ASTM D7544-23

Standard Specification for Pyrolysis Liquid Biofuel

ABSTRACT
This specification details the physical and chemical requirements for pyrolysis liquid biofuels produced from biomass that are intended for use in industrial burners equipped to handle these types of fuels. The type of biofuel covered here is not intended for use in residential heaters, small commercial boilers, engines, or marine applications. It shall remain uniform in medium-term storage and shall not separate into layers due to gravity. Properly sampled test specimens shall undergo test procedures to determine their adherence to the following requirements: gross heat of combustion; water content; pyrolysis solids content; kinematic viscosity; density; sulfur content; ash content; pH; flash point; and pour point.
SCOPE
1.1 This specification covers grades of pyrolysis liquid biofuel produced from biomass intended for use in various types of fuel-burning equipment under various climatic and operating conditions. These grades are described as follows:  
1.1.1 Grade G is intended for use in industrial burners equipped to handle the pyrolysis liquid biofuels meeting the requirements listed for Grade G in Table 1. The pyrolysis liquid biofuel listed under Grade G in Table 1 is not intended for use in residential heaters, small commercial boilers, engines, or marine applications.  
1.1.2 Grade D is intended for use in commercial/industrial burners requiring lower solids and ash content and which are equipped to handle the pyrolysis liquid biofuels meeting the requirements listed for Grade D in Table 1. The pyrolysis liquid biofuel listed under Grade D in Table 1 is not intended for use in residential heaters, engines, or marine applications not modified to handle these types of fuels.
Note 1: For information on the significance of the physical, chemical, and performance properties identified in this specification, see Appendix X1.  
1.2 This specification is for use in contracts for the purchase of pyrolysis liquid biofuel and for guidance of consumers of this type of fuel.  
1.3 Nothing in this specification should preclude observance of national or local regulations, which may be more restrictive.
Note 2: The generation and dissipation of static electricity may create problems in the handling of pyrolysis liquid biofuel. For more information on the subject, see Guide D4865.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4.1 Exception—BTU units are included for information only in 3.2.3.1.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Apr-2023
• ICS: 75.160.20 - Liquid fuels
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.E0 - Burner, Diesel and Non-Aviation Gas Turbine Fuels

Relations

• Refers: ASTM D445-24 - Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• Effective Date: 01-Apr-2024
• Refers: ASTM E203-24 - Standard Test Method for Water Using Volumetric Karl Fischer Titration
• Effective Date: 01-Jan-2024
• Refers: ASTM E70-24 - Standard Test Method for pH of Aqueous Solutions With the Glass Electrode
• Effective Date: 01-Jan-2024
• Refers: ASTM D4175-23a - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 15-Dec-2023
• Refers: ASTM D445-23 - Standard Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
• Effective Date: 01-Nov-2023
• Refers: ASTM D4865-23 - Standard Guide for Generation and Dissipation of Static Electricity in Petroleum Fuel Systems
• Effective Date: 01-Nov-2023
• Refers: ASTM D4175-23e1 - Standard Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
• Effective Date: 01-Jul-2023
• Refers: ASTM D93-20 - Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
• Effective Date: 01-Aug-2020
• Refers: ASTM D396-19a - Standard Specification for Fuel Oils
• Effective Date: 15-Dec-2019
• Refers: ASTM D7579-09(2019) - Standard Test Method for Pyrolysis Solids Content in Pyrolysis Liquids by Filtration of Solids in Methanol
• Effective Date: 01-May-2019
• Refers: ASTM D396-19 - Standard Specification for Fuel Oils
• Effective Date: 01-May-2019
• Refers: ASTM D396-18a - Standard Specification for Fuel Oils
• Effective Date: 01-Oct-2018
• Refers: ASTM D396-18 - Standard Specification for Fuel Oils
• Effective Date: 01-May-2018
• Refers: ASTM D396-17a - Standard Specification for Fuel Oils
• Effective Date: 01-Dec-2017
• Refers: ASTM D396-17 - Standard Specification for Fuel Oils
• Effective Date: 01-Jul-2017

Overview

ASTM D7544-23: Standard Specification for Pyrolysis Liquid Biofuel outlines the requirements and testing procedures for pyrolysis liquid biofuels derived from biomass. These biofuels are specifically intended for industrial burners and commercial burners equipped to handle such fuels. The standard establishes conditions for medium-term storage, uniformity, and physical and chemical properties such as heat value, water content, viscosity, density, sulfur and ash content, pH, flash point, and pour point. ASTM D7544 provides a framework for ensuring consistent performance and safety in the use of renewable pyrolysis oils in large-scale industrial settings.

