Integrated techno-economic and life cycle assessment of corn straw-derived fuel ethanol: A case study in china

The second-generation bioethanol faces the problems of high production costs and complex environmental impacts. This study combines life cycle assessment (LCA) and technical and economic analysis (TEA) to evaluate the production of corn straw ethanol in China. The factory has an annual production capacity of 50,000 tons. The results of the life cycle assessment show that the net energy ratio is 1.31 and the renewable index is 1.99, indicating good energy performance. When the E10 proportion is added, fossil fuel consumption is reduced by 6% compared to gasoline, but the global warming potential only decreases by 1%. The acidification degree increases by 37% and the eutrophication degree increases by 453%, mainly due to the use of fertilizers and coal-based backup energy. The technical and economic analysis shows that the production cost of each ton of ethanol is 6,092 yuan RMB, with the cost of corn straw and enzymes accounting for more than half of the total cost. The net present value of the benchmark project is -89.3 million yuan RMB, and the internal rate of return is only 7.15% (below the benchmark level of 12%), with a payback period exceeding 10 years. The sensitivity analysis indicates that the ethanol sales price is the most critical factor affecting the project's feasibility; if the price drops by 7.1%, the project will not be implemented. If the enzyme cost is reduced by 50% or a direct subsidy of 1,000 yuan RMB per ton of ethanol is provided, the internal rate of return can be increased to approximately 12%. Policy recommendations include production subsidies, carbon credits, and integrated biorefinery models. The research results emphasize the need for policy support to coordinate environmental benefits with economic feasibility.