Chemistry - Biofuels

List three advantages of bioethanol instead of fossil fuels.

1. A carbon neutral fuel source due to the infinite cycle of creation and combustion of energy. 2. Effectively inexhaustable since they derive from biomass that is constantly replenished. Fossil fuels are not renewable and will eventually run out. 3. Extremely low sulphur content compared to fossil fuels. Combustion leads to the emission of sulphur dioxide.

Disadvantages of fossil fuels. (carbon dioxide sulphur dioxide, mining, airborne toxins, acidity of ocean, extracted, spillage, millions, releases carbon)

1. Carbon dioxide released is significant and lead to global warming. Also releases oxides of nitrogen and sulphur. Sulphur dioxide prompts the formation of acid rain that leads to the destruction of environments. 2. Mining of fossil fuels destroy ecosystems and habitats. 3. Airborne toxins and pollutants from the widespread of burning fossil fuels is significantly detrimental to human health. 4. Carbon dioxide production affects the acidity of the ocean, leading to the degradation of marine ecosystems, bleaching corals and destroying marine flaura. 5. Extracted at an increasing rate, fossil fuels are infite and will run out within the next 70 years. 6. Spillage of oil in the ocean detrimentally effects nature. 7. Take millions and millions of years to form, they are not renewable. 8. Releases carbon back into the atmosphere.

List two disadvantages of biogas.

1. It is difficult to compress methane to allow for use as a mobile energy source (fuelling vehicles). 2. It is not as versatile as coal which can be transported from continent to continent with ease, as opposed to biogas which must be compressed for long journeys.

Advantages of biofuels. (potentially, sustainable, recycle, degrade, benefit, stimulate, foreign, carbon neutral)

1. Potentially be less expensive since they are effectively everlasting. 2. Considered sustainable as they are derived from biomass that is constantly replenished. 3. Derived from waste materials that is efficient in the recycling pathway and prevents these waste materials from going into landfills. 4. Do not degrade the land as much as fossil fuels. 5. Benefit communities who thrive off farming. 6. Stimulate the agrarian industry 7. Potentially cease foreign dependence on energy. 8. Carbon neutral as biofuels release the amount of carbon dioxide that they absorbed as live organics in the pocess of photosynthesis). However the transporting and processing of biofuels requires energy produced largely by the burning of fossil)

Disadvantages of Fossil Fuels and Biofuels. (Gases, sulphur dioxide, combustion, global warming, emissions, planting)

1. Produes a number of gases, mainly sulphur dioxide, carbon dioxide and nitrous oxide. 2. Sulphur dioxide can lead to the destruction of habitats, poisoning of water bodies and acid rain with the formation of sulphuric acid. 3. Carbon dioxide is the greatest pollutant from the combustion of fossil/bio fuels. 3. Carbon dioxide traps heat in the atmosphere and contributes to the process of global warming. 4. By investing in renewable energy sources such as solar, carbon dioxide emissions could be cut. 5. Planting more carbon dioxide absorbing flora.

Disadvantages of biofuels. (expensive, growth, technology, water, fertilizers, crops, manufacturing, fuel value)

1. Quite expensive to produce as currently there is not much being invested and a small supply. 2. Repetitive growth of one type of plant can damage agricultural land. 3. Technology used is not particularly effective. 4. Require large quantities of water. 5. The fertilizers used can potentially damage the enivronment. 6. The crops for feedstock take up agricultural space. 7. Manufacturing of biofuels means more carbon dioxide and other pollutants emitted. 8. Smaller fuel value than fossil fuels, more energy can generally be attained from a smaller amount of material).

Advantages of fossil fuels. (readily, transportability, produce, store, inexpensive).

1. Readily available as they are fairly easy to find within the Earth. 2. Transportability of fossil fuels means that power stations can be set up in almost any location. 3. Produce large amounts of energy and can be combusted easily. 4. Easy to store as most being unreactive carbon based substances. 5. Inexpensive as they are available worldwide.

List three significant environmental advantages of biogas.

1. methane is a more potent greenhouse gas than carbon dioxide. 2. waste material used prevent landfills and promote recycling. 3. combustion of methane reduces the presence of greenhouse gases and simultaneously produces energy.

How is petroleum made?

1. sea plants and animals buried on ocean floor. covered by layer of sand and sediement. 2. over millions of years, enormous heat and pressure from inside the earth and the rock above turned them into oil and gas. 3. drill down thousands of metres through layers to reach the rock formations that contain oil and gas deposits.

What is a biofuel?

Biofuels are essentially fuels that are derived from organic matter, biomass that replenishes itself on a human time scale that is considered a renewable and sustainable energy source.

What is the combustion of bioethanol?

C2H5OH(l) + 3O2 --> 2CO2(g) + 3H2O(g)

What is the chemical formula for the main component of bioethanol?

C2H6O

What is the chemical formula for the production of bioethanol?

C6H11O5 Enzymatic hydrolysis xC6H12O6 Yeast fermentation CH3CH2OH + CO2

What is the equation for the combustion of Biogas?

CH4(g) +2O2(g) --> 2H2O(l) + CO2(g)

What is petroleum?

Made up of various hydrocarbons. Octane is the major component on petrol.

State the primary use of biogas.

Power generation or heating and cooling.

What are examples of biomass?

Sugar cane, vegetable seeds, other agricultural and animal residues.

Why are ethanol blends (like E10) used instead of pure bioethanol?

The 10% ethanol blend is used as bioethanol attacks some of the materials currently used in car fuel systems. Engines would need modification to run on higher bioethanol blends.

Why are biofuels viewed as having such an important role in our future?

The Earth's fossil fuel resources are depleting at an incredible rate. The need for a sustainable, large scale renewable energy source is paramount to the survival of the human technological condition as it is today. The need for a 'greener' earth is significant for its sustainability.

Describe the production of bioethanol.

The processing of natural feedstock/domestic and agricultural waste. The sugar/starch crop is grown, harvested, crushed and then soaked to separate the sugar part. Yeast is added, the mixture ferments and then the resulting liquid alcohol is purified by distillation. The energy within the biofuel can be directly traced back to that of the sun.

Describe the production of biogas stating clearly the main component of biogas produced this way.

Waste materials such as sewerage are collected and fed into a digester. Anaerobic bacteria feed on orgnic material to form organic acids. The acids are processed by methanogenic bacteria which produces Biogas (methane and carbon dioxide) and a waste sludge.