Best Process to produce ethanol from Cellulosic Biomass

[Amelia]

I strongly believe in the prospects of cellulosic ethanol as a biofuel and would like to know the best process to derive ethanol from cellulosic biomass such as sawdust, corn stover and agricultural waste..

Thanks in advance!!

[sreevatsansumukhi]

I strongly believe in the prospects of cellulosic ethanol as a biofuel and would like to know the best process to derive ethanol from cellulosic biomass such as sawdust, corn stover and agricultural waste.

Cellulosic ethanol has indeed got a grewat future and there are a loads of companies working on cellulosic ethanol.. Each company produces its own enzymes, devises its own processes to derive cellulose based ethanol..

Here is an example of the cellulosic ethanol leader - Iogen and its technology ..

Generally, the conversion of cellulosic ethanol involves three steps. The technology employed by Iogen has been explained briefly in the preceding paragraphs.

Activation step
Biological conversion
Product recovery

The first step involves converting the raw cellulosic biomass into reactive intermediates. This is either by pretreatment, enzymatic hydrolysis, acid hydrolysis or gasification. Studies reveal that pretreatment and enzymatic hydrolysis serves to be the cheapest method in the activation step.

Companies like Iogen, who are world leaders in cellulose ethanol, have developed an efficient pretreatment method such as steam explosion. This method increases the surface area and the accessibility of the plant fibre to enzymes. This modified steam explosion process has not only improved the ethanol yields over the years but also has increased the pretreatment efficiency as well as reduces the overall cost.

Iogen produces some highly potent and efficient cellulose enzyme systems by themselves and those are tailored to the specific feedstock. This is followed by fermentation. Iogen has also developed reactor systems which have proved to fabricate high productivity and high conversion of cellulose into glucose. They have been able to do through a multi-stage hydrolysis process.

Again, I would like to highlight the fact that companies such as Iogen uses advanced microorganisms and fermentation systems which convert both C6 and C5 sugars to ethanol. This results in what is called “beer”. Further distillation is required to produce cellulose ethanol to be used as a fuel.

The last step involved is the process integration wherein energy efficient heat integration,
water recycling, and co-product production are performed to make the overall process economical as well as efficient.

[Amelia]

Thanks a lot for the information.. Does this company work specifically on cellulosic ethanol.. What feedstock does it use? Any idea??

[sreevatsansumukhi]

Iogen’s demonstration plant uses wheat straw, other potential feedstocks have been researched:

Corn stover
Switch grass
Miscanthus (elephant grass)
Oat/barley straw
Sugarcane bagasse
Hard wood chips
To be used with Iogen's cellulosic ethanol process, a feedstock must have at least 60% carbohydrate content, and to remain cost effective, must be available in large quantities. Also, soft wood is not compatible with Iogen’s technology)

[Lucy]

[quote][/quote]
Iogen produces some highly potent and efficient cellulose enzyme systems by themselves and those are tailored to the specific feedstock. This is followed by fermentation. Iogen has also developed reactor systems which have proved to fabricate high productivity and high conversion of cellulose into glucose. They have been able to do through a multi-stage hydrolysis process.

Thanks once again. You said that they produce enzymes on their own.. Are they genetically engineered enzymes ?

[sreevatsansumukhi]

“Genetically modified organisms” is a term used to describe many different biotechnologies, some of which are controversial. The enzymes Iogen manufactures are all natural enzymes, made by the fungus, Trichoderma reesei.
This production organism is classified as Risk Group 0, and therefore offers no risk to human health. Iogen’s process will have no impact on the ecosystem or the food chain.

[greeni]

Hi Ya,

I would like to know if all companies i.e. researchers and companies working on cellulosic ethanol production - do they use only genetically modified species for the bioethanol production...