Yang Shuo, Luo Jintao, Gao Yu, Wang Shaohui, Zhang Yupeng, Wang Yuhang, Ge Pushi, Li Wanqi, Zheng Yunyi, Cui Jie, Fu Yudong, Pan Honggang
Laboratory of Liaoning Province for Clean Combustion Power Generation and Heating Supply Technology, Shenyang Institute of Engineering, Shenyang 110136, China.
ACS Omega. 2024 Dec 11;9(51):50705-50719. doi: 10.1021/acsomega.4c08820. eCollection 2024 Dec 24.
There are many problems in the direct combustion of biomass, such as low combustion efficiency and easy slagging. In this paper, rice husk (RH) was taken as the research object, and the effects of different washing pretreatment conditions (washing time (WTI), washing temperature (WTE), and particle size) on the combustion characteristics and ash formation characteristics were discussed. The results show that the combustion characteristics of RH were significantly coupling-affected by the WTE and WTI, and the comprehensive characteristics of volatile release were significantly coupling-affected by the particle size and WTI. Specifically, under the condition of high-temperature washing, prolonging the WTI will increase the ignition temperature of washed RH powder. The particle size could affect the temperature of the maximum rate of decomposition. Under the same conditions, the temperature difference of maximum rate of decomposition between washed RH powder and RH was 5-10 °C. For the original RH, the longer the WTI, the more unfavorable it was to increase the maximum weight loss rate, and the opposite was true for RH powder. With the increase in WTE, the flammability index, burnout temperature, and volatile devolatilization initial temperature increased obviously. In addition, washing pretreatment could reduce the ashing quality of RH and RH powder to varying degrees, and the ash quality was decreased by about 15% compared with that of unwashed RH. The alkali metal removal effect of washed RH powder was better than that of washed RH. The proportion of alkali metal K was decreased from 1 to 4% (washed RH) to 0.2-1% (washed RH powder). The ash deposit and slagging phenomenon were obviously improved. Under the same WTI, the higher the WTE was, the better the removal effect of alkali metals was. Correspondingly, the proportion of the eutectic composite salt of Mg-Fe-Al with a high melting point increased in the high-temperature sintering stage, which effectively improved the ash melting point and reduced the probability of ash deposit and slagging.
生物质直接燃烧存在诸多问题，如燃烧效率低和易结渣等。本文以稻壳（RH）为研究对象，探讨了不同水洗预处理条件（水洗时间（WTI）、水洗温度（WTE）和粒径）对燃烧特性及灰分形成特性的影响。结果表明，WTE和WTI对RH的燃烧特性有显著的耦合影响，粒径和WTI对挥发分释放综合特性有显著的耦合影响。具体而言，在高温水洗条件下，延长WTI会提高水洗RH粉末的着火温度。粒径会影响最大分解速率温度。在相同条件下，水洗RH粉末与RH之间最大分解速率的温差为5 - 10℃。对于原始RH，WTI越长，越不利于提高最大失重率，而对于RH粉末则相反。随着WTE的增加，可燃指数、 burnout温度和挥发分初始挥发温度明显升高。此外，水洗预处理能不同程度降低RH及RH粉末的灰化质量，与未水洗RH相比，灰分质量降低约15%。水洗RH粉末的碱金属去除效果优于水洗RH。碱金属K的比例从1 - 4%（水洗RH）降至0.2 - 1%（水洗RH粉末）。积灰和结渣现象明显改善。在相同WTI下，WTE越高，碱金属去除效果越好。相应地，在高温烧结阶段，高熔点的Mg - Fe - Al共晶复合盐比例增加，有效提高了灰熔点，降低了积灰和结渣的概率。
