基于K循环的KOH活化石油焦制高比表面积活性炭联产氢气  

Activation of petroleum coke with KOH based on K recycle to produce high specific surface area activated carbon and co produce hydrogen

作　　者：王克超 徐绍平[1] 王雯雯 杜利军 WANG Kechao;XU Shaoping;WANG Wenwen;DU lijun(School of Chemical Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China)

机构地区：[1]大连理工大学化工学院,辽宁大连116024

出　　处：《低碳化学与化工》2024年第11期63-69,共7页Low-Carbon Chemistry and Chemical Engineering

基　　金：国家自然科学基金(21376046)。

摘　　要：KOH活化法制备高比表面积活性炭通常需要消耗大量KOH。为提高KOH利用效率,开发了一种基于K插层-脱插循环(以下简称“K循环”)的KOH活化石油焦制备高比表面积活性炭并联产H_(2)的方法:在升温活化过程,KOH与碳质原料反应转化为单质K、K_(2)O和K_(2)CO_(3)并析出H_(2),而K_(2)CO_(3)可继续反应生成单质K和K_(2)O;在降温脱插过程,脱插试剂水蒸气与插层K、游离单质K和K2O反应生成KOH和H_(2);生成的KOH在二次升温活化时再次与碳质原料反应,如此构成K循环。在水平舟式反应器中考察了碳质原料种类(石油焦和石墨)、活化剂KOH和其活化中间产物K_(2)CO_(3)对活化过程气体产物析出规律和产品活性炭孔隙结构性质的影响,并在此基础上分析了K循环机理。结果表明,K循环效率和H_(2)产量因所用碳质原料与活化剂不同而不同:石油焦的反应活性远高于石墨,KOH活化性能优于K_(2)CO_(3)。在KOH活化石油焦的K循环过程中,KOH转化率达80%,而K_(2)CO_(3)转化率为18.5%,经由K_(2)CO_(3)的转化环节决定了K循环效率。以石油焦为碳质原料、KOH为活化剂,在活化温度为800℃及脱插温度为250℃的条件下,4.5 g干燥后的石油焦与13.5 g KOH经二次活化-脱插,所得活性炭比表面积达2808 m^(2)/g,并联产1403 mL/g H_(2)(1 g石油焦产生1403 mL H_(2))。The preparation of high specific surface area activated carbon by KOH activation method usually requires a large amount of KOH consumption.In order to improve the utilization efficiency of KOH,a method based on intercalation and de-intercalation of K(hereinafter referred to as“K recycle”)for preparing high specific surface area activated carbon and co producing H_(2)from activation of petroleum coke with KOH was developed.During the heating activation process,KOH reacted with carbonaceous raw materials and converted into K,K_(2)O and K_(2)CO_(3)and produced H_(2),while K_(2)CO_(3)can continue to react to generate K and K_(2)O.During the cooling de-intercalation process,water vapour as the de-intercalation reagent was introduced to react with the intercalated K,free state K and K_(2)O to generate KOH and H_(2).The regenerated KOH can react again with the carbonaceous raw materials during the secondary heating activation process,forming the K recycle.The effects of different carbonaceous raw materials(petroleum coke and graphite),activation agent KOH and its activation intermediate K_(2)CO_(3)on the gas evolution during activation process and the pore structure properties of activated carbon were investigated in a horizontal boat reactor.Based on this,the K recycle mechanism was analyzed.The results show that the efficiency of K recycle and H_(2)production vary with the carbonaceous raw materials and activation agents.The reactivity of petroleum coke is much higher than that of graphite,and the activation ability of KOH is better than that of K_(2)CO_(3).In the activation process of petroleum coke with KOH,the conversion rate of KOH reaches 80%,while that of K_(2)CO_(3)is only 18.5%,indicating that the efficiency of K recycle is determined by the conversion of K_(2)CO_(3).With petroleum coke as carbonaceous raw materials and KOH as activation agent,under the conditions of activation temperature 800℃and de-intercalation temperature 250℃,4.5 g dried petroleum coke and 13.5 g KOH are subjected to secondary int

关 键 词：活性炭 石油焦 K循环 KOH 氢气 

分 类 号：TQ424.1[化学工程]