BIODIESEL FUEL

1
BIODIESEL FUEL
Biodiesel Fuel Prof. Mohamed El-Kassaby

• Prepared by
• Professor Dr/ Mohamed M. El-Kassaby

2

• What is it?
• Biodiesel is a liquid fuel that can replace
  regular diesel fuel. Its made from vegetable
  oil.
• Biodiesel is produced from any fat or oil such as
  soybean oil. The production processes for
  biodiesel are well known.
• Biodiesel can run diesel engines that are
  commonly found in big vehicles such as trucks,
  buses, or boats.
• On the island of Maui, Biodiesel fuel is already
  available to county and private fleets.

3

• Biodiesel fuels begin to spread out in a large
  scale in many countries such as USA, Italy,
  Germany and Denmark.
• The National Biodiesel Board has released the
  following sales volume estimates for the US
• 2006 -- 250 million gallons2005 -- 75 million
  gallons2004 -- 25 million gallons2003 -- 20
  million gallons2002 -- 15 million gallons2001
  -- 5 million gallons2000 -- 2 million
  gallons1999 -- 500,000 gallons

4

• Why Biodiesel?
• Regular diesel fuel particulates are carcinogenic
  (can cause cancer).
• Using biodiesel fuel, or blending it with
  regular diesel fuel, can reduce the production of
  these cancer-causing emissions. In other words,
  its healthier!

5

• Biodiesel can be made from waste vegetable oil
  (such as used oil from deep fryers at
  restaurants).
• This waste oil can be difficult to dispose of.
  Making fuel out of it can put it to a good use,
  and at the same time, reduce disposal problems.

6

• Biodiesel is a renewable fuel.
• Biodiesel can help create new jobs also, keeping
  our air clean helps everybody enjoy life more.
• Biodiesel may be used in existing diesel engines
  without necessitating engine modifications, and
  its use does not result in a shortening of engine
  life or the need for more frequent servicing.

7

• What are the benefits of Biodiesel?
• Biodiesel has many environmentally beneficial
  properties. The main benefit of biodiesel is that
  it can be described as carbon neutral. This
  means that the fuel produces no net output of
  carbon in the form of carbon dioxide (CO2). This
  effect occurs because when the oil crop grows it
  absorbs the same amount of CO2 as is released
  when the fuel is combusted. In fact this is not
  completely accurate as CO2 is released during the
  production of the fertilizer required to
  fertilize the fields in which the oil crops are
  grown.

8

• Biodiesel is rapidly biodegradable and completely
  non-toxic, meaning spillages represent far less
  of a risk than fossil diesel spillages.
• Biodiesel has a higher flash point than fossil
  diesel and so is safer in the event of a crash.

9
(No Transcript)
10

• What are the main issues when switching from
  conventional diesel to biodiesel?
• The main operating issues are cold weather
  operability, engine and fuel system
  compatibility, and the solvency properties of
  biodiesel. B100 does not flow as well as
  petroleum diesel in cold temperatures, and
  requires special additives or fuel heating
  systems to operate in colder climates. B100 may
  cause rubber seals and gaskets from engines older
  than 1994 to wear faster or fail. Biodiesel also
  acts as a solvent, which can dissolve sediments
  in diesel fuel tanks and clog fuel filters during
  an initial transition from petroleum diesel. 

11

• Despite these issues, some fleets are
  successfully using B100. Berkeley, California is
  successfully running 100 biodiesel in 90 of
  their public diesel fleet vehicles including fire
  trucks. Using B20 minimizes or eliminates most of
  the concerns with B100 and is therefore more
  widely used.

12

• Did you know?
• Biodiesel can be used in pure form or blended
  with regular diesel in any proportion.
• Biodiesel can even make engines smell better. An
  engine powered by biodiesel actually smells like
  French fries!
• Biodiesel fuel is a good lubricant, which helps
  engines to last longer.
• It also has a high Cetane rating, which improves
  engine operation.

13

• Adding just 20 biodiesel to regular diesel
  improves the diesels Cetane rating by 3 points,
  which makes it a "premium" fuel.
• Biodiesel buses are in use in Europe and in the
  Midwestern United States.

14

• The process
• Vegetable oils and animal fats are triglycerides,
  containing glycerin. The biodiesel process turns
  the oils and fats into esters (group CO),
  separating out the glycerin. The glycerin sinks
  to the bottom and the biodiesel floats on top and
  can be syphoned off.
• The process is called transesterification, which
  substitutes alcohol for the glycerin in a
  chemical reaction, using sodium hydroxide as a
  catalyst.
• Quantities
• 5 (Oil)1 (alcohol) by volume with almost twice
  the weight of alcohol used from sodium hydroxide
  NaOH

15

• There are some steps to use this method in
  producing biodiesel fuels such as
• Mixing of alcohol and catalyst The catalyst is
  typically sodium hydroxide (caustic soda) or
  potassium hydroxide (potash). It is dissolved in
  the alcohol using a standard agitator or mixer.
• Reaction The alcohol/catalyst mix is then
  charged into a closed reaction vessel and the oil
  or fat is added.
• The system from here on is totally closed to the
  atmosphere to prevent the loss of alcohol. The
  reaction mix is kept just above the boiling point
  of the alcohol (around 160 F) to speed up the
  reaction and the reaction takes place.
  Recommended reaction time varies from 1 to 8
  hours, and some systems recommend the reaction
  take place at room temperature. Excess alcohol is
  normally used to ensure total conversion of the
  fat or oil to its esters.

