Biodiesel has come a long way on the quality front since it was first brought to market. Manufacturers that diligently follow the guidelines set down by the National Biodiesel Broad make quality products that are up to the general quality experienced by more traditional fuels. However, there are some specific issues with biodiesel that require extra attention and if the supply source is less consistent in quality precautions can be taken to minimize any issues that might arise.
To understand the situation it helps to begin at the beginning. “Biodiesel is a transester of a natural oil such as soybean, rapeseed, canola, or meat tallow,” says Peter Guerra, vice president of marketing for FPPF Chemical Company Inc., a Buffalo-based maker of diesel fuel additives. “But natural oils won’t work in an engine. You must remove the glycerine and turn the product into an ester.”
Problems can arise because, adds Guerra, “(Some) biodiesel manufacturers don’t do a good job of removing the glycerine.” The challenge is not so much in the technology, since the chemical processes are well known, but due to economics. Biodiesel is still a very small market compared to that for conventional and ultra low sulfur diesel. “So it tends to attract smaller manufacturers who get government subsidies,” he observes.
With numerous small entities vying over a small market, price competition reigns. Biodiesel already costs about a dollar more per gallon to produce than conventional diesel. As a result, relates Guerra, “Some manufacturers will try to get oils as cheaply as possible which means there can be a lot of impurities.”
Jim Vrzak, sales director for performance fuel additives at Innospec Fuel Specialties of Littleton, Colo., agrees, “The larger biodiesel manufacturers have tightened their specifications, but the quality is more uneven with smaller manufacturers.” And Bob Tatnall, president of Fuel Right, a producer of additives in Wilmington, Del., reports, “Problems with biodiesel are caused by the wide variety of manufacturers. Biodiesel is a new opportunity that’s attracted a lot of small entrants.”
Tatnall also cites a geographic component in the equation, since biodiesel manufacturers tend to start up near ready sources of natural oils. In the mid-Atlantic region where Fuel Right is based, most biodiesel is produced from soybean oil. Further south, sawgrass is a common feedstock. By contrast, animal fats are a more economical source for Canadian producers.
“And biodiesel made from animal fats, for example, have extremely high pour points and tend to gel at higher temperatures than other biodiesels,” Tatnall continues. “So there’s a struggle in the industry to develop biodiesel specs that ensure consistency, predictability, and usability since we have so much variety in feedstocks. Right now, all the different sources are considered O.K. Yet they all have different chemical properties.”
Biodiesel offers undeniable environmental benefits because it emits fewer pollutants. “But the best biodiesel, made from the best quality starter oil, is also the most expensive,” Guerra states. “Given the economic realities of the market, that means product (can be) inconsistent.
Problems and Solutions
Even with the variability of biodiesels sold today, some generalizations can be made of the problems it presents as a motor fuel. These may be summarized as biodiesel’s tendencies—when compared to conventional diesels—to gel at higher temperatures, attract water and bacteria, destabilize when stored over several weeks, and plug filters when used the first time.
Because biodiesel gels at higher temperatures—according to Guerra, about 20°F higher—then the fuel will gel in the winter season sooner than conventional diesel. For this reason, pure biodiesel or B100 is presently impractical as a winter fuel. Even “bioblends” sold today, which may range from B5 to B20—or conventional diesel blended with 5 percent to 20 percent biodiesel—are at least somewhat susceptible.
“B100 has a pour point of about 32°F,” explains Vrzak, “and if you blend it into conventional diesel, especially at 5 percent or more, then you raise the pour point of the motor fuel you’re using. Traditional cold flow solutions for diesel, which inhibit formation of wax crystals, don’t work so well with biodiesel.”
Innospec has specially formulated its Bio Winterflow cold flow improver as a winter solution for biodiesel. For its part, FPPF has developed its Biodiesel Fuel Power additive, which the company offers in year-round and winter formulations. Both feature agents to burn excess water and stabilize fuel to keep it fresh, while the winter formula includes anti-gelling agents for both the biodiesel and the convention diesel components of a bioblend fuel.
“In the wintertime it’s a given that you must additize biodiesel,” affirms Dries van Wagenberg, head of marketing for Fuel Right. “After that, the additives you decide to use are a judgment call based on the quality of the fuel.”
