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  • Methane burns with a light blue flame, barely visible. No soot or ashes are produced
  • Biofuel

    1. 1. BIOFUELS Energy of the Future Saurabh Kumar Verma IIT Guwahati 16/4/2014
    2. 2. 080820 Sustainable means using less than is renewed; if water is withdrawn from a dam faster than it is refilled, the level drops and hydro power is lessened, and finally fails Non renewable Renewable Conventional Coal Oil Gas Nuclear Fission Wood Hydro Human/Animal Wind Water Pumping Alternative Geothermal Oil Shale, CTL Tar Sands Methane Hydrates Wind Solar Wave/Tide Ocean Current Biofuel
    3. 3. Fossil Fuels • Why are we looking for a replacement fuel’s like Biodiesel?
    4. 4. Biofuels
    6. 6. BIOETHANOL
    7. 7. CONTENTS I. What is bioethanol? II. Bioethanol Production III. Fuel Properties IV. Application V. Advantages VI. Disadvantages and Concerns VII.Comparison of Bioethanol and Biodiesel VIII.Future development
    8. 8. What is Bioethanol Bioethanol is an alcohol made by fermentation, mostly from carbohydrates produced in sugar or starch crops such as corn or sugarcane. Cellulosic biomass, derived from non-food sources such as trees and grasses, is also being developed as a feedstock for ethanol production
    9. 9. Contd. The principle fuel used as a petrol substitute is bioethanol Bioethanol fuel is mainly produced by the sugar or cellulose fermentation process Ethanol is a high octane fuel and has replaced lead as an octane enhancer in petrol
    10. 10. Bioethanol Production • Wheat/Grains/Corn/Sugar-cane can be used to produce ethanol. (Basically, any plants that composed largely of sugars) • Bioethanol is mainly produced in three ways. • Sugar ethanol • starch sugar ethanol • cellulose and hemicellulose ethanol
    11. 11. Bioethanol Production • Concentrated Acid Hydrolysis – ~77% of sulfuric acid is added to the dried biomass to a 10% moisture content. – Acid to be added in the ratio of 1/25 acid :1 biomass under 50°C. – Dilute the acid to ~30% with water and reheat the mixture at100°C for an hour. – Gel will be produced and pressed to discharge the acid sugar mixture. – Separate the acid & sugar mixture by using a chromatographic column .
    12. 12. Bioethanol Production • Dilute Acid Hydrolysis – oldest, simplest yet efficient method – hydrolyse the bio-mass to sucrose – hemi-cellulose undergo hydrolysis with the addition of 7% of sulfuric acid under the temperature 190°C. – to generate the more resistant cellulose portion, 4% of sulfuric acid is added at the temperature of 215°C
    13. 13. Bioethanol Production • Wet milling process – corn kernel is soaked in warm water – proteins broken down – starch present in the corn is released (thus, softening the kernel for the milling process) – microorganisms, fibre and starch products are produced. – In the distillation process, ethanol is produced.
    14. 14. Bioethanol Production • Dry milling process – Clean and break down the corn kernel into fine particles – Sugar solution is produced when the powder mixture (corn germ/starch and fibre) is broken down into sucrose by dilute acid or enzymes. – Yeast is added to ferment the cooled mixture into ethanol.
    15. 15. Bioethanol Production • Sugar fermentation – Hydrolysis process breaks down the biomass cellulosic portion into sugar solutions which will then be fermented into ethanol. – Yeast is added and heated to the solution. – Invertase acts as a catalyst and convert the sucrose sugars into glucose and fructose. (both C6H12O6).
    16. 16. Bioethanol Production Chemical reaction 1  The fructose and glucose sugars react with zymase to produce ethanol and carbon dioxide. Chemical reaction 2  Fermentation process requires 3 days to complete and is carried out at a temperature of between 250°C and 300°C.
    17. 17. Bioethanol Production • Fractional Distillation Process – After the sugar fermentation process, the ethanol still does contain a significant quantity of water which have to be removed. – In the distillation process, both the water and ethanol mixture are boiled. – Ethanol has a lower boiling point than water, therefore ethanol will be converted into the vapour state first  condensed and separated from water.