16

• Care must be taken to monitor the amount of water
  and free fatty acids in the incoming oil or fat.
  If the free fatty acid level or water level is
  too high it may cause problems with soap
  formation and the separation of the glycerin
  by-product downstream.
• Separation Once the reaction is complete, two
  major products exist glycerin and biodiesel.
  Each has a substantial amount of the excess
  methanol that was used in the reaction. The
  reacted mixture is sometimes neutralized at this
  step if needed. The glycerin phase is much more
  dense than biodiesel phase and the two can be
  gravity separated with glycerin simply drawn off
  the bottom of the settling vessel. In some cases,
  a centrifuge is used to separate the two
  materials faster.

17

• Alcohol Removal Once the glycerin and biodiesel
  phases have been separated, the excess alcohol in
  each phase is removed with a flash evaporation
  process or by distillation. In others systems,
  the alcohol is removed and the mixture
  neutralized before the glycerin and esters have
  been separated.
• In either case, the alcohol is recovered using
  distillation equipment and is re-used. Care must
  be taken to ensure no water accumulates in the
  recovered alcohol stream.

18

• Glycerin Neutralization The glycerin by-product
  contains unused catalyst and soaps that are
  neutralized with an acid and sent to storage as
  crude glycerin. In some cases the salt formed
  during this phase is recovered for use as
  fertilizer. In most cases the salt is left in the
  glycerin. Water and alcohol are removed to
  produce 80-88 pure glycerin that is ready to be
  sold as crude glycerin. In more sophisticated
  operations, the glycerin is distilled to 99 or
  higher purity and sold into the cosmetic and
  pharmaceutical markets.

19

• Methyl Ester Wash Once separated from the
  glycerin, the biodiesel is sometimes purified by
  washing gently with warm water to remove residual
  catalyst or soaps, dried, and sent to storage. In
  some processes this step is unnecessary. This is
  normally the end of the production process
  resulting in a clear amber-yellow liquid with a
  viscosity similar to petrodiesel. In some systems
  the biodiesel is distilled in an additional step
  to remove small amounts of color bodies to
  produce a colorless biodiesel.

20
(No Transcript)
21

• Advantages of biodiesel as diesel fuel
• Liquid nature portability.
• Ready availability.
• Renewability.
• Higher combustion efficiency.
• Lower sulfur and aromatic content than diesel.
• Higher cetane number.
• Inherent lubricity in the neat form.
• Risk of handling, transporting storage is less
  than diesel.

22

• High heating value, less than heating value of
  diesel.
• Sulfur content of petrodiesel is 20 50 times
  those of biodiesel.
• Biodegradability of biodiesel is faster 4 times
  than petrodiesel Its oxygen content improves
  the biodegradation process , all biodiesel fuels
  are readily biodegradable in aquatic environment
• After 28 days all biodiesel were 77 89
  biodegraded ,diesel only 18 biodegraded.

23

• Disadvantages of biodiesel
• Higher viscosity.
• Lower energy content.
• High cloud point pour point.
• High NOx emissions.
• Lower engine speed power.
• Injector cocking.
• High price higher engine wear.
• Power of biodiesel is less than that of diesel by
  5 at the same load.

24

• Costs and prices
• Biodiesel are using waste oil feedstock make
  biodiesel for 50 cents to US1 per US gallon.
• Regular diesel cost around 3 dollar per US gallon
  (September 2005)
• (Note Small quantities of methanol can cost the
  equivalent of US8 to 10 per US gallon, but
  experienced biodiesel are invariably buy it in
  bulk for about 2-3 per gallon.)

25

• Yields of common crops
• Crop kg oil/ha litres oil/ha lbs oil/acre
  US gal/acre
• corn 145 172 129 18
• cashew nut148 176 132 19
• Oats ???? 183 217 163 23
• Lupine???? 195 232 175 25
• Cotton 273 325 244 35
• Soybean 375 446 335 48
• Sunflowers800 952 714 102
• Jatropha 1,590 1,892 1,420 202
• oil palm 5,000 5,950 4,465 635

26

• General comparison between Diesel and Biodiesel
  properties
• Diesel Biodiesel
• Density kgL-1 _at_ 15.5?C 0.84 0.88
• Calorific value MJL-1 38.3 33 40
• Viscosity mm2s-1 _at_ 20?C4 5 4 6
• Viscosity mm2s-1 _at_ 40?C4 5 4 6
• Cetane number 45 45 65

27
(No Transcript)
28

• Experimental TEST
• Fuel properties
• Three blends of each of the biodiesel fuels were
  then tested 1. These were 5, 50 and 100 ( v/v)
  blends of Soya (S), Rape (R) and Waste (W)
  biodiesel, (referred to as S5, S50, S100, R5,
  R50, R100 and W5, W50 and W100 respectively).
  Standard diesel fuel No 2 (ESSO Ultra Low Sulphur
  Diesel ) was used for the baseline tests, and was
  also used to create the biodiesel blends.

