Sunday, 14 May 2017

Ethanol as a fuel intro

Ethanol as a fuel source

Introduction: The world as a fuel consumer
The world is growing larger and larger, and as the population is increasing, so are the demands. From cars to jets, the world is dependent on one thing: fuel. Fuel is used to power our cars to get to work and back, to transport tourists to other countries around the world and of course to send rockets into space. As our demands get larger, so must the supply. Petrol for our cars come from the extraction and processing of petroleum, which produces a variety of different hydrocarbons useful for different purposes. This process has been utilized for decades, and petroleum levels from the ground are dropping as this non-renewable resource is extracted at higher rates as time passes to supply our demand. The processing of petroleum is also an extremely environmentally unfriendly method as large amounts of CO2 emissions are subjected into the air each year. This has lead scientists and engineers to research and explore into alternative methods of producing fuel, both a renewable and more environmentally friendly way. Researchers have discovered a debatable new source of fuel, ethanol, which can be produced from plants (biomass) to provide a cleaner and more renewable source of fuel.


How ethanol is produced
Ethanol can be produced from biomass through a sequence of steps and processes. Biomass includes plants, crops and all organic matter, which contain cellulose, an important material in the production of ethanol. Around the world, countries use different crops to produce ethanol, including corn and sugar cane. Sugar cane is widely used to many countries such as Australia and Brazil.

Sugar cane is usually planted at a large scale across farmlands and fields. When the sugarcane is ready, the sugar cane is harvested and transported, both processing usually involving machines and vehicles. The sugar cane is transported to a mill, where it is cut and crushed and mixed with water. It is then milled, where it produces a juice in which %10-15 of sucrose is extracted. The juice contains many unneeded components, and the next step is to extract glucose from the mixture. This is done by the process of clarification, in which the juice is heated to 115 degrees and treated with lime and sulfuric acid. This precipitates the mixture and produces glucose. %10 molasses is also added to further enrich the quantity of the sucrose in the mixture.

The next step in the sequence is the process of fermentation.
C6H12O6   ------->      2CO2   +     2C2H5OH
Glucose   yeast  carbon dioxide       ethanol
In this final process, the fermentation reaction of glucose to ethanol is undertaken. In this process, yeast is mixed with glucose. The yeast acts as a mandatory catalyst to produce ethanol and carbon dioxide from glucose. The yeast must meet certain requirements and conditions in order to stay alive and produce the ethanol. The yeast needs anaerobic conditions, in which no air is supplied to the yeast, and the temperature should be around 30 degrees  in order for the yeast to live. Since this reaction is exothermic, it is important for the engineers and scientists to make sure that the conditions are met by keeping a temperature and oxygen appropriate environment for the yeast.
Long description below

Why we need a different fuel source; ethanol.
As mentioned above, fuel is a major aspect of our day-to-day life. Everyone needs fuel for a variety of reasons, the most prominent being car users. This demand is only getting bigger with the 1.05 billion cars around the world. Current fuels including petrol, which is processed from petroleum through a variety of steps. These steps are quite expensive and most importantly: non renewable. It is estimated that petroleum will run out in only 50 years, which means newer generations will need to find an alternative fuel source. It is extremely vital that a renewable energy source is found. Additionally, current methods of processing and extracting petroleum prove to be extremely environmentally unfriendly, as large amounts of carbon dioxide are pumped into the air. There is also big risks of oil spills while transporting the oil on sea, causing damage to marine life and native aquatic organisms. Other risk such as fires and injury whilst operating the dangerous machinery are also quite common.
Ethanol has recently become one of the latest new alternative consideration for a new fuel source. It has a range of benefits which could overpower our current non-renewable fuel sources. Currently, the ethanol can and has been implemented by many countries as a fuel extender in the form of E10. This is a mixture of fuel and ethanol, usually 10% ethanol, which can extend the life of our petroleum levels by mixing a renewable, cleaner component in our gas tanks. In the future, there are possibilities that ethanol can completely replace petrol. But why exactly do we specifically use ethanol as a fuel extender, and hopefully, a fuel source soon, instead of other known fuels? Well ethanol is environmentally friendly. It does not produce any harmful, deadly or toxic fumes such as sulfur dioxide in the air. The process of fermentation however does produce CO2, but this process produces low amounts of CO2, similar to how much plants do during photosynthesis, and therefore no excess CO2 is being emitted. Additionally, the effects of spills or accidents when dealing with ethanol are non existent, as ethanol is a risk free, non toxic and safe chemical to work with. One of the most important factors of ethanol is the fact that it is extremely renewable. Ethanol, as explained earlier, is created through a process of fermentation, which involves the use of glucose. Glucose is a sugary substance which derives from cellulose, which means that any organic material, including plants, crops, stalks, etc, which contain cells walls can be made into ethanol! All plants contain cell walls which means there is an extremely large amount of potential fuel around us every minute of the day. People can continuously grow crops and use them to ferment ethanol for an extremely long time. Alternatively, left over biomass which is not needed can be recycled and sent to processing plants to create ethanol. Even waste products of organic material can be used to make ethanol.


As mentioned above, this new fuel source comes with a range of different benefits and advantages against other sources of fuel such as petroleum. Ethanol as a fuel has been quite successful in some areas around the world. Many countries have slowly switched to using ethanol as a fuel extender, such as Australia, USA and Brazil. Brazil has also opted for even larger ordeals with ethanol. Brazil is considered to have the worlds first sustainable bio-fuel economies, and has extensively invested in ethanol production through sugar canes. It is the second largest producer of bio-fuel. This has greatly decreased the CO2 emission levels by Brazil and has created a safer environment for Brazil. This is one of the most prominent example of a successful story utilizing ethanol as a fuel.