    18. 18. Feedstocks • Sugar is required to produce ethanol by fermentation. – Plant materials (grain, stems and leaves) are composed mainly of sugars – almost any plants can serve as feedstock for ethanol manufacture • Choice of raw material depends on several factors – ease of processing of the various plants available – prevailing conditions of climate – landscape and soil composition – sugar content Crops used in Bioethanol production Brazil sugar cane USA corn India Europe sugar cane wheat and barley
    19. 19. Conversion of starch to sugar and then sugar to ethanol Eg:-1) wheat Fermentation conditions Temperature - 32˚C and 35˚C pH - 5.2.  Ethanol is produced at 10-15% concentration and the solution is distilled to produce ethanol at higher concentrations
    20. 20. Eg:- 2) sugar cane Simplest of all the processes • Fermentation conditions are similar to the above process
    21. 21. • This is usually done using molasses. • Molasses is a thick dark syrup produced by boiling down juice from sugarcane; specially during sugar refining. • As molasses is a by product, ethanol production from molasses is not done in a large scale around the world. The main reaction involved is fermentation C6H12O6 sugar (e.g.:-glucose) 2 C2H5OH ethanol 2 CO2 carbon dioxide + yeast Direct conversion of sugar to ethanol
    22. 22. The top five ethanol producers in 2010 Brazil - 16500 billion liters The United States -16270 billion liters China - 2000 billion liters The European Union - 950 billion liters India - 300 billion liters
    23. 23. Bioethanol Properties  Colourless and clear liquid  Used to substitute petrol fuel for road transport vehicles  One of the widely used alternative automotive fuel in the world (Brazil & U.S.A are the largest ethanol producers)  Much more environmentally friendly  Lower toxicity level
    24. 24. Fuel Properties • Reid vapour pressure (measure for the volatility of a fuel) – Very low for ethanol, indicates a slow evaporation – Adv: the concentration of evaporative emissions in the air remains relatively low, reduces the risk of explosions – Disadv: low vapour pressure of ethanol -> Cold start difficulties – engines using ethanol cannot be started at temp < 20ºC w/o aids Fuel Properties Gasoline Bioethanol Molecular weight [kg/kmol] 111 46 Density [kg/l] at 15⁰C 0.75 0.80-0.82 Oxygen content [wt- %] 34.8 Lower Calorific Value [MJ/kg] at 15ºC 41.3 26.4 Lower Calorific Value [MJ/l] at 15ºC 31 21.2 Octane number (RON) 97 109 Octane number (MON) 86 92 Cetane number 8 11 Stoichiometric air/fuel ratio [kg air/kg fuel] 14.7 9.0 Boiling temperature [ºC] 30-190 78 Reid Vapour Pressure [kPa] at 15ºC 75 16.5
    25. 25. Fuel Properties • Octane number – Octane number of ethanol is higher than petrol – hence ethanol has better antiknock characteristics – increases the fuel efficiency of the engine – oxygen content of ethanol also leads to a higher efficiency, which results in a cleaner combustion process at relatively low temperatures Fuel Properties Gasoline Bioethanol Molecular weight [kg/kmol] 111 46 Density [kg/l] at 15⁰C 0.75 0.80-0.82 Oxygen content [wt- %] 34.8 Lower Calorific Value [MJ/kg] at 15ºC 41.3 26.4 Lower Calorific Value [MJ/l] at 15ºC 31 21.2 Octane number (RON) 97 109 Octane number (MON) 86 92 Cetane number 8 11 Stoichiometric air/fuel ratio [kg air/kg fuel] 14.7 9.0 Boiling temperature [ºC] 30-190 78 Reid Vapour Pressure [kPa] at 15ºC 75 16.5
    26. 26. Application • transport fuel to replace gasoline • fuel for power generation by thermal combustion • fuel for fuel cells by thermochemical reaction • fuel in cogeneration systems • feedstock in the chemicals industry
    27. 27. Application • Blending of ethanol with a small proportion of a volatile fuel such as gasoline -> more cost effective • Various mixture of bioethanol with gasoline or diesel fuels – E5G to E26G (5-26% ethanol, 95-74% gasoline) – E85G (85% ethanol, 15% gasoline) – E15D (15% ethanol, 85% diesel) – E95D (95% ethanol, 5% water, with ignition improver)
