Renewable Fuel Production with MVR and Stillage-to-Olefin Integration
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Solution Overview
Problem
Current biogas production and ethanol production technologies are inefficient, leading to high carbon footprints and low energy density fuels, and there is a need for systems that produce stillage specifications with low nitrogen concentrations and high energy density fuels with zero or low carbon footprints.
Innovation Solution
A system for producing renewable hydrocarbons from carbohydrates, including a fractionation subsystem, fermentation subsystem, water treatment subsystem, alcohol enrichment subsystem, and hydrocarbon production subsystem, with energy management, utilizing mechanical vapor recompression and integrated heat systems to minimize external energy use and maximize energy density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If current biogas production and ethanol production technologies are used, then alcohol production is achieved, but the process creates waste products, has high nitrogen concentrations, and results in low energy density fuels with high carbon footprints
Solution Approach 1:
The patent combines multiple previously separate processes into an integrated system: anaerobic digestion for biogas production, distillation for alcohol recovery, and catalytic dehydration for ethylene production all occur within a unified process flow. This integration allows waste streams from one process to become feedstocks for another, eliminating waste products and reducing carbon footprint while maintaining high alcohol production efficiency
Solution Approach 2:
The system recovers and repurposes materials that would otherwise be discarded: stillage from distillation is fed to anaerobic digestion to produce biogas, and the biogas is then dehydrated and catalytically converted to ethylene and other valuable hydrocarbons. This circular approach eliminates waste products and reduces the carbon footprint by keeping carbon in the product stream rather than releasing it
2Reliability
If distillation and evaporation are used for fermentation product recovery, then alcohol is recovered, but large amounts of external energy are required
Solution Approach 1:
The system uses mechanical vapor recompression (MVR) technology that recovers and recompresses vapor from the distillation process itself to provide the heating energy needed for evaporation. The vapor that would normally be discarded is instead compressed and condensed to generate steam that returns to the distillation column, creating a self-sufficient energy cycle that dramatically reduces external energy requirements while maintaining reliable alcohol recovery
Solution Approach 2:
The patent exploits phase transitions of water and alcohol vapors to enable energy recovery. The MVR system compresses vapor phase material, condenses it to liquid phase to generate heat, and uses that heat for evaporation. This phase transition cycle is the core mechanism that enables the system to reduce external energy consumption while maintaining effective product recovery
3Quantity of substance
If renewable diesel is produced from fats, greases, and oils, then high energy density fuel is achieved, but the feedstock supply is limited and coproducts have low value
Solution Approach 1:
The patent fundamentally changes the feedstock parameter from fats, greases, and oils to carbohydrates (corn, wheat, sorghum, sugarcane, sugar beets). This parameter change enables the use of abundant, scalable feedstocks while maintaining high energy density fuel production. The catalytic dehydration process converts these carbohydrate-derived alcohols into hydrocarbons with energy densities comparable to petroleum fuels
Solution Approach 2:
The system converts what would be waste products (stillage from distillation) into valuable feedstocks for biogas production and subsequent hydrocarbon synthesis. The stillage, which has limited value, is transformed through anaerobic digestion and catalytic conversion into high-value fuel components, turning a disadvantage into a benefit and enabling scalable feedstock utilization
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Achieves a net zero energy use and zero carbon footprint by converting carbohydrates to hydrocarbons with an energy density of at least 100,000 BTU/gallon, reducing external process energy requirements to less than 20,000 BTU/gallon, and producing fuels with high energy density and low carbon intensity.
Implementation Method 1
a first mechanical vapor recompression system integrated with the distillation column
Implementation Method 2
compresses and condenses water vapor from the fermentation product stream
Implementation Method 3
a second mechanical vapor recompression system integrated with an anaerobic digestion system
Implementation Method 4
converting C1-C5 alcohols to a mixture of C2-C7 olefins
Data Source
AI summary
Disclosed are systems, methods, and compositions for producing renewable alcohols, conversion of C1-C5 alcohols to a mixture of C2-C7 olefins to generate stream for recycle to the alcohol conversion step to create or separate oligomerization conversion to generate a predominantly C4+ stream, oligomerizing stream into fuel range olefins to create a stream, separating stream into fractions appropriate for use as gasoline, jet, and diesel fuels. The disclosure also provides systems, methods, and compositions of bio-based ethanol that can be converted to ethylene and subsequently to mixtures of C3-C8 olefins in a single-step.