Management of Natural Gas Consumption during the Manufacturing of Lead-Acid Batteries

Abstract

The production of lead-acid batteries is an energy-intensive process where 28 to 35% of the energy is used in the form of heat, usually obtained from the combustion of fossil fuels. Regardless of the importance of heat consumption during battery manufacturing, there is no discussion available in the specialized literature that assesses heat during battery manufacturing. This study assessed natural gas consumption in a battery plant based on historical data, the thermographic evaluation of different equipment, and measurements of the combustion processes and combustion gases. Heat transfer models were used to calculate surface heat losses in the various assessed processes, while combustion theory was used to identify other saving potentials. Saving potentials equivalent to 16.6% of the plant’s total natural gas consumption were identified. Replacing the ingot casting system accounts for a potential saving equivalent to 13.6% of the plant gas consumption, improving the grid casting systems for 2.8%, and the leady oxide accounts for a low 0.1%. Implementing the saving measures related to surface heat loss and poor operational practice reduced natural gas consumption by an estimated 1.2% monthly. Savings could be increased to 3.2% by expanding the saving measures to the remaining grid casting systems. Overall, natural gas consumption was reduced by an estimated 777 m3/month, GHG emissions by 1.6 tCO2eq./month, and fuel costs by 1603 USD/month.