Synthesis of Biphenyl From Benzene in Microwave Low Pressure Discharge

It is attempted to optimize biphenyl yields in 2450 MHz. discharges in pure benzene vapor in the pressure range of 1 to 20 torr. For a benzene throughput of 100 gm/hr. in a ½" tube and for 100 watts dissipated in the discharges the following results were obtained: benzene conversion 10%, biphenyl yield 50%, biphenyl energy yield 45 gm/kWhr. These values are compared with data from other workers and with our investigations in other cold or non-equilibrium discharge plasmas in benzene vapor.