ASTM E3146-18

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Designation: E3146 − 18
Standard Test Method for
Determination of Carbonyls in Pyrolysis Bio-Oils by
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Potentiometric Titration
This standard is issued under the fixed designation E3146; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.1.1 Bio-Oil, n—The crude liquid product of converting
solid biomass into a liquid via fast pyrolysis or other thermo-
1.1 This test method covers the determination of the carbo-
chemical conversion process.
nyl content of bio-oils derived from thermochemical decom-
3.1.2 Carbonyl, n—The chemical functional group consist-
position of lignocellulosic biomass and their deoxygenated
ing of a carbon-oxygen double bond, C=O. For this method,
products. This method is used for determination of carbonyls
this includes all aldehydes and ketones; carboxylic acids,
between 0.5 and 8 mol/kg.
esters, and lactone groups are not measured by this method.
1.2 Review the current and appropriate Safety Data Sheets
3.1.3 fast pyrolysis, n—Pyrolysis conducted with rapid heat-
(SDS) for detailed information concerning toxicity, first aid
ing and short reaction time; within approximately 2 seconds.
procedures, and safety precautions and proper personal protec-
tive equipment.
3.1.4 pyrolysis, n—Chemical decomposition of organic ma-
terials by heating in the absence of oxygen.
1.3 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
4. Summary of Test Method
standard.
4.1 A bio-oil sample is dissolved in dimethylsulfoxide
1.4 This standard does not purport to address all of the
(DMSO) and solutions are added containing hydroxylamine
safety concerns, if any, associated with its use. It is the
hydrochloride (NH OH·HCl) and triethanolamine (TEA). The
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responsibility of the user of this standard to establish appro-
mixture is sealed, stirred, and heated to 80 °C for 2 hours.
priate safety, health, and environmental practices and deter-
Carbonyl compounds (aldehydes and ketones) react with
mine the applicability of regulatory limitations prior to use.
NH OH·HCl forming the corresponding oxime and liberating
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1.5 This international standard was developed in accor-
HCl. Liberated HCl is consumed by TEA, which drives the
dance with internationally recognized principles on standard-
reaction forward. After the reaction, unconsumed TEA is
ization established in the Decision on Principles for the
titrated with a standardized HCl titrant to determine the molar
Development of International Standards, Guides and Recom-
concentration of carbonyls in the sample.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
5. Significance and Use
5.1 While pyrolysis bio-oils are comprised of a large variety
2. Referenced Documents
of compounds and chemical functional groups, quantification
2.1 ASTM Standards:
of carbonyl groups is especially important. Carbonyls are
D664 Test Method for Acid Number of Petroleum Products
known to be responsible for the instability of bio-oil during
by Potentiometric Titration
both storage and processing. This method can be used to
D1193 Specification for Reagent Water
quantify the total carbonyl content of bio-oils.
D6299 Practice for Applying Statistical Quality Assurance
and Control Charting Techniques to Evaluate Analytical
6. Interferences
Measurement System Performance
6.1 The selectivity of the method was tested by using
1-butanol, 1-pentanol, tertiary-butanol, 2-propanol, ethyl
3. Terminology
acetate, acetic acid, xylose and glucose as model compounds,
3.1 Definitions:
representing alcohol, ester, carboxylic acid and carbohydrates
in the bio-oil. No interferences were seen for ethyl acetate or
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This test method is under the jurisdiction of ASTM Committee E48 on
acetic acid. Monosaccharides are measured using this method.
Bioenergy and Industrial Chemicals from Biomass and is the direct responsibility of
Addition of alcohols causes interferences, but it is dependent
Subcommittee E48.05 on Biomass Conversion.
on chain length. The reason is as yet undetermined but may be
Current edition approved Jan. 1, 2018. Published January 2018. DOI: 10.1520/
E3146–18. related to solvent properties of the alcohol rather than reaction
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E3146 − 18
with NH OH·HCl or TEA. Tests with primary, secondary and
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tertiary butanol have shown the same effect.
7. Apparatus
7.1 Analytical balance, accurate to 0.0001 g.
7.2 Mic
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