Closing the Circle

From marine lubricants to airplane fuel and feedstocks, ASTM International committees are moving the circular economy forward, finding ways to improve the sustainability of transportation and energy-related materials.
Jack Maxwell

Lines and circles. In the world of geometry, they’re straightforward, easily understood concepts.

Considered metaphorically, however, in the context of the relationship between the environment and the global economy, they point to a stark dichotomy: the linear take-make-waste model versus the more holistic approach often referred to as “the circular economy.”

The Ellen MacArthur Foundation describes the circular economy as the decoupling of economic activity from the consumption of finite resources. This approach is underpinned by a transition to renewable energy and materials, and it is based on three principles: designing out waste and pollution, keeping products and materials in use, and regenerating natural systems.

Efforts to nudge the massive world economy in the direction of greater sustainability — to convert that straight line into a circle — take many forms. This includes the environmental impact of two types of products vital to the transportation sector: marine lubricants and jet fuel. Others seek to develop standards that can be used to compare the relative sustainability of various biobased feedstocks and other products. 

READ MORE: 3 Important Standards for Airplane Emissions

ASTM International supports work in all three of these areas with the committees on petroleum products, liquid fuels, and lubricants (D02); ships and marine technology (F25); and bioenergy and industrial chemicals from biomass (E48). 

Oil and Water

The International Maritime Organization estimates that 90% of the world’s trade is carried via sea-going transport. A report produced several years ago by a European refinery industry trade group put the figure at 80% by volume and identified more than 50,000 merchant ships trading internationally at that time.

These statistics illustrate the vital part the global shipping industry plays in the world economy. The numbers also provide a sense of the potential scale of the pollution created by the marine lubricants that keep these vessels running smoothly. ASTM members have been instrumental in moving the needle on this issue, which in the United States tracks with the evolution of what is called the vessel general permit (VGP).

The U.S. Environmental Protection Agency (EPA) implemented the VGP in 2008 as a way to control discharges from commercial ships more than 79 feet (24 m) in length that operate in U.S. coastal and inland waterways and lakes. Gareth Fish, Ph.D., is a D02 member and technology manager for industrial additives and greases for Lubrizol. He notes that from 2008 to 2013, the use of what are referred to as environmentally acceptable lubricants (EALs) was voluntary.

Revisions to the permit program in 2013 mandated the use of EALs if they were available and shown to meet the necessary performance requirements. Since then, Fish notes, “EALs are self-certified by vendors as meeting VGP.”

This self-reporting approach is similar to that of Europe’s biolubricant schema as per EN16807 (more on that below), but can be easily verified by the end user,” explains Mathias Woydt, Ph.D. “In contrast, the European Ecolabel rates the eco-toxicology of individual components. The formulator must disclose the formulation on a confidential basis to a competent body in order to receive the label.” Woydt is an industry consultant with Matrilub and a member of the ASTM petroleum products committee.

Environmentally Acceptable Lubricants

Looming over this activity are two fundamental questions: What exactly is an environmentally acceptable lubricant? And how do ship operators distinguish among the many available options?

Regarding the first question, Fish points out that it depends on the organization. “The National Lubricating Grease Institute uses the phrase ‘containing a biobased fluid’ but does not seem to have a minimum concentration. Other organizations have their own — and typically different — definitions.” For instance, Europe’s liquid petroleum products — biolubricants — criteria and requirements of biolubricants and biobased lubricants (EN16807) standard is applied to fully formulated products and requires renewable content of at least 25%.

In the United States, the EPA defined biolubricants in a 2011 report on the subject as “products that have been demonstrated to meet standards for biodegradability, low aquatic toxicity, and bioaccumulation potential that minimize their likely adverse consequences in the aquatic environment, compared to conventional lubricants.” The U.S. Department of Agriculture’s (USDA) BioPreferred program lists the minimum amount of bioderived material in the lubricant.

This program also includes a voluntary labeling protocol for biobased products. Under the general heading of lubricants and greases, 13 types of products are listed. Included are greases, chain and cable lubricants, gear lubricants, multipurpose lubricants, and other lubricants, all of which have marine applications.

Standards for products like renewable jet fuels will help move the circular economy forward.

Standard Guide for EALs

Various industry stakeholders define biolubricants in different ways, so how can the different products on the market be distinguished from each other? To help answer this question, two ASTM committees began collaborating on a guide to EALs that comply with the U.S. VGP. 