    28. 28. Advantages • Exhaust gases of ethanol are much cleaner – it burns more cleanly as a result of more complete combustion • Greenhouse gases reduce – ethanol-blended fuels such as E85 (85% ethanol and 15% gasoline) reduce up to 37.1% of GHGs • Positive energy balance, depending on the type of raw stock – output of energy during the production is more than the input • Any plant can be use for production of bioethanol – it only has to contain sugar and starch • Carbon neutral – the CO2 released in the bioethanol production process is the same amount as the one the crops previously absorbed during photosynthesis
    29. 29. Advantages • Decrease in ozone formation – The emissions produced by burning ethanol are less reactive with sunlight than those produced by burning gasoline, which results in a lower potential for forming ozone • Renewable energy resource – result of conversion of the sun's energy into usable energy – Photosynthesis -> feedstocks grow -> processed into ethanol • Energy security – esp. Countries that do not have access to crude oil resources – grow crops for energy use and gain some economic freedom • Reduces the amount of high-octane additives • Fuel spills are more easily biodegraded or diluted to non toxic concentrations
    30. 30. Disadvantages and Concerns • Biodiversity – A large amount of arable land is required to grow crops, natural habitats would be destroyed • Food vs. Fuel debate – due to the lucrative prices of bioethanol some farmers may sacrifice food crops for biofuel production which will increase food prices around the world • Carbon emissions (controversial) – During production of bioethanol, huge amount of carbon dioxide is released – Emission of GHGs from production of bioethanol is comparable to the emissions of internal- combustion engines
    31. 31. Disadvantages and Concerns • Not as efficient as petroleum – energy content of the petrol is much higher than bioethanol – its energy content is 70% of that of petrol • Engines made for working on Bioethanol cannot be used for petrol or diesel – Due to high octane number of bioethanol, they can be burned in the engines with much higher compression ratio • Used of phosphorous and nitrogen in the production – negative effect on the environment • Cold start difficulties – pure ethanol is difficult to vaporise
    32. 32. Disadvantages and Concerns • Transportation – ethanol is hygroscopic, it absorbs water from the air and thus has high corrosion aggressiveness – Can only be transported by auto transport or railroad • Many older cars unequipped to handle even 10% ethanol • Negatively affect electric fuel pumps by increasing internal wear and undesirable spark generation
    33. 33. Future development • For bioethanol to become more sustainable to replace petrol, production process has to be more efficient – Reducing cost of conversion – Increasing yields – Increase the diversity of crop used • As microbes are use to convert glucose into sugar which is ferment in bioethanol – Microbiology and biotechnology will be helpful in the genetic engineering
    34. 34. BIODIESEL
    35. 35. Overview • Introduction • The Chemistry of Biodiesel • Advantages and Disadvantages • Biodiesel Feedstocks • Oil Processing • Small Scale Biodiesel Production – On-farm Case Studies • Fuel-making demonstration
    36. 36. What is Biodiesel? • Alternative fuel for diesel engines • Made from vegetable oil or animal fat • Meets health effect testing (CAA) • Lower emissions, High flash point (>300F), Safer • Biodegradable, Essentially non-toxic. • Chemically, biodiesel molecules are mono-alkyl esters produced usually from triglyceride esters Fatty Acid Alcohol Glycerin Vegetable Oil BiodieselFA FAFA FA
    37. 37. Chemistry of Triglycerides • Biodiesel is made from the combination of a triglyceride with a monohydroxy alcohol (i.e. methanol, ethanol…). • What is a triglyceride? Made from a combination of glycerol and three fatty acids:
    38. 38. Transesterification While actually a multi-step process, the overall reaction looks like this: CH2OOR1 catalyst CH2OH |  | CHOOR2 + 3CH3OH  3CH3OORx + CHOH | | CH2OOR3 CH2OH Triglyceride 3 Methanols Biodiesel Glycerin R1, R2, and R3 are fatty acid alkyl groups (could be different, or the same), and depend on the type of oil. The fatty acids involved determine the final properties of the biodiesel (cetane number, cold flow properties, etc.)
