Archive for Downsizer For an ethical approach to consumption
 


       Downsizer Forum Index -> Energy Efficiency and Construction/Major Projects
marigold

Scientists say biofuels are...

...bad for the environment . Can't say I'm astonished.

Did anyone hear Costing The Earth on R4 last night? Are mirrors in the desert a better idea?
Northern_Lad

That's not strictly what they said. They said that turning over large patches of land for the production of fuel was bad, but not bad per-say. Same as most industrialisation.
marigold

Do you mean "per se"? (I can be pedantic too Wink )
Northern_Lad

marigold wrote:
Do you mean "per se"? (I can be pedantic too Wink )


Probably.
Tilia

I was watching something the other day about bio-fuels from coppiced willow (I think) - the latest idea to avoid the need to use food-growing land for fuel. There was some sort of grass as well. The main point was to use land that couldn't be used for much else to grow the fuel - or something like that...

Probably not the most helpful info - sorry. Anyone else see it who could fill in the blanks?
Green Man

Biofuel crops are going to be a viable option to landowners when oil gets scarce. I don't know if we will have much control when that time comes.
vegplot

The fossil fuels we're currently using are the result of millions of years of deposition of plants and animals and we've used it up in a very short time, less than 200 years or so. That alone would make me think how on earth can we supply our current fuel and food demands from our available biological resources. I'm sure we can't and I'm also fairly confident we're going to make things worse by trying before we find out we can't.

We have to look elsewhere.
marigold

vegplot wrote:
The fossil fuels we're currently using are the result of millions of years of deposition of plants and animals and we've used it up in a very short time, less than 200 years or so. That alone would make me think how on earth can we supply our current fuel and food demands from our available biological resources. I'm sure we can't and I'm also fairly confident we're going to make things worse by trying before we find out we can't.

We have to look elsewhere.


Quite. And use less. And waste less. The Costing The Earth programme about solar power from the deserts sounded quite persuasive, but I'm wondering if it's another red herring?
Rob R

Pre-industrial revoultion, people moved for resources, now we move resources for people & people for people, it's just got silly & sooner or later the honeymoon perios will run out & thing will regress. Food is fuel & waste is waste.
vegplot

marigold wrote:
The Costing The Earth programme about solar power from the deserts sounded quite persuasive, but I'm wondering if it's another red herring?


I don't think so. It would require huge capital investment though and the technical difficulties are not small. However, it's a well proven technology and there are already large scale installations in place.
Slim

Tilia wrote:
I was watching something the other day about bio-fuels from coppiced willow (I think) - the latest idea to avoid the need to use food-growing land for fuel. There was some sort of grass as well. The main point was to use land that couldn't be used for much else to grow the fuel - or something like that...

Probably not the most helpful info - sorry. Anyone else see it who could fill in the blanks?


Coppiced willow, poplar are both popular. They're actively breeding poplars for this very thing. Already pretty well known in Sweden. I sort of started a preliminary study, with some poplars, and black locusts to fix nitrogen. Still just wee little sprouts right now. Have thought about trying out red maple and maybe an ash to see how well they coppice. The problem is how do you want to use it? Do you want to just cut it into three foot sections and burn it straight, or chip it, or wait for those folks to really perfect the cellulosic ethanol, etc, etc....
vegplot

When doing my MSc there was someone investigating producing wood ethanol using bacteria, a very efficient method but I've not heard any more.
Slim

Yes, there's been lots of advances in it. Grasses are easier as there was quite recently a soil bug discovered that will go directly from cellulose to ethanol. The woody crops are tougher as only one type of fungus can degrade lignin. Lots of folks are working on introducing that gene into bacteria which raises a discussion worthy of its own thread for sure....
Tilia

Yes, that sounds about right. It was still experimental and the main problem was that it wasn't as easy to convert to fuel. I'm sure there was a bacterial element involved somewhere...

I wish I could remember what it was I was watching.
Jamanda

cpg03 wrote:
Yes, there's been lots of advances in it. Grasses are easier as there was quite recently a soil bug discovered that will go directly from cellulose to ethanol. The woody crops are tougher as only one type of fungus can degrade lignin. Lots of folks are working on introducing that gene into bacteria which raises a discussion worthy of its own thread for sure....


