Assembly comprising a reactor, a waste heat boiler, an actuator, a shaft, a shaft sealing element, an axial bearing and a temperature control means, wherein the waste heat boiler is connected to the reactor, wherein the shaft, the shaft sealing element and the axial bearing are arranged on a common axis, wherein the waste heat boiler has an opening through which the shaft is passed and which is sealed by the shaft sealing element, wherein the actuator is arranged outside the waste heat boiler, wherein the temperature control means is arranged inside the waste heat boiler, wherein the actuator is coupled to the shaft at a first end and wherein the actuator is designed to effect rotational drive of the shaft, wherein the temperature control means is coupled to the shaft at a second end and is designed to be adjusted by rotational motion of the shaft, wherein the axial bearing is designed to counteract a motion of the shaft in the direction of the first end of the shaft.

An exhaust gas treatment system includes: a dust collection facility that includes a denitration layer on which a denitration catalyst is carried and through which exhaust gas passes; a carbon dioxide recovery device that is positioned on a downstream side of the dust collection facility in a flow direction of the exhaust gas; a first heat recovery device that is positioned on an upstream side of the dust collection facility in the flow direction of the exhaust gas and that performs heat exchange between the exhaust gas and a heat medium; a sensor that includes a first thermometer capable of detecting a temperature of the exhaust gas flowing between the first heat recovery device and the dust collection facility, and a second thermometer capable of detecting a temperature of the exhaust gas flowing between the dust collection facility and the carbon dioxide recovery device; and a control device.