Levulinic acid was recognized by the US Department of Energy as one of the top biobased platform chemicals of the future. It is a versatile building block with a clear value proposition in chemicals.
As the world moves from fossil to alternative feedstocks, levulinic acid can serve as an incredibly versatile building block for chemicals and materials derived directly from biomass.
Levulinic acid can successfully address many performance-related issues attributed to petroleum-based chemicals and materials.
- Versatility allowing a wide range of downstream transformations
- Feedstock flexibility, high conversion yields, high productivity and concentrated process streams result in cost-competitive economics
- Cost-competitive economics are key for fast and successful market introduction of levulinic acid, as well as substantial market growth in the coming years
Levulinic acid esters (LA-esters)
Levulinic acid esters are sold today as niche fruity flavor and fragrance ingredients. Ethyl levulinate is a potential replacement for valencene, a flavor currently extracted from oranges and used in most beverages. The increasing demand for green solvents has put levulinic acid esters on the agenda of many chemical companies. Because other ester solvents, e.g. ethyl acetate, are known to be harmful for humans and the environment, levulinic acid esters are a great cost-competitive alternative. Ethyl levulinate has been tested as an additive for transportation fuels to improve emissions of nitrogen oxides in high compression diesel engines.
With the new pricing range made possible by GFBiochemicals, GVL becomes economic as a solvent comparable to ethyl acetate. GVL has value advantages over commonly-used ester solvents with higher solvating power and lower vapor pressure. It is more functional for paint stripping, polymer softening or solubilizing intermediates in industrial processes.
GVL can be a monomer for polyester-polymers and starting materials for pyrrolidinone-isomers. In the medium-term GVL will become the key intermediate for the production of nylon monomers and specialty acrylates.
Conversion of levulinic acid into GVL is proven with existing catalysts, resulting in high yields at reasonable operating conditions. Catalysts widely applied include ruthenium and platinum on carbon support.
MeTHF is primarily used as a solvent for chemical reactions. It can substitute THF due to its environmental advantages. Because of its lower water solubility, it is easier to recover from waste streams than THF. It generates fewer VOC emissions due to its lower vapor pressure.
The melting point of -136°C and boiling point of 83°C offer one of the largest ranges of liquid matter state in common solvents. This makes MeTHF perfect for low temperature reactions where other solvents like diethylether or THF fail. MeTHF’s suitability as a fuel additive has led to its recognition and approval in fuel blends by the US Department of Energy (DoE).
MeTHF can be produced from levulinic acid using hydrogenation technology known in the industry. The Pacific Northwest National Laboratory (PNNL) has patented a commercial process from levulinic acid. This single-step, single-vessel catalytic hydrogenation process will produce MeTHF by employing a palladium-rhenium catalyst.
Methyl Butanediol (MeBDO)
MeBDO has potential as a monomer for polyurethanes. Levulinic acid offers cost-competitive MeBDO with additional environmental and safety advantages due to reduced potential leaching. Applications for MeBDO include the production of a controlled drug release agent. Like GVL and MeTHF, MeBDO can be obtained from levulinic acid via hydrogenation reactions, though with different catalyst and process conditions.
Alpha-mGVL is a top-performing product as a glass transition temperature booster to increase functionality and performance of low-cost plastics. In Plexiglass, it improves hardness and scratch resistance. It has great potential in consumer electronics, like touchscreens.
Delta-amino levulinic acid (DALA)
Delta-amino levulinic acid (DALA) is a naturally-occurring chemical with a large variety of functions. It is used as a herbicide on lawns and certain grain crops. Increasingly strict environmental protection regulations indicate that the volumes of traditional pesticide chemicals will decrease significantly. DALA is a suitable replacement for traditional herbicides and pesticides. It is also used in pharmaceuticals for diagnosis and treatment of cancer (photodynamic therapy).
Diphenolic acid (DPA)
DPA is used in protective and decorative finishes. In recent years, its use has been largely replaced by bisphenol A (BPA) which is cheaper but toxic. DPA shows potential as a more functional, sustainable and renewable alternative to bisphenol A. DPA is easily made from levulinic acid and will be far more attractive at the price range enabled by GFBiochemicals’ production route.
Levulinic acid is used in anti-inflammatory medication (e.g. indomethacin), anti-allergy agents, mineral supplements (e.g. calcium levulinate) and transdermal patches. The levulinic acid derivative delta-amino levulinic acid (DALA) is used in pharmaceuticals for diagnosis and treatment (photodynamic therapy) of cancer.
Delta-amino levulinic acid (DALA) is a naturally-occurring chemical with a large variety of functions. It is used as a herbicide on lawns and certain grain crops. DALA is a suitable replacement for traditional herbicides and pesticides.
Flavors and fragrances
Levulinic acid has a sweet, creamy, acidic, buttery, guaiacol-like odor and is commonly used in compositions to create caramel, butterscotch and maple flavors. Levulinic acid esters are often used as niche fruity flavor and fragrance ingredients. Ethyl levulinate is a potential replacement for valencene, a flavor currently extracted from oranges and used in most beverages.
In food applications, levulinic acid is used for multiple functions. For instance, as an alkaline earth metal salt to inhibit microbial growth in foods, a pH regulator for ingredients and a disinfectant of fruit surfaces. The derivative levulinate ester is also a flavoring agent.
Resins and coatings
Levulinic acid can be used in polyester coating resins, powder coatings, unsaturated polyester resins and polyester polyols to increase scratch resistance for interior and exterior coatings.
A derivative of levulinic acid, diphenolic acid (DPA), is used in protective and decorative finishes. DPA is a potential renewable alternative to bisphenol A in resins and other applications.
Levulinic acid and its derivatives are used in organic and natural cosmetic compositions for perfuming, skin conditioning and pH-regulating purposes. They give inherent fresh odor, prevent wrinkles and stabilize formulations and emulsions.
Polymers and plasticizers
Plasticizers are organic esters used to render plastics like polyvinyl chloride (PVC) more flexible. PVC is used in multiple end-markets because it is low cost, durable and versatile. Levulinic acid-derived ketal esters can replace major phthalate-based plasticizers which account for the majority of the world’s plasticizer market. Demand is increasing for renewable, phthalate-free plasticizers particularly in applications for children’s toys, as well as for products with human contact.
Fuel additives based on levulinic acid can replace current cetane improvers and cold-flow performers for diesel. They may also replace lubricity improvers.
Renewable biodiesel is produced by hydrogenating levulinic acid oligomer derivatives. Hydrogenation is used today for the production of biodiesel, using vegetable oils and animal waste fats that have limited availability and a high price. Levulinic acid oligomers can be produced at large scale from biomass feedstock and at a lower price to be hydrogenated in existing installations. The hydrogenated material formed can be further processed with existing technology to produce ‘drop-in’ renewable biodiesel and renewable jet fuel.
Methyltetrahydrofuran (MeTHF), a levulinic acid derivative, can be blended up to 50% with gasoline to increase vehicle performance and reduce air emissions.
At large-scale production, MeTHF is competitive with common fuel oxygenates like ethanol. MeTHF has low vapor pressure, so blending with gasoline is effective in reducing volatile organic compound (VOC) emissions.
Levulinic acid esters, gammavalerolactone and MeTHF are derivatives of levulinic acid that are suitable solvents for a number of applications. Gammavalerolactone can replace ethyl acetate as a solvent in many applications. MeTHF can replace the current applications of tetrahydrofuran (THF) in the fine chemical and pharmaceutical industry. Because of its lower water solubility, MeTHF is easier to recover from waste streams than THF. It also generates fewer VOC emissions due to its lower vapor pressure.