Building a Biodiesel Processor

1
Building a Biodiesel Processor
March 24, 2006 Hosted by Paul Feather and The
Collaborative Biodiesel Project
2
Outline

• Biodiesel and Vegetable Oil Basics
• How Biodiesel is Made
• Safety
• Small Scale Processor Design
• Economics

3
Basics
4
What Is Biodiesel?

• Biodiesel is a diesel fuel made from vegetable
  oil, methanol and a catalyst.
• Biodiesel is the only alternative fuel that has
  passed all of the EPA clean air fuel
  requirements.
• Biodiesel is fully compatible with any diesel
  engine. It has been tested more thoroughly than
  any other alternative fuel.
• Biodiesel is safe to handle and is biodegradable,
  it is less toxic than table salt.
• Best of all, Biodiesel can be made quite easily
  using recycled waste vegetable oil.

5
Biodiesel Blends

• Biodiesel is fully compatible with petroleum
  diesel, it can therefore be blended with diesel
  to
• decrease cost
• increase performance
• improve cold weather characteristics
• The state of Minnesota currently sells all diesel
  as a blend of B2
• Most common biodiesel blend is B20

6
Cold Weather and Biodiesel

• Everything is harder
• Oil quality is more important
• Collection is more difficult
• Settling is more difficult
• Pumping and filtration is more difficult
• Fuel gelling is a problem below 32F
• Your design must be tolerant of winter conditions

7
Emissions Reductions of Biodiesel Compared to
Diesel

8
Other Uses for Biodiesel

• Biodiesel makes a great degreaser
• Biodiesel as Home Heating Oil
• Emmisions are further reduced with open-flame
  combustion
• NOx emmisions eliminated compared to fuel oil

9
What is SVO?

• A Straight Vegetable Oil system requires a
  secondary, heated fuel tank.
• A valve is installed so that Diesel or SVO can be
  burned.
• Any oil can be used, but it must be filtered and
  water free.

10
Basics of an SVO System

• Two-Tank System
• Heated vegetable oil tank
• Usually heated using engines heat - via coolant
• Can be heated with electric elements
• Inline electric, or coolant fuel heaters, and
  heated filters are available.
• Fuel Switching Valve
• Allows you to start on Diesel(or Biodiesel)
  switch to vegetable oil while driving, then
  switch back to Diesel(or Biodiesel) for
  purge/shut-down.
• Second Fuel Filter
• Filters down to at least 10 microns
• Systems generally cost 500-1500 (see
  www.frybrid.com or www.biofuels.ca)

11
Biodiesel Vs. SVO

• SVO is (generally) free, but initial system cost
  is high
• Biodiesel is Pour and Go, SVO requires more user
  maintenance
• SVO emmisions are higher in idle and traffic
  conditions
• Biodiesels solvency will degrade rubber fuel
  lines, SVO will not

12
How Biodiesel Is Made

• Chemistry
• Recipe
• Titrations

13
Basic Recipe

1. Collect, process, and heat oil.
2. Measure 1 part methanol to 5 parts oil.
3. Measure lye and mix methoxide.
4. Mix oil and methoxide together for one hour.
5. Settle, and drain glycerin.

14
Chemistry

• The chemical structure of oil.
• Transesterification
• the biodiesel reaction.

CH2OORa catalyst
CH2OH
? CHOORb
3CH3OH ? 3CH3OORx CHOH

CH2OORc
CH2OH
Oil Methanol Biodiesel
Glycerin
15
Titration

• When oil is fried too hot too long, the fatty
  acids break off, acidifying the oil.
• Titration is necessary to determine the acidity
  of oil.
• Use a stock solution of known strength, and
  phenolphthalein indicator.
• Creates a 1/1000 scale reaction.

16
How much lye?

• Use 4 g NaOH per liter plus titration.
• Or use 6 g KOH per liter plus titration.
• KOH is more expensive
• NaOH doesnt dissolve as well, and the glycerin
  tends to solidify at higher temperatures?

17
Safety
18
Safety

• Potential hazards include, and are not limited
  to
• Fire
• Chemical exposure
• Spills
• Explosion
• Recommended personal protection measures
• Gloves
• Goggles
• Ventilation
• Acid for neutralization

19
Additional safety equipment to consider

• Fire extinguishers
• Secondary Containment
• Sealed vessels
• Respirators
• Explosion proof motors
• Pumps rated for volatile materials
• Grounding

20
Processor Design
21
Processor Design

• Oil Collection
• WVO Settling Tanks
• Heating System
• Filters
• Methoxide Mixing

• Processor
• Settling
• Wash/Dry
• Settling/Final Storage

22
Oil Collection

• Relationship with restaurants
• DC pump, or portable inverter
• Hand Dipping
• Hand pumps
• Legality issues

23
Oil quality

• De-watering
• Heat, gravity and time
• Filtration
• Hydrogenated oils
• Rancid oil
• Oil quality fuel quality

24
Heating

• You must have a way to heat oil
• Ideal reaction temperature is 120F
• Ideal settling temperatures are above 80F
• Heated space is sufficient for settling, but not
  reaction.
• The heating system is a vital component of the
  processor design.