“I believe the people working on this issue understood how important it was that the EALs perform well on vessels and also how little the marine industry as a whole knew about EALs,” says John Sherman. He is project lead for PAG (polyalkylene glycol) lubricant technology at Shell Lubricant Solutions (U.S.) Inc., and a member of both the petroleum products committee and the ships and marine technology committee. Sherman is also a key contributor to a recently approved standard that will increase that knowledge.

The process leading to the new guide for selection of environmentally acceptable lubricants for the EPA Vessel General Permit (WK68688) began in earnest in 2015, when Sherman began coordinating the efforts of two subcommittees that agreed to work together on this document: marine environmental protection (F25.06) and environmental standards for lubricants (D02.12). The initial draft was presented in December 2015 and served as the starting point for the collaboration that began in earnest the following year.

The draft standard was ready for an initial ballot in June 2018. However, the five-year update to the VGP that was pending at the time, along with the subsequent December 2018 enactment the Vessel Incidental Discharge Act (VIDA), which will ultimately supersede the 2013 VGP, delayed the process.

VIDA requires the EPA to develop national performance standards to address incidental commercial vessel discharges by December 2020. Two years after the EPA publication of these final Vessel Incidental Discharge National Standards of Performance, the U.S. Coast Guard (USCG) is required to develop corresponding implementation, compliance, and enforcement regulations for those standards.

“The law changes the way incidental discharges from vessels will be regulated by the EPA, based on national standards of performance and how those regulations will be implemented, complied with, and enforced by USCG and EPA. Until the VIDA regulations are finalized and found to be effective and enforceable, the provisions and requirements of the 2013 VGP will remain in effect,” Sherman says.

The legislative and regulatory activity surrounding the transition from VGP to VIDA did not stop an ASTM working group from forging ahead in this area, and the draft standard was first balloted in the fall of 2019. Comments and concerns were resolved, revisions were made, the revised version was submitted for concurrent ballot last December, and final approval of the D8324 guide for selecting VGP-compliant EALs is forthcoming.

“This document is trying to unify the various categorizations of these bioproducts, but it’s primarily focusing on meeting the actual requirements of the VGP,” says Mark Miller, CEO of Biosynthetic Technologies and vice chair of the environmental standards for lubricants subcommittee (D02.12). “Because the folks in our subsection are really struggling with what it means, and wondering: ‘How do I meet the Vessel General Permit requirements?’ They don’t want to inadvertently make a mistake.”

Flying Green

Another important standards development effort that will improve the sustainability of transportation infrastructure relates to work being done on jet fuel standards by the subcommittee on emerging turbine fuels (D02.JO.06).

In an October 2019 report, the Environmental and Energy Study Institute estimated that aviation produced 2.2% of global carbon dioxide (CO2) emissions in 2018. Though this number seems small, if aviation were a country, it would have ranked sixth that year among the nations of the world — between Japan and Germany — in emissions.

Looked at another way, the Boeing 737 family — one of the best-selling airliners in the world —uses 750 gallons (630 L) of fuel in an hour. That translates to about 12.5 gallons (47 L) per minute. This makes improving the efficiency of commercial aircraft an ongoing priority for the industry.

A watershed moment in addressing this issue occurred in 2006, when the European Union (EU) imposed carbon-emission requirements on all airlines flying into Europe. Since then, the EU Emissions Trading Scheme (ETS) has spawned various international standards designed to limit aircraft emissions worldwide. A recent example is the rules regarding greenhouse gas emissions recently released by the International Civil
Aviation Organization and EPA. The rules apply to certain new commercial jets, including all large passenger aircraft.

Filling up with renewable jet fuels is one way airlines can meet these global standards (buying offsets is the other). Low-emission aviation fuels can be made with a number of different conventional and synthetic blending components, including algae and plant material. But what are the criteria for these renewable options?

“From an ASTM perspective, safety is critical,” says Mark Rumizen, senior technical specialist, aviation fuels, with the U.S. Federal Aviation Administration, and chair of D02.J0.06. “Safety must take precedence over other considerations such as emissions and economics. ASTM’s role is to evaluate all new candidate alternative jet fuels and write specifications to make sure they’re as safe as possible and
perform properly.”

The specification for aviation turbine fuel containing synthesized hydrocarbons (D7566) is one such reference. Updated in January, this specification defines minimum property requirements for fuel that contains synthesized hydrocarbons or is derived from renewable sources. The standard also lists acceptable additives for use in civil-operated engines and aircraft. Developed for civil-aviation scenarios, the specification may also be adopted for government, military, and other specialized uses.

