A Firefighter’s Guide to Biodiesel

After numerous articles in the media about small (and sometimes large) fires at biodiesel plants, most of the articles I read end up saying something about how the fire department was ill-prepared or unsure about what chemicals were in the plant and whether they were hazardous.  In some cases, they even questioned whether the biodiesel itself was hazardous.   I’m not a firefighting expert, nor a chemist, but I’m going to attempt to explain in layman’s terms what can be found at the typical biodiesel plant and a little bit about each.

  1. Vegetable Oil – Health:1, Fire:1, Reactivity:1. Any type oil, soybean, canola, waste vegetable.  These oils are non-hazardous, non-toxic, and non-flammable.  Flash point is well over 450°F.   Most biodiesel plants will store vegetable oil in bulk tanks, but it may also be found in 300 gal IBC totes.  Treat as oil fire.   Foam, dry chemical, CO2, or water if necessary.  Water on oil fires is a last resort, as it tends to spread the oil (and thus the fire), and in some cases can actually flash to steam and create a more dangerous situation.  Potential fire sources in biodiesel plants are caused by using electric heating elements directly exposed to vegetable oil with lack of stirring or overheating.
  2. Biodiesel – Health:1, Fire:1, Reactivity:1. Chemical name Mono-Alkyl Ester.  Non-hazardous, non-toxic, and non-flammable.  CAS Number 67784-80-9.  Flash point typically over 300°F.   Treat as oil fire.   Foam, dry chemical, CO2, or water if necessary.  Use water spray, fog or foam. Do not use water jet.  Water on oil fires is a last resort, as it tends to spread the oil (and thus the fire), and in some cases can actually flash to steam and create a more dangerous situation.  Disbursement into ravines or water sources can be immediately threatening to wildlife in some cases (oil film on water surface, oxygen reducer), but researchers at the University of Idaho noted that after leaving biodiesel in an aqueous solution for twenty-eight days, ninety-five percent of biodiesel was gone—completely degraded.   Potential fire sources in biodiesel plants are caused by using electric heating elements directly exposed to biodiesel with lack of stirring or overheating.  In certain cases (in process biodiesel production) methanol may be added to the biodiesel, reducing the flash point and making a hazardous material.
  3. Glycerin –  Health:1, Fire:1, Reactivity:0. Chemical name propane-1,2,3-triol.  CAS Number: 8043-29-6.  Pure glycerin is a non-flammable and non-hazardous material.  Depending upon the feestock and purity, it can contain methanol, lipids (vegetable oil), and water.  In these cases the material may be considered slightly hazardous and flammable.  It is slightly hazardous in case of skin contact (irritant, permeator over long contact duration), of eye contact (irritant), of ingestion, of inhalation.  Flash point for pure glycerin is 320°F, but methylated glycerin can be much lower.   Most biodiesel plans will have both raw (with methanol) and finished (pure or near pure) glycerin.  All but refined glycerin will have a brownish to dark black color and syrup like viscosity.   It may be stored in barrels, 300 gallon IBC totes, or in bulk tanks.   Treat as oil fire.   Foam, dry chemical, CO2, or water if necessary.  Use water spray, fog or foam. Do not use water jet.  Glycerin is heavier than water and runoff into ditches, streams, and ponds may not be immediately visible because the material may be on the bottom.
  4. Methanol Health:3, Fire:3, Reactivity:1.  Chemical name: Methyl Alcohol.  CAS Number: 67-56-1.   Methanol is highly flammable, toxic, and hazardous.  It burns with a light blue flame, almost invisible during daylight.   Flash point is 54°F.  Most biodiesel plants will have pure methanol.  It may be stored in barrels, 300 IBC gallon totes, or bulk tanks.  Treat as oil fire.   Foam, dry chemical, CO2, or water if necessary.  Use water spray, fog or foam. Do not use water jet.  All pumps and motors involved in production for methanol related materials should be explosion proof.
  5. Sodium Methoxide or Sodium Methylate –  Health:3, Fire:3, Reactivity:3.  CAS Number: 124-41-4.   Definitely the most dangerous material at a biodiesel plant.  Some biodiesel plants may use Potassium Methylate in addition or instead (treat similarly).  This material will be in liquid form, and has a clear, viscous appearance.  Flash point is 91°F.  Treat as oil fire.   Foam, dry chemical, CO2, or water if necessary.  Use water spray, fog or foam. Do not use water jet.   Highly flammable and autoignition possible in presence of moisture. Flammable in presence of open flames and sparks, or heat.   Most small to medium sized biodiesel plants have this in small quantities, usually stored in drums or 300 gal IBC totes.  Some larger plants will store this in bulk tanks, which are usually stainless steel.  This material is highly reactive, caustic, hazardous and toxic.  Avoid contact with skin, inhalation, and exposure to eyes.  Do not flush caustic residues to sewer. Residues from spills can be diluted with water, neutralized with diluted acid such as acetic and hydrochloric. Absorb neutralized caustic residues on clay, sand, vermiculite or other absorbent material and place in a chemical waste container for disposal.
  6. Sodium HydroxideHealth:3, Fire:1, Reactivity:2.  CAS number: 1310−73−2 100.  Some biodiesel plants may use Potassium Hydroxide in addition or instead (treat similarly).  Corrosive, causes severe burns.  This is a corrosive solid that has a physical appearance of white flakes or white granules.  It is highly toxic and hazardous.  It is commonly stored in drums and 55 lb plastic bags (like potting soil).  Most small to medium sized plants will have 2,000 to 10,000 lbs on hand at a time. Avoid contact with skin, inhalation, and exposure to eyes.   Sodium hydroxide is slightly toxic in the aquatic environment. The toxic effect on aquatic organism is due pH increasing.  It is soluble in water and degrades quickly.  Not considered a fire hazard; however, for large fire use powder, foam extinguishing agents or carbon dioxide. Avoid water use if possible. Adding water to caustic solution generates large amounts of heat and steam! Do not flush caustic residues to sewer. Residues from spills can be diluted with water, neutralized with diluted acid such as acetic and hydrochloric. Absorb neutralized caustic residues on clay, sand, vermiculite or other absorbent material and place in a chemical waste container for disposal.

