O_2/CO_2气氛下稻秆添加磷酸二氢铵对固钾及灰熔融特性的研究  

Influence of ammonium dihydrogen phosphates additive on potassium fixation capacity and ash fusibility for rice straw combustion in an O_2/CO_2 atmosphere

作　　者：王茜[1] 韩奎华[1] 李辉[1] 齐建荟[1] 路春美[1] 

机构地区：[1]山东大学能源与动力工程学院燃煤污染物减排国家工程实验室,山东济南250061

出　　处：《燃料化学学报》2015年第8期955-960,共6页Journal of Fuel Chemistry and Technology

基　　金：国家自然科学基金(51206096);济南高校自主创新基金(201401275)

摘　　要：研究了21%O2/79%CO2气氛下,磷酸二氢铵对稻秆不同温度下的固钾能力及对灰熔融性的影响。利用电感耦合等离子体发射光谱(ICP-AES)、X射线衍射(XRD)以及扫描电子显微镜(SEM)等检测手段,对稻秆燃烧灰中K元素含量、产物物相以及微观形貌进行分析。固定床燃烧固钾实验表明,添加NH4H2PO4能够有效提高稻秆固钾率,900℃下稻秆自身固钾率为14.65%,添加NH4H2PO4后固钾率为68.79%,可以有效抑制生物质燃烧过程中碱金属以气态形式析出,并缓解了灰结渣现象。700℃燃烧条件下NH4H2PO4和钾反应的主要产物为KPO3;900℃下反应的主要产物为高熔点物质K2Ca P2O7,从微观形貌可以看出NH4H2PO4能够抑制灰颗粒的烧结,添加NH4H2PO4能有效提升稻秆灰熔点。Particle agglomeration,fouling on the heating surface and other issues are closely related to the alkali metals during biomass thermo-chemical conversion. The potassium fixation ability and ash fusing characteristics in the combustion of rice straw（ RS） added with ammonium dihydrogen phosphate（ NH4H2PO4） were studied in a 21% O2/79% CO2 atmosphere. The reaction residue from the experiment in a drop tube furnace was analyzed with inductively coupled plasma atomic emission spectrometer（ ICP-AES）,X-ray diffraction（ XRD） and scanning electron microscopy（ SEM）. The potassium retention ratio of co-combustion of RS and NH4H2PO4 is higher than that of RS alone,especially at 900 ℃,and the retention ratio increases from 14. 65% to 68. 79%.The reaction between NH4H2PO4 and alkali metals in rice strawleads to the formation of KPO3 at 700 ℃ and K2 Ca P2O7at 900 ℃, which is a high melting point compound. SEManalysis on residue indicates the agglomeration is inhibited,and the ash fusion temperature of RS is increased by adding NH4H2PO4. These results can be helpful to the research and development of high-alkali biomass clean utilization process.

关 键 词：生物质 O2/CO2燃烧 磷酸二氢铵 碱金属 

分 类 号：TK6[动力工程及工程热物理—生物能]