Fuels based on this standard that are made from synthetic or renewable sources will significantly reduce net greenhouse gas emissions. In a powerful example of circularity, CO2 emitted from jet engines will be offset by the CO2 consumed by the renewable feedstock used to make the fuel.

Rumizen also notes that several major aviation companies recently announced their intention to operate with unblended, or 100%, sustainable aviation fuel (SAF). “ASTM Subcommittee D02.J0 has been called into action and has formed a task group to develop specification updates that accommodate the use of these unblended SAFs. While just getting started, task group members are already busy developing concepts for discussion,” he says.

Determining True Sustainability

ASTM International activity in transportation and energy has many other facets, with a number of developing technologies showing great promise in moving the aviation industry toward a greener profile — one that would replace traditional petroleum-derived fuels with alternatives that rely to varying degrees on renewable, biomass-derived feedstocks.

FOR YOU: Plastics and the Circular Economy

For example, hydroprocessed esters and fatty acids synthetic paraffinic kerosene (HEFA-SPK, annex A2 of D7566) is a specific type of renewable fuel produced by deoxygenation and hydroprocessing of natural oils derived from algae or oil seed plants such as jatropha and camelina. Catalytic hydrothermolysis jet (CHJ) fuel uses a different method to convert oil from sources like algae, tallows, and other waste oils to a jet fuel product.

But how does one determine the relative sustainability of alternative fuels?

The committee on bioenergy and industrial chemicals from biomass (E48) is responsible for two key standards designed to facilitate evaluation of the relative sustainability of options when at least one option contains products derived from renewable resources. 

The practice for evaluating relative sustainability involving energy or chemicals from biomass (E3066), first approved in 2016, was updated last year. And, because an iterative process of measurement and evaluation is recommended to identify opportunities for improving sustainability, the point of comparison becomes a critical factor. Therefore, science-based practices and document-reference scenarios are needed when evaluating sustainability of bioproducts. The new standard practice for reference scenarios when evaluating the relative sustainability of bioproducts (E3256) addresses this need.

“E3256 is a more fundamental standard, developed to be a companion to E3066,” says Charles Corr, an industry consultant, D02 member, and technical adviser to E48. “To improve sustainability in the real world, we need to carefully compare options. To do this, the test scenario must be compared against what would have happened in the absence of the test scenario or a ‘business as usual’ scenario. E3256 was developed to provide standard guidelines and criteria for selecting the reference scenario.”

Keith Kline, a scientist at Oak Ridge National Laboratory, picks up the thread. “The goal is to help users apply clearly defined methods that support transparent, replicable, and fair comparisons. When dealing with complex biological systems involving forests or croplands, this is a challenge. Yet it is important to analyze and document the most probable alternative uses for land, crops, or residues. Cascading use and ultimate disposition of biomass in each scenario need to be defined. It is critical to clearly document data sources and assumptions for each scenario when assessing the impacts of a biobased product system. For example, how would land management, emissions, and landscape ecosystem services differ if one didn’t use specific crops or residues for energy products,” he asks.

Kline describes the challenge of identifying more sustainable options in a world of imperfect knowledge. “It is essential to include stakeholders in a systematic process to evaluate and test options that provide incremental improvements toward achieving defined goals and objectives. Adaptive management is required as circumstances change or new information becomes available. And context matters. The best options for producing clean, renewable jet fuels in Chicago today are likely to be distinct from those in Miami or Los Angeles, and the options will be different 20 years from now,” he says.

That’s where the new standards come in. Given how complicated reference scenarios become in any biological system, a standardized way to document them is valuable.

“The E48 effort approaches sustainability as a system for improvement,” states Corr. “Sustainability is not a steady state. We have developed standards to encourage a consistent and transparent approach to facilitate an equivalent comparison of options. The comparison can be between proposed refinements to a process or optional products from a feedstock. More traditionally, you might think of the comparison of a bioproduct against what would be used in the absence of the bioproduct, the traditional source.”

Changing out “traditional” sources for more sustainable ones is, Corr emphasizes, an ongoing process. And it’s a process with a long way to go. The organization Circle Economy estimates that today only 8.6% of the world economy can be considered circular, but it is hoped that the ASTM standards discussed here will help improve that percentage.

The payoff could be significant. The World Economic Forum believes elimination of waste and more careful use of resources can yield up to $4.5 trillion in economic benefits between now and 2030. ■

Jack Maxwell is a freelance writer based in Westmont, New Jersey.

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