CAJ | 학술논문

研究了固定床上生物质及热解焦 CO 2气化过程中碱金属及碱土金属(AAEMs)的析出特性。利用原子吸收光谱仪,考察了不同生物质种类、不同热解制焦温度对 AAEMs 析出的影响。不同生物质由于其挥发分含量不同引起气化失重率的差异,焦气化活性随制焦温度升高而降低。生物质及焦气化过程中 Na 析出率最大,其次是 K,碱土金属析出率低于碱金属,这与元素在生物质中的存在形式、金属价态有关。低温段 K 的析出率随热解制焦温度的提高而增加,而 Na 在热解与气化段总的析出率与制焦温度关系不大。生物质的种类尤其是灰中的 Si 含量对 Ca 和 Mg 的析出影响较大,气化效率高的生物质AAEMs 析出较多。热力学计算结果显示,气化过程中 Na、K 多以氯化物的形式存在并析出,Ca、Mg 则更倾向于形成硅酸化合物而不易析出。
연구료고정상상생물질급열해초 CO 2기화과정중감금속급감토금속(AAEMs)적석출특성。이용원자흡수광보의,고찰료불동생물질충류、불동열해제초온도대 AAEMs 석출적영향。불동생물질유우기휘발분함량불동인기기화실중솔적차이,초기화활성수제초온도승고이강저。생물질급초기화과정중 Na 석출솔최대,기차시 K,감토금속석출솔저우감금속,저여원소재생물질중적존재형식、금속개태유관。저온단 K 적석출솔수열해제초온도적제고이증가,이 Na 재열해여기화단총적석출솔여제초온도관계불대。생물질적충류우기시회중적 Si 함량대 Ca 화 Mg 적석출영향교대,기화효솔고적생물질AAEMs 석출교다。열역학계산결과현시,기화과정중 Na、K 다이록화물적형식존재병석출,Ca、Mg 칙경경향우형성규산화합물이불역석출。
The releasing characteristics of alkali and alkaline earth metals (AAEMs) during CO2 gasificationprocess of biomass and pyrolyzed char were explored in a fixed bed reactor. The amount of AAEMs releasing during the gasification of various feedstocks at different pyrolysis temperatures was determined by atomic absorption spectroscopy. Differences in weight loss of biomass during gasification are resulted from the diversity of volatile content in different biomass feedstocks. Along with the increasing of pyrolysis temperature, thereactivity of char gasification is decreased. It is found that the releasing amount of Na is larger than that of K , and that of alkaline earth metals is less, which is related to their existence form and metal valence. Theincreasing of pyrolysis temperature can improve the release of K at low temperatures on the release of Na during the whole pyrolysis and gasification process. The type of biomass especially the Si , while it has little influence content in ash has a significant impact on the migration of Ca and Mg, and higher char gasification conversionleads to a larger releasing amount of AAEMs. Results of thermodynamic calculations show that K and Na are released mostly in the form of chloride, while Ca and Mg mainly exist in the form of silicate which is hard torelease.