What is biofuel and how can it help us solve the current energy and pollution crises? These new fuels have received a lot of industrial, political and media attention recently. The idea of using ethanol from naturally grown plant matter as an alternative to crude oil for fuel is an appealing one. Of equal interest is the idea of producing biodiesel and its energy rich by-product glycerin from both used and new vegetable oils. This process is in turn dependent on supplies of methanol and sodium hydroxide, also called lye. It is possible to make lye at home but is is much easier and cheaper to purchase it pre made.
Biofuels carry with them an image of sustainability and environmentally friendliness and the promise of allowing us to continue our use of automobiles without damaging the planet. Some of these ideas have been realized at least in part, whereas other problems have come to light that are casting bio-sourced fuels in a less than green lime light.
The conversion of plant sugars into alcohol has been occurring for as long as history has been recorded. As far back as 10,000BC people were making beer, possibly even before bread was first produced. The process of distillation of an ethanol solution is very simple and has been and still is employed by home distillers around the world for making beverages such as fortified wines, whiskey, moonshine, vodka and so on. This is an effective process, so much so that some alcoholic beverages can act as fuels and burn once introduced to a flame.
The main fuel that can be produced at home is biodiesel.
Biodiesel can give you significant savings on your fuel bill if your vehicle can run on it. There production of the fuel requires a bio diesel kit and the chemicals to run it. This can be an effective way to turn used cooking oil into car fuel.
On an industrial scale however, there are significant biodiesel problems that need to be overcome before this fuel should be universally acclaimed as an energy solution.
In order to be economically viable, fuel crops need to produce the highest possible fuel output. In the United States corn is the politically preferred crop for bioethanol and it is the corn cob itself that is the source of the raw materials for making fuel.
Similarly in Australia and many south east Asia and South American countries, sugar cane one of the crops of choice. The stems of the cane plant are rich in simple sucrose that is easily converted into ethanol.
Both these crops have the immediate problem of using not only food producing land but the food itself as a fuel source. The recent surge in global demand and price of food makes this practice unsustainable. If bio-sourced fuels are to be adopted in a serious manner for the long term we need to develop ways of producing them that do not compromise food production.
In order to become a genuinely environmentally friendly addition to our energy supplies, biofuels need to be generated using land that is not presently being used for food production or that is covered with natural vegetation such as rainforests.
One developing possibility is the use of desert areas to produce algae biodiesel. This method harvests the fat content of the cell walls of these tiny organisms.
Making fuel out of the plant matter left over after a crop is harvested is another possibility. Plants are made mainly of cellulose which is simply very long chains of sugar molecules joined together. It is the intertwining and chemical bonding between strands of cellulose that make them so hard to digest. One way of breaking cellulose apart is using the enzyme cellulase. This enzyme dissolves the cellulose strands into simple sugars as do the enzymes in our mouths, for example when we suck on a piece of bread.
Cellulase is produced by very few organisms. Common garden snails produce it, which is why snails can feed on newspapers and cardboard. Another organism that produces it is the Trichonympha, which lives in the gut of termites. The termites eat dead wood which the Trichonympha digest. They are very efficient and produce more sugars than they need to survive. The termites survive on the excess sugar production and so this symbiotic relationship endures. Several other organisms including some plants and fungi are also able to produce cellulase.
Being able to produce the enzyme cellulase in commercial quantities would surely be a key advance toward developing truly environmentally friendly fuels. Since all plants are made virtually entirely from cellulose we could make fuel from any waste plant material; lawn clippings, bamboo, dead branches, driftwood, anything. Unfortunately use of cellulase in industrial applications for this purpose is still in the experimental phase.
Top Of Page
Return from What Is Biofuel to the Green Planet home page for more Solar Power Facts.
No comments:
Post a Comment