Key Topics

• Grades of Pyrolysis Liquid Biofuel:

  • Grade G: For industrial burners designed for higher ash and solids content.
  • Grade D: For commercial and industrial burners where lower ash and solids are required.
    Neither grade is suitable for residential heaters, small commercial boilers, engines, or marine applications.

• Physical and Chemical Requirements:

  • Gross heat of combustion
  • Water content
  • Pyrolysis solids and char content
  • Kinematic viscosity
  • Density
  • Sulfur and ash content
  • pH value
  • Flash and pour points

• Testing and Sampling Procedures

  • Emphasis on correct sampling, mixing, and handling to obtain representative fuel samples.
  • Standardized methods for evaluating each physical and chemical property, using established ASTM test methods.

• Storage and Handling Guidelines

  • Medium-term storage (up to 3 months): Fuel must remain homogenous without gravity-induced layer separation.
  • Long-term storage: May require agitation or circulation; materials of construction must be corrosion-resistant due to the acidic nature of pyrolysis biofuels.
  • Considerations for temperature control (typically 10–30°C) to prevent fuel degradation.

• Safety, Environment, and Quality

  • Special guidance on static electricity risks and the potential for microbial contamination.
  • Recommendations comply with international standards and regulatory obligations.

Applications

• Industrial Burners and Boilers:
  Pyrolysis liquid biofuels are used as renewable fuel sources in heavy industrial applications such as kilns, furnaces, and large utility boilers, supporting direct and indirect heating processes.

• Commercial Heating Systems:
  Suitable for commercial-scale burners requiring liquid renewable fuels with specified properties, especially where reduced sulfur emissions and alternative energy sources are desirable.

• Renewable Energy and Sustainability:
  By using biomass-derived pyrolysis oils as alternatives to fossil fuels, organizations can lower their carbon footprints and use a fuel with lower nitrogen dioxide emissions due to higher water content.

• Fuel Purchasing and Contracting:
  ASTM D7544 serves as a benchmark for contracts involving the purchase or supply of pyrolysis liquid biofuels, ensuring consistent quality and performance for end users.

Related Standards

• ASTM D4865 - Guide for Generation and Dissipation of Static Electricity in Petroleum Fuel Systems
• ASTM D396 - Specification for Fuel Oils
• ASTM D445 - Test Method for Kinematic Viscosity of Transparent and Opaque Liquids
• ASTM D4052 - Test Method for Density, Relative Density, and API Gravity
• ASTM D4294 - Test Method for Sulfur Content in Petroleum Products
• ASTM D482 - Test Method for Ash Content
• ASTM D5854 - Practice for Mixing and Handling Liquid Samples
• ASTM D6469 - Guide for Microbial Contamination in Fuels
• ASTM D7579 - Test Method for Pyrolysis Solids Content
• ASTM E70 - Test Method for pH of Aqueous Solutions

