Systems and methods for producing olefins

A method for producing olefins, the method comprising:

• contacting a hydrocarbon feed stream with a particulate solid in a reaction vessel thereby reacting the hydrocarbon feed stream to form an olefin-containing product stream, wherein:
• the reaction vessel is connected to a riser,
• the reaction vessel has a maximum cross sectional area that is at least 3 times a maximum cross sectional area of the riser,
• the reaction vessel operates as a fast fluidized, turbulent, or bubbling bed reactor and the riser operates as a dilute phase riser reactor,
• the hydrocarbon feed stream comprises one or more of ethyl benzene, ethane, propane, n-butane, i-butane, methanol, ethanol, propanol, or butanol, and
• the reacting comprises one or more of dehydrogenation reactions, dehydration reactions, and methanol-to-olefin reactions;
• passing the particulate solid through the riser, the riser extending through a riser port of an outer shell of a particulate solid separation section such that the riser comprises an interior riser segment positioned in an interior region of the particulate solid separation section and an exterior riser segment positioned outside of the outer shell of the particulate solid separation section, wherein the particulate solid separation section comprises at least the outer shell defining an interior region of the particulate solid separation section, the outer shell comprising a gas outlet port, a riser port, and a particulate solid outlet port, and wherein the outer shell houses a gas/solids separation device and a solid particulate collection area in the interior region of the particulate solid separation section, and wherein the riser port is positioned on a sidewall of the outer shell such that it is not located on a central vertical axis of the particulate solid separation section;
• separating the particulate solid from the olefin-containing product stream in the gas/solids separation device;
• and
• passing the particulate solid, separated from the olefin-containing product stream, to the solid particulate collection area located proximate the central vertical axis of the particulate solid separation section.