An Evaluation of the Energy Consumption and Co2 Emission associated with Corn Cob Ash Compared with the Cement Clinker

摘要

This study compares the energy consumption and the carbon dioxide emission associated with the production of Corn Cob Ash with a view to determining its viability and environmental sustainability as a pozzolan. CCA meeting the requirements of ASTM C618-12 (1994) was produced through two separate processes of open air burning and controlled incineration in an electric muffle furnace. In the first method the quantity of kerosene fuel used in the burning process was measured used in computing the external energy input and the associated CO 2 emission, using published World Bank data on heating, thermodynamic property and carbon content of various fuels. In the second method, the energy consumption was computed as a product of the name plate rating (in KW) of the muffle furnace and the time taken (in hours) to turn the measured quantity of corn cob to ash. The result reveals the ash yield of corn cob as an average of 3.6% and 1.7% for open air burning and controlled incineration respectively. Corresponding values for energy consumption were 4.3MJ and 216166MJ per kg of ash respectively. CO 2 emission associated with the fuel consumption in open air burning was 0.27Kg per Kg of pozzolanic ash. These compare more favorably with the corresponding data of 5.16MJ and 0.97Kg CO 2 established for Portland cement clinker production; in that less energy was consumed and less CO 2 was emitted and at the same time found an alternative use for the biomass waste. The paper concludes that CCA is a viable and environmentally sustainable source of pozzolan when it is derived from burning processes that take advantage of corn cob as a fuel, rather than being specially burnt in a furnace. The paper therefore recommends that biomass waste be should be promoted as a clean energy source and the resulting ash harnessed as pozzolan as a way of reducing the consumption of cement; leading to reduced green house gas emissions and contribution to global warming from the construction industry.