Should we use ethanol as a fuel source?

Ethanol has the potential to be an extremely good source of fuel for its range of benefits discussed above that follows it. Although this organic fuel source comes with its benefits, it also has limitations or disadvantages that comes with it. These are the advantages and disadvantages of both the current use and the potential use of ethanol as an alternate fuel source, all in one neat reading.

Advantages:

1) Ethanol is renewable: Glucose, the component used to ferment ethanol and use as a fuel, is extremely abundant and renewable, as it is present in all organic matter including plants and crops. Crops can be specifically grown to produce ethanol or left over organic matter such as crushed leaves or unwanted plant stalks can be recycled and used to make more ethanol for fuel.

2) Ethanol is environmentally friendly: The production of ethanol is generally clean, exhibiting minimal use of dangerous chemicals and does not emit dangerous fumes either. The production of ethanol however does produce CO2 at the fermentation stage, but this is process produces minimal CO2 emissions as plants produce the same amount during photosynthesis, meaning that no excess CO2 is being emitted.

3) Easily accessible: Unlike petroleum, which must be extracted from different areas each time, usually deep areas underground or underwater using heavy and expensive machinery, ethanol can be made from plants grown on land. Even left over recycled plants can be used to produce ethanol.

4) More jobs in the future: The production of ethanol involves a series of different processes, equipment and manual labor. Crops must be harvested, cut and transported which can provide jobs for manual handling workers. The creation, construction and maintenance of equipment used to process the ethanol production at different steps would also provide more jobs for a country. Additionally, scientists and engineers can be hired to make the entire process more efficient.

5) Minimizes the effects of global warming: Since less carbon dioxide is being produced compared to the combustion of petroleum, less CO2 will be emitted and the effects of global warming will be significantly decreased.

Disadvantages:

1) Requires a large amount of land: Large amounts of land must be dedicated to planting crops which will later be used to make ethanol (ethanol crops). This can lead to starvation as existing farmlands used to feed the population may have to be switched for ethanol production, especially if in the future, ethanol is completely replaced with petrol as opposed to being mixed with it, such as E10.

2) Can be quite expensive, both now and later: Some of the processes in the production of ethanol, including the breaking down of cellulose into glucose, can prove to be quite expensive as it is a process which require a high amount of energy and therefore money. The large amounts of crops needed can also be expensive as fertilizers, water and manual labor is needed to maintain the farmlands.

3) Petrol-ethanol mixture damages engine: The petrol-ethanol mixture used as a fuel extender can cause problems with the engine, as it increases the engine wear during combustion. This can cause many cause to be damaged and become dangerous on the road overtime, as well as increase maintenance costs on car owners.

4) New engine model required: Some variants of petrol-ethanol mixtures, especially if a %100 ethanol mixture was to be used, would require the design and implementation of a new engine model into every automobile. This can lead to complications and high costs of replacing existing engines or implementing the new engine model into future car designs.

5) Lower heat combustion compared to petrol: Compared to petrol, the energy created by burning one mass of ethanol compared to petrol is significantly lower. This means a larger amount of ethanol is needed to produce the same amount of energy which means ethanol as a fuel can be considered less efficient at energy production compared to petrol.

Conclusion
After much debate and research, followed by the review of both the advantages and disadvantages, it can be concluded that a compromise between the two arguments should be made. Since ethanol is a renewable, environmentally friendly and employment encouraging way of creating fuel for our cars, it should more than certainly be utilized in society. However, since it does bring with it limitations such as large amount of land required and large expenses, ethanol should not be used as a complete alternate petrol, but instead, as it has been, a fuel extender. Ethanol should be blended in petrol like it is currently in the world, and extend the life of our plummeting levels of petrol. In the future, new methods, research and science may just be able to make ethanol completely replace petrol as a source of fuel, but until then, we should utilize it at what its most efficient at, extending the life of our existing fuel to decrease pollution.





Sources/references:

"Ethanol As An Alternative Car Fuel - Easychem - The Best HSC Chemistry Notes, Syllabus Dot-Points, Past Papers And Videos". Easychem.com.au. N.p., 2017. Web. 15 May 2017.
http://www.easychem.com.au/production-of-materials/renewable-ethanol/ethanol-as-an-alternative-car-fuel

"Ethanol Fuel In Brazil". En.wikipedia.org. N.p., 2017. Web. 15 May 2017.
https://en.wikipedia.org/wiki/Ethanol_fuel_in_Brazil#Environmental_and_social_impacts

"What Is Ethanol Fuel And Advantages And Disadvantages Of Ethanol - Conserve Energy Future". Conserve Energy Future. N.p., 2017. Web. 15 May 2017.
http://www.conserve-energy-future.com/ethanol-fuel.php

"7.2 Sugarcane Ethanol Production | EGEE 439:". E-education.psu.edu. N.p., 2017. Web. 15 May 2017.
https://www.e-education.psu.edu/egee439/node/647

"Ethanol Fuel". En.wikipedia.org. N.p., 2017. Web. 15 May 2017.
https://en.wikipedia.org/wiki/Ethanol_fuel

"Alternative Fuels Data Center: Ethanol Fuel Basics". Afdc.energy.gov. N.p., 2017. Web. 15 May 2017.
http://www.afdc.energy.gov/fuels/ethanol_fuel_basics.html



Production of materials booklet provided in class was also used
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