Assessment of the Application of a Ca-Looping Cycle for CO2 Capture in an Egyptian Cement Kiln Plant

Autor: L. M. Farag
Rok vydání: 2017
Předmět:
Zdroj: Interceram - International Ceramic Review. 66:157-165
ISSN: 2523-8957
0020-5214
DOI: 10.1007/bf03401210
Popis: The mathematical model of mass and heat balance around a carbonator and calciner of a calcium looping cycle for capture of CO2 has been established. Such a model has been applied to evaluate the thermal energy requirement for the capture of CO2 evolved with preheater exit gases of an Egyptian cement kiln plant. Potentials for heat recovery from the outlet heat flows of the system have been assessed. The kiln plant operates with 15% kiln gas by pass ratio; the specific heat consumption attains 3151 kJ/kg of clinker. The entire CO2 emitted from the kiln plant attains about 0.7 kg CO2/kg of clinker or 4427.6 t CO2/d CO2/d; most of this (≈ 98%) evolves with the preheater gases. For the mass ratio of absorbant/CO2 ranging from stoichiometric (1.27) to 5, 100% CO2 capture degree and zero purged flow, heat consumption in the calciner has been estimated to be in range 5629–6790 kJ/kg CO2, corresponding to 3873–4671 kJ/kg of clinker. Fuel consumption would increase by about 20% for every kg purged CaCO3. It has been estimated that heat recovery from the cycle, e.g., through cooling of the outlet gas streams from 650 or 950°C to 150°C with 70% efficiency attains 2000–3442 kJ/kg of clinker, which represents more than 73% of the fuel consumption in the calciner. The increase of efficiency for heat recovery is accompanied by much regain of heat and better fuel economy.
Databáze: OpenAIRE
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