I heard on the radio about some guys who were trying to splice a gene for the removal of CO2 into bacteria in a bid to halt global warming. Didn't sound too well thought out to me.
Slim

Carbon isn't just removed... I mean it could use the CO2 for something, but then what has that become? It's called a carbon cycle for a reason
Jamanda

cpg03 wrote:
Carbon isn't just removed... I mean it could use the CO2 for something, but then what has that become? It's called a carbon cycle for a reason


It was specifically atmospheric CO2 that was being removed. Didn't catch how it was to be stored. I'll have to go and look it up now.
cab

vegplot wrote:
When doing my MSc there was someone investigating producing wood ethanol using bacteria, a very efficient method but I've not heard any more.


Not that efficient, but its do-able. Mot really that efficient though because wood is such a complex material, you probably can't ferment it straight down to ethanol from scratch.

cpg03 wrote:
Yes, there's been lots of advances in it. Grasses are easier as there was quite recently a soil bug discovered that will go directly from cellulose to ethanol. The woody crops are tougher as only one type of fungus can degrade lignin. Lots of folks are working on introducing that gene into bacteria which raises a discussion worthy of its own thread for sure....


Heck, there are shedloads of organisms producing lignin degrading enzymes, its just that you won't necessarily get a great deal of ethanol that way. Really, loads of bacteria and fungi can do it, for example lots of filamentous fungi, many actinomycete bacteria, etc. You're looking at lignases, hemicellulases, cellulases... it really is a complex substrate, which is why most biofuel effort has been directed towards simpler substrates, things like wheat, sugar beet, maize, etc. Wood and woody material are perhaps best treated by chemical processes, or thermally (gasification processes). Or, simply, burned.

Tillia wrote:

Yes, that sounds about right. It was still experimental and the main problem was that it wasn't as easy to convert to fuel. I'm sure there was a bacterial element involved somewhere...

I wish I could remember what it was I was watching.


The most common thing done with bacteria, or rather the most talked about process, involves various strains of Clostridium, which can be used to priduce butanol and acetone. If the fermentation is tightly controlled you get alot more butanol than acetone, and butanol can be pumped more or less staight into a petrol tank and used more or less as is, so its the focus of a lot of research effort in biofuels.

Jamanda wrote:
I heard on the radio about some guys who were trying to splice a gene for the removal of CO2 into bacteria in a bid to halt global warming. Didn't sound too well thought out to me.


Carbon sequestration to clean up the outflow from powerstations?
Slim

I've always been taught that white-rot fungi alone can degrade lignin. Here's a quote I nabbed after a bit of googling:
Quote:
Lignin is a natural polymer of the cell wall that gives strength to wood. White rot fungi, which use cellulose as a carbon source, possess the unique ability to degrade lignin completely to carbon dioxide to access the cellulose molecule.


(my emphasis on the unique)

from: http://www.ehponline.org/docs/1993/101-3/innovations.html
Slim

But yes, I agree that wood is best burned or pyrolized. (just what is the past tense of pyrolysis?)
cab

cpg03 wrote:
I've always been taught that white-rot fungi alone can degrade lignin. Here's a quote I nabbed after a bit of googling:
Quote:
Lignin is a natural polymer of the cell wall that gives strength to wood. White rot fungi, which use cellulose as a carbon source, possess the unique ability to degrade lignin completely to carbon dioxide to access the cellulose molecule.


(my emphasis on the unique)

from: http://www.ehponline.org/docs/1993/101-3/innovations.html


Thats a slightly misleading statement, in that I would wager that white rot fungi between them will have more genetic diversity than all mammals put together; they're a pretty broad group. And yes, you may not find any one organism that can do the whole job outside of the white rot fungi (although I seriously doubt that), but I'll bet you could put together a system with two actinomycetes or, better, two actinomycetes and a yeast to do the job faster and more efficiently.
Slim

yeah, but you know us humans, love our monocultures! Very Happy
cab

cpg03 wrote:
yeah, but you know us humans, love our monocultures! Very Happy


Yep, especially in many of the modern fermentations! But if we're going to make biofuels work on the kind of scale needed to even make a small dent, and if it is to be done by microbial processes, then we've got two choices. Lots of expensive systems to do monocultures, to get a guaranteed product every time, or done big and dirty, which means selecting culture conditions to get complex populations of microbes to do the job we want. Its like the difference between making penicillin and making soy sauce.
Ricardo Pronto

You need a different set of fungi/bacteria to breakdown the lignin-cellulose plant material. One of the carbohydrates making up cellose is Xylose. It has 5 carbon atoms. The Sugars the fermenting yeasts, Saccharomyces, convert into ethanol have 6 carbon atoms. Hence research into alternative fungi/bacteria. But I am pretty sure pretreatment to break the biomass down will be needed. An existing route to break cellulose down for fermentation is to pretreat with acids or enzymes.

