Depending on its composition and quantity, portions of stream 46 may be recycled to reaction section 210 of reactor 200 via stream 466, sent to quench section 310 via stream 461 for reaction quenching or subsequent cooling, or recycled via stream 462 to the quench section 310 outlet stream 312, burned as fuel, exported, used for other purposes, such as electrical power generation (not shown), or c