DEEP: Biodiesel


FAQs about Biodiesel
Biodiesel as a Heating and Transportation Fuel 
Additional Resources

FAQs about Biodiesel

What is biodiesel? {Biodiesel Bus}

Biodiesel is an alternative fuel, produced from either virgin vegetable oils (such as soy, canola) or from waste greases or other renewable resources. Biodiesel contains no petroleum, but it can be blended with petroleum diesel to create a biodiesel blend. Although 100% biodiesel can be used directly as a fuel, it is most often blended with conventional diesel fuel up to the 20% level, to minimize potential concerns with filter plugging, hose and seal degradation, cold weather flow properties, and engine modification requirements. Typically, biodiesel blends, ranging from 5% biodiesel with 95% diesel up to 20% biodiesel with 80% diesel, are being used in the Northeastern U.S. in compression-ignition (diesel) engines and for home heating.

Read more about biodiesel in the P2 View Newsletter, Fall 2005, page 5 (pdf).

How is biodiesel made?

The oils and fats are filtered and preprocessed to remove water and contaminants. The pretreated oils and fats are then mixed with an alcohol (usually methanol, sometimes ethanol) and a catalyst (usually sodium or potassium hydroxide). This chemical process is called transesterification and results in the glycerin being separated from the fat or vegetable oil. The process leaves behind two products -- methyl esters (the chemical name for biodiesel) and glycerin (a valuable by-product usually sold to be used in soaps and other products).

Prior to use as a fuel, it is important that the finished biodiesel be analyzed to ensure it meets ASTM specifications (ASTM D6751-03a). The ASTM standard is designed to ensure full product reaction and adequate removal of glycerin, catalyst, alcohol, and the absence of any free fatty acids. This standard covers pure biodiesel (B100 or "neat" biodiesel), for blending with petroleum diesel in levels up to 20% by volume. In addition, biodiesel products must be registered with the USEPA under 40CFR Part 79.

The 20% blend level is also required for the fuel to be recognized as an "alternative fuel" under the federal Environmental Policy Act. Biodiesel is slightly heavier than petroleum diesel. Therefore, it is typically splash blended on top of petroleum diesel to ensure proper mixing.

Where is biodiesel being made, what is the potential for the industry and how should it be handled?

Biodiesel is being made throughout the United States. The National Biodiesel Board maintains a map of biodiesel production facilities.  Independent Connecticut Petroleum Association maintains a list of CT biodiesel dealers.

Biodiesel Handling and Use Guidelines, 2006
Report by the US Department of Energy with information for fleet operators on handling and use of biodiesel including issues dealing with cold flow properties, stability, microbial growth, safety and more.

Environmental Laws Applicable to Construction and Operation of Biodiesel Production Facilities, November 2008, EPA-001EPA-907-B-08-001

2007 Connecticut Biodiesel Legislation - June 2007 Special Session 

PA 07-04, Sections 51-59 (pdf), Financial incentives for biodiesel producers and distributors. Brief summary of incentives:


  • Eligible for grants per gallon of production:  first 5 million gallons, .$30/gallon; next 5 million gallons, $.20/gallon; third 5 million gallons, $.10/gallon.
  • One time grant for equipment or construction, modification or retrofitting production facilities ($3 million, 25% of costs).

Distributers are also eligible for grant money for the cost of creating storage and distribution capacity up to $50,000 for any one distributer at any one site.

2.  Biodiesel in Connecticut (pdf), 11/27/2008. Presentation for Solid Waste Management Plan Advisory Committee, Organics Subcommittee.
3. Biodiesel for Heating Workshop,  9/26/05.  A workshop for fuel oil distributors and users on "bioheat", including its availability in Connecticut.  Speaker presentations and contact information:
  • Biodiesel 101: Introduction and Technical Overview, Paul Nazzaro, Advanced Fuel Solutions, Inc.
  • Biodiesel fuel supply and quality (pdf), Joe Mead, World Energy
  • Impacts of biodiesel on heating systems (pdf), C.R. Krishna, Brookhaven National Laboratory
  • Biodiesel and the oil heat industry: integration with current infrastructure
    • A Wholesalers View (pdf), Sprague Energy, Tom Keaveney
    • Opportunities and Challenges for CT distributors, Tom Santa, Santa Energy, Michael Devine, Devine Bros.

4. Biodiesel for New England, Can We Make It In New England?, 3/2003. Institute for Sustainable Energy at Eastern CT State University. Topics and speakers are listed below.
  • Biodiesel for New England, Keith Ciampa, World Energy
  • Basics on Restaurant Grease Generation, Norman Gridley, Wright-Pierce
  • Biodiesel from Recycled Vegetable Oil, Rick Geise, Griffin Industries, Inc
  • Biodiesel Technology and Feed stocks, Dr. K. Shaine Tyson, National Renewable Energy Lab (NREL)
  • Small Scale Modular Units & the Future of Biodiesel, Christian Fleisher, Biodiesel Technologies
Note: DEP and the co-sponsors of these workshops do not endorse any product, technology or company who participated in the workshop. Workshops were presented as an information and networking opportunity for all attendees.

Biodiesel As A Heating Fuel (also called "bioheat")

Independent Connecticut Petroleum Association maintains a list of CT biodiesel retailers. The National Biodiesel Board also maintains a list of companies that offer heating oil blended with biodiesel.

Reports on bioheat testing and pilot projects done in New York and Rhode Island include the following:

  • Combustion Testing Of A Bio-Diesel Fuel Oil Blend In Residential Oil Burning Equipment )
  • Low-Cost BioHeating Oil Application
  • Biodiesel Blends in Space Heating Equipment, Brookhaven National Labs 
  • Warwick, RI Public Schools B20 for heating several buildings.
Biodiesel As A Transportation Fuel
Biodiesel and biodiesel blends are being used to operate diesel engines throughout New England and other parts of the country. Certain fleets, bus operators and individuals have begun to utilize biodiesel.
   Lesson ideas for schools
Other biodiesel sites
These websites are provided for information only.  DEEP does not endorse any products or services.
Facility permit information
Robert Hannon, Program Planning & Development,
Regulatory questions Ross Bunnell, Materials Management & Compliance  Assistance, 860-424-3274
General information
Connie Mendolia, Program Planning & Development,
Air issues Paul Kritzler, Toxics and Mobil Source, 860-424-3441  

  Content Last Updated October 2016