1. Sustainable Energy Systems Engineering Peter Gevorkian Ch 13: Biofuels and Biogas Technology Brevard Community College EST1830 Bruce Hesher

2. Introduction p283 Biomass is the stored energy in plant and animal tissues and materials in chemical form. Biomass is the stored energy in plant and animal tissues and materials in chemical form. The use of biomass as a source of energy dates back to the discovery of fire by humans. The use of biomass as a source of energy dates back to the discovery of fire by humans.

3. The Chemical Composition p283 The chemical composition of biomass is dependant on the various types of tissues found in plant and animal species. In general, plant structures consist of 25% lignin and 75% carbohydrates and sugars. Carbohydrates are composed of many types of sugar molecules that are linked together in long chains called polymers. Lignin is the mortar that holds plants together and gives them physical structure. The chemical composition of biomass is dependant on the various types of tissues found in plant and animal species. In general, plant structures consist of 25% lignin and 75% carbohydrates and sugars. Carbohydrates are composed of many types of sugar molecules that are linked together in long chains called polymers. Lignin is the mortar that holds plants together and gives them physical structure.

4. Origins of Biomass p284 Biomass in nature is formed when carbon dioxide from the atmosphere and water from the earth are combined in the photosynthetic process to produce carbohydrates and sugars. Energy from the sun drives the process and energy is stored in chemical bonds. Biomass in nature is formed when carbon dioxide from the atmosphere and water from the earth are combined in the photosynthetic process to produce carbohydrates and sugars. Energy from the sun drives the process and energy is stored in chemical bonds. CO 2 + H 2 O + trace minerals + solar energy  biomass CO 2 + H 2 O + trace minerals + solar energy  biomass When biomass is burned energy is released: When biomass is burned energy is released: O 2 + C  CO 2 + H 2 O + energy + ash O 2 + C  CO 2 + H 2 O + energy + ash This is a cyclic process ! High levels of CO 2 in the atmosphere promotes plant life!

5. Biomass Energy Potential p285 The energy potential of biomass is enormous. It can be made into electricity, liquid or gaseous fuels like ethanol, solid fuels, etc. The energy density of biomass is less than that of coal but it has less ash and heavy metals, so it burns cleaner. The ash content of biomass is much lower than that of coal and it is relatively free of toxic metals. The energy potential of biomass is enormous. It can be made into electricity, liquid or gaseous fuels like ethanol, solid fuels, etc. The energy density of biomass is less than that of coal but it has less ash and heavy metals, so it burns cleaner. The ash content of biomass is much lower than that of coal and it is relatively free of toxic metals. Ethanol fuel is ethanol (ethyl alcohol), the same type of alcohol found in alcoholic beverages. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline.biofuel See Energy Content chart on page 286.

6. Unintended Consequences In the USA 40% of the corn grown in 2010 is being used for ethanol. This raises the cost of food! Corn is important for both human consumption and as a feed for livestock. Many countries are faulting the U.S. for squandering food on transportation. There is only so much land in the U.S. that is suitable for growing corn. But there is a lot of unused land that is suited for growing other crops that can be used for biofuels; some of them are better than corn!

7. Benefits of Biomass Energy p286 Biomass technology and the extended use of bioenergy based fuels which maximize the use of otherwise discarded agriculture, industrial, and animal waste can create industrial infrastructure and jobs. The U.S. department of agriculture estimates that 17,00 jobs are created for every million gallons of ethanol created. Biomass technology and the extended use of bioenergy based fuels which maximize the use of otherwise discarded agriculture, industrial, and animal waste can create industrial infrastructure and jobs. The U.S. department of agriculture estimates that 17,00 jobs are created for every million gallons of ethanol created. 5 quadrillion Btu’s of electricity on 50 million acres of land could increase farm income by $12 billion annually. Note: the U.S. consumes about 90 billion quadrillion Btu annually. 5 quadrillion Btu’s of electricity on 50 million acres of land could increase farm income by $12 billion annually. Note: the U.S. consumes about 90 billion quadrillion Btu annually. Should this be promoted ? If so, should government do the promoting ?

8. Impact of Biomass Energy on Climate Conditions p287 Burning fossil fuels releases gasses and particles into the atmosphere. Carbon Di-oxide (CO 2 ) and methane (CH 4 ) are greenhouse gasses. Methane is the more powerful but lasts less time. CO 2 is removed from the atmosphere by plants. Capturing landfill gasses, waste treatment gasses etc. can have positive impact on CH 4 in the air. Carbon Di-oxide (CO 2 ) and methane (CH 4 ) are greenhouse gasses. Methane is the more powerful but lasts less time. CO 2 is removed from the atmosphere by plants. Capturing landfill gasses, waste treatment gasses etc. can have positive impact on CH 4 in the air. Sulfur and nitrogen oxides form fossil fuels adds to acid rain. Burning cleaner fuels can help. Sulfur and nitrogen oxides form fossil fuels adds to acid rain. Burning cleaner fuels can help. Planting biomass crops on marginal land can help prevent soil erosion and water contamination. Planting biomass crops on marginal land can help prevent soil erosion and water contamination.

