UBUHANZI
UBWIZA N'UBUZIMA
UBUKORIKORI
UMUCO N'AMATEKA
IMYIDAGADURO
IBIDUKIKIJE
IBIRIBWA N'IBINYOBWA
UBWUBATSI BUSUBIRA INYUMA
UBUMENYI
SIPORO
IKORANABUHANGA
IBYAMBARWA
Para-Xylene by Three-Stage Crystallisation from Xylene
Para-xylene melts at 15 °C (Lunge, 1887), so it crystallises out of mixed xylene when this is chilled hard. This is Talbot's three-stage process (US 2,985,694, 1961): chill the dry feed to about −95 °F and spin off the crystals, then warm them in stages in their own recycled liquor and spin again, until they are 98.5 % para-xylene. Para-xylene is the raw material for terephthalic acid and so for PET.
The picture: our diagram of the three stages.
Hejuru
1 day
Amabwiriza
1
1
Take out the ortho-xylene (preferred)
Take out the ortho-xylene (preferred)
If you can, first distil off ortho-xylene as the bottoms of a tall column: more than 35, better about 60, theoretical plates. The patent prefers this but does not require it.
Ibikoresho by'iyi ntambwe:
Ksilene1 as requiredIbikoresho bikenewe:
Iteraniro ry'inkingi yo gupika
Inkono itanga umwuka w'amazi
Igipima Ubushyuhe cy'Ubushakashatsi2
2
Dry the feed and add a little methanol
Dry the feed and add a little methanol
Remove all water from the xylene (calcium chloride is our choice of drier). Add methanol so ice does not plug the cold equipment: the patent's example uses 49 lb methanol to 13,430 lb feed.
Ibikoresho bikenewe:
Kloridi ya kalisiyumu
Metanol
Ikigega cyo gukora kirisitali3
3
Chill to about −95 °F and spin
Chill to about −95 °F and spin
Cool slowly, over about 20 minutes, to between −75 and −120 °F (−59 to −84 °C); the example uses −95 °F (−71 °C). Spin the slurry in a centrifuge: the liquid (about 8 % para) goes out, the crystals are about 74 % para-xylene.
Ibikoresho bikenewe:
Kirisitalizeri ikonjesha
Santrifuje y'igiteboIgipima Ubushyuhe cy'Ubushakashatsi
Uturindantoki twihanganira ubushyuhe
Amadarubindi yo Kwirinda Ibinyabutabire4
4
Reslurry, bring to −30 °F, spin
Reslurry, bring to −30 °F, spin
Stir the crystals into the liquid from the next stage and bring the slurry to between 0 and −30 °F (−18 to −34 °C); the example uses −30 °F. Centrifuge again: the crystals are now about 91 % para-xylene.
Ibikoresho bikenewe:
Ikigega cyo gukora kirisitaliKirisitalizeri ikonjeshaSantrifuje y'igiteboIgipima Ubushyuhe cy'UbushakashatsiUturindantoki twihanganira ubushyuhe5
5
Reslurry warmer, spin and melt
Reslurry warmer, spin and melt
Stir these crystals into the liquid from the last spin and bring to 10–45 °F (−12 to 7 °C). Centrifuge: the crystals are 98.5 % para-xylene. Melt them and bottle. Return the liquids to the earlier stages.
Ibikoresho bikenewe:
Ikigega cyo gukora kirisitaliKirisitalizeri ikonjeshaSantrifuje y'igiteboIgipima Ubushyuhe cy'Ubushakashatsi
Amacupa y'ikirahuri afite ibipfundikizoIbikoresho bikenewe
11- Umwanya
- Umwanya
- Umwanya
- Umwanya
- Umwanya
Iki gishushanyo gikora
Blueprint zijyanye
Izi blueprint zisangira ubumenyi — uburyo, ibikoresho cyangwa amahame
CC0 Umurenge rusange
Iyi blueprint yasohowe munsi ya CC0. Ushobora gukoporora, guhindura, gukwirakwiza no gukoresha nta kwemererwa.
Shyigikira Umuremyi ugura ibicuruzwa binyuze muri Blueprint ye Komisiyo y'Umuremyi byashyizweho n'Abacuruzi, cyangwa kora verisiyo nshya y'iyi Blueprint ukayinjiza nk'isano muri Blueprint yawe kugira ngo musangire inyungu.