Effect of additives on fusion characteristic
of ashes during rice straw combustion
MA Xiao-qin1,2, QIN jian-guang1, LUO Zhong-yang1, YU Chun-jiang1,
FANG Meng-xiang1, CEN Ke-fa1
1. Stake Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou, China, 310027 China;
2.School of Mechanics and Electronics , Henan Institute of Science and Technology ,Xinxiang, 453003 China
In order to provide references and bases for solving the problem of slag and agglomeration that occurred during biomass thermal chemical transformation of straw, experiments on combustion of pure pulverized straw and mixture of pulverized straw with additives were carried out in a pilot plant. The additives which selected by thermal equilibrium calculation included aluminum powder, silicon powder, Al2O3, SiO2, Ca3(PO4)2, CaSiO3, CaCO3, Al2(SO4)318H2O, CaSO4, CaO and (NH4)H2PO4. By analyzing ash samples, we singled out ideal additives. They are (NH4)H2PO4, Al2(SO4)318H2O, CaSO4, CaO and CaCO3. According to XRD measurements, potassium in rice straw can be turned into high melting point of potassium in the form of K2CaP2O7 with (NH4)H2PO4 as additive. CaSO4 and Al2(SO4)318H2O can make potassium be fixed in the form of K2SO4. CaO and CaCO3 are not directly involved in the reaction with alkali metals, but can react to other elements in the system, which promotes potassium in the straw to be separated from bottom ash. The result shows that adding additives to straw is one of the effective ways to solve straw ash fusion problem caused by alkali metals．
MA Xiao-Qin, QIN Jian-Guang, JIA Zhong-Yang, TU Chun-Jiang, FANG Meng-Xiang, CEN Ge-Fa. Effect of additives on fusion characteristic
of ashes during rice straw combustion. J4, 2010, 44(8): 1573-1578.
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