About chemical engineering blog

March 22, 2011 1 comment


Due to social media and internet boom around the world, i decided to make chemical engineering blog so that i can share my ideas and bit of knowledge that i have  with you my friends…

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Ethanol…..Blessings and disasters!!!

February 2, 2011 2 comments

let me tell you little bit about the brief history of this precious chemical.It was 1898 when first commercial process for its production  was developed and once again the Germans were up to the mark.That  process involved the dilute acid hydrolysis ( the cellulose possessed  by cellulosic material was converted to glucose first and then glucose  was further converted into ethanol ).Though the conversion efficiency was very low around 18 gal/ton but Germans soon developed an optimized process yielding around 50 gallons of ethanol / ton of biomass.Soon after Americans developed a single stage dilute sulfuric acid process but the yield was 50% less than the original German process.
The process keep itself improving day by day.But the last two decades  brought some real discoveries in this field.It was enzymatic hydrolysis process which revolutionized the production process.With the improvement in enzyme technologies we are able to extract good amount of ethanol from biomass but you know There’s always room for improvement.

Let me tell you briefly about the production methods which the world is using these days….

  • Cellulysic process
  • Gasification process

Cellulysic is basically the more conventional method of manufacturing ethanol.It requires hydrolysis in first stage and then fermentation to produce ethanol.In the gasification process biomass is gasified which produces carbon mono oxide and hydrogen.Then CO and H2 are reacted together to form ethanol.

Back to our topic, let we analyze the advantages and disadvantages of C2H5OH.

Ethanol as a fuel

Ford Motor Company has created the first hybrid vehicle that runs on an ethanol blend, the Escape Hybrid E85. The hybrid is able to run on a blend of gasoline and up to 85 percent ethanol very high percentage, a clean-burning, corn-based additive.

Ford says that if just 5 % of the U.S. vehicles were powered by hybrids operating on E85 ethanol, oil imports could be reduced by about 140 million barrels a year, very large amount!!. The E85 hybrid produces 25 percent less carbon dioxide (CO2) than a gasoline-fueled Escape Hybrid.(Ford sources)

Let we analyze deeply ethanol as a fuel….

The world is buzzing with E85 after EPA has approved this blend.But are we focusing on source where it is coming form. Ethanol is mainly produced from sugar cane and corn grains and both are major ingredients in our diet as well as animal source feed. The years 2007–2008 saw sharp shoot up in world food prices, creating a global crisis and causing political and economical instability and social unrest in both poor and developed nations. Between 2006 and 2008 average world prices for rice rose by 217%, wheat by 136%, corn by 125% and soybeans by 107%.In late April 2008 rice prices hit 24 cents  (U.S.) per U.S. pound  more than doubling the price in just seven months. Interestingly nearly all of them are major sources for the production of ethanol these days. The 2007–2008 world food price crises  is blamed partly on the increased demand for bio fuels.

see production process of ethanol from corn

 

Will the production of ethanol lead to food shortage?

Ethanol use as a fuel has gained a lot of importance in the present era. Recent studies report that ethanol production doubled in the past three years. Corn is one of the most effective components in the production of ethanol. On the other hand corn is important to nourish both livestock and people. This raises a question, what happen to people and livestock when farmers sell their harvest for ethanol production for sake of more profit? Increased production of ethanol has disturbed the agriculture economy because there exists a strong link between energy and feed markets.

A group of researches have a opinion that ethanol production from corn is contributing to global food crises. Some People are also criticizing government policies that are in favor to promote ethanol consumption as a fuel for future. They have a point of view, “the available land for food crops is used to grow feedstock for bio fuel”Many economists come out against ethanol-increased production; they label bio fuel production from such food items as “ a battle against mankind”.

Supporters of bio fuel production say such discussions ignore the other variables that are involved in food crises. They argue that world has a plenty of food to feed the people. The present food crises exist in only such countries that are politically unstable. Corn is not the only source that is used in ethanol production. Cellulosic ethanol can be made from paper pulp, agriculture waste products such as corn stover, citrus and also from switch grass, rice straw

Now it’s up to us, what will we choose? Either bio fuel production or feed the world

EPA Green lights:

It is know considered as “important first step” to use ethanol  blend.EPA has given green signal to raise the mixture from E10 to E15.This decision will be applied to 42 million vehicles in US.It mean that this decision will be applied to nearly 50% of total vehicle fleet in US.Mo rover it will provide jobs and reduce our oil dependence.

But EPA has also announced some limitations as well.it says that this blend will only be charged in newer vehicles which will eliminate most of the older road machines.They are around 62.8 million sharing around 25% of total light duty vehicles in US.It means that they are neglecting very large percentage of global warming bombs!

Ethanol fuel will cost you more

let us look at the ground facts about ethanol as it takes 115 British Thermal Units (BTU s) to produce 100 BTU s of power. In simple words one gallon of ethanol produces only 76,000 BTU s of energy, whereas a gallon of gasoline produces 116,090 BTU of energy huge difference!. You will have to buy 1.53 gallons of ethanol to 1.00 gallon of gasoline to run your car and get the same power.

Is EPA ignorant of the ground facts??

The term “net energy” is extensively used by our green energy specialists these days.Net energy means that how much energy is required to produce specific amount of ethanol. No doubt that it is environment friendly and can reduce GH gasses.But have they ever made calculations that how much energy is required to produce on gallon of ethanol and what is the source of energy we are using in production process?

let we analyze…

According to Cornell University professor of agriculture David Pimentel producing ethanol actually creates a net energy loss.According to calculations
1 gallon(3.7 liters) of ethanol contains 77,000 BTU of energy right but to make 1 gallon of ethanol we require 131,000 BTU of energy!!!

Now come towards the fuel source…

what is the nature of fuel we are burning to produce ethanol these days.Most of the plants these days are operating on fossil fuels like gasoline and diesel.when we burn these fuels to produce ethanol we already have polluted the environment before the ethanol come into our engines.

I am not against this technology but this process is not very energy efficient at this stage to be commercialized.Yes in future when the technology will grow up, this process will become energy efficient hopefully.but at this stage i don’t agree with EPA about the commercialization.

Ford says that if just 5 % of the U.S. vehicles were powered by hybrids operating on E85 ethanol, oil imports could be reduced by about 140 million barrels a year, very large amount!!. The E85 hybrid produces 25 percent less carbon dioxide (CO2) than a gasoline-fueled Escape Hybrid.(Ford sources)
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