Biodiesel

BiodieselBasil Khan, James Hohman, Max Mueller

ME 539 Internal Combustion Engines, Summer 2015

Introduction

Introduction

Biodiesel is an alternative fuel to petroleum derived diesel.

Biodiesel can be made from variety of feedstocks.

Biodiesel Feedstock

Animal FatsAlgae

Vegetable Oils

Technically

Biodiesel is comprised of “long-chain alkyl esters”

Manufactured by “chemically reacting lipids with an alcohol producing fatty acid esters”

Specifically meant to be used in standard diesel engines NOT alternative fuel converted diesel engines.

Space-filling model of methyl linoleate, a common molecule in

soybean produced biodiesel

Technically

Rated by the B-system, indicating ratio of bio- to petrol- diesel.

B100 = 100% Biodiesel.

B20 = 20% Biodiesel / 80% Petrodiesel.

Most standard diesel engines can run up to grade B20 with no or minor modification.

>B20 and engine will require modification to prevent damage or maintenance issues.

Fuel Properties

Biodiesel similar to Petrodiesel, but some differences.

Lower caloric content

Increased lubricity

Improved burn properties

Increased Water and Hygroscopic Properties

Increased Viscosity

Overall, one parameter does not give a clear picture of performance.

For instance, caloric content is 9% lower than petrodiesel, BUT increased lubricity and better combustion properties compensate.

Why Biodiesel?

World population growing

Existing population moves towards industrialization and modernization

Energy security and environmental impact become paramount

Fossil fuels exist in finite supply

The Psychopaths

Maintaining the empire requires vast expenditure of human lives and financial capital

Perpetual wars are

extremely profitable to the geopolitical elite

and the military industrial complex

Normal, less psychopathic humans see benefit of reducing dependence on foreign oil

History

History

Amazingly, “biodiesel” was invented 40 years before the invention of the diesel engine!

Biodiesel is created via transesterification process.

Patrick Duffy created the first “biodiesel” in 1853.

Rudolph Diesel invented the Diesel engine in 1893.

In that time, French Government Empire requested diesel engine be made that ran on arachide (peanut) oil.

Because their imperial African colonies were rich in peanuts.

Production

Transesterification

Biodiesel is produced from vegetable or animal oil feedstock in a transesterification reaction where the orgranic group of an ester is replaced with the organic group of an alcohol.

Don’t ask me what that means.

Transesterification gives the fuel combustion properties similar to diesel.

Production Levels

2006 biodiesel production was 6 million metric tons (mt).

Total global diesel use 490 million mt.

Total global vegetable oil production 110 million mt.

Production is small relative to demand.

But, sustained growth of 40% per year between 2002-2006.

Continued investment and research means biodiesel will make significant inroads in the future.

Economic Analysis Biological organisms, logistic-chain nightmare—

determining total economy of the crop is difficult.

Conversion of food crops to fuel crops has severe impact on developing economies.

Which feedstock produces optimal yield?

How much land and water use required?

Various Feedstock Yields

Vegetable Feedstock

Soybean, jatropha, and rapeseed are some of the main candidates for biodiesel production.

As stated earlier soybean seems illogical as a candidate due to it requiring more fossil fuel to cultivate than it yields.

Rapeseed is a cabbage-like vegetable.

The yield is excellent 12.5-16.5x the fossil fuel inputs.

France and others have invested in rapeseed production.

Vegetable Feedstock

Jatropha is promising as it is poisonous and not a food crop.

Does not compete in fuel-food dichotomy of other stocks.

Natural toxicity means it behaves as a natural pest repellant and can augment existing food crops.

Hardy, grows well in marginal lands.

Analysts predict jatropha will increase output capacity by 200-300% over the next 10 years.

Animal Feedstock

Raising animals or catching them is not a viable means to produce biodiesel as it is resource intensive.

However, with existing livestock economy, the immense waste of animal carcasses can be reprocessed into biofuel.

This energy production can be fed back into the rendering plant, reducing the energy requirements.

Tyson chicken is building a $5 million plant, that will produce 3 million gallons of biodiesel from 2.2 billion pounds of chicken waste annually.

Algae Feedstock

Current research indicates algae is promising.

Not a food.

Does not compete for arable land.

Does not require potable water.

Can have dual use: sewage wastewater treatment and biofuel generation.

Algae strips wastewater of excess nitrogen and phosphorus.

Algae sequesters heavy metals from wastewater.

Comparison of Feedstocks

To supplant global diesel usage would require land area 2x the United States for soybean, or x for rapeseed.

Again contradicting data—soybean requires 27% more fossil fuel to cultivate than biodiesel it yields.

However, rapeseed crops produce 12.5-16.5 L per 1L petrol.

Research on algae indicate it may produce 30x more energy per acre than soybean.

Chemistry of Biodiesel

Chemical Composition of Diesel and Biodiesel

Diesel

Hydrocarbon

Fractional distillation of crude Oil

Biodiesel

Hydrocarbon + Methylester

Transesterification of vegetable oil/ animal fat

Chemical Composition of Diesel and Biodiesel

Properties of Diesel and Biodiesel

Ideal Combustion Reactions of Diesel and Biodiesel

Diesel

Energy Content= 43 MJ/Kg

Biodiesel

Energy Content= 38 MJ/Kg

Biodiesel in an Internal Combustion Engine

Fuel Spray Characteristics Higher viscosity, surface tension and density

Inhibit atomization

Narrower spray angles

Longer spray tip penetrations

Longer breakup times

Wear Performance

Replace plastic parts with durable elastomers

Significant lubricity

Engine Output Performance

Less heating value

less power output

Greater fuel consumption

Emission Analysis

Higher NOx emissions

Oxygen in fuel

Advanced injection timing

causes higher temperatures

Resolve with additives,

pre-injection and EGR

Lower HC emissions

Sustainability and Prospects

Alternative fuel must be desirable by consumers and producers

Its strengths must overcome its weaknesses

Government Induced Sustainability

Biodiesels are not currently able to compete with Petroleum in capitalistic market.

Government credit $1 per gallon sold

Future Prospects To be sustainable, there must be an increased

supply of biodiesels on the market

The higher the supply, the lower the market price

Future Prospects

The price differential between blended biodiesel and petroleum has decreased

This increases demand for biodiesels

Conclusion

Biodiesel is:

Less powerful than petroleum

More environmentally friendly

Competitive on the consumer market

Increasing its production rates