The present invention is directed to processes for the production of 1233zd from 240fa and HF, with or without a catalyst, at a commercial scale. The 240fa and HF are fed to a reactor operating at high pressure. The resulting product stream comprising 1233zd, HCl, HF, and other byproducts is treated to one or more purification techniques including phase separation and one or more distillations to provide purified 1233zd, which meets commercial product specifications, i.e., having a GC purity of 99.5% or greater.