Understanding Biofuel Standards

October 2, 2016 |
Angela Fivga

Angela Fivga

zsuzsa-mayer-photo-254x300

Zsuzsa Mayer

By Angela Fivga, PhD and Zsuzsa A. Mayer, PhD, Lee Enterprises Consulting, Inc.

Special to The Digest

The analysis and standardization of biofuels are in constant development, therefore in many studies they follow a historic view or borrow unsuitable methods from fossil fuel analysis. An overview of the current standards helps to achieve better results.

Due to historic reasons the most common way of grouping biofuels is based on the feedstock (food crops, agriculture waste, algae etc.), generations (1st generation, 2nd generation etc.) or technology (chemical, thermochemical or biological). However, there are strong arguments for grouping biofuels in categories like oils (e.g. biodiesel consisting methyl esters) or alcohols (e.g. bio-ethanol consisting ethyl alcohol), as the chemical composition of the fuel limits or determines the applications rather than the three above mentioned categories.

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Biofuels are also challenging in analysis and standardization. When compared to fossil fuels (mixture of hydrocarbons, relatively easy to analyze or predict their characteristics), they have significantly different chemical composition. This means different physical and fuel properties.

Hydrocarbon fuels also have a very extensive system of industrial standards and testing laboratories, while biofuel tests are constantly adapting to the development of the latest technologies.

Composition and registration

There are a large number of synonyms and trade names in use for the same chemical compounds. For example, ethanol is known by many names: ethane monoxide, ethyl hydrate, ethylol, methylcarbinol etc. Regulatory bodies and industry need to standardize and prefer to use an internationally recognized and unique numeric identifier called CAS Registry Number. The CAS number of bioethanol is the same as for ethanol (64-17-5); for Biodiesel 100 it is the same as for methyl esters of C14-C24 fatty acid (67784-80-9). CAS Registry also integrates chemical and substance information from patent and non-patent sources under the supervision of the American Chemical Society.

Biodiesel standards in EU and in USA

Technologies producing biofuel also need standardization. Regulating bodies are required to establish technical standards as they aim at the standardization of biofuel quality.

The EU is responsible for issuing mandatory environmental directives, concerning fuel quality, and the European Standards Organization (CEN) is responsible for developing industrial standards to comply with those directives. The CEN’s mission is “to promote voluntary technical harmonization in Europe in conjunction with worldwide bodies and its European partners”.[1]

CEN developed two standards for automotive fuel quality in 1993, the EN 590 for diesel and the EN 228 for gasoline (petrol). Although the application of those standards was voluntary, they were widely adopted by all fuel suppliers in Europe. The first mandatory environmental regulations concerning fuel quality were introduced by the EU in 1998 (Directive 98/70/EC), which were revised in 2003 (Directive 2003/17/EC) and again in 2009 (Directive 2009/30/EC). To comply with these directives, the fuel properties in the CEN standards were updated. These changes included the lead and sulphur content for gasoline, cetane number, sulphur content, and FAME (Fatty Acid Methyl Esters) biodiesel content for diesel. The 2009 directive also developed sustainability criteria for biofuels to ensure that they fulfil their greenhouse gas intensity reduction obligation.

In 2003, the EU introduced Directive 2003/30/EC, which specified that 5.75% of road transport energy should be from biofuels, by the end of 2010, with an intermediate target of 2%, by 2005. This was updated in 2009 (Renewable Energy Directive 2009/28/EC) to 10% by the end of 2020, highlighting the need for developing suitable standards to promote biofuels expansion. This 10% target was modified in 2015 by another Directive[2], to increase the use of advanced biofuels from waste feedstocks by limiting the percentage of biofuels produced from ‘food’ crops to 7%.

Directive 2003/30/EC led to the development of a biodiesel specification standard in 2003,[3] which allowed FAME to be used at 100% in adapted vehicles. This standard was revised several times, in 2008, 2010, and 2012. Specifically, the 2012 revision, introduced a number of changes including; an expansion of the scope to cover the use of biodiesel as heating fuel; updates to cover blends up to B10; and an additional set of climatic classes based on monoglycerides content. The EN 590, European standard for diesel specification, was updated to allow blends up to 5% of FAME in diesel, in 2003, increasing this to 7% in the 2009 revision.

