文献类型：期刊文献

中文题名：生物质与煤共气化过程碱金属的迁移与转化

英文题名：Migration and transformation of alkali and alkaline earth metals during co-gasification of biomass and coal

作者：梁阳[1];亚力昆江·吐尔逊[1];高干[1];钟梅[1];代正华[1];李建[1];刘洋[1];张显显[1];袁万能[2];许晓兵[2];李涛[2];沈中杰[3]

机构：[1]新疆大学省部共建碳基能源资源化学与利用国家重点实验室,新疆乌鲁木齐830017;[2]宝钢集团新疆八一钢铁有限公司,新疆乌鲁木齐830022;[3]华东理工大学资源与环境工程学院,上海200237

年份：2025

卷号：53

期号：12

起止页码：1817

中文期刊名：燃料化学学报(中英文)

外文期刊名：Journal of Fuel Chemistry and Technology

收录：;EI(收录号：20255019693780);北大核心:【北大核心2023】；

基金：新疆维吾尔自治区重点研发计划(2022B03026-1);新疆维吾尔自治区自然科学基金(2023D01D02);省部共建碳基能源资源化学与利用国家重点实验室开放课题(KFKT2022ZD-00002-1)资助~~。

语种：中文

中文关键词：生物质;共气化;AAEMs;赋存形态

外文关键词：biomass;co-gasification;AAEMs;occurrence form

摘要：本工作利用固定床反应器研究了次烟煤与两种典型生物质(榆树和棉秆)的共气化过程,通过在不同气化剂(空气和CO_(2))及不同停留时间下对气化残留焦炭进行逐级浸出实验,分析了不同赋存形态碱(土)金属元素(AAEMs)的迁移转化规律。研究结果表明,碱金属的挥发行为可分为两个特征阶段:第一阶段为热解脱挥发分阶段,该阶段碱金属元素挥发量占总挥发量的40.74%-93.10%,大量碱金属在热解过程中被瞬时释放的挥发分携带进入气相。在0-5min空气气氛下煤/棉秆混合样品中钾元素(K)的挥发率为30%,钠元素(Na)为32%,而煤/榆树混合样品中K的挥发率高达49%;随着反应温度升高,挥发量显著增加,延长停留时间至5min后,K的挥发量提升至44%,Na提升至63%。空气气氛下煤/棉秆混合样品中的钙元素(Ca)比煤/榆树样品更易挥发,而CO_(2)气氛则显著改变了Ca的挥发特性。第二阶段为气固反应灰化阶段,该阶段反应速率相对较慢,K、Ca、Na、Mg等碱(土)金属元素在气化半焦与气化剂(空气或CO_(2))的持续接触过程中发生显著的赋存形态转变。在5-120min空气气氛下棉秆样品中的水溶态K、不溶态K和乙酸铵溶态K逐步转化为盐酸溶态和挥发相;煤/榆树混合样品中的Ca元素在空气气氛下,其盐酸溶态含量从35%降至13%,而挥发相比例从11%增至27%。同时,各类赋存形态的Na(包括水溶态、乙酸铵溶态和难溶态)均向挥发相转化;镁元素(Mg)主要以乙酸铵溶态(55%)存在,且其赋存形态随停留时间变化较小。随着停留时间延长,在空气气氛下K和Ca会与S、Al、Si等元素结合形成CaSO4、KAlSiO4等稳定化合物;而在CO_(2)气氛下则主要生成CaCO3、CaS、MgS等特征组分。
This paper utilized a fixed-bed reactor to study the co-gasification process of sub-bituminous coal with two typical types of biomass(elm and cotton stalk).Through stepwise leaching experiments on gasification residual char under different gasifying agents(air and CO_(2))and different residence times,it systematically analyzed the migration and transformation patterns of alkali and alkaline earth metallic(AAEMs)elements with different occurrence modes.The research results indicate that the volatilization behavior of alkali metals can be divided into two characteristic stages:The first stage is the devolatilization stage during pyrolysis,during which the volatilization amount of alkali metal elements accounts for 40.74%?93.10%of the total volatilization;a significant amount of alkali metals is carried into the gas phase by the instantaneously released volatiles during pyrolysis.Within the reaction time of 0?5 min,the volatilization rate of potassium(K)in the coal/cotton stalk mixed sample under air atmosphere was 30%,and that of sodium(Na)was 32%,whereas the volatilization rate of K in the coal/elm mixed sample reached 49%;with increasing reaction temperature,the volatilization amount increased significantly.After extending the residence time to 5 min,the volatilization amount of K increased to 44%,and that of Na increased to 63%.Notably,calcium(Ca)in the coal/cotton stalk mixed sample under air atmosphere is more volatile than in the coal/elm sample,while the CO_(2)atmosphere significantly altered the volatilization characteristics of Ca.The second stage is the gas-solid reaction char-ash transition stage,during which the reaction rate is relatively slow;significant transformations in the occurrence modes of alkali and alkaline earth metallic elements(K,Ca,Na,Mg,etc.)occur through sustained contact between gasification semi-char and the gasifying agent(air or CO_(2)).Within the residence time of 5?120 min,water-soluble K,insoluble K,and ammonium acetate-soluble K in the cotton stalk sample under air atmosphere progressively transformed into hydrochloric acid-soluble forms and the volatile phase;in the coal/elm mixed sample under air atmosphere,the hydrochloric acid-soluble Ca content decreased from 35%to 13%,while the proportion of the volatile phase increased from 11%to 27%.Concurrently,all occurrence forms of Na(including water-soluble,ammonium acetate-soluble,and residual forms)converted to the volatile phase.Magnesium(Mg)primarily existed in the ammonium acetate-soluble form(55%),with minimal variation in its occurrence mode over residence time.With prolonged residence time,K and Ca combined with elements such as S,Al and Si under air atmosphere to form stable compounds like CaSO4 and KAlSiO4;whereas under CO_(2)atmosphere,characteristic components such as CaCO3,CaS and MgS were predominantly generated.