Biofuels PDF

Biofuel Production MBBT 41813 and PLBL 41863 Conducted by Dr. D V S Kaluthanthri 1  IMPORTANCE OF BIO-FUELS Fossil fuels: main source of energy for many years Unsustainable, cause environmental issues Unrelenting population growth will require mor...

Biofuel Production MBBT 41813 and PLBL 41863 Conducted by Dr. D V S Kaluthanthri 1  IMPORTANCE OF BIO-FUELS Fossil fuels: main source of energy for many years Unsustainable, cause environmental issues Unrelenting population growth will require more and more energy and consumer products Global warming becoming a reality Challenges allow fossil fuels to be substitute by a renewable form of energy such as bio-fuels Disadvantages of fossil fuels  Nonrenewable  Environmental Hazards  Accidents can be disastrous  Effect on Human Health  Price fluctuations  Overdependence  Need Huge Amount of Reserves  Impact on Aquatic Life by oil spill Biofuels  Energy enriched chemicals generated through the biological processes or derived from the biomass of living organisms, such as microalgae, plants and bacteria.  Biofuels  Can be produced from Photosynthetic bacteria Micro and macro algae Vascular plants  Primary products of Biofuels can be in Liquid Gas Solid Products can be further processed by biochemical, physical and thermochemical methods Biofuels Alcohol Biodiesel Biogas Alcohol as Biofuel Use of alcohol as bio-fuels is nothing new In 1872, when Nikolaus Otto invented the internal combustion engine, gasoline was not available Ethyl alcohol at 180-190 proof was the fuel then Alcohol and Gasoline Gasoline is a mixture of hydrocarbons Simplest member is a methane These substances are gases under ordinary conditions however with the increase of C they turn into liquid, oilier, waxier and finally solid  Biofuels Primary Secondary First Second Third Generation Generation Generation Biofuels Sugar is the basic substrate to produce bioethanol and biomethanol Use of photosynthetic microorganism as a source of Biofuel is Cheap Feasible i.e. atmospheric CO2 serves as C source and sunlight serve as an energy source Photosynthesis is a product of biomass accumulation Plant biomass is a raw material for Biofuel synthesis First generation Biofuels Obtained from woody and cellulosic matter mainly derived from fermentation of starch (Wheat, barley, corn, potatoes) and sugars (sugar cane and beet) Biodiesel produced by Oil crops (rapeseed, soybean, sunflower, etc.) Used cooking oil and animal fats Crops used to produce Biofuels Ethanol: A modern renewable biofuel Microbes can produce ethanol from variety of Carbon and energy resources Cereals and sugar crops have been uses as the major source of Energy First commercial scale cellulosic ethanol production : 2013 Substrate: Waste biomass Sources of Bioethanol production Agricultural waste Lignocellulosic biomass Rice straw Sugarcane Feedstocks, such as sucrose from sugarcane, Sugar Beet Starch from corn Wheat or lignocellulosic materials from straw, wood and bagasse Bioethanol from Sugarcane Sugarcane ethanol is an alcohol-based fuel produced by the fermentation of sugarcane juice and molasses. Because it is a clean, affordable and low-carbon biofuel, sugarcane ethanol has emerged as a leading renewable fuel for the transportation sector. Ethanol Bioethanol Can be used in two ways Blended with gasoline levels ranging from 5 to 27.5 percent to reduce petroleum use, boost octane ratings and cut tailpipe emissions Pure ethanol  Fuel made up of 85 to 100 percent ethanol depending on country specifications – can be used in specially designed engines Importance of Bioethanol Cleaner Air: Ethanol adds oxygen to gasoline which helps reduce air pollution and harmful emissions Reduced Greenhouse Gas Emissions: Compared to gasoline, sugarcane ethanol cuts carbon dioxide emissions by 90 %. That’s better than any other liquid biofuel produced today at commercial scale. Better Performance: Ethanol is a high-octane fuel that helps prevent engine knocking and generates more power in higher compression engines. Lower Petroleum Usage: Ethanol reduces global dependence on oil. Sugarcane ethanol is one more good option for diversifying energy supplies. Organisms for ethanol production Maize as Biofuel  Pretreatment methods There are a number of biological, physical and chemical technologies available Use of enzymes Ball milling Steam explosion Acid, alkali, lime and wet oxidation Steam explosion method  Popping treatment for rice straw  Popping pretreatment of rice straw prior to downstream enzymatic hydrolysis and fermentation was found to increase cellulose to glucose conversion efficiency.  