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Industries around the world are adopting green technologies to lower greenhouse gas emissions, and the industrial burner market is no exception. According to the U.S. Environmental Protection Agency, in 2020, the total amount of emissions across all economic sectors totaled a whopping 5,981 million metric tons of carbon dioxide.^[1]

One of the ways to reduce the adverse effects of burners on the environment is to convert legacy fuel trains in industrial heating and steam applications from running on petroleum and other fossil fuels to renewable and biodegradable biofuels. Unlike fossil fuels, which form slowly over time from dead plant and animal remains, biofuels are produced over a short period from plant-based biomass such as wood, agricultural residues, farm and household wastes, and even fast-food restaurant oils.

One major type of biofuel is biodiesel, which is derived from vegetable oils, animal fats and non-edible raw materials such as the frying oils in fast-food restaurants. It can be used as a drop-in, standalone fuel or blended with conventional fuels like petroleum to power diesel engines and distribution infrastructure.

Although biodiesel is a good carbon-neutral fuel upgrade for legacy combustion systems, there are still regulatory considerations to keep in mind when working with these fuel sources. Let’s explore some of these considerations to help those considering the switch to minimize their industrial burners’ carbon footprint as much as possible.

Biofuels are produced from plant-based biomass, including fast-food restaurant oils. | Credit BanksPhotos/Creatas Video/Getty Images

Biodiesel vs. Renewable Diesel

Biodiesel, a biofuel, is a cleaner-burning alternative to diesel fuel. It can be produced from renewable resources such as vegetable oils, animal fats and recycled cooking grease (see sidebar). It is produced in a process called transesterification, during which the fat or oil reacts with an alcohol to create fatty acid methyl esters (FAME).

Renewable biodiesel is a higher quality biofuel that can be used in concentrations up to 100 percent. Also known as hydrotreated vegetable oil (HVO), renewable biodiesel does not involve transesterification. Unlike biodiesel, it does not produce glycerol as a byproduct of the chemical process.

Despite their differing chemical processes and makeup, biodiesel and renewable diesel have lower emissions compared to traditional fossil fuels and can reduce greenhouse gases over the entire lifecycle of the burner or boiler.

FIGURE 1. State biodiesel targets by year are shown. | Photo credit Asco Valve/Emerson

Emerging Regulatory Requirements

Given biodiesel’s potential to lower emissions, the Intergovernmental Panel on Climate Change (IPCC) released guidelines for governments and industries to invest in biodiesel as a fuel source for industrial burners and boilers. The U.S. government, for example, tasked the EPA with creating biodiesel targets that align with IPCC guidelines. Early adopters of these targets include states like New York, Rhode Island and Connecticut (figure 1).

In response to the EPA’s biodiesel targets, major standards organizations like the standards-development body ASTM International and Underwriters’ Laboratories (UL) have created and released regulatory requirements for the use of biodiesel. These requirements cover various biodiesel blends as well as the components used in the heating equipment. For example, UL recently updated its oil burner standard, UL 296, to include blends with 20 volume percent biodiesel (B20) — i.e., blends with 20 percent biodiesel and 80 percent petroleum diesel.

Other examples of new and evolving biodiesel standards include the following:

• ASTM D6751. It covers pure biodiesel (B100) in Grades S15 and S500 for use as a blend component with middle distillate fuels.
• ASTM D7467. It applies to fuel blend grades of 6 volume percent biodiesel (B6) to B20, with the remainder being a light middle or middle distillate diesel fuel. These grades are suitable for many diesel engines.
• UL 296. It covers oil burners intended for firing appliances and devices. Oil burners covered by this standard are intended for use with various grades of fuel oil and biodiesel blends, including B20 and B100.
• UL 428B. It applies to electrically operated valves and other components used in heating diesel up to B20.

FIGURE 2. Safety shutoff valves (SSOVs) certified for use with biodiesel blended fuel are ready for use with industrial burners. | Photo credit Asco Valve/Emerson

Implementing the Biofuel-Ready Components

By upgrading boiler fuel trains to support biodiesel, it is possible to reduce emissions by as much as 50 percent, moving a facility closer to net-zero targets and avoiding state penalties for emissions levels. To ensure compliance, it is important to work with boiler manufacturers that use components — the valves on the fuel and pilot lines, for example — that meet the new B20 standards.

Another best practice is to source only BQ-9000-approved biodiesel. You can check with the National Biodiesel Accreditation Program, which ensures fuel manufacturers comply with the proper specifications. This agency even lists already approved companies, making it easier to source high quality fuels.

Specific components also meet the B20 standards. For example, one manufacturer offers safety shutoff valves (SSOVs) certified for use with biodiesel blended fuel in industrial and commercial boilers in the Americas (figure 2). Valves like these make it possible to transition to a more sustainable energy source, simplifying compliance with evolving regulations and reducing greenhouse gas emissions.

As part of their compliant design, these valves include elastomers that have undergone testing to ensure their long-term chemical compatibility with biodiesel. The valve is certified to UL 429 (electrically operated valves) while the valve’s elastomers are certified to UL 428B for biodiesel blends up to 20 percent (B20).