9. Biomass Technologies p288 Microturbine Generators use very high internal combustion pressure to provide rotational power to the shaft of an electric generator. They can use a variety of gas or liquid fuels including: land fill gas, natural gas, and hydrogen. Microturbine Overview Commercially AvailableYes (Limited) Size Range25-500 kW FuelNatural gas, hydrogen, propane, diesel Efficiency20-30% (Recuperated) EnvironmentalLow (<9-50 ppm) NOx Other FeaturesCogeneration (50-80°C water) Commercial StatusSmall volume production, commercial prototypes now.

10. Economic Benefits of Using Landfill Gas p294 Landfill projects benefit all parties involved. Land owners, the local utility, and community. They initially provide construction jobs then once active provide electricity with low fuel costs. Landfill Gas Conversion to Green Energy The gas produced by the Cocoa Landfill (methane) is extracted through a vacuum system run by LES (Brevard Energy LLC) which in turn is connected to a power grid at the FP&L Facility (Oleander Plant) and converted to Green Energy.

11. Land Fill Gas

12. Environmental Benefits of Using Landfill Gas p294 Converting LFG to energy offsets the need for nonrenewable resources, such as coal and oil and reduces emission of air pollutants that contribute to smog and acid rain. Converting LFG to energy offsets the need for nonrenewable resources, such as coal and oil and reduces emission of air pollutants that contribute to smog and acid rain.

13. Case Study of Successful Application of Microgenerator Technology p294 The HOD landfill in Antioch Illinois is a superfund site consisting of approx. 51 acres of landfill. In 1998 the EPA issued a Record of Decision (ROD) that required specific landfill closure activities. It also required the installation of a LFG collection system. The system has 35 dual gas extraction wells that produce 300ft 3 /min of LFG that is sent to a local high school where 12 microturbines use it to produce 369KW of electricity. Together with recovered heat it meets most of the energy needs of the high school. The HOD landfill in Antioch Illinois is a superfund site consisting of approx. 51 acres of landfill. In 1998 the EPA issued a Record of Decision (ROD) that required specific landfill closure activities. It also required the installation of a LFG collection system. The system has 35 dual gas extraction wells that produce 300ft 3 /min of LFG that is sent to a local high school where 12 microturbines use it to produce 369KW of electricity. Together with recovered heat it meets most of the energy needs of the high school.superfundRODsuperfundROD

14. Cal Poly Biogas Case Study p299 An interesting application of biogas in farming. Done by Cal Poly Univ. in California. Converts animal waste to heat and electricity using a microturbine. A farm with 300 cows and other animals kept the cows in a barn with a concrete floor. The manure is periodically washed into covered lagoons where it creates methane gas by anaerobic digestion. Digested biogas from the lagoon is compressed and dried in a desiccant tank and is then used by a Capstone 30KW 440V microturbine that is connected to the grid. An interesting application of biogas in farming. Done by Cal Poly Univ. in California. Converts animal waste to heat and electricity using a microturbine. A farm with 300 cows and other animals kept the cows in a barn with a concrete floor. The manure is periodically washed into covered lagoons where it creates methane gas by anaerobic digestion. Digested biogas from the lagoon is compressed and dried in a desiccant tank and is then used by a Capstone 30KW 440V microturbine that is connected to the grid. The project cost $225K and produces $16K annually in the value of electricity and heat it produces.. This gives it a financial payback of about 14 years.

15. Biomass Energy p301 For thousands of years people have used biomass in the form of burning wood for heat and to cook food without impact to the environment. Plants remove CO2 and replenish O2 and the system was in balance. The rate at which CO2 and other gasses are being produced in modern times may be a source of concern. The use of biomass energy such as plants, agriculture waste, forestry and lumber residue, commercial and industrial waste help to offset theses concerns. For thousands of years people have used biomass in the form of burning wood for heat and to cook food without impact to the environment. Plants remove CO2 and replenish O2 and the system was in balance. The rate at which CO2 and other gasses are being produced in modern times may be a source of concern. The use of biomass energy such as plants, agriculture waste, forestry and lumber residue, commercial and industrial waste help to offset theses concerns.

