摘要
通过填料的选择、气液流动状态的比较和反应器长径比的考察,探讨了管式填料反应器中乙醛液相氧化合成过氧乙酸的新工艺。结果表明,大比表面多孔性填料和低比表面光滑性填料都不利于过氧乙酸的合成;表面粗糙的非孔性填料SA-5118能在高转化率下获得较好的选择性和收率;下向并流的气液流动状态和大的长径比更有利于PAA的合成。其中,以SA-5118为填料,采用下向并流工艺,在长径比40的管式填料反应器内,当T=55℃,Cc=9.85%(wt),Gr=200mL·min-1,P=8.136×105N·m-2,可在6.87min停留时间内,得到90.16%的转化率、84.15%的收率和93.34%的选择性。研究表明,管式填料反应器中的下向并流工艺,能在提高乙醛转化率的同时缩短反应时间,解决了提高乙醛转化率后过氧乙酸收率下降的难题,是乙醛液相氧化合成过氧乙酸并获得高收率的一条经济有效的生产工艺。
The new process of peracetic acid synthesis by acetaldehyde liquid-phase oxidation in a tubular packed reactor was studied via selecting the suitable packing material, comparing the gas-liquid flow pattern and considering the effect of the length-to-inner diameter ratio of the reactor. The results show that both the packing materials having many pores and with large specific surface area or those having very smooth surface and with small specific surface area are not appropriate for peracetic acid synthesis, and using the non-porous material with rough surface, SA-5118, as packing material, the high acetaldehyde conversion with high yield and selectivity of peracetic acid can be obtained. The gas-liquid with parallel downward flow pattern and the reactor with large length-to-inner diameter ratio are more preferable for peracetic acid synthesis. Under the reaction conditions of T = 55 ℃, Cc = 9.85%（wt）, Gr = 200mL·min^-1 and P = 8.136×10^5N·m^-2, with gas-liquid parallel downward flow pattern in the reactor having the length-to-inner diameter of 40 and packed with SA-5118, the highest yield of 84.15% and the highest selectivity of 93.34% for peracetic acid can be achieved with the residence time of 6.87 min. It can be concluded that taking the gas-liquid parallel downward flow pattern in the tubular packed reactor filled with packing SA-5118, the peracetic acid synthesis by acetaldehyde liquid-phase oxidation can be performed with high acetaldehyde conversion and high yield and selectivity of peracetic acid at shorter residence time and relatively higher temperature of 55℃. It means that the proposed new process is an economical and efficient process for peracetic acid synthesis with high yield.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2007年第2期350-355,共6页
Journal of Chemical Engineering of Chinese Universities
关键词
过氧乙酸
乙醛
液相氧化
管式填料反应器
peracetic acid
acetaldehyde
liquid-phase oxidation
tubular packed reactor
