1234ze and trans hfo 1234ze with hfo 1234ze being generally preferred and trans hfo 1234ze being highly preferred in certain embodiments although the properties of cis hfo 1234ze and trans hfo 1234ze differ in at least some respects it is contemplated that each of these compounds is adaptable for use either alone or together with other compounds including its stereo isomer in connection with each of the applications methods and systems described herein for example trans hfo 1234ze may be preferred for use in certain systems because of its relatively low boiling point u2014 19 u00b0 c while cis hfo 1234ze with a boiling point of 9 u00b0 c may be preferred in other applications of course it is likely that combinations of the cis and trans isomers will be acceptable and or preferred in many embodiments accordingly it is to be understood that the terms u201c hfo 1 234ze u201d and 1 3 3 3 tetrafluoropropene refer to both stereo isomers and the use of this term is intended to indicate that each of the cis and trans forms applies and or is useful for the stated purpose unless otherwise indicated hfo 1234 compounds are known materials and are listed in chemical abstracts databases the production of fluoropropenes such as cf 3 ch ch 2 by catalytic vapor phase fluorination of various saturated and unsaturated halogen containing c 3 compounds is described in u s pat nos 2 889 379 4 798 818 and 4 465 786 each of which is incorporated herein by reference ep 974 571 also incorporated herein by reference discloses the preparation of 1 1 1 3 tetrafluoropropene by contacting 1 1 1 3 3 pentafluoropropane.