16. Biofuels Production p302 There are several processes used to create Biofuels: PyrolysisPyrolysis: a method of processing a base fuel to produce a more efficient one. Involve the heating of the original fuel material in the absence of air to temps of 300-500°C until the volatile matter has been evaporated. The residue is often charcoal which has about twice the energy density of the original material and burns at a higher temperature. Pyrolysis A thermal degradation of carbonaceous material in an oxygen-free reactor. Pyrolytic oils, fuel gas, chars, and ash are produced in quantities that are highly dependent on temperature, residence time, and the amount of heat applied. A thermal degradation of carbonaceous material in an oxygen-free reactor. Pyrolytic oils, fuel gas, chars, and ash are produced in quantities that are highly dependent on temperature, residence time, and the amount of heat applied.

17. GasificationGasification: based upon the extraction of flammable gas mixtures of hydrogen, carbon monoxide, methane, and other nonflammable by-products from coal and wood. The process involves partially burning and partially heating the biomass in the presence of charcoal. When produced, gases are compressed and liquefied a d used as a substitute for gasoline. Such fuels generally reduce the power output of a car by about 40%! Gasification Synthetic FuelsSynthetic Fuels: Made by a gasification process that involves oxygen rather than air. Produces mainly H2, CO, and CO2. When the CO2 is removed the remaining is synthetic gas. Synthetic Fuels

18. EthanolEthanol: A very high energy fuel used as a direct substitute for gasoline. The fuel that is produced from fermentation of the sugar solution left over in the sugar cane or beet harvest; has been successfully produced in large quantities in Brazil Ethanol

19. Some Interesting Facts About Bioenergy p306 According to the CEC, California produces 60 million tons of biomass each year, only 5% of which is burned to generate electricity. If all of it were burned; 2000MW or enough energy for 2 million homes would be produced. According to the CEC, California produces 60 million tons of biomass each year, only 5% of which is burned to generate electricity. If all of it were burned; 2000MW or enough energy for 2 million homes would be produced. As of 2010 biomass provides about 3-4% of the U.S. energy needs. By 2020 this is expected to be 7%. As of 2010 biomass provides about 3-4% of the U.S. energy needs. By 2020 this is expected to be 7%.

20. Biodiesel p307 Considered one of the most promising alternatives to petroleum based diesel fuel. Looks like yellow cooking oil. It is made from vegetable oil or animal fats. Chemically it is a combination of long chain fatty acids known as monoalkylesters. The process of producing biodiesel is called trans-esterification, which involves removal of esters or fatty acids. Upon completion of the process biodiesel becomes combustible! Considered one of the most promising alternatives to petroleum based diesel fuel. Looks like yellow cooking oil. It is made from vegetable oil or animal fats. Chemically it is a combination of long chain fatty acids known as monoalkylesters. The process of producing biodiesel is called trans-esterification, which involves removal of esters or fatty acids. Upon completion of the process biodiesel becomes combustible!trans-esterification Biodiesel has a flash point of 150°C. Gasoline has a flash point of 45°C, and petroleum has a flashpoint of 64°C. OSHA classifies biodiesel as a non- flammable liquid. Biodiesel has a flash point of 150°C. Gasoline has a flash point of 45°C, and petroleum has a flashpoint of 64°C. OSHA classifies biodiesel as a non- flammable liquid.

21. Fluidized Bed Boilers p309 Based on a mixture of limestone and coal. The limestone acts as a sponge to absorb the sulfur and other pollutants in the coal. As coal burns in a fluidized bed boiler. It releases sulfur; however the tumbling action of the limestone around the coal captures the sulfur. The chemical process of the limestone capturing the sulfur results in calcium sulfate powder that can be removed from the boiler. The calcium sulfate can then be used in the production of drywall for construction. Fluidized boilers can burn very “dirty” coal and remove 90% of the sulfur and nitrogen pollutants. Based on a mixture of limestone and coal. The limestone acts as a sponge to absorb the sulfur and other pollutants in the coal. As coal burns in a fluidized bed boiler. It releases sulfur; however the tumbling action of the limestone around the coal captures the sulfur. The chemical process of the limestone capturing the sulfur results in calcium sulfate powder that can be removed from the boiler. The calcium sulfate can then be used in the production of drywall for construction. Fluidized boilers can burn very “dirty” coal and remove 90% of the sulfur and nitrogen pollutants. Over 300 installations of fluidized boilers are in use in the U.S. Over 300 installations of fluidized boilers are in use in the U.S. See this DOE article on fluidized bed boilers See this DOE article on fluidized bed boilersfluidized bed boilersfluidized bed boilers