Furfural

Product Name:

Furfural

CAS:

98-01-1

MF:

C5H4O2

MW:

96.08

EINECS:

202-627-7

Mol File:

98-01-1.mol

Melting point 

−36 °C(lit.)

Boiling point 

54-56 °C11 mm Hg

density 

1.16 g/mL at 25 °C(lit.)

vapor density 

3.31 (vs air)

vapor pressure 

13.5 mm Hg ( 55 °C)

FEMA 

2489 | FURFURAL

refractive index 

n20/D 1.527

Fp 

137 °F

storage temp. 

2-8°C

solubility 

95% ethanol: soluble1ML/mL, clear

form 

Liquid

color 

very deep brown

PH

>=3.0 (50g/l, 25℃)

explosive limit

2.1-19.3%(V)

Water Solubility 

8.3 g/100 mL

FreezingPoint 

-36.5℃

Sensitive 

Air Sensitive

Merck 

14,4304

JECFA Number

450

BRN 

105755

Henry's Law Constant

1.52(x 10-6 atm?m3/mol) at 20 °C (approximate - calculated from water solubility and vapor pressure)

Exposure limits

NIOSH REL: IDLH 100 ppm; OSHA PEL: TWA 5 ppm (20 mg/m3); ACGIH TLV: TWA 2 ppm (adopted).

Stability:

Stable. Substances to be avoided include strong bases, strong oxidizing agents and strong acids. Flammable.

CAS DataBase Reference

98-01-1(CAS DataBase Reference)

NIST Chemistry Reference

2-Furancarboxaldehyde(98-01-1)

EPA Substance Registry System

Furfural (98-01-1)

Hazard Codes 

T,Xi

Risk Statements 

21-23/25-36/37-40-36/37/38

Safety Statements 

26-36/37/39-45-1/2-36/37

RIDADR 

UN 1199 6.1/PG 2

WGK Germany 

2

RTECS 

LT7000000

F 

1-8-10

Autoignition Temperature

599 °F &_& 599 °F

Hazard Note 

Irritant

TSCA 

Yes

HS Code 

2932 12 00

HazardClass 

6.1

PackingGroup 

II

Hazardous Substances Data

98-01-1(Hazardous Substances Data)

Toxicity

LD50 orally in rats: 127 mg/kg (Jenner)

Description

Furfural is an essential renewable, non-petroleum based, chemical feedstock which is primarily composed of various agricultural byproducts, including oat husks, wheat bran, corncobs, and sawdust. Chemically, furfural is an organic compound belonging to an aldehyde of furan with the odor of almonds. It is typically produced for industrial purposes, which can be used as a selective solvent in the process of refining lubricating oils and used in the manufacture of transportation fuels to improve the characteristics of diesel fuel and catalytic cracker recycle stocks. Besides, furfural is applied widely for producing resin-bonded abrasive wheels and purifying butadiene needed for the manufacture of synthetic rubber. It is also used to make other furan chemicals, such as furoic acid and furan itself. Other products of furfural include weed killer, fungicide, other solvents and etc.

Description

Furfural is a colourless to amber-like oily liquid with an almond-like odour. On exposure to light and air, it turns reddish brown. Furfural is used in making chemicals, as a solvent in petroleum refining, a fungicide, and a weed killer. It is incompatible with strong acids, oxidisers, and strong alkalis. It undergoes polymerisation on contact with strong acids or strong alkalis. Furfural is produced commercially by the acid hydrolysis of pentosan polysaccharides from non-food residues of food crops and wood wastes. It is used widely as a solvent in petroleum refining, in the production of phenolic resins, and in a variety of other applications. Human exposure to furfural occurs during its production and use, as a result of its natural occurrence in many foods and from the combustion of coal and wood.

Chemical Properties

colourless to reddish-brown oily liquid with almond odour

Chemical Properties

Furfural is a colorless to yellow aromatic het erocyclic aldehyde with an almond-like odor. Turns amber on exposure to light and air.

Chemical Properties

Furfural has a characteristic penetrating odor. Furfural is prepared industrially from pentosans that are contained in cereal straws and brans; these materials are previously digested with diluted H2S04, and the formed furfural steam is distilled.

Chemical Properties

Furfural has a characteristic penetrating odor typical of cyclic aldehydes.