Significantly lower environmental impact and greater saccharification efficiency over similar methods used conventionally  Greater efficiency likely resulting from modification of the substrate that greatly enhances accessibility of desired cell wall components to enzymes Rice straw fermentation 1. Simultaneous saccharification and fermentation (SSF) 2. Separate enzyme hydrolysis fermentation (SHF) 3. Consolidated bioprocessing (CBP) Simultaneous Saccharification and Fermentation (SSF)  Advantage: Low cost  Disadvantage: Different optimum temperature of the hydrolyzing enzymes and fermenting microorganisms  This problem has usually been tackled by applying  thermotolerant microorganisms such as Kluyveromyces marxianus, Candida lusitaniae and Zymomonas mobilis  mixed culture of some microorganisms like Brettanomyces clausenii and Saccharomyces cerevisiae Cellulose is transferred to glucose and ethanol Separate Enzyme Hydrolysis Fermentation (SHF) Rice straw was successfully converted to ethanol by separate enzymatic hydrolysis and fermentation by Mucor indicus, Rhizopus oryzae, and Saccharomyces cerevisiae Enzymes: Cellulase and β-glucosidase Consolidated Bioprocessing (CBP) Consolidated bioprocessing (CBP) of lignocellulose to bioethanol refers to the combining of the four biological events required for this conversion process in one reactor. 1.Production of saccharolytic enzymes 2. Hydrolysis of the polysaccharides present in pretreated biomass 3.Fermentation of hexose sugars 4.Fermentation of pentose sugars Biofuel from mustard seed ( Biodiesel) Transesterification Transesterification Reaction , also called as alcoholysis Alcoholysis Displacement of alcohol from an ester by another alcohol in a process similar to hydrolysis except that an Alcohol is used instead of water. This process is used to prepare Bio-diesel from mustard oil Itis the process of using an alcohol – Methanol / Ethanol / Butanol, in the presence of a catalyst – NaOH / KOH, to break the molecule of the oil chemically into methyl or ethyl esters, with Glycerol as a byproduct. Biodiesel Biodiesel is an alternative fuel similar to conventional or ‘fossil’ diesel. Biodiesel can be produced from straight vegetable oil, animal oil/fats and waste cooking oil. 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). Second generation biofuels  Second-generation biofuels are produced from non- food biomass, including lignocellulosic materials like agricultural residues, forest residues, and dedicated energy crops.  These biofuels offer several advantages over first- generation biofuels, which are made from food crops Third generation biofuels Algae are another source of bio ethanol production (Also used in biohydrogen production). Recently, it has been reported that algae are a Potential feedstock for biofuel generation Algae contain ~50% of lipids for production of biodiesel and rest component sugar and proteins for bioethanol production. Biofuel from Algae Microalgae is being considered as an attractive feedstock for biofuels production Depending on species and cultivation method microalgae can produce Bio-hydrogen Bio-methanol Bio-ethanol Bio-diesel Carbohydrates The algal derived biofuels production requires only sunlight, CO2 and water and generates multiple renewable energy products Algal-based biofuels production is about hundred times higher than that of higher plants. Photosynthetic yields: 3%-8% energy can be converted by algae into Biomass while 0.5% can be converted by plants The algal biomass can be further processed to produce biofuels during fermentation by microorganisms Advantages of microalgae biofuel Grow rapidly Yields significantly more biofuel per hectare than oil plants Can sequester excess carbon dioxide as hydrocarbons Contains no sulfur and has low toxicity Highly biodegradable Does not compete significantly with food, fiber or other uses Does not involve destruction of natural habitats  Algae consumes CO2 as they grow.  