*luu chon t thich hop

-phan ung tong hop NH3 la phan ung trong he ko dong nhat , khi ran, thuan nghich va toa nhiet. t toi uu giam dan theo  hieu suat chuyen hoa cang tang.khi t tang --->[NH3] giam va nguoc lai.khi khong che t theo duong t thich hop thi se cho toc do phan ung la max. t lam viec cua xuc tafc co gioi han.thong thuong t tang thi hoat tinh xuc tac tang trong khoang t [475---500*C] thi [NH3] max,duy tri t giam dan tu 500--->475*C thi thoa man cac chi tieu tren

-neu truyen nhiet trung gian thi duong t lam viec la duong gap khuc,neu la truyen nhiet noi bo thi duong t lam viec la duong tron va nam sat duong t thich hop

*lua cho ap suat

-tang p lam cho chuyen dich can bang ,lam tang toc do cua phan ung thuan, cung nhu lam giam toc do cua phan ung nghich, tao dieu kien de dang cho phan tach NH3 san pham khoi dong khi tuan hoan, cuong do san xuat cua thiet bi lon, hieu ung nhiet lon han che duy nhat cua p lon la dau tu cho thiat bi trong day chuyen, muc do kho khan doi voi yeu cau cua thiet bi. P tang =>[NH3] can bang tang suy ra toc do phan ung lon, t lam lanh de ngung tu NH3 cao, giam chi phi chat lam lanh. ngoai ra con doi hoi nang luong nen khi lon , thiet bi phuc tap, toc do an mon cao. Ptb=320at la phu hop voi dieu kien cua nuoc ta.

*toc do khong gian(KG)

-khi tang toc do KG --> phan ung cang xa can bang toc do phan ung lon --> luong NH3 tao thanh tren 1m3 xuc tac cang cao nen nhugn lam tang phu tai cua cac thiet bi trao doi nhiet , tang nang luong nen va van chuyen khi, tro luc tang va ton cong khac phuc tro luc.nhiet phan ung tren 1 dvi V phan ung tang --> luong nhiet mang ra khoi thiet bi cao, lam pha vo che do nhiet cua xtac, kho dieu chinh t tang xtac. do vay phai tinh toan toc do KG phu hop. o P=200--320 at , duy tri toc do KG=2000--3000(H^-1);P=450-->500 at duy tri v=5.10^4-->6.10^4(H^-1) P cang cao thi toc do KG cang lon

*ti le H2:N2=3:1

-day la ti le toi uu can bang con ti le H2:N2=1,5 la toi uu cho toc do phan ung.do phan ung tong hop NH3 hieu suat thap nen ta quan tam nong do NH3 ra khoi thap,vi vay chon ty le H2:N2=3:1  la phu hop voi tieu hao ty luong va cang gan voi can bang, duy tri ty le nay trong suot qua trinh phan ung

*nong do NH3 tuan hoan tro lai thap

-luong NH3 tuan hoan tra lai thap  giam => nang luong tag nhung lam giam nhiet ngung tu lam lanh de tach NH3. o 300 at chi can giam nong do NH3 tro lai thap tu 3-->1% la nhiet ngung tu NH3 trong hon hop khi giam tu -5--->-23(*C)=> rat ton chat lam lanh khi tinh den cac chi tieu ve kinh te nguoi ta lua chon NH3 tuan hoan tro lai thap tu 2-->6%

*nong do khi tro

-khi tro ko tham gia vao p/u no tuan hoan lien tuc lam nong do khi tro tang dan, can phai xa bo de duy tri nong do khi tro vao thap tong hop tu8-->12%. neu de khi tro voi nong do cao qua no se anh huong xau toi can bang va toc do p/u (<=>lam giam P he p/u). neu nong do khi tro thap qua thi luong khi xa bo nhieu gay lang phi N2,H2 va NH3. can luu chon hop ly giua tac hai lam giam toc do phan ung va ton that N2,H2,NH3 do thai bo.khi tro chu yeu laCH4 va Ar