While this is certainly not an exhaustive list of materials found at biodiesel plants, it contains the primary components that nearly every biodiesel plant in the Unites States uses on a daily basis.  Our plant is located in the city of Wilson, NC and we regularly have visits and familiarization drills with the firefighters in the town to acquaint them with the materials we use in our plant, and where they are stored.  These drills become invaluable when the need arises in order to minimize the potential danger to the firefighters and the community should disaster strike.

Biodiesel Myth #9 – Biodiesel Will Gel Up My Tank or My Engine

In a multi-part series about biodiesel, this is one of several articles in an attempt to dispel the myths about biodiesel and it’s use in commercial and private diesel engines.

Myth #9 – Biodiesel Will Gel Up My Tank or My Engine in Winter

Most likely, no.  While it’s true the biodiesel has a higher gel point than diesel fuel, the fact is that both petroleum diesel and biodiesel will gel if it gets cold enough.   If it’s not very cold, biodiesel will not gel up at all.

Biodiesel responds to anti-gel treatments in much the same manner as petroleum diesel.  By adding compounds that inhibit wax formations to accumulate, the fuel in effect remains liquid instead of gelling (or waxing) as the temperature decreases.

The temperature at which untreated biodiesel gels is variable, just like it is with untreated petroleum diesel.  The common temperature at which most people will say untreated diesel will begin to gel is 12°F.   The common temperature at which most people agree biodiesel will begin to gel, although it’s largely based upon feedstock so we’re going to assume soy biodiesel, is 30°F.   Adding anti-gel compounds significantly lowers that temperature in both fuels.

Cold Flow Additives Help Any Fuel Blend in Winter

Further, in winter time, diesel fuel not only has anti-gel additives in it, it usually is mixed with #1 Diesel (kerosene) in colder climates.  Kerosene is a light fuel oil, which has a gel point of -30°F.  Adding it in a 1/20 ratio to biodiesel or a biodiesel blend will further winterize your fuel.   However, for most temperate climates, it’s not necessary.  Regular B20 biodiesel (with #2 winter diesel) will work just fine down to about  -5°F.   Always make sure your diesel (and biodiesel) fuel has been winterized in cold weather months, and it wouldn’t hurt to add it yourself just to be sure.  It beats being stranded on the side of the road.

What do you do if the fuel has already gelled in your tank?

You wake up on the morning to go to work and your vehicle will not start.  Your fuel has gelled in the tank overnight.  What do you do?   The time proven remedy is to add a gallon of kerosene for each 10 to 20 gallons of fuel to the tank, then allow it to sit long enough for the kerosene to diffuse into the fuel.  In weather below -20 degrees F, one gallon of kerosene for 10 gallons of fuel will keep things moving, but fuel economy will be reduced because kerosene has a lower BTU value per gallon than #2 diesel fuel.   Block heaters and tank heaters are also added in severe climates to help ensure fuel is flowing.    Store your vehicle in a garage if possible.

For more information, visit the NBB website at http://www.biodiesel.org/pdf_files/fuelfactsheets/COLD_BIOGenrlFactShtNOSOY.pdf.


Biodiesel Myth #8 – Biodiesel Emissions Are No Better Than Regular Diesel

In a multi-part series about biodiesel, this is one of several articles in an attempt to dispel the myths about biodiesel and it’s use in commercial and private diesel engines.

Myth #8 – Biodiesel Emissions Are No Better Than Regular Diesel

Biodiesel is the only alternative fuel that has completed all the testing requirements of the Clean Air Act. Biodiesel contains oxygen and it burns more completely than diesel fuel, resulting in reduced emissions. All major pollutants are reduced dramatically in biodiesel exhaust (most of them at least 50% for B100), except one—nitrogen oxides (NOx)—and that’s only for blends over B20 (see my post on the subject).  In fact, NOx emissions from biodiesel increase or decrease depending on the engine family and testing procedures. NOx emissions (a contributing factor in the localized formation of smog and ozone) from pure (100%) biodiesel increase on average by 10 percent.  However, biodiesel’s lack of sulfur allows the use of NOx control technologies that cannot be used with conventional diesel. Additionally, some companies have successfully developed additives to reduce NOx emissions in biodiesel blends.  In fact, in certain independent studies using more modern engines than the EPA study have shown that biodiesel use actually reduced NOx emissions.

The most common report when users switch to biodiesel is the noticeable decrease in diesel smoke (the black, sooty clouds). B20 reduces air toxics (the most damaging pollutants for human health) by 20-40%, while B100 reduces them by as much as 90%. Sulfur oxides and sulfates (major contributors to acid rain) are almost completely eliminated. The only caveat is that nitrogen oxide (NOx) emissions can increase up to 10% with B100. If you would like to evaluate this for yourself, see the National Biodiesel Board’s emissions fact sheet.

New diesel technology like the Mercedes BlueTec and the 2009 Jetta TDI eliminate this problem by reducing NOx emissions by 80-90%.

All-in-all, biodiesel offers such a substantial reduction in emissions that it’s frequently used in sensitive areas like national parks and marine habitats. School districts all over the country have also turned to biodiesel as a way to reduce children’s’ exposure to toxic diesel exhaust.