Cellulose-fermenting organisms can be found in the rumen of sheep, goats and cows but isolates from these habitats only produce low yields of alcohol. Particular interest is now focused on a group of 'thermophilic' clostridia (clostridium) isolated from various locations including compost heaps. Thermophilic or "heat-loving" organisms grow optimally at temperatures between about 50-70 C.

Research is ongoing. The advantages of getting bioethanol from cellulose as opposed to the sugar sap, as you get more biomass per hectare, and so you can use land sutalbe for tree growth as opposed to land for food.

Rich
Slim

Ricardo Pronto wrote:
You need a different set of fungi/bacteria to breakdown the lignin-cellulose plant material. One of the carbohydrates making up cellose is Xylose. It has 5 carbon atoms. The Sugars the fermenting yeasts, Saccharomyces, convert into ethanol have 6 carbon atoms. Hence research into alternative fungi/bacteria. But I am pretty sure pretreatment to break the biomass down will be needed. An existing route to break cellulose down for fermentation is to pretreat with acids or enzymes.

Cellulose-fermenting organisms can be found in the rumen of sheep, goats and cows but isolates from these habitats only produce low yields of alcohol. Particular interest is now focused on a group of 'thermophilic' clostridia (clostridium) isolated from various locations including compost heaps. Thermophilic or "heat-loving" organisms grow optimally at temperatures between about 50-70 C.

Research is ongoing. The advantages of getting bioethanol from cellulose as opposed to the sugar sap, as you get more biomass per hectare, and so you can use land sutalbe for tree growth as opposed to land for food.

Rich


obviously you know nothing about the complexities of which we are discussing! Laughing

Thanks for the input and welcome!
cab

Ricardo Pronto wrote:
You need a different set of fungi/bacteria to breakdown the lignin-cellulose plant material. One of the carbohydrates making up cellose is Xylose. It has 5 carbon atoms. The Sugars the fermenting yeasts, Saccharomyces, convert into ethanol have 6 carbon atoms. Hence research into alternative fungi/bacteria. But I am pretty sure pretreatment to break the biomass down will be needed. An existing route to break cellulose down for fermentation is to pretreat with acids or enzymes.


This all depends on what you think that biofuel production should be about. Is it about the total degradation of plant matter to produce only one product, or is it more about converting some of it for one fuel, then taking the residue and doing something else with it? The economic models don't suggest to me that the complete approach is necessarily the right approach. But, yes, if the goal is the total degradation of plant matter you'll need a more complex approach than feeding it straight to yeast.

I'm not convinced that ethanol is the right target anyway; butanol has a lot to offer.


Quote:

Cellulose-fermenting organisms can be found in the rumen of sheep, goats and cows but isolates from these habitats only produce low yields of alcohol. Particular interest is now focused on a group of 'thermophilic' clostridia (clostridium) isolated from various locations including compost heaps. Thermophilic or "heat-loving" organisms grow optimally at temperatures between about 50-70 C.

Research is ongoing. The advantages of getting bioethanol from cellulose as opposed to the sugar sap, as you get more biomass per hectare, and so you can use land sutalbe for tree growth as opposed to land for food.

Rich


Yep, thats all true. Look out for clostridium, there will be a lot of it about in biofuel production (in one form or another) in the future.
Ricardo Pronto

cpg03 wrote:


obviously you know nothing about the complexities of which we are discussing! Laughing

Thanks for the input and welcome!


It was the Jack Daniels talking Laughing
I'm convinced the demand for ethanol will carry the research forward in these 2nd generation liquid biofuels. Out of interest the UK production whilst small is expanding. I found this on the National non-food Crops Centre website showing operational and planned projects for biodiesel and bioethanol http://www.nnfcc.co.uk/metadot/index.pl?id=5680;isa=DBRow;op=show;dbview_id=2539

Rich
       Downsizer Forum Index -> Energy Efficiency and Construction/Major Projects
Page 1 of 1
Home Home Home Home Home