Enzymatic hydrolysis of cellulose- How do you do it with off the
shelf stuff ?

Appologies if this is the wrong forumn but hopefully someone can steer
me in the right direction.

I have been looking into ways of converting cellulose into Ethanol to
run the car as fuel prices are becoming annoying. The problem is I
don't know a anything about biochemistry. Having said this I have read
as much as I can and would like to give this "Enzymatic hydrolysis of
cellulose" a go.

From what I understand the following is the case :

Cellulose is a long chain of laminar pollysaccarides. Specifically
Glucose.
Because of the tightly packed nature and composition of cellulose you
need several enzymes to b reak it down ;

1. An endoglucanase - random chomps at the chain producing new ends
2. An exoglucanase - a progressive chomp
3. A ß-glucosidase - a break down of the broken bits further to
D-Glucose

Now not being a biochemist I am kind of hoping someone out there knows
what all this means and has a shopping list of stuff that will equate.

Anyone out there know where to get all this stuff or how to do this at
the laymans level ?

Any advice greatly appreciated ...


Steve

In article . com,
wrote:

Appologies if this is the wrong forumn but hopefully someone can steer
me in the right direction.

I have been looking into ways of converting cellulose into Ethanol to
run the car as fuel prices are becoming annoying. The problem is I
don't know a anything about biochemistry. Having said this I have read
as much as I can and would like to give this "Enzymatic hydrolysis of
cellulose" a go.

From what I understand the following is the case :

Cellulose is a long chain of laminar pollysaccarides. Specifically
Glucose.

Right.

Because of the tightly packed nature and composition of cellulose you
need several enzymes to b reak it down ;

1=2E An endoglucanase - random chomps at the chain producing new ends
2=2E An exoglucanase - a progressive chomp
3=2E A =DF-glucosidase - a break down of the broken bits further to
D-Glucose

Yes. And this is such a difficult stunt that very few organisms can do it
on their own. Most herbivores have to use microbes to do it for them.

Now not being a biochemist I am kind of hoping someone out there knows
what all this means and has a shopping list of stuff that will equate.

Anyone out there know where to get all this stuff or how to do this at
the laymans level ?

While it's conceivable that a knowledgable layman could do this on a
kitchen or garage scale, the cost of producing glucose by this method
would be absurdly high. Enzymes are really expensive, and the process
would require substantial effort and care. The result will be sugar,
which you can buy far more cheaply at the supermarket. It's possible
that someone might develop a microbial fermentation system to do it,
but to my limited knowledge, no one has. Industrial ethanol production
starts with sugar or starch, which are extremely cheap if purchased at
an industrial scale.

Any advice greatly appreciated ...

Starting with sugar or starch, it's not at all difficult to produce
ethanol. People have been doing it for millennia with the crudest of
equipment. There are, however, a few problems with this approach as a
money-saver as well. One is that by the time nicely-packaged,
food-quality starch or sugar appear at the supermarket, they'll cost
you a couple of orders of magnitude more per kilogram than an
industrial ethanol manufacturer pays for trainloads of dirty
feedstock. The other is that many governments have laws against
producing substantial quantities of alcohol without special permits and
substantial taxes.

There are a few more approaches you might consider. One is that most
diesel engines can be tuned to run partially or completely on vegetable
oil with minimal (but knowledgable) effort. Vegetable oil is less
energy dense, however, and IIRC, it takes something like 4 liters to
equal 3 liters of diesel fuel. Again, the problem of small scale bites
you in the ankles -- it will be a long time, if ever, before
supermarket vegetable oil is more economic than diesel fuel. Even at
an industrial level, it's iffy -- after all, diesel fuel is used to grow
the plants that provide the oil. If you live near an oilseed crushing
plant, you might investigate whether you can buy oil from them by the
barrel, but I suspect they won't be interested in bothering with such a
small customer. During the oil crunch in 1973, farmers in Manitoba ran
their tractors partly on sunflower oil, but they were the suppliers to
the crusher, and there were a lot of them using a fair bit of oil.

A second approach is generating methane from anaerobic fermentation of
manure and a cellulose feedstock like straw or sawdust. This can work
well on a home scale. It's used in some tropical countries to provide
cooking fuel and gas lighting on small farms. Back in the 1950's or
60's, some people in England adapted their cars to run off onboard
fermentation tanks loaded with chicken manure. Of course, these cars
were small and light, and the distances travelled were generally small,
but it's a tested home-scale technology. It's used on a larger scale
in municipal sewage systems and similar systems on large hog farms.
The methane is used to heat the system in cold climates, to cook hog
swill, or to generate electric power on a small scale.

I've got a vague memory of reading that during WWII the Germans
produced sugar on an industrial scale by hydrolysing cellulose with
sulfuric acid. At the time they were blockaded and couldn't get cane
sugar from abroad. While this works, it's an awful messy and
potentially dangerous job, and even if you buy concentrated sulfuric
acid by the barrel, it may not be economic on a home scale. How much
are your time, clothing, flooring (including the concrete floor of your
garage) and skin worth? And then you still have to ferment it to
alcohol and distill it (more fuel), with the associated legal hassles.

Note that external combustion engines using cellulose (wood) as fuel
can also be used as motive power. A hundred years ago, steam cars were
produced commercially and wood-burning steam locomotives and other
applications are still used in some remote areas in the Third World.
You can also produce methane and methanol by destructive distillation
of wood, another messy and potentially dangerous operation. You can
produce an appallingly dangerous mix of carbon monoxide and methane by
adding water to coal at high temperatures under anaerobic conditions:
this is what was in the gas pipes in cities before the advent of
natural gas. It explains how all those desperate fictional heroines
managed to kill themselves by sticking their heads in an unlighted
oven.

Overall, if you want to save money on fuel, the best way is to do less
driving. Walk or use a bicycle or public transit for short trips.
Move closer to your job, or get a job closer to your home. Carpool.
Stuff like that. Your car will last longer and your insurance rates
may drop. You'll spend less on parking and car repairs. If it were
economic to produce fuel ethanol from cellulose, businesses would
already be doing it more cheaply than you can. If you like to tinker,
go for it, but you can't count on saving money doing so.

Btw, ethanol for fuel is intrinsically uneconomic under present
conditions even at an industrial scale. Feedstock starch and sugar are
cheap only because US agriculture, which consumes immense amounts of
petrochemicals, is so heavily subsidized by taxes. Presently,
producing a calorie of carbohydrate costs about 5 calories of
petroleum. By the time you ship the corn around and make cornstarch,
corn sugar and ethanol out of it, the whole situation is even more
absurd. It makes sense only politically.