New Zealand tallow sourced biodiesel a review of the resource, production and engine performance

1
New Zealand tallow sourced biodiesel a review
of the resource, production and engine performance

• R R Raine1, T R Johnson2, B Blackett3, M M
  Farid4, S Behzadi4 and S T Elder1
• 1 Department of Mechanical Engineering, The
  University of Auckland, New Zealand
• 2 Energy Efficiency and Conservation Authority,
  Wellington, New Zealand
• 3 BP Oil (NZ) Ltd, Wellington, New Zealand
• 4 Department of Chemical and Materials
  Engineering, The University of Auckland, New
  Zealand

U21 International Conference on Energy
Technologies and Policy 8th to 10th September 2008
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Outline

• Historical Context
• Government perspective
• Industry perspective
• Technical Development in production
• Engine performance and NOx emissions
• Conclusions

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Historical Context

• Late 1970s use of tallow methyl ester (TME)
  proposed as a diesel supplement
• 1983 project initiated by LFTB
• TME in buses as a B10 blend
• ICI and BP commissioned to manufacture
• A Wellington Bus Company to operate
• Worley Consultants, NZ and Perkins Engines, UK to
  monitor
• Trial a success but not continued due to the
  relatively high cost of tallow and the fall in
  oil prices in 1986

4
Government perspective

• Sept 2001 National Energy Efficiency and
  Conservation Strategy (NEECS)
• April 2002 indicative target of 30PJ of new
  renewable energy including 2PJ of renewable
  transport energy ( 1 of current land transport
  fuel use)
• June 2005 New Zealand Standard Automotive
  Biodiesel - Specification for manufacture and
  blending published

5
Government perspective

• Feb. 2007 Prime Minister announces biofuels
  sales obligation policy

• Oct. 2007 Biofuels Bill tabled in parliament
• June 2008 Select committee reports
• July 2008 Revised sales obligation

6
Industry perspective

• BioDiesel Oils Limited, Auckland with BP New
  Zealand manufacturing TME using a conventional
  manufacturing process currently the largest New
  Zealand producer
• Biodiesel New Zealand, a subsidiary of state
  owned Solid Energy to manufacture biodiesel from
  rapeseed grown in the South Island
• Ecodiesel Ltd based near Auckland who will use
  tallow

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BPNZ trials with B5 and B20 from 2004

• Captive commercial fleets
• Mainly New Zealand Bus, Auckland
• Last year 20 buses on B5 without incident
• One bus depot placed all buses (150) on a B5
  blend for a few months but some filter blocking
  problems so trial discontinued
• Filters fitted to the depot storage tank were not
  heated and occasionally suffered blockage in wet,
  winter conditions.

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Experience gained

• FAME (fatty acid methyl ester) is compatible with
  new technology diesel engines
• Tallow is a more difficult material to convert to
  FAME than rapeseed oil or soybean oil
• Important to reduce glycerides, especially
  monoglycerides to very low levels
• Organic acids can form soaps with alkaline and
  alkaline earth metal ions
• A high level of oxidation stability is required
  to avoid gums and deposits forming in the
  fuelling system and injectors

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Technical Development in production

• Target a pilot plant to produce satisfactory
  product with a processing capability of 5 kg/hr
  which could be used as a prototype for the
  manufacture of an industrial reactor
• pilot plant should achieve a conversion of 90-95
  
• residence time of less than 1 minute
• process would be suitable for tallow as feedstock

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University of Auckland Continuous Process
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University of Auckland Continuous Process

• atomized fat increases contact surface area
• higher reaction temperatures (up to 200 oC), not
  limited to the boiling point of the methanol (65
  oC)
• high methanol to fat ratio methanol can be
  recycled
• generates biodiesel at an overall conversion of
  85-96
• desired output flowrate achieved

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Engine performance and NOx emissions

• unmodified engine - performance is equal to that
  of the mineral diesel fuelled engine when using
  blends up to 100 biodiesel
• rack setting, and the amount of fuel injected, is
  higher for biodiesel blends than for mineral
  diesel, largely due to the difference in fuel
  energy content
• NOx emissions effect of fuel composition and
  injection timing

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Technical Development in production
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Engine performance and NOx emissions

• changing the injection timing has a significant
  effect on NOx emissions
• effect very similar in the case of D100 (mineral
  diesel) and for B100 (100 biodiesel)
• NOx emissions increase linearly with advancing
  timing over the range tested

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Conclusions

• Tri-partite support for biodiesel
• Government, commercial and research
• It is still not a smooth process