These referenced ASTM standards reinforce the reliability, safety, and performance of pyrolysis liquid biofuel in industrial and commercial applications and contribute to advancing renewable energy adoption. For complete information and implementation, always consult the official published ASTM D7544-23 standard.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D7544 − 23
Standard Specification for
Pyrolysis Liquid Biofuel
This standard is issued under the fixed designation D7544; 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* responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
1.1 This specification covers grades of pyrolysis liquid
mine the applicability of regulatory limitations prior to use.
biofuel produced from biomass intended for use in various
1.6 This international standard was developed in accor-
types of fuel-burning equipment under various climatic and
dance with internationally recognized principles on standard-
operating conditions. These grades are described as follows:
ization established in the Decision on Principles for the
1.1.1 Grade G is intended for use in industrial burners
Development of International Standards, Guides and Recom-
equipped to handle the pyrolysis liquid biofuels meeting the
mendations issued by the World Trade Organization Technical
requirements listed for Grade G in Table 1. The pyrolysis liquid
Barriers to Trade (TBT) Committee.
biofuel listed under Grade G in Table 1 is not intended for use
in residential heaters, small commercial boilers, engines, or
2. Referenced Documents
marine applications.
2.1 ASTM Standards:
1.1.2 Grade D is intended for use in commercial/industrial
D93 Test Methods for Flash Point by Pensky-Martens
burners requiring lower solids and ash content and which are
Closed Cup Tester
equipped to handle the pyrolysis liquid biofuels meeting the
D97 Test Method for Pour Point of Petroleum Products
requirements listed for Grade D in Table 1. The pyrolysis liquid
D240 Test Method for Heat of Combustion of Liquid Hy-
biofuel listed under Grade D in Table 1 is not intended for use
drocarbon Fuels by Bomb Calorimeter
in residential heaters, engines, or marine applications not
D396 Specification for Fuel Oils
modified to handle these types of fuels.
D445 Test Method for Kinematic Viscosity of Transparent
NOTE 1—For information on the significance of the physical, chemical,
and Opaque Liquids (and Calculation of Dynamic Viscos-
and performance properties identified in this specification, see Appendix
ity)
X1.
D482 Test Method for Ash from Petroleum Products
1.2 This specification is for use in contracts for the purchase
D4052 Test Method for Density, Relative Density, and API
of pyrolysis liquid biofuel and for guidance of consumers of
Gravity of Liquids by Digital Density Meter
this type of fuel.
D4175 Terminology Relating to Petroleum Products, Liquid
1.3 Nothing in this specification should preclude observance
Fuels, and Lubricants
of national or local regulations, which may be more restrictive.
D4294 Test Method for Sulfur in Petroleum and Petroleum
Products by Energy Dispersive X-ray Fluorescence Spec-
NOTE 2—The generation and dissipation of static electricity may create
trometry
problems in the handling of pyrolysis liquid biofuel. For more information
on the subject, see Guide D4865.
D4865 Guide for Generation and Dissipation of Static Elec-
tricity in Petroleum Fuel Systems
1.4 The values stated in SI units are to be regarded as
D5854 Practice for Mixing and Handling of Liquid Samples
standard. No other units of measurement are included in this
of Petroleum and Petroleum Products
standard.
D6469 Guide for Microbial Contamination in Fuels and Fuel
1.4.1 Exception—BTU units are included for information
Systems
only in 3.2.3.1.
D7579 Test Method for Pyrolysis Solids Content in Pyroly-
1.5 This standard does not purport to address all of the
sis Liquids by Filtration of Solids in Methanol
safety concerns, if any, associated with its use. It is the
E70 Test Method for pH of Aqueous Solutions With the
Glass Electrode
This specification is under the jurisdiction of ASTM Committee D02 on
Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of
Subcommittee D02.E0 on Burner, Diesel and Non-Aviation Gas Turbine Fuels. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved May 1, 2023. Published May 2023. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2009. Last previous edition approved in 2017 as D7544 – 12 (2017). Standards volume information, refer to the standard’s Document Summary page on
DOI:10.1520/D7544-23. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7544 − 23
TABLE 1 Detailed Requirements for Pyrolysis Liquid Biofuels
Property Test Method Grade G Grade D
Gross Heat of Combustion, MJ/kg, min D240 15 15
Water Content, % mass, max E203 30 30
Pyrolysis Solids Content, % mass, max D7579 2.5 0.25
2 A
Kinematic Viscosity at 40 °C, mm /s, max D445 125 125
Density at 20 °C, kg/dm D4052 1.1–1.3 1.1–1.3
Sulfur Content, % mass, max D4294 0.05 0.05
Ash Content, % mass, max D482 0.25 0.15
pH. E70 Report Report
Flash Point,°C, min D93, Procedure B 45 45
