Prospects towards sustainability: A comparative study to evaluate the environmental performance of brick making kilns in Pakistan

Abstract

For years the brick kiln industry has been perceived as the main stationary source of environmental pollution. Life cycle assessments (LCA) are necessary to comprehend and improve process leakages and environmental risks associated with the expansion of this sector. The present study offers a comparative approach to analyse economic statistics and environmental impacts of three different brick-making technologies in Pakistan. Emission factors for various pollutants were calculated from the three brick kilns followed by determining the concentration of various pollutants. SimaPro software was used to perform LCA analysis on all stages of brick making at selected brick kilns sites. At the Hoffman kiln, the brick production-based emission factors for CO, PM2.5, CO2, and SO2 resulted in 33%, 82%, 29%, and 58% reduction compared to the Fixed Chimney Bull's Trench Kiln (FCBTK) technology. The characterized impacts indicated that woods chips burdened 9 out of 10 impact categories at FCBTK while at Induced Draught Zigzag Kiln (IDZZK) and Hoffman kiln, the hard coal turned out to have a major negative influence on the environment. An on-grid photovoltaic (PV) system of 47 kW at Hoffman kiln was modeled on RETScreen expert software generating a total of 64,544 kWh units of electricity, delivering 64,284 kWh to the kiln load, and exporting 260 kWh back to the grid on annual basis. The system generated substantial financial and environmental benefits with the payback time of 3 years, benefits to cost ratio of 12.2, and reduction of 66.3 tons of CO2releasedper year thus reducing the problem of harmful emissions being released at power generation end. The outcome of this study highlights that Hoffman kilns in Pakistan can result in lesser emissions, better resource efficiency, increased sustainability, and better quality of bricks.