稻草的水热碳化研究

Study on hydrothermal carbonization of rice straw

利用水热碳化技术,在1 000 mL的反应釜中,考察了反应温度和停留时间对于稻草水热碳化的影响。结果表明,稻草碳化得到的气相产物主要为CO2、液相产物主要为乙酸和葡萄糖。随着反应温度和停留时间的提高,CO2、乙酸的产率以及生物炭(固相产物)的能量密度呈上升趋势,而生物炭的产率则呈现相反的趋势。在低温条件下(200℃左右),可获得较高葡萄糖产率。生物炭的吸水性实验表明,在反应温度为260℃,停留时间为1 h的条件下,生物炭的产率达到稳定。扫描电镜分析结果说明,经过碳化后的稻草整体呈现碎片状态,并伴有大量蜂窝状结构。

The influences of reaction temperature and residence time on hydrothermal carbonization （HTC） of rice straw were investigated in a 1 000 mL autoclave. It was shown that the major gas product was carbon diox-ide. Acetic acid and glucose were the major liquid products. The amounts of carbon dioxide and acetic acid in-creased with the increment of reaction temperature and residue time. As regards to the energy density of hio-char, a same trend was observed. However, the yield of bio-char decreased with increasing reaction temperature and residue time. The formation of glucose was enhanced at lower reaction temperature （about 200℃ ）. The re-sults of moisture absorption experiments conducted on bio-char indicated that the yield of bio-char reached a sta-ble level at 260℃ for 1 h. The scanning electron microscope （SEM） analysis of bio-char showed a splintered morphology with various cellular structures.