Pour Point,°C, max D97 –9 –9
A
Without filtering.
E203 Test Method for Water Using Volumetric Karl Fischer power generation and in manufacturing processes. These
Titration boilers can be classified as utility/large industrial boilers with a
heat input greater than 105 GJ/h (100 × 10 BTU/h) or small
3. Terminology
industrial boilers with a heat input of between 10.5 GJ ⁄h to
105 GJ ⁄h (10 to 100 × 10 BTU ⁄h).
3.1 Definitions:
3.1.1 For definitions of terms used in this specification, refer
3.2.4 long-term storage, n—storage of fuel for longer than
to Terminology D4175.
3 months after it is received by the user.
3.1.2 fuel degradation products, n—those materials that are
3.2.5 medium-term storage, n—storage of fuel for up to
formed in fuel during storage, usage, or exposure to high
3 months after it is received by the user.
temperatures and pressures.
3.2.5.1 Discussion—It is recommended that fuel be con-
3.1.2.1 Discussion—Insoluble degradation products can
sumed within 6 months of receipt.
combine with other fuel contaminants to enhance deleterious
effects. Soluble degradation products (soluble gums) are less
3.2.6 pyrolysis, n—chemical decomposition of organic ma-
volatile than fuel and can carbonize to form deposits due to
terials by heating in the absence of oxygen.
complex interactions and oxidation of small amounts of
3.2.7 pyrolysis liquid biofuel, n—liquid product from the
olefinic or sulfur-, oxygen-, or nitrogen-containing compounds
pyrolysis of biomass.
present in fuels. The formation of degradation products can be
3.2.7.1 Discussion—Pyrolysis liquid biofuel is comprised of
catalyzed by dissolved metals, especially copper and zinc.
a complex mixture of the decomposition products of renewable
When dissolved copper and zinc are present it can be deacti-
resources such as ligno-cellulosic biomass including highly
vated with metal deactivator additives.
oxygenated organic compounds. It is produced from the
3.2 Definitions of Terms Specific to This Standard:
pyrolysis of biomass, followed by the rapid condensation of its
3.2.1 char, n—fine carbonaceous powder that is separated
vapors.
from the vapors of biomass during pyrolysis.
3.2.1.1 Discussion—Pyrolysis liquid biofuel contains uni- 3.2.8 pyrolysis solids, n—solid particles contained within
the pyrolysis liquid biofuel.
formly suspended char.
3.2.8.1 Discussion—Pyrolysis solids is comprised of ash
3.2.2 commercial burner, n—device which produces heat for
and char.
commercial use through the combustion of liquid fuels.
3.2.2.1 Discussion—Commercial burners are typically de-
4. General Requirements
signed for processes that provide direct heating. Commercial
boilers or heaters—small to medium indirect heating units
4.1 The pyrolysis liquid biofuel specified in this specifica-
which transfer thermal energy to water or other fluids or gases
tion shall remain uniform in medium-term storage and not
for use in heating in commercial settings, power generation and
separate by gravity into layers.
in manufacturing processes. These boilers can be classified as
small or medium commercial boilers with a heat input of NOTE 3—Long-term storage or equipment down time can necessitate
circulation of pyrolysis liquid biofuel in-tank to prevent such separation.
between 10.5 GJ ⁄h to 105 GJ/h (10 to 100 × 10 BTU/h).
The buyer and seller should agree on any requirements for long-term
3.2.3 industrial burner, n—device which produces heat for
storage. If minor separation occurs during medium-term storage, mild
industrial use through the combustion of liquid fuels.
agitation or product circulation should reverse such separation.
3.2.3.1 Discussion—Industrial burners are typically de-
signed for one of two applications: (1) industrial furnaces— 5. Detailed Requirements
integral components of manufacturing processes that provide
5.1 The various grades of pyrolysis liquid biofuel shall
direct heating; for example, in aggregate, cement, lime, or
conform to the detailed requirements shown in Table 1.
phosphate kilns; coke ovens; or blast, smelting, melting,
refining, or drying ovens and (2) industrial boilers—large 5.2 The properties selected for limitation are those that are
indirect heating units which transfer thermal energy to water or believed to be of the greatest significance in obtaining accept-
other fluids or gases for use in heating in industrial settings, able performance of the burner.
D7544 − 23
6. Sampling 6.3 Sample Size—A minimum of 1 L is recommended.
6.1 Review all intended test methods prior to sampling to
7. Test Methods
understand the importance and effects of sampling technique,
7.1 The requirements enumerated in this specification shall
proper containers, and special handling required for each test
be determined in accordance with the following test methods:
method. See Table 2.
7.1.1 Gross Heat of Combustion—Test Method D240.
6.2 As indicated in 4.1, during medium-term storage, py- 7.1.2 Water Content—Test Method E203.
rolysis liquid biofuel shall remain uniform and not separate 7.1.3 Pyrolysis Solids Content—See Test Method D7579.
into layers. Note, however, that separation may occur during 7.1.4 Kinematic Viscosity—Test Method D445.