In the USA the Congress passed the Energy Policy Act in 1994 – and more recently in 2005 – to promote renewable fuels. The Congress further supported the renewable fuels program under the Energy Independence and Security Act of 2007, leading to the development of biodiesel standards.

The first American standard for biodiesel, was developed by the American Society for Testing & Materials (ASTM), for biodiesel (B100) blend stock, for distillate fuels (ASTM D6751). The standard was adopted in 2002, and covers the use of biodiesel (B100) as a blending component with petroleum diesel fuels. Unlike the EU standards which allow the use of both neat biodiesel, and biodiesel as a blending component, this standard was not applicable to neat biodiesel when used as an automotive fuel. The USA standard for petroleum diesel was then updated to include blends of up to 5% biodiesel, in 2008.[4] This standard was then updated in 2012 to define two grades of biodiesel; grade 2-B (identical to biodiesel defined by earlier versions of the standard); and grade 1-B with tighter controls on monoglycerides and cold soak filterability.

In 2008, the ASTM published a new Biodiesel Blend Specification, the ASTM D7467. This standard covers fuel blends from 6% to 20% biodiesel with the remainder being a light middle or middle distillate diesel fuel, respectively designated as B6 to B20. The biodiesel and petroleum diesel used in these blends need to comply with the ASTM D6751 and ASTM D975 standards, respectively.

Biodiesel standards in the USA allow the use of both fatty acid methyl esters (FAME) and fatty acid ethyl esters (FAEE), in contract with the EU which only allows the use of FAME.

Bioethanol standards in EU and in USA

The United States Environmental Protection Agency (EPA)[5] is responsible for regulating fuel quality as it relates to emissions, under the authority of the Clean Air Act Amendments of 1990. The environmental goals set by the Act, led to the development of two bioethanol standards, by ASTM, the ASTM D 4806 and the ASTM D 5798.

The first standard for bioethanol was a denatured fuel ethanol specification.[6] This arrived in 1999, and allowed blending of denatured ethanol with unleaded or leaded gasolines at 1 to 10 volume %, for use as a spark-ignition automotive engine fuel. Denatured alcohol is ethanol blended with various additives, such as methanol and isopropanol, to make it unfit for human consumption, for tax relief reasons. The chemical properties for bioethanol contained in the EN 15376 specification are similar to those contained in the ASTM D 4806 specification, with the exception of the maximum water content, which is substantially lower in the European standard. Additionally, the ASTM D 4806 only concerns with denatured fuel ethanol.

The second standard, released in 1999 was developed to allow for an ethanol blend to be used in specially designated vehicles as a gasoline substitute.[7] This standard allowed the blend of 75 to 85 volume % denatured fuel ethanol and 25 to 15 additional volume % hydrocarbons for use in ground vehicles with automotive spark-ignition engines.

Due to its later adoption as a transport fuel in Europe, the first standard for bioethanol arrived in 2007.[8] This first standard was a bioethanol specification to allow blending with gasoline. The EN 228, European standard for gasoline specification, was updated to allow blends up to 5% bioethanol, in 2008. This is now aligned with the 2009 directive (2009/30/EC), allowing up to 10% bioethanol in gasoline.

Pyrolysis oil

The constant development of emerging technologies like pyrolysis now allows us to convert challenging feedstock like wood, plastics or industrial waste into fuel; the high temperature and inert atmosphere during fast pyrolysis break down polymers into lighter compounds. Compare to bioethanol or biodiesel pyrolysis liquid is a very complex mixture of hundreds of chemical compounds.

CEN/TC 19/WG 41 is currently developing standards for fast pyrolysis oils, in response to EC mandate M/525 (2013), since there is currently no standardization in the EU. These will include specifications for using pyrolysis oils as heavy fuel oil, light fuel oil, and for use of bio-oils in stationary combustion engines. In contrast, the USA has developed the ASTM D7544, which covers the specification of pyrolysis liquid produced from biomass, for use in various types of fuel-burning equipment.

Material Safety Data Sheets

The composition of biofuels affects not only its quality but also safety related properties. Manufacturers[9] are required to gather and provide safety related information on their product in the form of a Material Safety Data Sheet (MSDS) for workplace users.[10]

In the USA the Occupational Safety & Health Administration (OSHA) specifies the information to be included in the MSDS. These information are: product or chemical identity used on labels; chemical and common names of each hazardous ingredient; physical and chemical characteristics of all hazardous chemicals (e.g. vapor pressure and flash point), physical hazards (potential for fire, explosion etc.); permissible exposure limit (PEL)[11]; ACGIH threshold limit value (TLV)[12] procedures for spills, leaks, clean-up etc.

