Cau 5: nhiet do thich hop

Trong qua trinh oxihoa SO

2 -> SO3 nguoi ta luon mong muon thuc hien qua trinh o nhiet do ung voi duong nhiet do thich hop, nhung do phan ung oxihoa la phn ung toa nhiet, dong thoi nhiet do thich hop luon thay doi trong qua trinh oxihoa SO2 nen tren thuc te ta khong the thuc hien qua trinh tren duong nhiet do thich hop ma chi co the thuc hien o nhiet do dao dong xung quanh duong nhiet do thich hop.

Dau tien, we tien hanh gia nhiet cho hon hop khi SO2 va O2 toi nhiet do hoat tinh cua xuc tac ( 440-450

oC) roi dan vao lop xuc tac thu nhat. Tai day, do phan ung oxihoa la toa nhiet, dong thoi do chuyen hoa SO2 -> SO3 la kha lon (60-70%) nen nhiet do cua hon hop khi SO3 ra khoi lop xt 1 la cao nhat ( khoang 600oC). Truoc khi vao lop xt thu 2, we lam nguoi hon hop khi bang cach bo sung truc tiep 1 luong SO2 vao hon hop, viec nay khong chi lam nguoi hon hop khi ma con lam giam do chuyen hoa SO2 -> SO3, vi vay qua trinh nay ung voi doan BC tren do thi. Hon hop khi ra khoi cac lop xt tiep theo co do chuyen hoa va nhiet do tang. De nhiet do cua qua trinh luon dao dong quanh duong nhiet do thix hop, nguoi ta dat giua cac lop xt thiet bi truyen nhiet ttrung gian, loai nam ngang. Trong qua trinh nay, nhiet do cua hon hop khi giam nhung do chuyen hoa k giam, vi vay qua trinh nay ung voi cac doan nam ngang tren do thi.

Cau 4: tac dung

Trong cong ngiep nguoi ta san xuat H2SO4 bang phuong phap tiep xuc theo so do:

Dot nguyen lieu -> trao doi nhiet lam nguoi khi -> loc bui xiclon -> loc bui dien -> thap rua 1 -> thap rua 2 -> loc dien uot 1 -> tang am -> loc dien uot 2 -> say -> tach dau mo

-> oxihoa hon hop khi tao SO3 -> trao doi nhiet lam nguoi SO3 -> hap thu SO3 san xuat H2SO4

Tac dung cua tung thiet bi:

lo dot: dot nguyen lieu pirit, luu huynh ban dau sinh khi SO2

noi hoi tao doi nhiet, co 2 tac dung: + lam nguoi hon hop khi

+ lang 1 luong bui trong hh khi (15-20%)

xiclon loc bui, loc bui bang phuong phap li tam, lam sach khoang 90% bui trong khi

loc dien: loc bang cac tam luoi tinh dien, hieu suat lam sach cao ( len toi 99.9%)

thap rua 1: thuc hien nhungnhiem vu:

+ ha nhiet do cua hon hop khi, tu 350-400oC xuong con 80-90oC

+ tach cac tap chat nhu As2O3, SeO2 ... ra khoi hon hop khi

+ tach mu acid hinh thanh tu giai doan truoc ra khoi khi

+ tach 1 luong bui ra khoi hon hop khi

thap rua 2: thuc hien nhiem vu:

+ tiep tuc ha nhiet do cua hon hop khi ( tu 80-90 xuong con 30-40)

+ tach mu acid

+ laoi tap chat ra khoi hon hop khi

loc dien uot. Tach triet de luong bui ra khoi hon hop khi, dong thoi loai 1 phan mu acid

tang am, cung cap 1 luong am vao hon hop khi nham thuc day qua trinh ngung tu cua mu acid

loc dien uot 2 . tach triet de mu acid ra khoi khi

thap say : tach hoi nuoc ra khoi hon hop khi truoc khi vao giai doan oxh

tach dau mo: loai bo tap chat va dau mo trong thiet bi bi cuon theo hon hop khi

thap oxihoa: oxihoa SO2 thanh SO3

trao doi nhiet SO3 voi dong khi nguyen lieu di vao thap tiep xuc nham ha nhiet do cua SO3, dong thoi gia nhiet hon hop khi nguyen lieu toi nhiet do phan ung truoc khi vao thap tiep xuc

hap thu SO3 tao acid hoac oleum