The Isothermal Methanol Converter, or IMC, is a quasi-isothermal converter in which the reaction heat is continuously removed by means of special heat exchanging plates directly embedded in the catalyst.

The converter typically includes only single isothermal bed, with the gas flowing through the catalyst outside the plates, in an axial or axial radial flow path. All the reaction gas enters the reactor through a nozzle on the top part. The catalyst temperature is controlled by circulating BFW within the plates, which partly vaporizes as it flows upwards. The generated steam+BFW mixture is collected upon leaving the plates and conveyed outside the reactor trough a nozzle.

The reactor is equipped with BFW recycling pumps and a steam drum.