The vast range of applications for enzymes in the production of biofuels has led to a major increase in market demand in recent years. Cellulase's high cost and poor catalytic efficiency are two key barriers to its industrial usage in the production of lignocellulosic fuels in biorefineries. In this study, the techno-economic evaluation of cellulase production in solid-state fermentation (SSF) was undertaken by designing two schemes (batch and fed-batch) to optimize the process. SuperPro Designer Software was used to develop a process model that estimated the economic analysis of the fermentation processes while Monte Carlo software was used to conduct the sensitivity analysis investigation. Cellulase yield, productivity, aeration rate, and specific power input were evaluated based on their effects on the unit production cost (UPC) of the cellulase enzyme. Results showed that the batch process had a higher aeration requirement when compared to the fed-batch process. In comparison to the batch process, the fed-batch process approach had a shorter payback period of less than 2 years, a high internal rate of return (IRR) (39.14%), and a positive net present value ($142,089,000). The fed-batch process approach was also more economically feasible than the batch process route since it was more certain to achieve its base case value of UPC at the maximum. This study was able to develop a process route that lowered the cost of producing cellulase while expanding its supply on the market for the manufacture of sustainable fuel in a biorefinery.