Alcohol from Cellulose – A Green Fuel Option

In my recent article on economic downturn I wrote about the stimulus package and the type of projects on which it needs to be used. One of the options I mentioned was the so called green technologies. Here I would like to elaborate a little bit on certain specific areas of green technology requiring funding and attention. The list I have made is only partial. I must also add that the material that follows is strictly meant for the laymen.
All of us will agree that the most important project category requiring huge funding is related to renewable energy source. More specifically,the following technologies could make a very big impact in the coming years when successful:
1.Cellulosic ethanol
2.Algae based Biodiesel
3.Making Solar energy cheaper and making innovative use of solar panels in a way useful to rural and urban electrification
4.Wind energy
5.Energy efficient gadgets/bulbs, making LED cheaper
6.Biodegradable Substitutes for polyethylene / polypropylene
7.Conversion of plastic wastes to liquid / gas fuels
8.Green house gas emission control technologies
9.Biotechnology as a tool for replacing conventional chemical process technologies

Today almost all the above fields are hot areas of research in industries as well as universities the world over.
I will deal with a few of the above areas briefly in the following posts,starting with Cellulosic ethanol in the present article.

Cellulosic ethanol (that is fuel grade ethanol from cellulose) projects are being pursued in the USA like Manhattan Project with a lot of federal funding and through public-private partnerships. $1 billion has been committed and it has been doubled in the recent past. An institute(Energy bioscience institute)was setup at at the university of California(Berkely) with a clear mandate to manage the switch over from corn based ethanol (I will explain later in this article why the switch over is essential) to cellulose based ethanol in 10 years.

What is cellulose? Cellulose constitutes 70% of most of the plants and is present in wood,grass,stem etc. Entire cellulose is non-edible for human consumption.
Briefly,the project involves the use of cellulose as a source for making ethanol. Ethanol is a proven fuel which generates the least amount of pollution(both gaseous and particulate)when burnt in an automotive engine. Today processes exist but are not cost competitive with conventional gasoline(the cost is around $4/barrel versus 1.3 for gasoline). Some plants are already operating although not on big commercial scale. Most of the work is focused on reducing the cost.
The basic issues of technology are:
1.Finding a suitable efficient enzymatic process to breakdown cellulose to glucose
2.Reducing overall cost through innovations in engineering / scale-up.
While hectic research activity is in progress to sort out scientific/technology issues,at least 2 companies have reported commercial plant operations – one is the Ottawa based Iogen and the other is Lousiana based Verenium.

In view of the above developments,my personal view is that we should forthwith stop spending on research,technology and commercial production for converting corn to ethanol.
All of us are familiar with ‘food versus fuel debates’ an year ago when the USA was actively pursuing corn based ethanol projects on a very large scale. While cellulose process uses 70% of the plant(stem,grass,wood),’Corn to ethanol’ process uses only the seed. Obviously,therefore, the latter process would require a lot more agricultural land.
There is yet another disadvantage of the ‘corn to ethanol’ process. The process is not carbon neutral,meaning that there is net carbon dioxide(global warming gas) generation in the process. The main reason for this is that one needs to burn natural gas for distillation(purification) of alcohol formed. In contrast, in the process involving cellulose, the residue left after enzymatic hydrolysis can be used as fuel for distillation of alcohol.

In my next post I will deal with Algae as the source of Biofuel.

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Published in: on March 17, 2009 at 6:46 pm  Leave a Comment  
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