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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 6820-1992 Ethanol for industrial use, and the following main technical changes have been made with respect to GB/T 6820-1992.
——The standard name is revised to Ethanol for industrial use
——The scope is modified (see Clause 1 hereof; Clause 1 of Edition 1992);
——The 99.5% ethanol type is added (see Clause 3 hereof);
——The type index of 95.0% ethanol is classified into three grades: superior product, first-grade product and acceptable product; four test items of isopropanol, n-propanol, acetate and sulfuric acid are added; the original fusel oil project is changed to C4 + C5 alcohol project; the chromaticity is changed from No. 10 to No. 5 for first-grade product; ethanol content: the volume fraction is changed from 96.0% to 95.0% for first-grade product; the aldehyde content is changed from 0.0020% to 10 mg/L for superior-grade product, changed from 0.0040% to 15 mg/L for first-grade product; the methanol content is changed from 0.02% to 100 mg/L superior-grade product, changed from 0.03% to 150 mg/L for first-grade product; the potassium permanganate oxidation time is changed from 20 min to 25 min for superior-grade product, changed from 15 min to 20 min for first-grade product; the evaporation residue is changed from 0.0025% to 20 mg/L for superior-grade product, changed from 0.0030% to 25 mg/L for first-grade product(see Table 1 hereof; Table 1 of Edition 1992);
——The gas chromatographic test methods for methanol and C4 + C5 alcohol projects are added (see 5.8 hereof);
——Type inspection items are added: evaporation residue, sulfuric acid test chromaticity and water miscibility test are determined as type inspection items (see 6.1 hereof).
This standard was proposed by the China Petroleum and Chemical Industry Association.
This standard is under the jurisdiction of Subcommittee on Organic Chemical Industry of National Technical Committee on Chemical of Standardization Administration of China (SAC/TC 63/SC 2).
The previous editions of this standard are as follows:
——GB 6820-1986 and GB/T 6820-1992.
Ethanol for industrial use
1 Scope
This standard specifies the product classification, requirements, test methods, inspection rules as well as marking, packaging, storage, transportation and safety of ethanol for industrial use.
This standard is applicable to the ethanol for industrial use.
Molecular formula: C2H5OH
Structural formula:
Relative molecular mass: 46.07 (according to international relative atomic mass in 2011)
2 Normative references
The following referenced documents are indispensable for the purpose of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 190 Packing symbol of dangerous goods
GB/T 191 Packaging—Pictorial marking for handling of goods
GB/T 394.2-2008 General methods of analysis for ethanol
GB/T 601 Chemical reagent—Preparations of reference titration solutions
GB/T 602 Chemical reagent—Preparations of standard solutions for impurity
GB/T 603 Chemical reagent—Preparations of reagent solutions for use in test methods
GB/T 3723 Sampling of chemical products for industrial use—Safety in sampling
GB/T 6283 Chemical products—Determination of water—Karl·Fischer method (general method)
GB/T 6324.1 Test method of organic chemical products—Part 1: Water miscibility test of liquid organic chemical products
GB/T 6324.2 Test method of organic chemical products—Part 2: Determination of dry residue after evaporation on a water bath for volatile organic liquids
GB/T 6678 General principles for sampling chemical products
GB/T 6680 General rules for sampling liquid chemical products
GB/T 6682 Water for analytical laboratory use—Specification and test methods
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
GB/T 9722 Chemical reagent—General rules for the gas chromatography
3 Product classification
The ethanol for industrial use is classified into 95.0% ethanol and 99.5% ethanol.
4 Requirements
4.1 Appearance: transparent liquid without visible mechanical impurities.
4.2 The ethanol for industrial use shall meet those specified in Table 1.
Table 1 Technical indexes
Item 95.0% ethanol 99.5% ethanol
Superior product First-grade product Acceptable product Superior product First-grade product
Chromaticity/Hazen unit (platinum-cobalt color code) ≤ 5 10 5
Ethanol content, φ/% ≥ 96.0 95.0 99.9 99.5
Moisture content, ω/% ≤ — 0.10 0.50
Acid content (counted by acetic acid)/(mg/L) ≤ 10 20 30 10 20
Aldehyde content (counted by acetaldehyde)/(mg/L) ≤ 10 15 20 10 15
Methanol/(mg/L) ≤ 100 150 200 50
Isopropanol/(mg/L) ≤ 50 100 150 200
N-propanol/(mg/L) ≤ 100 150 200 50
Acetatea/(mg/L) ≤ 100 200 — 200
C4 + C5 alcohol b/(mg/L) ≤ 20 50 20 50
Potassium permanganate oxidation time/min ≥ 25 20 15 20 15
Evaporation residue/(mg/L) ≤ 20 25 30 20 25
Sulfuric acid test chromaticity/No. ≤ 10 30 80 20 30
Water miscibility test Pass (1 + 9) Pass (1 + 19) — Pass (1 + 9)
a Acetate refers to ethyl acetate, isopropyl acetate and other esters.