long-term storage. Therefore, samples should be well mixed 7.1.5 Density—Test Method D4052.
when transferring from the primary sampling process or 7.1.6 Sulfur—Test Method D4294.
container, or both, to another container or analytical apparatus, 7.1.7 As
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7544 − 12 (Reapproved 2017) D7544 − 23
Standard Specification for
Pyrolysis Liquid Biofuel
This standard is issued under the fixed designation D7544; 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 Scope*
1.1 This specification covers grades of pyrolysis liquid biofuel produced from biomass intended for use in various types of
fuel-burning equipment under various climatic and operating conditions. These grades are described as follows:
1.1.1 Grade G is intended for use in industrial burners equipped to handle the pyrolysis liquid biofuels meeting the requirements
listed for Grade G in Table 1. The pyrolysis liquid biofuel listed under Grade G in Table 1 is not intended for use in residential
heaters, small commercial boilers, engines, or marine applications.
1.1.2 Grade D is intended for use in commercial/industrial burners requiring lower solids and ash content and which are equipped
to handle the pyrolysis liquid biofuels meeting the requirements listed for Grade D in Table 1. The pyrolysis liquid biofuel listed
under Grade D in Table 1 is not intended for use in residential heaters, engines, or marine applications not modified to handle these
types of fuels.
NOTE 1—For information on the significance of the physical, chemical, and performance properties identified in this specification, see Appendix X1.
1.2 This specification is for use in contracts for the purchase of pyrolysis liquid biofuel and for guidance of consumers of this type
of fuel.
1.3 Nothing in this specification should preclude observance of national or local regulations, which may be more restrictive.
NOTE 2—The generation and dissipation of static electricity may create problems in the handling of pyrolysis liquid biofuel. For more information on
the subject, see Guide D4865.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4.1 Exception—BTU units are included for information only in 3.1.53.2.3.1.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
This specification is under the jurisdiction of ASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of Subcommittee
D02.E0 on Burner, Diesel, Diesel and Non-Aviation Gas Turbine, and Marine Turbine Fuels.
Current edition approved Oct. 1, 2017May 1, 2023. Published November 2017May 2023. Originally approved in 2009. Last previous edition approved in 20122017 as
D7544D7544 – 12 (2017).–12. DOI:10.1520/D7544-12R17. DOI:10.1520/D7544-23.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7544 − 23
TABLE 1 Detailed Requirements for Pyrolysis Liquid Biofuels
Property Test Method Grade G Grade D
Gross Heat of Combustion, MJ/kg, min D240 15 15
Water Content, % mass, max E203 30 30
Pyrolysis Solids Content, % mass, max D7579 2.5 0.25
2 A
Kinematic Viscosity at 40 °C, mm /s, max D445 125 125
Density at 20 °C, kg/dm D4052 1.1–1.3 1.1–1.3
Sulfur Content, % mass, max D4294 0.05 0.05
Ash Content, % mass, max D482 0.25 0.15
pH. E70 Report Report
Flash Point,°C, min D93, Procedure B 45 45
Pour Point,°C, max D97 –9 –9
A
Without filtering.
2. Referenced Documents
2.1 ASTM Standards:
D93 Test Methods for Flash Point by Pensky-Martens Closed Cup Tester
D97 Test Method for Pour Point of Petroleum Products
D240 Test Method for Heat of Combustion of Liquid Hydrocarbon Fuels by Bomb Calorimeter
D396 Specification for Fuel Oils
D445 Test Method for Kinematic Viscosity of Transparent and Opaque Liquids (and Calculation of Dynamic Viscosity)
D482 Test Method for Ash from Petroleum Products
D4052 Test Method for Density, Relative Density, and API Gravity of Liquids by Digital Density Meter
D4175 Terminology Relating to Petroleum Products, Liquid Fuels, and Lubricants
D4294 Test Method for Sulfur in Petroleum and Petroleum Products by Energy Dispersive X-ray Fluorescence Spectrometry
D4865 Guide for Generation and Dissipation of Static Electricity in Petroleum Fuel Systems
D5854 Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products
D6469 Guide for Microbial Contamination in Fuels and Fuel Systems
D7579 Test Method for Pyrolysis Solids Content in Pyrolysis Liquids by Filtration of Solids in Methanol
E70 Test Method for pH of Aqueous Solutions With the Glass Electrode
E203 Test Method for Water Using Volumetric Karl Fischer Titration
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this specification, refer to Terminology D4175.
3.1.2 fuel degradation products, n—those materials that are formed in fuel during storage, usage, or exposure to high temperatures
and pressures.
3.1.2.1 Discussion—
Insoluble degradation products can combine with other fuel contaminants to enhance deleterious effects. Soluble degradation
products (soluble gums) are less volatile than fuel and can carbonize to form deposits due to complex interactions and oxidation
