Advanced Bio-Butanol Production From Corn Stover
Designing a full-scale biochemical process for sustainable ABE fermentation.
Project Type: Group Design Project (Master’s Programme)
Year: 2020
Institution: University of Bath (UK)
Context
Bio-butanol has emerged as a promising low-carbon alternative to petrochemical fuels, offering higher energy density and compatibility with existing fuel infrastructure. However, large-scale production faces challenges related to feedstock availability, process efficiency, and solvent recovery. This design project explored the full transformation of corn stover, a widely available agricultural residue, into acetone-butanol-ethanol (ABE) solvents through an integrated biochemical pathway.
Our team developed a full industrial process design covering pretreatment, hydrolysis, fermentation, product recovery, waste treatment, and heat integration. The goal was to determine whether a corn-stover-to-butanol system could be technically feasible, economically competitive, and environmentally sustainable at industrial scale.
Research Objectives
1. Develop a Complete Process Model
A full mass- and energy-balanced process model was developed, integrating mechanical size reduction, alkaline hydrolysis and enzymatic saccharification, Clostridium-based ABE fermentation, and solvent separation via distillation. The model quantified material flows, utility demands, and performance metrics across all unit operations.2. Detailed Process Flow Diagram (PFD)
A comprehensive PFD was constructed to capture biomass conversion pathways, fermenter configurations, product-recovery sequences, and waste-handling and heat-integration systems. This diagram formed the basis for equipment sizing and all downstream design calculations.3. Techno-Economic Assessment (TEA)
Capital and operating costs were evaluated across feedstock logistics, fermentation performance, distillation energy demand, and equipment and utilities. This assessment established the overall financial viability of the process and enabled comparison with conventional petrochemical butanol production.4. Environmental & Sustainability Assessment
Environmental performance was assessed through energy requirements, process emissions, wastewater impacts, and opportunities for heat recovery and waste valorisation. This provided an integrated view of the system’s sustainability profile.
Key Findings
1. Technical Performance
Using 211,338 tonnes of corn stover annually enabled production of 40,000 tonnes of butanol, plus ethanol and acetone by-products. Saccharification and fermentation achieved high sugar-conversion rates under optimised conditions.
Integrated distillation successfully recovered solvents to marketable purity.
2. Energy & Process Efficiency
Heat integration strategies (e.g., waste-heat recovery) significantly reduced steam demand. Fermenter design and improved sugar availability enhanced solvent productivity.
Equipment sizing and recycle loops proved scalable and industrially realistic.
3. Economic & Environmental Insights
The proposed system demonstrated: Potential profitability, with competitive operating costs.
Reduced environmental burden compared to fossil-derived butanol.
Strong improvement pathways, including enhanced microbial yields and alternative separation technologies.
Overall Impact
This design project demonstrated that corn-stover-based butanol production can be technically feasible, economically competitive, and environmentally advantageous. The system we developed provides a credible blueprint for scaling bio-based fuels and advancing the circular bioeconomy.
The work highlights how agricultural residues can be converted into high-value chemicals through integrated, sustainable, and systems-driven engineering design.
Tools & Methods
Mass & Energy Balancing
Aspen / Process Modelling Principles
Fermentation & Biochemical Engineering
Equipment Sizing & Design
Techno-Economic Analysis
Environmental Assessment
Aspen / Process Modelling Principles
Fermentation & Biochemical Engineering
Equipment Sizing & Design
Techno-Economic Analysis
Environmental Assessment
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