So, they could be used to capture CO2 from power stations and other industrial plants that would other wise go into atmosphere Selection of a strain Very important Some algae naturally manufacture hydrocarbons that are suitable for high energy fuels Botryococcus braunii contains more than 50% oil, mostly from hydrocarbons Types of biofuels from microalgae 1. Biodiesel Requires Triglycerides that are derived from oil extracted from the algal biomass Triglycerides are comprised of three chains of fatty acids joined by a glycerol molecule In transesterification or alcoholysis, the glycerol needs to be replaced by methanol  Transesterification occurs step by step Triglycerides first convert to diglycerides and then to monoglycerides and finally to glycerol One triglyceride molecule and three methanol molecules are converted to three fatty acid methyl ester (FAME) molecules and one glycerol molecule. The molecules in biodiesel are primarily FAMEs. Glycerol is a higher-value side product of this process Required excess methanol  Disadvantages Unsatisfying growth rates Insufficient cell densities 2. Bio ethanol Algae is consisting of High content of carbohydrates/polysaccharides and low content of lignin and hemicellulose as compared to crop plants Spirogyra and Chlorococum species have been shown to accumulate high levels of polysaccharides both in their complex cell walls and as starch 3. Bio methane Biomethane can be produced from algae using various methods Gasification Pyrolysis Anaerobic digestion Biomass from marine macroalgae offer the highest potential for biomethanation Methane also can be used as a fuel to generate electricity. Methane is a gas under normal conditions, handling is complicated and its use as a transportation fuel is limited The application of methane fermentation technology (anaerobic digestion) to algae has received considerable attention because it also produces valuable by-products such as biogas The gas from fermentation mainly consists of a mixture of Methane (55–75%) CO2 (25–45%) However, the production costs of (macroalgal) biomethane need to be reduced significantly to be competitive with fossil fuels 4. Gasoline and aviation fuel These advanced fuels from algae are comparable to the equivalent fuels derived from petroleum and they have performed excellently in tests United Airlines even flew a Boeing 737 from Houston to Chicago on a 40 percent blend of algal jet fuel and 60 percent conventional jet fuel becoming the first U.S. commercial flight powered in part by algae-based biofuel.  5. Bio hydrogen Hydrogen (H2) offers tremendous potential as a clean, renewable energy source Higher heating value Water is the main product, thus, hydrogen is regarded as a clean non-polluting fuel Other uses  Methanol production  Fuel in rocket engines  Manufacture of ammonia  Removal of impurities in oil refineries Hydrogen airships - Future in algal biofuel production On top of producing clean energy, the floating station can also play an incredible observatory of the sea fauna and flora and fight for the protection of the ecosystem. The concept hydrogenase is certainly far off futuristic concept but perhaps one day in future we will see ships floating in the sky, acting as both vehicle and an environmental scavenger Fourth Generation Biofuels  Fourth-generation biofuels represent the latest advancements in biofuel technology and focus on producing sustainable, carbon-negative fuels.  These biofuels not only aim to be renewable and environmentally friendly but also actively contribute to reducing atmospheric carbon dioxide levels.  Algal Biofuels: Algae can be genetically modified to increase lipid production. The lipids are extracted and converted into biodiesel, bio-oil, or biojet fuel. Algae also capture CO2 during growth, making the process carbon-negative. Synthetic Biology: Engineering microorganisms to efficiently convert biomass or CO2 into biofuels. These organisms can be designed to produce a variety of fuels, including ethanol, butanol, and drop-in fuels.  Biochar Production: Biomass is pyrolyzed to produce biochar, a stable form of carbon that can be buried in soil to sequester carbon. The gases and liquids produced during pyrolysis can be converted into biofuels. Carbon-Negative Bioenergy with Carbon Capture and Storage (BECCS): Combines biomass energy production with CCS. The CO2 produced during biofuel production is captured and stored underground, effectively removing CO2 from the atmosphere.  Bioplastic Bioplastics are a type of plastic derived from renewable biomass sources, such as vegetable fats and oils, corn starch, pea starch, or microbiota. Unlike traditional plastics, which are made from petrochemicals, bioplastics aim to reduce environmental impact by using sustainable resources and often offering better biodegradability.  Types of Bioplastics Starch-Based Bioplastics Cellulose-Based Bioplastics Polylactic Acid (PLA) Polyhydroxyalkanoates (PHA) Bio-Polyethylene (Bio-PE): Bio-Polyethylene Terephthalate (Bio-PET)