AGAVE- FUTURE SOURCE FOR ETHANOL
Agave is the plant popularly distilled to make tequila--is being explored as an ethanol biofuel crop that won't compete with food. Agave has a huge advantage, as it can grow in marginal or desert land, not on arable land," and therefore would not displace food crops. Agave, however, can grow on hot dry land with a high-yield and low environmental impact. The researchers proposing the plant’s use have modeled a facility in Jalisco, Mexico, which converts the high sugar content of the plant into ethanol.
Bioethanol as an alternative source of energy has received special attention worldwide due to depletion of fossil fuel. In India sugarcane molasses is the main raw material for ethanol production but now the short supply and increased cost is the main hindrance for its use. The sugary substrates available are comparatively expensive than molasses but can be easily used for ethanol production with some modification the process. On the other hand cellulosic materials are cheaper and available in plenty but their conversion to ethanol involves many steps and is expensive. In recent years because of increase in price of molasses and its limited availability, ethanol production has been greatly affected in 285 molasses based Indian distilleries. Under such circumstances a novel approach is essential to use easily available starch and abundantly available ligno substrates.
Zymomonas mobilis, Gram negative anaerobic bacterium, is another suitable organism for ethanol production and has advantage over yeast i.e., 98% efficiency in ethanol production and a specific rate twice bigger. Agave leaves, for example, have 3-15% lignin and up to 68% cellulose. In the Agave, the sugars are present in a proportion of about 9:1 fructose: glucose .The sugars are fermented primarily by yeasts which produce ethanol and acetic acid, compounds toxic to microorganisms. The desert plants used to distil tequila could cut emissions from transport by providing an important new biofuel crop, according to new research.
Agave fibers contain 65 percent to 78 percent cellulose. With new technology, it may be possible to breakdown over 90 percent of the cellulose and hemicellulose structures, which will increase yield of ethanol and other liquid biofuels from lignocellulosic biomass drastically.
In India Agave plants are grown along railway line, road sides, and river banks and as a hedge plant in dry land areas throughout the country. Till date, it is grown in patches and as border crop in neglected condition. The crop comes up on dry soils unsuitable for crop cultivation but grow vigorously on dry, well drained sandy loam soils. Agave cultivation has been carried out in the southern region in India, eventually setting up a micro distillery at Chittor in Andhra Pradesh.
YIELD OF ETHANOL FROM AGAVE
Yet there has been no reported use of agave feedstock for ethanol production in commercial facility. An agave variety with stems of 150 kg and 27 percent sugar content, grown at a density of 3,000 plants per hectare and harvested in six years has a potential annual ethanol yield of 7,500 liters per hectare. Higher yielding varieties of agave still can be developed from elite plants that are seldom found in the plantations. Second-generation ethanol production from cellulose contained in leaves and the waste pulp of the agave stem will considerably increase the yield. Though yield from agaves raised are not presently competitive with sugarcane and corn, the high-yielding varieties in development may make the feedstock to become a viable and competitive option for ethanol production.
The researchers proposing the plant‘s use have modeled a facility in Jalisco, Mexico, which converts the high sugar content of the plant into ethanol. The research, published in the journal Energy and Environmental Science, provides the first ever life-cycle analysis of the energy and greenhouse gas balance of producing ethanol with agave. Each mega joule of energy produced from the agave-to-ethanol process resulted in a net emission of 35 grams of carbon dioxide, far below the 85g/MJ estimated for corn ethanol production. The characteristics of the agave suit it well for bioenergy production, but also reveal its potential as a crop that is adaptable to future climate change.
PROPERTIES OF AGAVE
Modern medical study has confirmed agave's remedial properties. Agave nectar applied to the skin has been found effective against pyogenic (pus producing) bacteria such as Staph aureus. Most agave sweeteners are produced from the blue agave plant. The core of the plant contains the aguamiel or "honey water," the substance used for syrup production (and, when fermented, tequila). Processing the aguamiel yields a product with either a dark amber or light color, and a consistency much like maple syrup. The light-colored nectar resembles maple syrup or honey in flavor, but the taste is more delicate which has made agave a popular sweetener for energy drinks, teas, nutrition bars, and more. Agave Nectar is the natural caloric sweetener with the lowest glicemic index. Under medical control it can be used by diabetic people. The Agave Nectar oligo-organic contents help the well functioning of gall bladder, helping to saponification of fats. Its oligo-organic contents also work against the blocking of arteries and veins due to high cholesterol levels. Agave Nectar enhances flavors, keeping the perfect flavor for a longer period of time. Agave Nectar has the same sugar proportions as found in the plant itself. Agave Nectar does not contain processing chemicals. Agave Nectar is safe and recommended for children. Agave Nectar can be used for baking, cooking and anywhere else where you would normally use sugar or a chemical, artificial sweetener. Agave Nectar is low calorie.
USES OF AGAVE
The juice obtained by processing Agave could be fermented (by spitting into it) into pulque, a beer-like drink. The juice or syrup also was used medicinally. The agave contains polysaccharides which are bactericidal, and saponins and sapogenins that have antibiotic, fungicidal, and antiviral properties. The stalks can be used for a variety of building purposes and they make good, light, strong walking sticks. It can be used to sweetened food and drink. Fiber is extracted from the spiked leaves. The cut leaves are allowed to dry or are baked, then pounded to loosen the pulp, which is combed out with a sharp stick and washed away with water. The cleaned fibers are used to make clothing, rope, baskets and brushes. Amber and dark agave nectar taste similar to caramel, and can be used like maple syrup on pancakes and waffles.
