Bioethanol of 1st and 2nd generation

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					               Bioethanol Production
                                      of 1st and 2nd Generation

3rd REBEL Partner Meeting, 27 May 2010                       Sara Helmberger

Upper Austrian University of Applied Sciences Research and Development Ltd, Campus Wels
Content


•     Introduction

•     World-leading bioethanol producing countries

•     Bioethanol production of 1st and 2nd generation

•     Various possible feedstocks

•     Production and processing technologies




    3rd REBEL Partner Meeting, 27 May 2010              page 2
Introduction
•   Fossil fuels are responsible for 73 % of the CO2 production in the atmosphere

•   Extreme contribution to global warming




•   Interest in development of methods, reducing green house gases

•   Bioethanol as alternative to petroleum-derived transportation fuels




3rd REBEL Partner Meeting, 27 May 2010                                      page 3
Definition Bioethanol
•     Ethyl alcohol, grain alcohol, CH3-CH2-OH or EtOH

•     = Liquid biofuel

•     Advantages,                                 •   Disadvantages,
      compared to gasoline:                           compared to gasoline:

      - higher octane number                          - lower energy density
      - broader flammability limits                   - its corrosiveness
      - higher flame speeds                           - low flame luminosity
      - higher heats of vaporization                  - lower vapor pressure
      - higher compression ratio                      - miscibility with water
      - shorter burn time

•     Possible feedstocks: plant oils, sugar beets, cereals, organic waste,
                           processed biomass


    3rd REBEL Partner Meeting, 27 May 2010                                       page 4
World-leading
bioethanol producing countries

•   World-wide production of fuel ethanol more than tripled from 2000 until now




•   About 60% of global bioethanol production are obtained from sugar cane
    and 40% from other crops (e.g. maize)

3rd REBEL Partner Meeting, 27 May 2010                                  page 5
North American
Ethanol production

•   The United States are with over 41 % the world´s leader in ethanol production




•   Feedstocks: maize
                wheat, barley, sorghum


3rd REBEL Partner Meeting, 27 May 2010                                     page 6
South American
Ethanol prodution
•   South America contributes with roughly 35 % to world´s ethanol production, with
    Brazil being the leader country




•   Feedstock: sugar cane

•   ~ 20 % exported to US, EU, others



3rd REBEL Partner Meeting, 27 May 2010                                     page 7
European
Ethanol production
•   Europe contributes with 9 % to world´s ethanol production
    -> Comparable to the US ethanol market of roughly ten years ago
•   Plants in France, Spain, Sweden, UK, Austria (Pischelsdorf, Lower Austria)
•   In 2000, the EU introduced a Biofuel Directive
•   Commission of the European Communities (2007) -> binding minimal target
    of 10 % biofuels by 2020




•   Feedstock: wheat, sugar beet, waste from the wine industry

3rd REBEL Partner Meeting, 27 May 2010                                    page 8
European
Ethanol production
     Bioethanol Plant in Pischelsdorf, Lower Austria




3rd REBEL Partner Meeting, 27 May 2010                 page 9
Production technology
Feedstocks




 3rd REBEL Partner Meeting, 27 May 2010   page 10
Bioethanol production
of 1st generation
•   Major feedstocks for world´s ethanol production:

Sugar-containing feedstock: Sugar cane          Starchy feedstock: Maize




3rd REBEL Partner Meeting, 27 May 2010                                     page 11
Bioethanol production
of 1st generation
Starchy materials (e.g. maize)

•   US: 2 types of maize processing facilities:
    - Wet milling (since 1980s)
    - Dry grind (newer technology)

•   Starch = a polysaccharide carbohydrate,
    with a large number of sugar-molecules

•   Break down of the chains of this carbohydrate to obtain the single (individual) sugars
    -> Hydrolysis technique




•   Fermentation with microorganisms (e.g. yeasts)


3rd REBEL Partner Meeting, 27 May 2010                                      page 12
Bioethanol production
of 1st generation
Sugar-containing feedstocks
(e.g. sugar cane, beet molasses, sweet sorghum)

•   provide the single sugars (e.g. sucrose, glucose and fructose), which can be readily
    fermented by microorganisms (yeast) -> no hydrolysis is necessary


•   Brazil: sugar cane
    - harvest
    - pressing
    - Fermentation of sugar juice by microorganisms (yeast)

•   Europe: Beet molasses

•   Developing countries (e.g. Africa): Sweet sorghum




3rd REBEL Partner Meeting, 27 May 2010                                      page 13
Bioethanol production
of 2nd generation

•   Feedstocks: Alternative or lignocellulosic materials

•   = non food crops:

    - waste and remnant biomass
    - stalks of wheat and corn
    - wood
    - grass
    - straw

•   These most abundant reproducible feedstocks on Earth are of

    - high yields
    - low costs
    - good suitability for low quality land
    - low environmental impacts


3rd REBEL Partner Meeting, 27 May 2010                            page 14
Bioethanol production
of 2nd generation
Lignocellulosic biomass

•   3 basic polymers:
    - Cellulose
    - Hemicelluloses
    - Lignin

•   Processing of lignocellulosic material to bioethanol
    1. Pre-treatment            3. Fermentation
    2. Hydrolysis               4. Product separation




3rd REBEL Partner Meeting, 27 May 2010                     page 15
Bioethanol production
of 2nd generation
Pre-treatment

•   Size-reduction
•   Removal of structural and compositional impediments
    -> Lignocellulosic biomass is made more accessible for subsequent hydrolysis

•   Pre-treatment possiblities:
    - mechanical
    - chemical
    - biological pre-treatment
    - “Steam Explosion”

•   Steam Explosion:
    - Biomass is extruded at high temperature and pressure




3rd REBEL Partner Meeting, 27 May 2010                                  page 16
Bioethanol production
of 2nd generation
Pre-treatment: Steam Explosion




3rd REBEL Partner Meeting, 27 May 2010   page 17
Bioethanol production
of 2nd generation
Hydrolysis

•   = Saccharification of lignocellulosic biomass

•   Cellulose and Hemicellulose have to be broken down into single (individual) sugar
    molecules

•   Catalyst:
    - dilute acid
    - concentrated acid
    - enzymes (so-called cellulases)

•   Enzymatic hydrolysis
    - Cellulases are produced from both fungi and bacteria
    - Hydrolysis at mild conditions (50°C and pH 5.0)
    - Effective cellulose and hemicellulose breakdown

3rd REBEL Partner Meeting, 27 May 2010                                     page 18
Bioethanol production
of 2nd generation
Fermentation
•   The hydrolysate (mixed sugar-solution) is then fermented by microorganisms
    (e.g. yeast)

•   The sugar-solution contains not only one kind of sugar, but several different kinds
    -> Microorganisms are required, that can convert all sugars to high yields of EtOH


•   Most effective producer of bioethanol: Saccharomyces cerevisiae
    - can ferment only one kind of sugar

    - metabolic engineered strain or
      adapted strain of yeast is required




3rd REBEL Partner Meeting, 27 May 2010                                       page 19
Bioethanol production
of 2nd generation

Product separation, Distillation

•   Distillation

    - Bioethanol is separated from water
    - Ethanol is concentrated to about 95.6 %


•   Value-added co-products (e.g. lactic acid)

    - processing into plastics or other products


•   Lignin

    - usage in various value-added applications


3rd REBEL Partner Meeting, 27 May 2010             page 20
Bioethanol
usage




3rd REBEL Partner Meeting, 27 May 2010   page 21
   Thank you for your attention !
3rd REBEL Partner Meeting, 27 May 2010   page 22

				
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