原木，粒径较大，热解时间≈10 min，因此自气化可能很重要。
A novel mechanism for gasifying a char is described. For thermally large particles (i.e., Bi > 0.1) the temperature distribution is non-uniform. Because different temperature regimes exist in the particle, the stages of drying, devolatilization (or pyrolysis), and reaction of the char may overlap. At some point the particle’s surface is fully devolatilized, while the particle’s interior is still undergoing drying and devolatilization. As H2O and CO2flow out from the particle they pass through the hot surface layers of char. If the temperature is high enough, the char may be gasified. Black liquor was used here as a sample fuel. It has desirable properties for such auto-gasification; thermally large particles, a high initial water-content and a very porous and highly reactive char. Detailed numerical simulations suggest that 30 to 40% of the char may be converted simultaneously with devolatilization by auto-gasification. The larger the particle and the higher the temperature, the larger is the fraction of char gasified. For coal and peat, a typical particle size is too small for this mechanism to play any role when fired in pulverized fuel or fluidized bed furnaces. For burning wooden logs, the particle size is large and the pyrolysis time is ≈10 min., so then auto-gasification might be important.
DOI：
--
发表时间：
2007
期刊：
影响因子：
--
作者：
A.I.Volokitin;B.N.J.Perssion;H.Ueba;H. Ueba;H. Ueba;H. Ueba
通讯作者：
H. Ueba