Another issue that additives can address is the tendency of biodiesel to attract more water than conventional diesel, a tendency which in turn provides more opportunities for bacteria to grow. “Water is always a problem with any diesel fuel,” states Tatnall, “even just from handling and transportation.” That being the case, the presence of biodiesel exacerbates the challenge.
Then, too, because biodiesel “comes from oils that are natural, edible products, the fuel is even more attractive to bacteria,” says FPPF’s Guerra. “Add that to the presence of water, and you can get a higher incidence of bacterial contamination.” He says the company’s Biodiesel Fuel Power additive “is unique because it eliminates water.” And at Innospec, Vrzak notes that biodiesel users can employ its Dritek additive as a water dispersant and Predator 6000 as a biocide.
Biodiesel’s origin as a natural oil also leads to stability problems over time since the fuel “can go rancid in just four to six weeks—just like butter that’s left out too long—if it sits in an engine or a fuel storage tank ,” explains Guerra. The Biodiesel Fuel Power additive from FPPF contains a stabilizer to keep biodiesel fresh in storage, while Innospec offers its own solution in the Biostable 403E product.
Finally, Guerra notes that biodiesel has a strong detergent effect when used for the first time in an engine so that loosened matter can plug fuel filters. “That solvent effect,” concurs Fuel Right’s Tatnall, “can create a panic.” One way to address the problem, advises Vrzak, is by additizing biodiesel with a dispersant such as the Ecoclean product from Innospec.
Discussion about biodiesel, suggests Tatnall, should take into account the pure B100 is uncommon and that biodiesel in the United States is most often blended into conventional diesel to make motor fuels such as B5, B10, and B20. “The western world,” he believes, “isn’t ready for B100.”
Bioblends may be driven by state mandates to increase usage of renewable fuels. “But because the quality of biodiesel can vary,” Tatnall continues, “one load of bioblend can be good and then the next load can be bad. And you might not know it, since biodiesel is sometimes added to conventional diesel without a user’s knowledge. That’s a concern when a bad load can cost you $50,000 in disposal costs and downtime.”
Tatnall tells the story of a North Carolina renewable fuels mandate that led to widespread use of B20 in state government vehicles. But when the next winter arrived, state vehicles and equipment in the mountainous western part of North Carolina would not operate on B20.
Using more biofuels may be a laudable goal, “but the issue is also one of practicality and economics,” Tatnall believes. “Biodiesel additives can be more expensive. It might cost 6-8 cents to additive a gallon of biodiesel, versus 2-3 cents for conventional diesel. Who’s going to pay that extra cost?”
In Tatnall’s area the average tanker load is 7,500 gallons. Given the current intensity of price competition and the downward pressure on margins, the fuel seller’s profit on that load is likely between $50 and $150. At the same time, the seller is also carrying the cost of the load as a receivable until paid by the end user.
“That makes the extra cost of additizing biodiesel difficult for the seller to bear,” observes Tatnall. “If the fuel supplier can’t bear the cost, the user must pay it—except that users don’t want to pay. They want to buy fuel as cheaply as they can. And so nobody ends up doing the additizing that’s needed—even though the technology is available to address the problems with biodiesel.”
The real problem, Tatnall contends, is that “fuel costs so much already, it’s hard to add more costs with additives. So the problem won’t be solved until additive solutions are developed that users are willing to pay for, or until users are educated by fuel sellers on why additives are worth the extra costs.”
For that reason, fuel marketers who sell biodiesel or packaged additives to end users “should work with an additives supplier that will help you do your homework,” advises Tatnall. Guerra suggests that working with a supplier that specializes in diesel additives can bring added knowledge to the relationship. “The gasoline additive tends to be dominated by big companies like STP,” he notes, “so that our niche is the diesel market.”
Guerra counsels fuel marketers who do their own blending of additives into biodiesel to “make sure you’ve gotten a quality batch of biodiesel to start with by checking the percentage of glycerine and water content.” After that, he concurs with Tatnall about the need for diligent homework. “Additizing biodiesel will add cost,” he says, “which means you need to educate your customers on why these solutions are worth it.”