A multi-bed catalytic converter comprising at least a first catalytic bed, a second catalytic bed and a heat exchanger arranged between said first bed and said second bed, wherein said heat exchanger is arranged to transfer heat from the hot effluent of the first bed to a cooling medium; said heat exchanger comprises a plurality of stacked round plates, wherein adjacent plates define gaps therebetween, and the effluent of the first catalytic bed and the cooling medium are respectively fed into alternate gaps.