US Patent 7879920 Oxygenate to olefin manufacture and recovery process

This invention is directed to methods for forming an olefin stream from a methanol stream. A lower grade methanol, such as chemical grade or crude methanol, can be used as feed to form the olefin stream. The process uses a relatively simple distillation type step to vaporize a portion of the methanol feed stream and send the resulting vapor stream to a reaction unit to form the olefin stream. In addition, the invention provides the ability to operate the downstream recovery units with reduced fouling or plugging due to the presence of fine solids components.