    39. 39. Individual step of Transesterification First step, triglyceride turned into diglyceride, methoxide (minus Na) joins freed FA to make biodiesel, Na joins OH from water (from methoxide formation) to make NaOH. Other H joins the diglyceride. H O H | | | HCOR1 H HCO H O | | | | | HCOOR2 + HCONa +H2O  CHOOR2 + HCOR1 + NaOH | | | | HCOR3 H HCOR3 H | | | | H O H O Triglyceride + Methoxide + H2O  Diglyceride + Biodiesel + NaOH
    40. 40. Transesterification (the biodiesel reaction) Fatty Acid Chain Glycerol Methanol (or Ethanol) One triglyceride molecule is converted into three mono alkyl ester (biodiesel) molecules Biodiesel Triglyceride
    41. 41. Characteristics of Biodiesel • Liquid varying in color • Immiscible • High boiling point of 360–640°F (182– 338°C) • Low vapor pressure: < 2 mmHg • Flash point 199°F (93°C)
    42. 42. Characteristics of Biodiesel • Specific gravity between 0.86 & 0.90 • Vapor density > 1 • Less hazardous in terms of flammability
    43. 43. Uses of Biodiesel and Biodiesel Blends • Fuel for vehicles most common use • Heating fuel in commercial & domestic boilers: – Bioheat Property of DOE, reprinted with permission
    44. 44. Comparison of Bioethanol and Biodiesel Bioethanol Biodiesel Process Dry-mill method: yeast, sugars and starch are fermented. From starch, it is fermented into sugar, afterwards it is fermented again into alcohol. Transesterification: methyl esters and glycerin which are not good for engines, are left behind. Environment al Benefit Both reduce greenhouse gas emissions as biofuels are primarily derived from crops which absorb carbon dioxide. Compatibility ethanol has to be blended with fossil fuel like gasoline, hence only compatible with selected gasoline powered automobiles. Able to run in any diesel generated engines Costs Cheaper More expensive Gallons per acre 420 gallons of ethanol can be generated per acre 60 gallons of biodiesel per acre soybeans cost of soybean oil would significantly increase if biodiesel production is increased as well. Energy provides 93% more net energy per gallon produces only 25% more net energy. Greenhouse- gas Emissions (GHG) 12% less greenhouse gas emission than the production and combustion of regular diesel 41% less compared to conventional gasoline.
