A discharge system for a destructive distillation apparatus wherein the discharge solids act as plug to avoid the unwanted flow of product gas or ambient air therethrough while effectively discharging finely divided, disperse solids material from a continuously operating distillation apparatus. The use of a positive displacement two-stage auger having close clearance between the auger and auger cylinder wall, combined with an open section within the auger cylinder where a sealing material plug forms, results in improved sealing of the inventive system from unwanted transfer of gases. The hot, disperse, and finely divided solids exiting a distillation apparatus, such as carbon black formed from the distillation of automobile tire chips, is effective in the formation of a seal plug. The solid material sealing plug feature of the present invention is primarily intended as an additional sealing feature useful in conjunction with conventional drop or lock hoppers, but in some circumstances the use of these additional mechanical systems can be eliminated when using the sealing plug technology of the present invention. Also, the provision of inert gas systems as part of the discharge system may be eliminated by the employment of the inventive sealing plug system. The provision of a sealing plug section within the auger conveyor apparatus, along with the provision of small clearances between the outer edge of the auger flight and the auger cylindrical casing, allows the continuous operation of the distillation system without unwanted passage of ambient air into the system, or the passage of distillation product gases through the discharge system, and inhibits the passage of gas surges from the distillation apparatus through the auger conveyor to the solids disposition area.