الفهرس 
Chapter 1 : IntroductionOnly 14 pages are availabe for public view
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Abstract
Sweet sorghum is belonging to the Genus Sorghum bicolor ( L.) Moench which is the best multipurpose crop; sorghum grain is used for human food and as feed for animals; the plant stem and foliage are used for green chop, hay, silage, and pasture; in some areas the stem is used as building material; juice of sweet sorghum stalk is used for making syrup, gaggery and ethanol; bagasse and green foliage is considered an exellent fodder for animals as a biomass for gasification system as organic fertilizer or for paper manufacturingSorghum is the fifth most important cereal crop in the world after wheat, rice, corn and barley. Moreover, sweet sorghum has a great tolerance to a wide range of climatic and soil conditions. It is a short duration crop of 110-130 days as compared to 12- 24 months in sugarcane. In addition its water and fertilizer requirement is much less, resulting in lower cost of cultivation than sugarcane.
There are approximately four thousand varieties of sweet sorghum through out the world. Ripe sweet sorghum typically consists of approximately 75% cane, 10% leaves, 5% seeds and 10% roots by weight. It could produce 21 tones of crushable stalks, 1.25 tones of grains and 7.15 tones of leaves and stem tops per Feddan.
Sorghum syrup is obtained by concentration of the juice extracted from sorghum stalks. Like sugar cane syrup, sweet sorghum syrup can be used as a popular food and liquid sweetener in various food products which would save sugar cane for sugar production. Accordingto SCC (1), the area cultivated with sugar cane for syrup production was about 12479 feddans. In Egypt, the production of sucrose was about 2.1 million tons meantime, the consumption was about 2.8 million tons. Sweet sorghum can be an additional or an alternative to sugar cane for syrup production in order to close the vast gap between the sugar production and consumption.
High contents of carbon dioxide in the atmosphere that are contributing towards global warming is said to be caused by the use of fossil fuels around the world. On the other hand, the ever rising cost of fossil fuel internationally has forced major world economics to examine renewable and cheaper alternatives to fossil fuel to meet their energy demands. Bioethanol has emerged as the most suitable renewable alternatives to fossil fuel as their quality constituents match diesel and petrol, respectively. In addition, they are less polluting than their fossil fuel counterparts. Environmental concerns and the desire to beless dependent on fossil fuel have intensified worldwide efforts for production of ethanol from starch and sugar producing crops. Added in small amounts, 10 % of ethanol to gasoline that fuels our cars, it reduces greenhouse emissions like carbon monoxide and nitrogen oxides. Bioethanol used as a replacement for gasoline can reduce vehicle carbon dioxide emissions by 90 %.
Among the biomass energy crops sweet sorghum is the first important competitor. In fact sweet sorghum has been cultivated as energy plant in many countries. Sweet sorghum stalk are rich in sugars which can beprimarily used for biofuel production. It can produce up to 7000 L of ethanol /ha.
The Department of energy of the U.S.A. estimated that after 1990 sweet sorghum can top all crops such as cereals and sugar cane as the best resource for alcohol production. Program of Brazil has also selected sweet sorghum together with sugar cane and cassava as the three main biomass resources.
Sweet sorghum has major advantages compared to other sugar and biomass crops. Firstly, sorghum is a species showing extensive genetic variation, including drought and heat tolerant genotypes, which enable the usage of marginal land that is not suitable for cultivating other crops. Secondly, competition between the use of land for food or for energy is less because the grains can be used for food or feed while stems can be used for biofuel production. The stem juice of sweet sorghum is rich in fermentative sugar and is a desirable alcoholic fermentation material. In addition to fermentative sugar, other kindsof sugars are also found in the stem juice of sweet sorghum. There are also some organic acids and minerals in the juice, measuring their contents enables us to use sweet sorghum better with multi-purpose.