    45. 45. Biodiesel-Blended Fuels • Can be used alone / blended • B20: 20% biodiesel • B99: 99% biodiesel • B100: pure biodiesel Property of DOE, reprinted with permission
    46. 46. Advantages of Biodiesel • Biodegradable • Non-toxic • Favorable Emissions Profile • Renewable • Carbon Neutrality
    47. 47. Advantages of Biodiesel • Requires no engine modifications (except replacing some fuel lines on older engines). • Can be blended in any proportion with petroleum diesel fuel. • High cetane number and excellent lubricity. • Very high flashpoint (>300°F) • Can be made from waste restaurant oils and animal fats
    48. 48. Relative Greenhouse Gas Emissions 0 20 40 60 80 100 120 140 160 Gasoline CNG LPG Diesel Ethanol 85% B20 Diesel Hybrid Electric B100 B100 = 100% Biodiesel B20 = 20% BD + 80% PD
    49. 49. ** B100 (100% biodiesel) with NOx adsorbing catalyst on vehicle Relative emissions: Diesel and Biodiesel 0 20 40 60 80 100 120 Total Unburned HCs CO Particulate Matter **NOx Sulfates PAHs n-PAHs Mutagenicity CO2 Percent B100 ** B20 Diesel
    50. 50. Biodiesel Emissions Sources: EPA, 2002 Biodiesel Emissions Database; McCormick, Bob, 2007, Presentation: The Truth about NOx Emissions & TxLED Update Biodiesel vs. Petroleum Diesel Emission B100 B20 Carbon Monoxide -47% -12% Hydrocarbons -67% -20% Particulate Matter -48% -12% Sulfates -100% -20% Nitrogen Oxides +/- ?? +/- ?? Ozone formation (speculated HC) -50% -10% PAH -80% -13%
    51. 51. Vegetable Oil as Feedstocks • Oil-seed crops are the focus for biodiesel production expansion • Currently higher market values for competing uses constrain utilization of crops for biodiesel production • Most oil-seed crops produce both a marketable oil and meal – Seeds must be crushed to extract oil – The meal often has higher market value than the oil
    52. 52. Biodiesel Feedstocks 1 Biodiesel Magazine, Feb. 2007 2 O’Brian, Richard D. Fats and Oils: Formulating and Processing for Applications, 2004 Land Crop Yields based on US average 2006 Crop Avg Harvest (lbs) Oil content % (avg)2 Gal/acre (approx.) Peanut 2874 47 175 Canola 1366 43 76 Soybean 2562 19 63 Sunflower 1211 40 63 Camelina1 1300 35 59 Safflower 1069 33 46 Corn 8946 4 46 Cottonseed 819 19 20
    53. 53. Oil Processing • Oil-seed crops must be crushed to extract oil – This can be done on-farm or at a crushing facility – Small scale systems use mechanical crushing – Commercial crushers often also use hexane extraction • Hexane is toxic but removes >99% of oil • Before conversion oil must be degummed: – Treat with phosphoric acid for 4-8 hours (300- 1000 ppm for soy, 1000-3000 ppm for canola) – Water Wash – Vacuum Drying – Oil often purchased as “Crude, degummed.” RBD = Refined, Bleached, Deoderized
    54. 54. After Glycerin removal, biodiesel now just needs to be cleaned/purified before use:
    55. 55. Disadvantages of biodiesel • Lower Energy Content – 8% fewer BTU’s per gallon, but also higher cetane #, lubricity, etc. • Poor cold weather performance – This can be mitigated by blending with diesel fuel or with additives, or using low gel point feedstocks such as rapeseed/canola. • Stability Concerns – Biodiesel is less oxidatively stable than petroleum diesel fuel. Old fuel can become acidic and form sediments and varnish. Additives can prevent this. • Scalability – Current feedstock technology limits large scalability
    56. 56. 0 50,000,000 100,000,000 150,000,000 200,000,000 250,000,000 1999 2000 2001 2002 2003 2004 2005 2006 Biodiesel Production (gallons) in US 500,000 2 Million 30 million 75 million
    57. 57. Jatropha biodiesel plant
    58. 58. JATROPHA TREE
    59. 59. Jatropha • Biodiesel from Jatropha • Seeds of the Jatropha nut is crushed and oil is extracted • The oil is processed and refined to form bio-diesel.
    60. 60.  Jatropha can be cultivated anywhere along canals,roads,railway tracks, on border of farm and even an alkaline soils.  Grown in high as well as low rainfall.  In high rainfall yield is more.  Occurs mainly at lower altitude(0-500Cm) with average annual temperature above 200C, and rainfall of 300-1000mm.
    62. 62. Jatropha curcas plantations at Rashtrapati Bhawan (2004)
    63. 63. BIOGAS
    64. 64. Gasification Technology • Gobar gas Production • Biogas • Synthesis gas
    65. 65. Bio Mass • Biomass already supplies 14 % of the world’s primary energy consumption. On average, biomass produces 38 % of the primary energy in developing countries. • USA: 4% of total energy from bio mass, around 9000 MW • INDIA is short of 15,000 MW of energy and it costs about 25,000 crores annually for the government to import oil.
