Patent ID: 8435470

Claim:
An improved method for separating CO 2 from combustion exhaust gas produced in a furnace through the combustion of carbon based fuels or wastes with air as an oxidizing agent, the method comprising the following steps: discharging the CO 2 -containing combustion exhaust gas mass flow from the furnace into a carbonator of a carbonate looping system, the carbonate looping system including at least one carbonator and at least one calciner and having a carbonate-forming sorbent flowing within the loop; combining the sorbent with the CO 2 of the combustion exhaust gas mass flow within the carbonator to form a carbonate; sending the carbonate as a carbonate-solids mass flow to the calciner; burning the carbonate in the calciner at a carbonate-specific calcination temperature by adding heat produced by an additional firing that uses oxygen as the oxidant, whereby a regenerated sorbent and a gas substantially containing CO 2 are formed; sending the hot regenerated sorbent to the carbonator as a sorbent-solids mass flow for carbonization of CO 2 ; and sending the hot gas as a gas mass flow for further treatment; wherein the improvement comprises replacing at least a portion of the additional firing with heat that is removed from one or more heat sources and is sent through indirect heat exchange to the carbonate-solids mass flow before the carbonate-solids mass flow enters the calciner; and wherein the sorbent-solids mass flow is used as a heat source and the removal of a part of its contained heat by the carbonate-solids mass flow takes place in a heat exchanger prior to the entry of the sorbent-solids mass flow into the carbonator, the heat exchanger physically separating the carbonate-solids mass flow from the sorbent-solids mass flow.