Reduction of greenhouse gas emissions by integration of cement plants, power plants, and CO 2 capture systems

Cement plants and power plants are two of the most significant sources of greenhouse gases emissions. Many CO 2 reduction options have been proposed in literature for both sectors. They are mainly focused on CO 2 capture in power plants, but, in the short‐term, industrial processes are going to play an important role in achieving this objective. In particular, one of the disadvantages in cement plants is that CO 2 has two sources: fuel combustion and lime calcination. For this reason, proposed solutions could partially reduce a limited quantity of emissions. The sector is forced to use CO 2 capture systems for further reductions. Preliminary results about the implementation of post‐combustion and oxyfuel combustion systems for CO 2 capture show low energetic penalties and important emissions reduction. Nevertheless, a detailed analysis, not only of CO 2 emissions, but of raw materials and its disposal, primary energy and waste energy, could give optimum results from an environmental, energetic, and economic perspective. The combination/integration by industrial symbiosis of a power plant, a cement plant and a CO 2 capture system is proposed in this work. Calcium‐looping is chosen as the most suitable CO 2 capture option for this application. The re‐use of waste CaO coming from CO 2 capture in the cement plant, and the utilization of waste energy from a clinker cooling and capture system to produce additional power are the main advantages of this proposal. Process flow diagrams and heat and mass balances are calculated and presented in this work. Results show a low value of the CO 2 avoided cost, 12.4 €/t, that is smaller than in any other combination of power plant with capture system or cement plant plus capture system, making this proposal economically very attractive. Moreover, an important amount of CO 2 emissions is avoided ‐ 94% ‐ due to the energetic efficiency augmentation, the reduction of raw and decarbonizated materials, and the CO 2 capture system. © 2011 Society of Chemical Industry and John Wiley & Sons, Ltd