    66. 66. • Bio Mass from cattle manure, agricultural waste, forest residue and municipal waste. • Anaerobic digestion of livestock wastes to give bio gas • Digester consumes roughly one third the power it’s capable of producing. • Fertilizers as by product. • Average electricity generation of 5.5kWh per cow per day!!
    67. 67. Overview •Goals & Objectives •Anaerobic Digestion •Biodigesters •Biogas •Design Specifications •Recommendations Source: Source:
    68. 68. What is a Biodigester? • A device that mimics the natural decay process of organic matter • Biogas is produced from anaerobic decay (decay that occurs without oxygen)
    69. 69. Anaerobic Digestion in a Biodigester • Digester is fed a mixture of water and waste called a slurry • Daily, fresh slurry is added, displacing previous days load that bacteria have started to digest • First, digestible organic matter is broken down by acid-producing bacteria • By-products are then broken down by methane- producing bacteria (
    70. 70. Biogas: Green Energy • 50-70% methane; • 30-40% carbon dioxide; • Insignificant amounts of oxygen and hydrogen sulfide (H2S). • Biogas burns without soot or ash being produced • Methane is a combustible gas • Biogas will be used to generate energy for the cooking needs here at Rosalie Forest Eco Lodge (plascoenergygroup)
    71. 71. How Much Biogas Can I Get From My Waste? • Amount of biogas depends on the waste itself and design of the digester. • Some digesters can yield 20 liters of biogas per kilogram of waste up to 800 liters per kilogram. • Factors: digester design, temperature, system operation, presence of oxygen.
    72. 72. How Much Energy is in Biogas? • Average fuel value of methane = 1000 BTU/ft3 • Average fuel value of propane = 2500 BTU/ft3 • 1 BTU/ft3 = 37.2589 KJ/m3
    73. 73. How Much Energy is in Biogas? • Therefore, using the SI system, Fuel Value units: • FV methane = 1000 * 37.2589 KJ/m3 = 37258.9 KJ/m3 • FV propane = 2500 * 37.2589 KJ/m3 = 93147.3 KJ/m3 • FV propane / FV methane = 2.5 • When both fuels are burned completely, propane produces 2.5 times more energy per unit of volume.
    74. 74. How Much Biogas Do I Need? • For Example: We want 40 lbs of propane-equivalent per week. • Biogas is 50-70% methane, 30-50% CO2 and 5-15% N2, H2, etc. • 40 lbs propane * 2.5 = 100 lbs of methane • 100 lbs of methane / 60% = 166.67 lbs of biogas
    75. 75. How to calculate Organic Loading Rate (OLR) • OLR = kg VS added / day / m3 reactor • Organic Loading Rate: 2.02 kg VS added / day / m3 reactor
    76. 76. Floating drum planet
    77. 77. Fixed dome planet
    78. 78. Design of digester • Motors for collectors operate every three hours and has a power of 1 Kwatt. • Dry mass tank construct from galvanized steel plate, has a dimension of 1.5 X 1.5 X 2 . • Screw pump feeding once a day , has a velocity of 1 m/s, flow rate 50 L/s. • Digester size is calculated depending on the equation : Vd (m3) = Sd (m3/day) * RT (days) Substrate input (Sd) = biomass (B) + water (W) (m3/d) • Digester size equals to 320 m3 , for factor of safety it assumed to be 430 m3 . • Gasholder size is calculated depending on the equation : Vg1 = Gc max* Tc max • Gasholder size equals to 240 m3 .
    79. 79. Environmental Benefits •Reduction of waste • Extremely low emission of greenhouse gases compared to fossil fuels • Ethanol is Carbon neutral and forms a part of the carbon cycle • Growing variety of crops increases bio-diversity
    80. 80. ALGAE FUEL
    81. 81. Bio-refinery • A facility that integrates biomass conversion processes and equipment to produce fuels, power, and chemicals from biomass. • Analogous to today's petroleum refineries • It is based on the “Sugar Platform“ and the “Thermochemical Platform“