gamma-Valerolactone

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gamma-Valerolactone[1]
Gamma-valerolactone.png
Identifiers
CAS number 108-29-2 YesY
PubChem 7921
ChemSpider 7633 YesY
UNII O7056XK37X YesY
ChEBI CHEBI:48569 YesY
ChEMBL CHEMBL195593 YesY
Jmol-3D images Image 1
Properties
Molecular formula C5H8O2
Molar mass 100.116
Appearance colorless liquid
Density 1.0465 g/mL
Melting point −31 °C (−24 °F; 242 K)
Boiling point 207 to 208 °C (405 to 406 °F; 480 to 481 K)
Solubility in water >=100 mg/mL
Thermochemistry
Std enthalpy of
formation
ΔfHo298
-461.3 kJ·mol−1
Std enthalpy of
combustion
ΔcHo298
-2649.6 kJ·mol−1
Hazards
R-phrases R36, R37, R38
S-phrases (S2), S46
NFPA 704
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g., diesel fuel Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
Flash point 81 °C (178 °F; 354 K)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
 YesY (verify) (what is: YesY/N?)
Infobox references

gamma-Valerolactone (GVL) is an organic compound with the formula C5H8O2. This colourless liquid is one of the more common lactones. GVL is chiral but is usually used as the racemate. It is readily obtained from cellulosic biomass and is a potential fuel and green solvent.

Synthesis[edit]

GVL is produced from levulinic acid, which is obtained from hexoses. In a typical process, cellulosic biomasses, such as corn stover, sawgrass, or wood, is hydrolysed into glucose and other sugars using acid catalysts. The resulting glucose can then be dehydrated via hydroxymethylfurfural to yield formic acid and levulinic acid, which can then be hydrogenated to gamma-hydroxypentanoic acid, which readily cyclises to gamma-valerolactone, which has potential applications as a liquid fuel.[2]

Cyclization of levulinic acid.svg

Potential applications[edit]

GVL has been identified as a potential green solvent. Because of its herbal odor, it is used in the perfume and flavor industries.[3] It is a structural isomer of delta-valerolactone.

Potential fuel[edit]

Since it is readily obtained from glucose, GVL has long been identified as a potential "green fuel."[4] GVL retains 97% of the energy of glucose and can be blended by itself in gasoline where it performs comparably to ethanol/gasoline mixtures.[5][6] However, due to blending limits for use in conventional combustion engines, it may be more efficient to convert GVL into liquid alkenes (or alkanes). The first step in this process is the ring-opening of GVL to yield a mixture of pentenoic acids. These acids can then be decarboxylated to produce butene and CO2. These conversions can be performed with zeolite catalysts.[7] After this stream is dehydrated, the products can be oligomerized at elevated pressures in the presence of a common acid-catalyst to yield alkenes with higher molecular weights, targeted for gasoline and other fuel applications.[8]

One of the main advantages that allows GVL to be a practical biofuel is that it is relatively inexpensive to produce. Using a cheap feedstock, this biofuel can be produced at prices between 2-3 US$/gallon.[5] The conversion of GVL to transportation fuel capable alkenes only requires a system containing two flow reactors, two phase separators, and a simple pumping arrangement for the delivery of an aqueous GVL feed. Since the use of precious metal catalysts is not required, this also decreases the total price of fuel production.[7]

Potential production of biomass-derived fuels[edit]

Apart from its value as a potential fuel in its own right, gamma-valerolactone has shown promise in laboratory-scale thermocatalytic production of soluble carbohydrates from corn stover and wood at high yields. The biomass reacts in a solvent mixture of water, dilute sulfuric acid, and gamma-valerolactone, itself derived from biomass. The gamma-valerolactone promotes thermocatalytic hydrolysis into monosaccharides by complete solubilization of the raw material, including lignins. The saccharide products can be recovered from the lactone into water solution by antisolvent addition of salt or liquid carbon dioxide. The product can be used as feedstock for producing furans or ethanol at high yield, while the gamma-valerolactone is returned to the catalytic cycle.[9]

See also[edit]

References[edit]

  1. ^ NIH National Toxicology Program
  2. ^ Huber, George W.; Iborra, Sara; Corma, Avelino (2006). "Synthesis of Transportation Fuels from Biomass: Chemistry, Catalysts, and Engineering". Chemical Reviews 106 (9): 4044–4098. doi:10.1021/cr068360d. PMID 16967928. 
  3. ^ GoodScentsCompany.com
  4. ^ Huber, G. W.; Corma, Avelino (2007). "Synergies between Bio- and Oil Refineries for the Production of Fuels from Biomass". Angewandte Chemie International Edition 46 (38): 7184. doi:10.1002/anie.200604504. 
  5. ^ a b Savage, Neil (2011). "Fuel Options: The Ideal Biofuel". Nature 474 (7352): S11. doi:10.1038/474S09a. 
  6. ^ Horváth, I. T.; Mehdi, H.; Fábos, V.; Boda, L.; Mika, L. T. (2008). "γ-Valerolactone—a sustainable liquid for energy and carbon-based chemicals". Green Chemistry 10 (2): 238. doi:10.1039/b712863k. 
  7. ^ a b Bond, Jesse Q.; Alonso, David Martin; Wang, Dong; West, Ryan M.; Dumesic, James A. (2010). "Integrated Catalytic Conversion of γ-Valerolactone to Liquid Alkenes for Transportation Fuels". Science 357 (5969): 1110–1114. doi:10.1126/science.1184362. 
  8. ^ Mantilla, A.; et al. (2005). "Oligomerization of isobutene on sulfated titania: Effect of reaction conditions on selectivity". Catalysis Today. 107-108: 707. doi:10.1016/j.cattod.2005.07.153. 
  9. ^ Luterbacher, Jeremy S.; Rand, Jacqueline M.; David; Alonso, Martin; Han, Jeehoon; Youngquist, J. Tyler; Maravelias, Christos T.; Pfleger, Brian F.; Dumesic, James A. et al. et al. (2014). "Nonenzymatic Sugar Production from Biomass Using Biomass-Derived gamma-Valerolactone". Science 343 (6168): 277–280. doi:10.1126/science.1246748. PMID 24436415. 

External links[edit]

General Safety Information