Ethanol: Liquid Pork, Holy Water or Fields of Gold?

Kris HoffMike ElderXinkai Wu

CE 5212

Introduction The United States' increasing dependence on foreign oil is

widely recognized as one of the nation's biggest problem. One possible solution, ethanol, is a form of biofuel.

Ethanol is grain alcohol, produced from crops of grain and corn. Ethanol helps reduce our dependence upon foreign imports By mixing ethanol with gasoline it decreases the fuel's cost,

increases the fuel's octane rating and decreases gasoline's harmful emission.

However many are opposed to the use of ethanol due to its low energy input to output ratio.

This case study focuses on: Corn and cellulosic ethanol: analyzing the efficiency, economic

issues, environmental impacts, production, the effect on car industry, the current affairs and future concerns of ethanol.

Case Study: Brazil’s ethanol program which has been active longer than any other country’s.

Corn Ethanol

Different Views

“It’s a sinister idea to convert food into fuel”~Fidel Castro

“Renewable ethanol represents a clear opportunity to grow a significant portion of our own fuel locally and begin to break the hold imported fuels have on us.”

~Mike May

Definition

Ethanol - a flammable, colorless, slightly toxic chemical compound, and is often referred to simply as alcohol.

molecular formula -> EtOH, CH3CH2OH, C2H5OH empirical formula -> C2H6O

Corn-Based Ethanol - is ethanol produced from corn through industrial fermentation, chemical processing and distillation

Production

Dry Milling Starts with liquefied cornstarch produced by heating

corn meal with water and enzymes. This starch is converted to sugars with a second

enzyme and then fermented by yeast into ethanol and carbon dioxide.

Wet Milling Separates the germ, fiber and protein from the

starch before it is fermented into ethanol.

Usage

Pure ethanol fuel is not used as a motor fuel; rather it is mixed with unleaded fuel. E85 is 85% ethanol and 15%

unleaded gasoline E15 is 15% ethanol and 85%

unleaded gasoline.

E85 Flex Fuel Vehicles

Benefits Reduce the environmental impacts of

gasoline consumption Renewable Environmentally friendly Cleaner than gasoline Reduces harmful tailpipe emissions Helps U.S. agriculture development Reduces dependence on foreign oils

Problems

Raises corn prices Low efficiency Temporary solution Negative effects on US livestock Use of fossil fuels throughout

production Sustainability Need for ethanol pipeline

Corn Prices

Policies

1990 Clean Air Act Amendments Most recent energy bill

By 2012 the US must use at least 7.5 billion gallons of renewable fuel per year

Currently a push is being made for 15 billion gallons per year

Minnesota law requires change in amount of ethanol in all

gasoline sold in the state from 10% to 20% by 2012

Rise of Ethanol

Rise of Ethanol

Ethanol vs. Gasoline

Cellulosic Ethanol

“To meet President George Bush’s ambitious goal which required to reducing the nation's dependency on foreign oil by producing 35 billion gallons a year of renewable and alternative fuels by 2017, cellulosic ethanol is an attractive alternative”.

What is Cellulosic Ethanol Unlike corn ethanol, which is only

produced from sugars and starches, cellulosic ethanol can be produced from a wide variety of cellulosic biomass feedstock including agricultural plant wastes (corn stover, cereal straws, sugarcane bagasse), plant wastes from industrial processes (sawdust, paper pulp) and energy crops grown specifically for fuel production, such as switchgrass

How is Cellulosic Ethanol Made?

Step 1: Break down cell walls of the raw plant feedstock by thermochemical treatment and make the cellulose accessible;

Step 2: Add enzymes to convert the cellulose and hemicellulose molecules into the simple sugars glucose and Xylose;

Step 3: Convert the sugar into a mixture of ethanol and water by fermentation yeast;

Step 4: Refine and purify the ethanol.

What Are the Advantages of Cellulosic Ethanol?

Abundance: Cellulosic ethanol has no this limit because it use the feedstock such as wheat straw, grass, and wood chips, as the source which is cheap and abundant.

Expected to be less expensive and more energy-efficient than other ethanol because it can be made from low-cost feedstock:

Table 1: Cost (Data Source: Zfacts, 2004)

What Are the Advantages of Cellulosic Ethanol?

The third advantage of cellulosic biofuel is that it will soften impact to world food price

Percentage changes in world prices of feedstock crops under three scenarios (Data source: Rosegrant, M. W et al., 2006)

What Are the Advantages of Cellulosic Ethanol?

The fourth advantage of cellulosic biofuel is that it reduces greenhouse gas emission compared to grain based ethanol

The research done by Farrell A. E (2006) indicated that “GHG (greenhouse gas) emissions from ethanol made from conventionally grown corn can be slightly more or slightly less than from gasoline per unit of energy, but ethanol requires much less petroleum inputs.

What Are the Problems of Cellulosic Ethanol?

Conceptually, it is easy to convert cellulose to ethanol. Scientists have long known how to turn trees into ethanol, but doing it profitably is another matter (Evan Ratliff, 2007).

The problem is that cellulose is a tough molecule to break down.

To deal with this issue, there are three potential methods.

One is advocated by Lee Lynd, who is trying “to create a bacterium that serves as an all-in-one fuel factory, instead of using enzymes to make sugar out of plant material and then using yeast to convert that sugar to ethanol” (Evan Ratliff, 2007).

The second method is to reduce the cost of enzyme mixture by producing the new enzymes which can be much faster.

The third potential method is to try to find the better enzymes.

Case Study: Brazil

1973 – Yom Kippur War OAPEC – Arab OPEC

members,Egypt,Syria

OPEC Oil Embargo US, Western allies, Japan Results – Inflation, explosion in oil

prices

Case Study: Brazil

1975 - National Alcohol Program Programa Nacional do Álcool (Proálcool)

Case Study: Brazil

Objectives of Proálcool

Decrease Brazil’s dependence on foreign oil by replacing gasoline consumption with ethanol consumption

Stimulate economy by producing fuel from local sugarcane as opposed to foreign oil

Case Study: Brazil

Gasohol ~24% ethanol, 76% gasoline All automobile fuel in Brazil

incorporates at least 22% ethanol

E95, E100 – Near pure ethanol Require “flex-fuel” engines

Case Study: Brazil

Between gasohol and high-ethanol content fuels, about 40% of all automobile fuel consumed in Brazil is ethanol

Energy independence – Brazil will export as much oil as it imports, scheduled to be achieved this year

Case Study: Brazil

Corn starch must first be converted to sugar in order for it to be distilled into ethanol – extra process step

Sugarcane is already in sugar form, and it is thus much cheaper to produce ethanol from cane than corn

Case Study: Brazil

US has enacted high tariffs on imported sugar and ethanol in order to protect Midwestern farmers’ corn interests

US cannot domestically produce enough sugarcane for cane-based ethanol to be viable on a large scale

Conclusions Although it is clear in the United States that we cannot

continue to live in the manner to which we have become accustomed with regards to fossil fuel consumption, it is as yet unclear what forms of alternative energy will be used predominantly in order to wean our dependence on foreign sources of oil.

One of these alternatives is ethanol-based automobile fuel.

However, given the tradeoffs with gasoline, mainly fuel efficiency and production cost versus output, it is unlikely that the United States will become independent of Middle Eastern oil as a result solely of corn ethanol.

The future of alternative energy in the United States rather appears to be in cellulosic ethanol, so we must wait and see what that future holds.

Discussions

What forms of alternative energy will be used predominantly in order to wean our dependence on foreign sources of oil?

The future of alternative energy in the United States rather appears to be in cellulosic ethanol, is it true?