The global initiative to find alternative fuel sources to fossil fuels is an ongoing process. As such, bioethanol is used as a fuel blend with petrol. However, large number of solid wastes is produced from ethanol plants sourcing from grain and inedible plant wastes, for example, WDGS (wet distiller’s grain with soluble) and DDGS (dry distiller’s grain with soluble) produced from ethanol plants using corn. This study investigates alternative methods for using these co-products through combustion and anaerobic digestion. Process simulation and economic analysis were conducted using current market prices to evaluate the viability of the processes. Products in the form of energy are produced. Optimization of the corn ethanol plant was also explored for re-using the heat and electricity produced in those processes. The profits of combustion and anaerobic digestion were compared. It was found that these processes will supply more viable options to simply selling the grain as feed for livestock. The anaerobic digestion of WDGS to produce electricity scenario was found to have the biggest profit among the four scenarios which can bring the annual income of 14.1 million Australian dollar to the ethanol plant. An environmental analysis of the CO2 emissions was also conducted. Using the Australian state emission factor, the amount of CO2 offset through both combustion and anaerobic digestion can be seen. The anaerobic digestion of WDGS to supply heat to the plant was proved having the largest CO2 abatement with the value of 0.58 kg-CO2e/L-EtOH.