Modular system for reducing sulfur dioxide

A system for reducing sulfur dioxide comprising a reactor vessel divided into a plurality of modular reactor vessel sections, each section including a lower hopper portion and an upper portion having at least one wall connecting with a wall of said hopper portion, said sections being connected in an abutting relation so that said walls together define an upper boundary wall of the reactor vessel, partition means disposed within said upper boundary wall for dividing the upper portion of said vessel into a plurality of compartments respectively communicating with said hopper portions, a coal inlet located in the upper portion of each compartment, a single coal supply means for continuously supplying coal to each compartment through the respective coal inlets so that the coal will pass downwardly by gravity through said compartments and their corresponding hopper portions, a gas inlet located in each hopper portion, gas supply means for continuously supplying gas to each hopper portion through the respective gas inlets so that the gas will pass upwardly through said hopper portions and their corresponding compartments and contact said coal in a counterflow relation, gas discharge means located in the upper portion of each compartment, and coal discharge means located in the lower portion of each hopper.