Levulinic acid
[CAS# 123-76-2]

Identification

• Classification: Chemical reagent >> Organic reagent >> Fatty acid
• Name: Levulinic acid
• Synonyms: Laevulinic acid; 4-Oxopentanoic acid; 4-Oxovaleric acid; gamma-Ketovaleric acid; Levulic acid; 4-Oxo-pentanoic acid
• Molecular Formula: C₅H₈O₃
• Molecular Weight: 116.12
• CAS Registry Number: 123-76-2
• EC Number: 204-649-2
• FEMA: 2627
• SMILES: CC(=O)CCC(=O)O

Properties

• Density: 1.13
• Melting point: 33-35 ºC
• Boiling point: 245-246 ºC
• Refractive index: 1.4396-1.4426
• Flash point: 137 ºC

Safety Data

• Hazard Symbols: GHS05;GHS07 Danger
• Hazard Statements: H302-H315-H318
• Precautionary Statements: P264-P264+P265-P270-P280-P301+P317-P302+P352-P305+P351+P338-P305+P354+P338-P317-P321-P330-P332+P317-P337+P317-P362+P364-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute toxicity	Acute Tox.	4	H302
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319
Serious eye damage	Eye Dam.	1	H318
Skin sensitization	Skin Sens.	1	H317
Specific target organ toxicity - single exposure	STOT SE	3	H335
Skin corrosion	Skin Corr.	1B	H314
Substances or mixtures corrosive to metals	Met. Corr.	1	H290
Skin corrosion	Skin Corr.	1C	H314
Eye irritation	Eye Irrit.	2A	H319

Discovory and Applicatios

Levulinic acid, also known as 4-oxopentanoic acid, is an organic compound that has gained significant attention due to its versatility as a platform chemical derived from biomass. First identified in the 19th century, levulinic acid has become a crucial intermediate in the transition toward sustainable chemical production, particularly as the world seeks alternatives to fossil-fuel-derived chemicals. It can be produced through the acid-catalyzed hydrolysis of lignocellulosic biomass, making it a renewable resource that can play a significant role in green chemistry.

Levulinic acid’s discovery is tied to the early exploration of biomass conversion processes. The compound was initially obtained through the treatment of carbohydrates, such as glucose, with strong acids, resulting in the breakdown of the carbohydrate structure and the formation of levulinic acid. As the study of biomass conversion developed, researchers recognized the potential of levulinic acid as a versatile platform chemical that could serve as a precursor to numerous value-added chemicals and materials.

One of the key applications of levulinic acid is in the production of bio-based solvents, such as gamma-valerolactone (GVL). GVL is derived from levulinic acid through catalytic hydrogenation and is considered a promising green solvent due to its low toxicity and excellent performance in various industrial applications. GVL is not only used as a solvent but also as an intermediate in the production of fuel additives, polymers, and pharmaceuticals. The ability to convert levulinic acid into such a useful compound highlights its significance in the development of sustainable chemical processes.

In addition to its role in solvent production, levulinic acid is used as a precursor for the synthesis of various bio-based chemicals. Among these is diphenolic acid, which is produced by reacting levulinic acid with phenol. Diphenolic acid is used as a substitute for bisphenol A (BPA) in the production of polycarbonates and epoxy resins, offering a more environmentally friendly alternative to petrochemical-based feedstocks. This application is particularly important as industries seek to reduce their reliance on BPA, which has raised health and environmental concerns.

Levulinic acid also has potential in the production of biofuels. One of the most promising avenues is its conversion into fuel additives, such as ethyl levulinate, which can be used to improve the performance of diesel and gasoline fuels. Ethyl levulinate is produced by esterifying levulinic acid with ethanol, and it has shown potential in enhancing fuel combustion efficiency and reducing harmful emissions. The ability to integrate levulinic acid into biofuel production further underscores its importance in the shift toward renewable energy sources.

The pharmaceutical industry has also found applications for levulinic acid. It can be used as a precursor for various active pharmaceutical ingredients (APIs) and as an intermediate in drug synthesis. Levulinic acid derivatives are being explored for their anti-inflammatory and antimicrobial properties, expanding the scope of its use beyond industrial chemicals and into the realm of medicine.

Levulinic acid’s relevance extends into the polymer industry as well. It can be used to produce bio-based polymers, such as polyurethanes, which are derived from renewable sources. These bio-based polymers are being developed as alternatives to conventional, petroleum-derived plastics, contributing to the reduction of plastic waste and the environmental impact of polymer production.

Research into levulinic acid continues to explore its potential for expanding its application base. One area of ongoing interest is the development of new catalytic processes to increase the efficiency of levulinic acid production from biomass. By improving the conversion processes and reducing production costs, levulinic acid could become a more economically viable feedstock for large-scale industrial applications.

Levulinic acid's combination of versatility, renewability, and utility across multiple industries makes it a critical component in the growing portfolio of bio-based chemicals. Its ability to serve as a building block for various value-added products positions it as a key player in the shift toward sustainable chemical manufacturing and a circular economy.

References

2012. Conversion of Hemicellulose to Furfural and Levulinic Acid using Biphasic Reactors with Alkylphenol Solvents. ChemSusChem.
DOI: 10.1002/cssc.201100608

2019. Pretreatment for biorefineries: a review of common methods for efficient utilisation of lignocellulosic materials. Biotechnology for Biofuels and Bioproducts.
DOI: 10.1186/s13068-019-1634-1

2024. Tungstic Acid-Functionalized Natural Zeolite as a Solid Acid Catalyst for Levulinic Acid Esterification. Catalysis Surveys from Asia.
DOI: 10.1007/s10563-024-09442-1