A study case of energy efficiency, energy profile, and technological gap of combustion systems in the colombian lime industry

In this work, the energy audits and evaluation of the kilns used in the calcination stage of the calcium oxide production process of two Colombian factories are shown. The energy intensity and usage distribution were evaluated, as well as the technological state of the presently used heating equipment as compared with the most advanced technology available for the calcination process. For the energy audits, key process data - such as fuel consumption, flue gas temperature and composition, material flows, wall temperature, and furnace configuration - was gathered in-field during visits to production plants. The energy efficiency of the vertical kilns was calculated according to the ISO – 13579 Standard.Substantial heat losses were found especially through the flue gases and kiln walls. The kiln thermal efficiencies calculated were in the range of 54% - 59%, with combustion efficiencies of 74% - 78%. The energy performance indicators of the vertical kilns were significantly below those of the most advanced technology available for the calcination stage. Potential energy savings through the introduction of the state-of-the-art kiln technology in the Colombian lime industry is discussed.