摘要
采用硅循环技术回收NaY含硅滤液中的硅制备硅铝胶回用于NaY分子筛合成过程。考察NaY含硅滤液放置时间、悬浮物含量、硅铝胶回用NaY合成比例、硅铝胶放置时间对制备硅铝胶质量及硅铝胶合成NaY分子筛物化性质的影响。结果表明,在滤液悬浮物(300~3200)mg·L^(-1)时,60℃恒温放置不超过11 h,滤液中无P型杂晶产生;滤液夹带悬浮物能促进Y型晶体加速增长;放置(11~23)h滤液中悬浮物开始产生P型杂晶,不利于Y型晶体增长,滤液放置时间对制备硅铝胶的物化性质无明显影响。制备硅铝胶回用于合成NaY,随着硅铝胶回用比例提高(20%~35%),NaY晶体增长速率先快后慢,当硅铝胶回用比例27%时,NaY晶体增长速率最快。硅铝胶机搅(96~120)h,回用于硅铝胶合成NaY后不能制备合格的NaY分子筛。
Silica-recycling technology is used to recover silicon in the NaY silica-containing filtrate to prepare silica-alumina gel and recycle it to the NaY zeolitesynthesis process.Effects of storage time of silica containing filtrate,content of suspended solids,proportion of NaY zeolite synthesized by recycling silica-alumina gel and the storage time of silica-alumina gel on quality of as-prepared silica-alumina gel and quality of NaY zeolite synthesized by silica-alumina gel were investigated.The results showed that there is no p-type hybrid crystal in the filtrate while suspended solids in the filtrate,which promotes the growth of Y-type crystals,of(300-3200)mg·L^(-1) are stored at fixed temperature of 60℃for no more than 11 hours.The suspended solids in the filtrate stored for(11-23)h begin to produce p-type hybrid crystals,which inhibits growth of Y-type crystals.Storage time of the filtrate has no significant effect on physicochemical properties of the prepared silicon aluminum gel.The growth rate of NaY crystal first accelerates and then slows down with increasing recycle ratio of silicon aluminum gel(20%-35%).Fastest growth rate of NaY crystal was attained at silicon aluminum gel recycle ratio of 27%.Qualified NaY molecular sieve can not be synthesized by silicon aluminum gel when it is stirred for(96-120)h.
作者
单高峰
袁海亮
常玮
Shan Gaofeng;Yuan Hailiang;Chang Wei(Sinopec Catalyst Co.,Ltd Changling Division,Yueyang 414012,Hunan,China)
出处
《工业催化》
CAS
2021年第10期32-37,共6页
Industrial Catalysis
关键词
催化剂工程
NAY分子筛
含硅滤液
硅循环
P型杂晶
catalyst engineering
NaY zeolite
silica-containing filtrate
silicon recycle
P-type crystal
