Levulinic Acid Oxidative Cleavage via Diluted Gas Phase
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Solution Overview
Problem
The economic viability of lignocellulosic biorefineries is hindered by the difficulty in converting biomass into cost-competitive industrial commodities, particularly due to the high costs and inefficiencies in producing lignocellulosic fuels, while chemical products derived from biomass are more promising but lack a robust market.
Innovation Solution
The production of maleic acid, fumaric acid, or maleic anhydride via gas-phase oxidative cleavage of levulinic acid in a single packed bed reactor over a reducible oxide catalyst, utilizing an apparatus that vaporizes levulinic acid and mixes it with inert and oxidizing gases before heating to reaction temperature, thereby avoiding polymerization and optimizing the conversion process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If levulinic acid is directly heated to reaction temperature for oxidative cleavage, then the conversion efficiency increases, but polymerization occurs causing process failure
Solution Approach 1:
The patent applies preliminary action by pre-mixing levulinic acid with inert gas (nitrogen or carbon dioxide) before heating. This dilution step prevents polymerization during the heating process by maintaining levulinic acid concentration below the polymerization threshold, while still allowing efficient oxidative cleavage to occur in the diluted gas phase mixture.
2Productivity
If levulinic acid concentration is maintained high to maximize product yield, then productivity increases, but polymerization occurs reducing process reliability
Solution Approach 1:
The patent changes the concentration parameter of levulinic acid by diluting it with inert gas to maintain levels below the polymerization threshold (typically <10-20% v/v). This parameter change allows the process to proceed reliably while still achieving high productivity through optimized contact time, temperature control, and catalyst selection in the diluted gas phase system.
3Adaptability or versatility
If extensive upgrading is performed on lignocellulosic fuels to match petroleum fuel properties, then market compatibility improves, but production cost increases significantly
Solution Approach 1:
The patent extracts levulinic acid as a valuable chemical intermediate from lignocellulosic biomass through acid hydrolysis, bypassing the need to produce and upgrade transportation fuels. This extraction approach targets the chemical products market where levulinic acid and its derivatives (such as γ-valerolactone, esters, and other oxygenates) can be directly utilized without extensive upgrading, thereby reducing production costs while maintaining market compatibility.
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
This approach enables the conversion of levulinic acid into valuable chemical products with higher profit margins, potentially making lignocellulosic biorefineries economically viable by targeting existing commodity chemical markets and offering a more efficient pathway to maleic acid derivatives.
Implementation Method 1
gas-phase, oxidative cleavage of levulinic acid (or angelicalactones, which form reversibly from levulinic acid under reaction conditions) in a single packed bed reactor over a reducible oxide catalyst
Implementation Method 2
oxidative cleavage of levulinic acid (or angelicalactones, which form reversibly from levulinic acid under reaction conditions) in a single packed bed reactor over a reducible oxide catalyst
Implementation Method 3
an apparatus that vaporizes levulinic acid and mixes it with inert and oxidizing gases before heating to reaction temperature
Implementation Method 4
heating to reaction temperature, which generally ranges from 200-500° C.
Data Source
AI summary
The production of maleic acid and fumaric acid (or the anhydride form of either, maleic anhydride) via gas-phase, oxidative cleavage of levulinic acid in a single packed bed reactor over a reducible oxide catalyst. The production may be carried out in an initial mixing vessel into which levulinic acid is continuously charged and mixed with both inert (He, N2, Ar, etc.) and oxidizing (O2, air, etc.) gases. The feed stream can then be safely heated to reaction temperature, which generally ranges from 200-500° C., without initiating polymerization, in a second stage preheater that thermally equilibrates the gaseous mixture of LA, O2, and inert diluent and fed to a third stage catalytic reactor for final processing.