OSHA provides a form that meets the Hazard Communication Standard requirements but does not prescribe the precise format of a MSDS. Other regulating bodies like the United Nations’ Globally Harmonized Classification and Labelling System (GHS) requires a 16 section format MSDS with additional information and subheadings appropriate and relevant to the countries. EU legislations follow guidance on MSDS prepared by the European Chemicals Agency (ECHA) and it has a format adapted to the regulations of GHS.

Biofuel manufacturers, importers and distributors are required to provide a data sheet and it is their responsibility to ensure that the provided information on the fuels is both accurate and sufficient.

Working with less traditional biofuels and mixtures (e.g. advanced biofuel derived from fast pyrolysis) requires a different approach for both testing or preparing a new MSDS. The expert team of Lee Enterprises is happy to advice on test methods and procedures to gather the right information on any biofuels.

[1] https://www.cen.eu/

[2] Directive (EU) 2015/1513

[3] EN 14214AUTOMOTIVE FUELS – FATTY ACID METHYL ESTERS (FAME) FOR DIESEL ENGINES – REQUIREMENTS AND TEST METHODS

[4] ASTM D975 – Standard Specification for Diesel Fuel Oils

[5] https://www.epa.gov/

[6] ASTM D4806 – Standard Specification for Denatured Fuel Ethanol for Blending with Gasolines for Use as Automotive Spark-Ignition Engine Fuel

[7] ASTM D5798 – Standard Specification for Ethanol Fuel Blends for Flexible-Fuel Automotive Spark-Ignition Engines

[8] BS EN 15376 – Automotive fuels. Ethanol as a blending component for petrol. Requirements and test methods

[9] According to Occupational Safety & Health Administration “when a chemical is distributed outside of the laboratory then the distributor is a chemical manufacturer”. A distributor who “blends, mixes, or otherwise changes the composition of a chemical” is also considered a chemical manufacturer.

[10] Specialized end users may prepare workplace-specific MSDS. Please note that for transport the MSDS is not the main source of information.

[11] Permissible Exposure Limit (PEL) is the maximum amount or concentration of a chemical that a worker may be exposed to under OSHA regulations.

[12] Threshold Limit Values (TLV’s) are guidelines prepared by the American Conference of Governmental industrial Hygienists, Inc (ACGIH)

About the authors

Angela Fivga received her BEng and MEng. Mechanical Engineering (specializing in Management of Renewable Energy Resources) from the University of Western Macedonia in Greece. She received her Ph.D. in Chemical Engineering and Applied Chemistry from Aston University, UK. She is a mechanical and chemical engineer with a strong background in pyrolysis, biomass, plastic waste management, and thermochemical conversion technologies. Her Ph.D. thesis contributed to the EC Biosynergy project, which evaluated bio-refineries for transport fuels.  In addition her many research activities, she has experience with process design, PFD, P&ID, HAZOP and techno-economic simulations using HYSYS Aspen, and has worked on the development and optimization of both small, and large pyrolysis systems (including establishing design and operating parameters for commercial versions of prototype systems).  Her most recent work has been as the head of R&D for Recycling Technologies, where she focused on enabling mixed plastic waste to be converted to heavy fuel substitutes and refined feedstock for plastics production. 

Zsuzsa Mayer has an M.Sc. and a Ph.D. in Chemical Engineering and Applied Chemistry. She is a chartered chemical engineer and scientist specializing in intermediate and fast pyrolysis, and an analytical chemist specializing in biomass characterization (energy crops, micro algae, industrial and agriculture waste etc.), bio-oil characterization (physical, chemical and fuel properties) and char characterization (both for soil and for energy applications). Zsuzsa has designed and set up cutting edge laboratories, and published several peer reviewed research papers and patents. She is a hands on expert of a very wide range of analytical instruments necessary for the effective support of R&D activities and industrial scale fuel production. Zsuzsa is an expert of several advanced statistical methods essential for pyrolysis process optimization, product upgrading and quality control. She joined the European Bioenergy Research Institute in 2009 and currently works as a Principal Analytical Chemist and Biofuel Researcher in Oxford, UK.

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