Physical properties

Colorless to yellow liquid with an almond-like odor. Turns reddish brown on exposure to light and air. Odor and taste thresholds are 0.4 and 4 ppm, respectively (quoted, Keith and Walters, 1992). Shaw et al. (1970) reported a taste threshold in water of 80 ppm.

Uses

In the manufacture of furfural-phenol plastics such as Durite; in solvent refining of petroleum oils; in the preparation of pyromucic acid. As a solvent for nitrated cotton, cellulose acetate, and gums; in the manufacture of varnishes; for accelerating vulcanization; as insecticide, fungicide, germicide; as reagent in analytical chemistry. In the synthesis of furan derivatives.

Purification Methods

Furfural is unstable to air, light and acids. Impurities include formic acid, .-formylacrylic acid and furan-2-carboxylic acid. Distil it in an oil bath from 7% (w/w) Na2CO3 (added to neutralise acids, especially pyromucic acid). Redistil it from 2% (w/w) Na2CO3, and then, finally fractionally distil it under vacuum. It is stored in the dark. [Evans & Aylesworth Ind Eng Chem (Anal ed) 18 24 1926.] Impurities resulting from storage can be removed by passage through chromatographic grade alumina. Furfural can be separated from impurities other than carbonyl compounds by the bisulfite addition compound. The aldehyde is steam volatile. It has been purified by distillation (using a Claisen head) under reduced pressure. This is essential as is the use of an oil bath with temperatures of no higher than 130o which is highly recommended. When furfural is distilled at atmospheric pressure (in a stream of N2), or under reduced pressure with a free flame (caution: because the aldehyde is flammable), an almost colourless oil is obtained. After a few days and sometimes a few hours, the oil gradually darkens and finally becomes black. This change is accelerated by light and occurs more slowly when it is kept in a brown bottle. However, when the aldehyde is distilled under vacuum and the bath temperature kept below 130o during the distillation, the oil develops only a slight colour when exposed to direct sunlight during several days. The distillation of very impure material should NOT be attempted at atmospheric pressure; otherwise the product darkens very rapidly. After one distillation under vacuum, a distillation at atmospheric pressure can be carried out without too much decomposition and darkening. The liquid irritates mucous membranes. Store it in dark containers under N2, preferably in sealed ampoules. [Adams & Voorhees Org Synth Coll Vol I 280 1941, Beilstein 17/9 V 292.]

Furfural Preparation Products And Raw materials

Raw materials

Sulfuric acid -->Sodium carbonate-->Acetone-->D(+)-Sucrose-->pentosan

Preparation Products

Furfuryl alcohol-->Furan-->2-Methylfuran-->3-Hydroxy-2-methyl-4H-pyran-4-one-->5-Nitrofurfural -->Ethyl maltol-->3-(2-FURYL)PROPANOIC ACID-->5-Nitro-2-furoic acid-->5-Nitro-2-furaldehyde diacetate-->ETHYL 3-(2-FURYL)PROPIONATE-->Tetrahydrofurfuryl alcohol-->5-ETHYL-2-FURALDEHYDE-->5-FORMYL-2-FURANCARBOXYLIC ACID-->ETHYL 3-(2-FURYL)ACRYLATE-->2-Furonitrile-->(ACETYLOXY)(2-FURYL)METHYL ACETATE-->3-(5-Nitro-2-furyl)acrylic acid-->Furazolidone-->FURFURYL ALCOHOL RESIN-->Industrial gear oil-->Nitrofurantoin-->N-METHYLFURFURYLAMINE-->Industrial gear oil,weight load-->2-Furaldehyde diethyl acetal-->2,2'-Thiobisethylamine-->Industrial gear oil,middle load-->2-Formylfuran-5-boronic acid-->5-[2-CHLORO-4-(TRIFLUOROMETHYL)PHENYL]-2-FURALDEHYDE-->5-[2,6-DICHLORO-4-(TRIFLUOROMETHYL)PHENYL]-2-FURALDEHYDE-->5-[4-FLUORO-3-(TRIFLUOROMETHYL)PHENYL]-2-FURALDEHYDE-->5-(4-Bromophenyl)furfural-->5-[4-(TRIFLUOROMETHOXY)PHENYL]-2-FURALDEHYDE-->1,3-DIMETHYL-2-(2-FURYL)IMIDAZOLIDINE