2-Furfural 2-Furaldehyde

Structural formula

• Numbering system
• Physical property data
• Toxicological data
• Ecological data
• Molecular structure data
• Computing chemical data
• More
  • Properties and Stability
  • Storage method
  • Synthesis method
  • Purpose

Numbering system

CAS number:98-01-1

MDL number:MFCD00003229

EINECS number:202-627-7

RTECS number:LT7000000

BRN number:105755

PubChem ID:None

Physical property data

1. Properties: colorless to yellow oily liquid with almond-like odor. ^[1]

2. Melting point (℃): -36.5^[2]

3. Boiling point (℃): 161.8^[3]

4. Relative density (water = 1): 1.16^[4]

5. Relative vapor Density (air=1): 3.31^[5]

6. Saturated vapor pressure (kPa): 0.27 (20℃)^[6]

7. Heat of combustion (kJ/mol): -2338.7^[7]

8. Critical pressure (MPa): 5.5^[8]

9. Octanol/water partition coefficient: 0.41~0.69^[9]

10. Flash point (℃): 60 ( CC)^[10]

11. Ignition temperature (℃): 315^[11]

12. Explosion limit (%): 19.3^[12]

13. Lower explosion limit (%): 2.1^[13]

14. Solubility: Slightly soluble in cold water, soluble in hot water, ethanol, ether, and benzene. ^[14]

15. Refractive index (20ºC): 1.52608

16. Refractive index (25ºC): 1.52345

17 .Ignition point (ºC): 490

18. Heat of evaporation (KJ/mol): 43.25

19. Heat of fusion (KJ/mol): 14.36

20. Specific heat capacity (KJ/(kg·K), 25ºC, constant pressure): 1.64

21. Solubility parameter (J·cm^-3)^0.5: 23.644

22. van der Waals area (cm²·mol^-1): 6.120×10⁹

23. van der Waals volume (cm³·mol^-1): 47.260

24. Gas phase standard Heat of combustion (enthalpy) (kJ·mol^-1): -2388.2

25. Gas phase standard claims heat (enthalpy) (kJ·mol^-1): -151.0

26. Gas phase standard entropy (J·mol^-1·K^-1): 333.29

27. Gas phase standard free energy of formation (kJ·mol^-1): -102.9

28. Liquid phase standard combustion heat (enthalpy) (kJ·mol^{– 1})The area should be equipped with emergency spill response equipment and appropriate containment materials.

Synthesis method

1. It is obtained by hydrolyzing, dehydrating and distilling pentosan-rich agricultural waste, such as corn cobs, cottonseed hulls, rice bran and sugar beet pulp, with dilute acid.

2. Furfural was originally obtained from furfural. Agricultural and sideline products mostly contain polypentoses which undergo hydrolysis to generate furfural. The stems, bark, and shells of many crops contain polypentosides and can therefore be used as raw materials for the production of furfural. During production, raw materials such as corn cobs, cotton seed husks or sugarcane bagasse are treated with sulfuric acid and water vapor, and then steam distilled, layered, and distilled under reduced pressure to obtain a product with a purity of 99%. The recovery of furfural is related to the raw materials, the type and concentration of the acid and other conditions, and is usually quite different from the theoretical yield. There are two main methods for manufacturing furfural industrially. The pressurization method is suitable for large-scale production. The raw materials and dilute sulfuric acid are cooked under pressure, and the reaction product is taken out with high-pressure or superheated steam. After fractionation, the finished furfural product is obtained; the normal pressure method is to combine the raw materials with inorganic salts such as salt and Boil with dilute sulfuric acid and steam out furfural at the same time.

3. Crush 100kg corn cobs into small pieces of 0.5~1cm², add 25kg 90% sulfuric acid and 125kg salt and water to prepare a hydrolyzate. The volume is 2.5 times that of corn cob. After the corn cobs and hydrolyzate are stirred evenly, they are heated to boiling, and then the dilute solution of furfural begins to distill out, and is condensed and collected in a separator. Leave to stand for 1 to 2 hours to separate the aqueous phase and obtain crude furfural. Refined by steam distillation to obtain pure product.

Refining method: Furfural is produced when placed The acidic substances and resins can be removed by washing with water and distilling under reduced pressure. It can also be dried with calcium chloride, anhydrous magnesium sulfate or anhydrous sodium sulfate and then distilled under reduced pressure. The recovery method of used furfural is steam distillation followed by fractionation. Other refining methods include distillation in the presence of 7% sodium carbonate, distillation with 2% sodium carbonate added to the distillate, and finally fractionation under reduced pressure at 800 Pa to obtain the pure product.

Purpose

1. Furfural is a raw material for preparing a variety of drugs and chemical products, such as 2-furancarboxylic acid, furan, and tetrahydrofuran. 1,4-dichlorobutane can be produced from tetrahydrofuran, which is then substituted by a cyano group and then hydrogenated to obtain 1,6-hexanediamine, which is the basic raw material for the synthesis of nylon 66. Furfural can also be used to produce nitrofuracil, furanocrolein, furanoacrylic acid, furfuryl alcohol, etc. These are important raw materials for the synthesis of medicines, pesticides, veterinary drugs, dyes, spices and other products.

2. Used as an extraction agent, it has good effects on extracting unsaturated hydrocarbons from hydrocarbon mixtures, extracting butadiene from C4 hydrocarbons, and extracting aromatic hydrocarbons from mixtures of aliphatic hydrocarbons and aromatic hydrocarbons. It is also used for the refining of lubricants, natural oils, crude anthracene, etc., the concentration of vitamins A and D, and the solvent of natural resins. In addition, furfural is also used in the preparation of furan resins, electrical insulation materials, varnishes, nitrofuracil, maleic anhydride, tetrahydrofuran, furfuryl alcohol, etc.

3. Determination of cobalt and determination of sulfate. Reagents for the determination of aromatic amines, acetone, alkaloids, vegetable oils and cholesterol. Used as a standard when measuring pentoses and polypentoses. Synthetic resin, refined organic matter, nitrocellulose solvent, dichloroethane extractant.

4. Used as a chromogenic reagent for the determination of carbamates by thin layer chromatography. It is also used as a standard reagent for the determination of pentoses and polypentoses. And used in organic synthesis and as solvent.

5. Used as a solvent, and as an intermediate for the synthesis of fragrances, furfuryl alcohol, and tetrahydrofuran. ^[27]