of small amounts of olefinic or sulfur-, oxygen-, or nitrogen-containing compounds present in fuels. The formation of degradation
products can be catalyzed by dissolved metals, especially copper and zinc. When dissolved copper and zinc are present it can be
deactivated with metal deactivator additives.
3.2 Definitions of Terms Specific to This Standard:
3.1.1 bulk fuel, n—fuel in the storage facility in quantities over 190 L.
3.2.1 char, n—fine carbonaceous powder that is separated from the vapors of biomass during pyrolysis.
3.2.1.1 Discussion—
Pyrolysis liquid biofuel contains uniformly suspended char.
3.2.2 commercial burner, n—device which produces heat for commercial use through the combustion of liquid fuels.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
D7544 − 23
3.2.2.1 Discussion—
Commercial burners are typically designed for processes that provide direct heating. Commercial boilers or heaters—small to
medium indirect heating units which transfer thermal energy to water or other fluids or gases for use in heating in commercial
settings, power generation and in manufacturing processes. These boilers can be classified as small or medium commercial boilers
with a heat input of between 10.5 GJ ⁄h to 105 GJ/h (10 to 100 × 10610 BTU/h).
3.1.4 fuel degradation products, n—those materials that are formed in fuel during extended storage or exposure to high
temperatures.
3.1.4.1 Discussion—
During storage, reactive organic compounds in pyrolysis liquid can act together to form larger molecules (fuel degradation
products), which can become insoluble or increase the fuel viscosity, or both.
3.2.3 industrial burner, n—device which produces heat for industrial use through the combustion of liquid fuels.
3.2.3.1 Discussion—
Industrial burners are typically designed for one of two applications: (1) industrial furnaces—integral components of
manufacturing processes that provide direct heating; for example, in aggregate, cement, lime, or phosphate kilns; coke ovens; or
blast, smelting, melting, refining, or drying ovens and (2) industrial boilers—large indirect heating units which transfer thermal
energy to water or other fluids or gases for use in heating in industrial settings, power generation and in manufacturing processes.
These boilers can be classified as utility/large industrial boilers with a heat input greater than 105 GJ/h (100 × 10610 BTU/h) or
small industrial boilers with a heat input of between 10.5 GJ ⁄h to 105 GJ ⁄h (10 to 100 × 106 BTU10 BTU ⁄h).
3.2.4 long-term storage—storage, n—storage of fuel for longer than 3 months after it is received by the user.
3.2.5 medium-term storage—storage, n—storage of fuel for up to 3 months after it is received by the user.
3.2.5.1 Discussion—
It is recommended that fuel be consumed within 6 months of receipt.
3.2.6 pyrolysis, n—chemical decomposition of organic materials by heating in the absence of oxygen.
3.2.7 pyrolysis liquid biofuel, n—liquid product from the pyrolysis of biomass.
3.2.7.1 Discussion—
Pyrolysis liquid biofuel is comprised of a complex mixture of the decomposition products of renewable resources such as
ligno-cellulosic biomass including highly oxygenated organic compounds. It is produced from the pyrolysis of biomass, followed
by the rapid condensation of its vapors.
3.2.8 pyrolysis solids, n—solid particles contained within the pyrolysis liquid biofuel.
3.2.8.1 Discussion—
Pyrolysis solids is comprised of ash and char.
4. General Requirements
4.1 The pyrolysis liquid biofuel specified in this specification shall remain uniform in medium-term storage and not separate by
gravity into layers.
NOTE 3—Long-term storage or equipment down time can necessitate circulation of pyrolysis liquid biofuel in-tank to prevent such separation. The buyer
and seller should agree on any requirements for long-term storage. If minor separation occurs during medium-term storage, mild agitation or product
circulation should reverse such separation.
5. Detailed Requirements
5.1 The various grades of pyrolysis liquid biofuel shall conform to the detailed requirements shown in Table 1.
5.2 The properties selected for limitation are those that are believed to be of the greatest significance in obtaining acceptable
performance of the burner.
D7544 − 23
6. Sampling
6.1 Review all intended test methods prior to sampling to understand the importance and effects of sampling technique, proper
containers, and special handling required for each test method. See Table 2.
6.2 As indicated in 4.1, during medium-term storage, pyrolysis liquid biofuel shall remain uniform and not separate into layers.
Note, however, that separation may occur during long-term storage. Therefore, samples should be well mixed when transferring
from the primary sampling process or container, or both, to another container or analytical apparatus, or both. Sampling from an
active circulation loop or a well mixed or agitated tank is preferred. Refer to Practice D5854 for more guidance on mixing and
handling samples.
6.3 Sample Size—A minimum of 1 L is recommended.
7. Test Methods
7.1 The requirements enumerated in this specification
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