29

• RESULTS
• 1- FUEL PROPERTIES

30
(No Transcript)
31
(No Transcript)
32
(No Transcript)
33
(No Transcript)
34

• THE END

35
(No Transcript)
36

• 2- ENGINE POWER

37

• The power output of the engine will be reduced
  with biodiesel (biodiesel has less LHV).
• W100 has the highest CN and the highest power
  output. This would suggest that for unblended
  oils CN is a better indicator of performance than
  LCV.

38

• 3- SPECIFIC ENERGY CONSUMPTION

39

• The data shows that there is little variation for
  5 blends, and the 50 blends tend to show
  slightly higher SES than for mineral diesel.
• As expected, the reduced as load is increased)
  and the values tend to converge to similar values
  near 100 load.

40

• It is unsurprising that SEC is higher for the
  biodiesel fuels, given their lower LCV.
• At low loads, the operating temperature is
  lower, which results in poor spray
  characteristics as the biodiesel fuels have
  higher viscosity.
• The net effect is that more fuel is required to
  produce the same power output.

41

• 4- Brake Specific NOX EMISSIONS

42

• The difference in emissions of Bs NOx for all 5
  blends compared with diesel are so small as to be
  negligible.
• The most marked differences are observed at low
  loads where significant reductions in BsNOx are
  observed with biodiesel. For R100 and S100, BsNOx
  was reduced to approximately half of the diesel
  value.
• BsNOx emissions were the lowest for soy
  biodiesel, which also has the lowest fuel borne
  oxygen content (table A3).

43

• A second reason for the lower BsNOx recorded in
  this study is thought to be due to the higher
  viscosity of the fuels leading to poor spray
  characteristics that reduced combustion
  efficiency and hence maximum combustion
  temperature 2.
• It is interesting to note that Salvatore and
  Maddaleena 3 found that NOx in a biodiesel
  fuelled engine can be significantly reduced by an
  EGR system that includes an oxidizing catalyst.

44

• The convergence of BsNOx emission levels beyond
  50 load is probably due to the increased in
  cylinder operating temperatures that reduce the
  effect of the increased viscosity of the
  biodiesel fuels compared with No 2 diesel.

45

• Higher viscosity in biodiesel fuels is known to
  result in poorer atomization, reduced spray
  penetration, decreased cone angle 4, and a
  greater droplet size, resulting in a lower amount
  of air entrainment leading to poorer combustion
  efficiency and hence lowers combustion
  temperatures which are confirmed by the extended
  ignition delays in figure 5.

46

• SMOKE EMISSIONS
• At low load (up to approximately 5 kW) there is
  negligible difference between the smoke emissions
  of any biodiesel as compared to mineral diesel.
• Beyond 25 load, the emissions of smoke are
  always lower than for corresponding mineral
  diesel operation, except for the 5 blends where
  there is negligible difference, as shown in
  figure 4.

47

• As the proportion of biodiesel is increased in
  the blend, the emissions of visible smoke
  decrease, except for the waste oil where the
  results from 50 blend and pure waste oil were
  virtually the same. Overall, the lowest smoke
  emissions were always recorded with rape blends.

48
(No Transcript)
49

• IGNITION DELAY
• The ignition delay was calculated as the crank
  angle interval between start of injection and
  start of combustion, (found from experimental
  data).
• Start of injection was defined as the crank angle
  where fuel line pressure first exceeded the
  nozzle opening pressure of 235 bar, and start of
  combustion was found from the heat release rate
  analysis.

50
(No Transcript)
51

• Conclusion
• A blend of 5 by volume of a biodiesel fuel in
  mineral diesel does not affect any of the
  measured performance or emissions
  characteristics.
• This would imply that the addition of small
  quantities of biodiesel to mineral diesel is a
  suitable strategy for increasing alternative fuel
  consumption, at least in agricultural engines.

52

• The initial findings presented in this paper
  suggest that for 5050 mixtures of biodiesel and
  mineral diesel, there is evidence of a two stage
  ignition process, with the diesel fuel igniting
  first, and hence controlling the combustion
  pattern of biodiesel. Whether this is only a
  result of blending procedure remains a subject
  for further research.

53

• Ignition delay is longer with biodiesel than for
  mineral diesel, and shows complicated trends
  where biodiesel is blended with mineral diesel.
  This leads to delayed combustion and lower peak
  cylinder pressures than for mineral diesel, which
  contradicts the effects of the higher CN of the
  biodiesel fuels .

54

• -NOx emissions were reduced at low load with
  negligible effect on soot at high load soot
  emissions were reduced with negligible effect on
  NOx. Thus the use of biodiesel fuels would appear
  to present a beneficial means of manipulating the
  traditional NOx/smoke trade-off. Overall, in an
  unmodified engine, rape derivative fuel gave the
  best combustion and emissions performance.

55

• Thank you

56
(No Transcript)