焙烧温度对3种竹材焙烧炭性能的影响

Effect of torrefaction temperature on the properties of three types of torrefied bamboo charcoal

为研究焙烧温度对竹材焙烧炭性能的影响，以毛竹、绿竹和雷竹3种竹材为原料，采用一体化程控高温炉在不同焙烧温度、保温时间30 min条件下制备得到焙烧炭，并对产品进行性能指标、元素含量、热值、可研磨性等相关参数的测定和分析。结果表明：随着焙烧温度的提高，所得到的竹材焙烧炭的得率下降，其灰分含量增加、挥发分含量下降、固定碳含量增加，可研磨性能提高。综合3种竹材焙烧炭的表现，随着焙烧温度的提高，热值会随之增加，通过线性拟合发现固定碳含量和热值成正比关系；温度对其元素变化的影响主要为C元素的增加和0元素的减少，S元素含量极少，在0．1％-0．2％的范围内且远低于煤，因此，竹材焙烧炭是一种清洁能源。通过对失重率和热值增量比值的分析对比可以发现，在保温时间30 min下毛竹加工剩余物的最适宜焙烧温度为260℃，比值为1．14；绿竹的最适宜焙烧温度为260 ℃，比值为0．92；雷竹的最佳焙烧温度为300℃，比值为1．05。

To explore the effect of temperature on the properties of torrefied bamboo charcoal from different bamboo spe-cies, a heating technique at different temperatures followed with 30 min heat preservation in the high temperature furnacewith integrated program temperature control was utilized to produce torrefied bamboo charcoal. The performance index,element contents, calorific values and other relevant parameters of the products were tested. The results showed that,with the rising of torrefaction temperature, the yield of the bamboo torrefied charcoal and the volatile matter decreased,but the ash content and the fixed carbon content increased, and the grinding performance enhanced. In respect of threekinds of torrefied bamboo charcoals, with the rising of torrefaction temperature, the calorific value of torrefied bamboocharcoal increased. Linear fitting illustrated that the fixed carbon content was in direct proportion with calorific value.The change of torrefied charcoal＇ s element contents under the influence of temperature were reflected in the increasingof C and the decreasing of O, and the S elemental content was extremely low at 0. 1%-0. 2%, which was much lowerthan that of coal. Hence, torrefied bamboo charcoal was a clean energy. Through the analysis and comparison of theweight loss and the calorific value, the optimal torrefied process for moso bamboo was 260℃, and the ratio was 1.14;for oldhami bamboo was 260 ℃, and the ratio was 0.92; forphyllostachys praecox bamboo was 300 ℃, and the ratio was1.05.