b C4 + C5 alcohol refers to 2-butanol, isobutanol, n-butanol, isoamyl alcohol and n-amyl alcohol, etc.
5 Test methods
Warning—The operator shall take appropriate safe and health measures, for some test procedures specified in the test methods may cause danger.
5.1 General requirements
For the purpose of this standard, unless otherwise specified, all the reagents and water used refer to analytical reagents and Grade 3 water specified in GB/T 6682.
The standard titration solution, impurity standard solution, preparation and products used in the analysis are prepared in accordance with GB/T 601, GB/T 602 and GB/T 603.
5.2 Appearance determination
Take an appropriate amount of laboratory samples into a colorimetric tube with stopper and visually inspect under daylight lamp or sunlight.
5.3 Determination of chromaticity
It shall be determined in accordance with the method specified in 4.1, GB/T 394.2-2008.
5.4 Determination of ethanol content
It shall be determined in accordance with the method specified in Clause 5, GB/T 394.2-2008.
5.5 Determination of moisture content
It shall be determined in accordance with GB/T 6283.
The arithmetic average obtained from the parallel determination results shall be taken as the determination result, and the absolute difference of two parallel determination results shall not be greater than 0.01%.
5.6 Determination of acid content
It shall be determined in accordance with the method specified in Clause 11, GB/T 394.2-2008.
5.7 Determination of aldehyde content
It shall be determined in accordance with the method specified in Clause 8, GB/T 394.2-2008. The iodometry is the arbitration method.
5.8 Determination of methanol, isopropanol, n-propanol, acetate and C4+C5 alcohol content
5.8.1 Method summary
Under the selected chromatographic conditions, use the gas chromatography to separate the specimen by chromatographic column, then detect by flame ionization detector, and quantify by internal standard method, external standard method or calibration area normalization method. Among them, the internal standard method is the arbitration method.
5.8.2 Reagents and solutions
5.8.2.1 Reference ethanol: ethanol with volume fraction of 95%, in which the limit of main impurities is: methanol is less than 2 mg/L; isopropanol is less than 2 mg/L; n-propanol is less than 2 mg/L; higher alcohol (C4 + C5 alcohol) is less than 1 mg/L; ester is less than 1 mg/L; there shall be no impurities interfering with the internal standard when detected by this method.
5.8.2.2 Standard solution: weigh 1g of chromatographic pure methanol, isopropanol, n-propanol, ethyl acetate, isopropyl acetate, 2-butanol, isobutanol, n-butanol, isoamyl alcohol and n-amyl alcohol respectively (accurate to 0.0001g) into a 1,000 mL volumetric flask, and dilute it to the scale with reference ethanol. Shake well and obtain the 1 g/L standard solution.
5.8.2.3 Internal standard solution: weigh 1g (accurate to 0.0001g) of chromatographically pure n-hexane into a 1,000 mL volumetric flask, and dilute it to the scale with reference ethanol. Shake well and obtain the 1 g/L internal standard solution.
5.8.2.4 Nitrogen: with volume fraction not less than 99.95%, dried and purified by silica gel and molecular sieve.
5.8.2.5 Hydrogen: with volume fraction not less than 99.9%, dried and purified by silica gel and molecular sieve.
5.8.2.6 Air: dried and purified by silica gel or molecular sieve.
5.8.3 Apparatus
5.8.3.1 Gas chromatograph: flame ionization detector with capillary column, the sensitivity and stability of the whole machine shall meet relevant requirements of GB/T 9722.
Foreword i
1 Scope
2 Normative references
3 Product classification
4 Requirements
5 Test methods
6 Inspection rules
7 Marking, packaging, transportation and storage
8 Safety
Annex A (Normative) Typical gas chromatograms and retention for determination of methanol, isopropanol, n-propanol, acetate and C4 + C5 alcohol