25
Solar Thermal Heating
26
Heating Options

• Electric elements
• Relatively cheap (ballpark 2/gallon). Easy to
  control
• Exports emissions elsewhere
• Passive solar (greenhouses, black tanks, etc.)
• Free. No emissions. Great for pre-heating.
• Active solar
• Can be an expensive installation. Great
  investment.
• Gas, wood, biodiesel, oil, and other fuels.
• Processor should be indirectly heated. Price
  varies with fuel.

27
Filtration

• Filter oil
• Only practical if oil is hot, or if the filter
  can slowly drain.
• Large surface area. (sock filters, etc.)
• Provides higher quality glycerine.
• Filter biodiesel
• 10 microns at least.
• Water separator removes glycerine.

28
Methoxide Mixing

• Most dangerous activity in the process.
• Hand pumps are safe for small scale.
• KOH dissolves easily.
• Spraying methanol over KOH is sufficient.
• NaOH should be mixed or re-circulated.
• Sealed tank.

29
Processor

• Designed to mix methoxide and oil. Optionally
  designed to separate glycerin.
• Sealed. Probably heated.
• Propellers are great, but tricky to install in a
  sealed tank.
• Pump mixing is effective in small scale,
  especially when combined with a mixing tube.

30
Settling

• Settling is valuable at every stage in the
  process.
• Allows you to drain glycerin, water, particles,
  oil, etc.
• Every tank should drain from the bottom, and
  conical tanks are very helpful.
• Settling will not occur below 45F

31
Washing

• New fuel contains unreacted or partially reacted
  material, glycerin, soaps, water, and methanol.
• Settling removes most of this material.
• For completely clean fuel, you have to wash it.
• Mist and/or bubble water through the fuel.
• Use magnesium silicate. (Magnesol).

32
Water washing

• Most impurities would rather dissolve in water
  than biodiesel.
• Water is heavy, and settles out, carrying
  impurities with it.

Pros Cons
Well tested Time Consuming
Water is cheap Fuel must be dried
Wastewater
33
Magnesol washing

• Magnesium Silicate absorbs impurities, and is
  then filtered out.

Pros Cons
Fast Some particles are extremely small. (1 micron)
No wastewater Somewhat expensive. Ballpark 6/gallon.
Cant make it yourself.
34
Drying after a water wash.

• Heat, time and gravity.
• Air flow helps with drying. Warm air can absorb
  more water than cold air.
• Well washed fuel dries easily.

35
Quality Control and Testing

• Visual inspection for clarity.
• Specific gravity 0.86
• Emulsion tests
• Cloud and gel point measurements.
• Cloud point should be 25-32F
• Gel point should be about 15F
• Water content should be very low. (weigh, boil
  and weigh again).
• Total and free glycerin measurements with
  spectrophotometry
• Gas chromatography

36
Byproducts

• Methanol recovery is safe, responsible, and
  economical
• Can be distilled. Methanol boils at 148F
  (lower in a vaccuum)
• Distillation in the processor is convenient.
• Glycerin
• Contains methanol if you dont recover it.
• Good for soap, compost, and many other things.
• Wash water
• Low quality fuel and oil

37
Glycerin Soap
Terra is boiling the methanol off of some
glycerin so that it can be made into soap
38
Materials Compatibility
Good
Bad

• Aluminum
• Stainless
• Steel
• Flourinated plastics
• Teflon, viton, nylon
• Fiberglass

• Zinc
• Copper, brass, bronze
• Nitrile rubber
• Polypropylene
• Polyvinyl
• Tygon

Biodiesel Handling and Use Guidelines, NREL, 2004.
39
Processors
40
Economics consumables.

• Oil is still free.
• Methanol is the most expensive ingredient (about
  150 for a 55 gallon drum). That represents 55
  per gallon of biodiesel.
• KOH costs around 1/lb, representing 6 per
  gallon of biodiesel. Alternatively, NaOH adds
  about 3 per gallon.
• Fuel for heating depends on your situation.

41
Economics

• Labor.
• Labor times are short, but spread out.
• Oil collection can be labor intensive, and
  requires fuel.
• Space.
• Need an indoor space in winter. Building codes
  and restrictions can be a problem.

42
Economics

• Capital
• Tanks
• Can be recycled water heaters, fuel oil tanks,
  etc.
• Can be off-the-shelf plastic or stainless.
• Pumps
• Can spend 35 to 700 on a pump.
• Plumbing
• Fittings add up quick.

43
Great Biodiesel Websites
www.biodieselcommunity.org Great Grassroots,
Beginners Website biodiesel.infopop.cc- THE
discussion board for all things
Biodiesel www.biodiesel.org The Industry
Webpage, news, pump locations, etc. www.biodiesel.
appstate.edu ASU Biodiesel Project, soon to be
a bastion of quality info on small scale
biodiesel design www.utahbiodieselsupply.com
Great source for homebrew supplies www.pumpbiz.com
Great source for high quality
pumps www.me.iastate.edu/biodiesel - Technical
info on Biodiesel www.biofuels.coop Piedmont
Biofuels website, Home to the world-famous
Energy Blog
44
The Collaborative Biodiesel Project

• Contact
• Dr. Jeff Ramsdell
• ramsdellje_at_appstate.edu
• Paul Feather
• pf65033_at_appstate.edu
• Jeremy Ferrell
• jcferrell_at_care2.com