筛板塔精馏实验

实验结果处理：将塔顶、塔底温度和组成，以及各流量计读数等原始数据列表及其处理结果（1）全回流时：原始数据项目全回流状态全回流状态（质量百分数）乙醇的摩尔数全回流(摩尔百分数）塔顶温度/℃77.5塔底温度/℃90.7进料温度/℃20.9回流液温度/℃42塔顶乙醇含量%89.783886.205585881.8740340.778209807塔底乙醇含量%8.09677.573583420.1646430.032492006塔顶水含量%10.21629.613814120.534101塔底水含量%91.903388.245816584.902545第一块塔板乙醇含量%Xn-190.212786.618445021.883010.786496637Xn88.861685.317876161.8547360.760713274第十块塔板乙醇含量%Xn-161.033958.530932141.2724120.380506635Xn17.044616.186831960.3518880.073679565第一块塔板水含量%Xn-19.78739.200954980.511164Xn11.138410.501523840.583418第十块塔板水醇含量%Xn-138.966137.288467862.071582Xn82.955479.632568044.424032（2）部分回流时：原始数据项目部分回流状态部分回流状态（质量百分数）乙醇（水）摩尔数乙醇摩尔分数进料液流量F塔顶温度/℃6塔底温度/℃90塔釜残余液流量W进料温度/℃21.64.5回流液温度/℃41.1塔顶产品流量D塔顶乙醇含量%86.042982.60461.79580.70981.5塔底乙醇含量%8.0017.48150.16260.0321塔顶回流流量L进料乙醇含量%37.720536.08950.78460.19122塔顶水含量%13.957113.21480.7342回流比R塔底水含量%91.99988.33794.90771.3333进料水含量%62.279559.72993.31832.按全回流和部分回流分别用图解法计算理论板数。（1）全回流时由图可知NT=5，NP=10所以全塔效率ET=NT-1/NP=5-1/10=0.4单板效率：EML=xn-1-xn/xn-1-xn＊对第一块塔板：xn-1=0.78650，xn=0.76071，全回流yn=xn=0.76071则由气液平衡相图可知xn＊=0.71346则EML=xn-1-xn/xn-1-xn＊=(0.78650-0.76071)/(0.78650-0.71346)=0.3531同理：对第十块塔板：xn-1=0.38051，xn=0.07368全回流yn=xn=0.07368则由气液平衡相图可知xn＊=0.006353则EML=xn-1-xn/xn-1-xn＊=（0.38051-0.07368）/(0.38051-0.006353)=0,8201（2）部分回流时：附注：质量百分数y与响应百分数x之间数学关系：y=0.9626x-0.2203摩尔百分数=醇的摩尔数/(醇的摩尔数+水的摩尔数)精馏段回流液流量L=2.0l/h，进料量F=6.0l/h,塔顶产品流量D=1.5l/h由于是冷液进料，xF=0.1912时，查图知泡点温度为84℃，乙醇汽化热为1025KJ/Kg，水为2550KJ/Kg，进料温度为21.6℃则平均温度为（84+21.6）/2=52.8℃，该温度下水和乙醇的比热容分别为2.92KJ/(Kg*℃),4.26KJ/(Kg*℃),其对应的CP=2.92*46*0.1912+4.26*18*(1-0.1912)=87.795KJ/(Kmol*℃)rm=0.1912*1025*46+(1-0.1912)*2550*18=46139KJ/Kmolq=CP*△T/rm+1=1.119回流比R=(1+x)*L/D,其中x=CP*△T/rm,△T=汽化t-实际t（进料）=84-21.6=62.4℃,x=0.119R=(1+x)*L/D=1.119*2.0/1.5=1.492由上开始做精馏段操作线：过（xD，xD）点，y轴截距y=x