Lecture 25 Chapter 17 Biomass: From Plants to Garbage

What is Biomass? Energy derived from living matter –Field crops –Trees –Water plants –Municipal Solid Waste (MSW) –Agricultural and Forestry waste

Biomass as a fuel Solid fuels –Wood chips –Plant residue Liquid fuels –Solid conversion by chemical or biological action to ethanol or methanol Gaseous fuels –Produced by high temperature and high pressure processes

Biomass conversion is releasing stored energy from the sun Photosynthesis CO 2 + H 2 O + light energy  2 + carbohydrates Respiration –Reverse of Photosynthesis –Takes place in plants and animals –Plants use photosynthesis during the day and respiration at night –CO 2 concentrations are highest in spring and lowest in fall at the end of growing season

Facts you may have wondered about 20% of 48 states is crop land –Largest crop is corn –Followed by soybeans and oats 30% is commercial forest and woodlands U.S. land base totals 2260 million acres –Could supply 1.3 billion dry tons of biomass/yr –Enough to supply 1/3 of our transportation needs

Processes for conversion of biomass to other energy forms Biochemical processes –Decomposition of organic waste in oxygen deficient environment (anaerobic bacteria) –Controlled fermentation for production of alcohols (ethanol and methanol) Direct Combustion –Burn for fuel to produce space heating or steam power generation Pyrolysis –Thermal decomposition of wastes into gas or liquid fuels

History of Ethanol Ethanol made from grain mixed with gasoline was used with first cars

History of Ethanol Used for lamp fuel in late 1800’s US and Germany used it to fuel vehicles during WWII Limited use in 1950’s and 60’s due to cheap oil 1970’s introduced ethanol again as “gasohol” during oil crisis Recently, Flexible Fuel Vehicles (FFV) became available, E85 6+ million FFV’s on the road today (See NEVC)NEVC

Harvest Grind it Dissolve starch (long chains of glucose) Add Steam Add enzymes to break down starch to glucose. SACCHARIFICATION FERMENTATION Add YEAST converts glucose to ethanol Distillation, collects ethanol Ethanol Production

2 ways of making ethanol: –Dry mill –Wet mill

Ethanol Production Wet mill Steep: breaks corn kernel down into its components

Ethanol Production The key is breaking the cellulose and hemicellulose down into simpler sugars: glucose and sucrose Cellulose, 6 carbon sugar, glucose Hemicellulose, 5 carbon sugars, xylose and arabinose Source: Basics/cell_wall.gif (expired) Sucrose Glucose

Ethanol Production This process can use anything that contains cellulose (wood, sugar cane, corn, paper, etc.) All processes vary in economics and availability Sugar cane Very economical because sugar is easily turned into ethanol Not available – can only be grown in some states A lot of labor needed to grow it

Ethanol Production Economics and availability –Wood, paper, certain grasses Very abundant, can be grown in many places Little work or fertilizer needed Not efficient because not as much sugar available in the wood (more cellulose) –Corn is “in the middle” Able to be grown in many states Not that difficult or labor intensive to grow (compared to sugar cane) Has more sugar immediately available than wood This can be plotted in the following…

Comparison of Economics and Availability ABUNDANT & AVAILABLE ECONOMICAL Corn Starch Switch Grass Paper Sugar Cane Cottonwoods Stover Wood Chips Corn Fiber

Table 17-1, p. 552

p. 552

p. 553

Fig. 17-4, p. 554 See Harold BateHarold Bate

p. 571

Table 17-2, p Hectare = 2.47 Acres

Fig. 17-5, p. 557

p. 557 Southern California Rapid Transit District

Bio-Diesel Three main ingredients –Alcohol –Vegetable oil (soy, palm, corn, canola, peanut, sunflower) –Catalyst Alcohol –Methanol (made from natural gas) –Ethanol (just presented) Usually not used in large scale because of the amount needed and more catalyst needed

Process of Making Bio-Diesel Vegetable oil –The amount oil / acre varies Palm – 4,585 lb oil / acre Soybean – 345 lb oil / acre Corn – 135 lb oil / acre Animal fat can be used in place of oil but: –Need to process –Hard to process

Process of Making Bio-Diesel Catalyst –Used to speed up the reaction –Sodium hydroxide used with methanol –Potassium hydroxide used with ethanol End products –Glycerin (ends up in bottom) –Bio-Diesel (on top) –Needs 8 hours for complete separation

Bio-Diesel – Advantages Any Diesel engine can run on bio-Diesel with little or no modifications Reduces import of foreign oil Cleaner emissions compared to regular Diesel Diesel exhaust smell replaced with that of fried food!

Yield per acre: Algae: 1800 gpa or more (est.- see soy figures and DOE quote below) Chinese tallow: 503 gpa gpa Palm oil: 508 gpa Coconut: 230 gpa Rapeseed: 102 gpa Soy: gpa in Indiana (Soy is used in 80% of USA biodiesel) Peanut: 90 gpa Sunflower: 82 gpa

Bio-Diesel – Disadvantages Results in a 5% decrease in torque, power, and fuel efficiency compared to regular Diesel fuel Not all manufacturers will cover warranty of an engine that used bio-Diesel Bio-Diesel gels more than regular Diesel –Anti-gel agents exist to counteract this Bio-Diesel dissolves rubber parts (fuel lines, etc.) –Vehicles newer than 1993 have synthetic parts and are not affected –Viton good synthetic material replacement of rubber

Fig. 17-6, p. 558 Municipal Solid Waste

p. 559

Fig. 17-7, p. 562

Table 17-3, p. 563

Fig. 17-9, p. 566 Conventional Fireplace

Fig , p. 567 Airtight Stove with Secondary Chamber

Table 17-4a, p. 569

Table 17-4b, p. 569

Table 17-5, p. 570

Table 17-6, p cord = 128 ft 3 = 8' x 4' x 4' stack of wood