Popular Science has an interesting read for those of you interested in making your own ethanol. According to the author it is as simple as putting cornmeal, water, enzymes, and yeast into a vat and letting it sit for a few days. This mixture is called the mash. The enzymes will turn the cornmeal into sugar and then the yeast will turn the sugar into ethanol. Eventually the yeast will die as it will be poisoned by the ethanol. The author then goes on to talk about the distillation process:
“Distillation increases the alcohol concentration: 50 percent is vodka, 95 percent is fuel. Alcohol vaporizes at a lower temperature than water, so heating the fermented mash turns the alcohol to vapor that collects on a cold condenser.”
Overall the article seems to be lacking in details which would be necessary for someone who actually wanted to create ethanol. For example, how could anybody possibly distill ethanol to remove water without knowing the boiling point of ethanol? Fortunately the boiling point which is 78.4 degrees Celsius is readily available via Wikipedia. (The boiling point of water is 100 degrees Celsius.) The key is to make sure that the ethanol/mash mixture is somewhere between 78.4 and 100 degrees Celsius which will enable the ethanol and not the water to evaporate. Also it is important to make sure that the vats are sealed without air in them or the yeast will not be able to produce ethanol and will instead produce CO2 and water (aerobic respiration). Also, you cannot buy simply “enzymes” and expect anything worthwhile to happen (seriously now…), you actually need to mix a specific type of enzyme known as amylase into your mash.
Since this is a cellulosic ethanol site, I thought it would be interesting to outline a general procedure that could work for making your own cellulosic ethanol. The previous procedure was for corn ethanol, now lets try to make the good stuff out of wood fiber shall we?
The first order of business would be to find some paper without any ink on it. Any paper will do although if you can find any made from hardwood with lower calcium carbonate content it would be preferred. The purer the pulp concentration the better the results will be. Hardwood is preferred since hardwoods have a higher cellulose content than softwoods. Newsprint is less desirable as it is typically pulped via grindstone rather than via a kraft or sulfite process which will remove lignin and some hemi-cellulose.
Once you have your “feedstock”, get a bucket and put it on a scale. Zero the scale with the bucket on it. Now add the feedstock to the bucket which should still be on the scale and weigh it. The density of water is roughly the same as that of paper (1 g/ml), so once you have the weight of the paper, add water until the total mass is ten times what it was with only paper in it. Now put your water/paper mixture into a blender. Blend the mixture for as long as you think your blender can last. Literally you can not blend for too long which means that you are limited by the capabilities of your blender (note: blenders do overheat so be careful to give it a few chances to cool down before continuing with the rigorous workout), and the extent of your patience. You are trying to produce as much surface area as possible since you wont be using any dilute acid pre-treatment in order to disrupt the structure. (or for that matter any other methods) You are trying to give the enzyme as much surface area to attack as you can. Congratulations, you now have a 10% consistency slurry.
The next step would be to put the slurry into a vat with a cellulase enzyme. You will probably need to purchase this enzyme online (one place to look would be Dyadic) and find out how much you need to add based on how much paper you added as consistency requirements vary dramatically. Also include yeast in the vat. Give the vat a few days to work and you should have made some ethanol. Then just follow the procedure that has been outlined in the corn ethanol section for distillation and voila, you should have ethanol at a purity of your choosing.
As the Popular Science article mentions, distilling alcohol is illegal without a license and it is important to remember to never heat glass over an open flame. Also make sure that any distillation that occurs, occurs in a controlled, closed environment as alcohol vapor is explosive. Also if you choose paper with ink on it, remember that different inks react differently to heat and consequences may be less than desirable. Also some paper has added chemicals which can react unexpectedly. Never drink anything unless you have a way of guaranteeing the purity. What this basically comes down to is do at your own risk as you could potentially be working with explosive and/or toxic chemicals and neither this website nor it’s owners are responsible if you hurt yourself, your property, or if you do anything illegal.
October 29, 2007 at 9:00 am |
I am doing a senior thesis project on the economics and science of cellulose ethanol; if you could help me, that will be great!
According to your article, “find out how much you need to add based on how much paper you added as consistency requirements vary dramatically”, I was wondering where could I find the information for the proportions for cellulase to paper-water slurry.
In addition, what precautions should I take for synthesizing cellulosic ethanol?
Sincerely,
Emily
Feel free to contact me @ hahaseashells@gmail.com
January 15, 2008 at 4:09 pm |
i would like a recipy to make mash from 10 lbs. of switchgrass.