الفهرس 
1. INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 120 |  |  |
| | | from | 120 | | |
Abstract
Increasing population growth and technological development require more energy to accomplish the various processes which human life is based on it. The limitations of fossil fuels require new and renewable ways of energy. One of the methods for obtaining the energy which is used of different wastes whose resulted of human activity and agricultural waste.
Also, the problem of burning the agricultural waste in the fields which air pollution results of due to different emissions. So the wastes should be disposed of with safe methods.
Agricultural residues are resulted of harvest operations of various crops which the workers in the field new and renewable energy call biomass energy.
Therefore, the main objective of this research uses one of the agricultural waste (corncobs) with a safe way to produce energy and use it in the drying industry of the agricultural products (onions).
To achieve the objective of this study a biomass oven was designed, developed, and manufactured for disposing of the agricultural wastes in Lakana village, Shoubrakheat, El Beheira Governorate; the residence of the student to get rid of the wastes in a good environmental method under the supervision of the Department of Agricultural Engineering Faculty of Agriculture University of Menoufia.
The study includes the following:
1- The manufacture of a biomass oven to burn agricultural waste (corncobs) which includes two chambers to burn the waste (corncobs) and another chamber for drying the agricultural product (onions).
2 - Quantities of the waste are used in different proportions according to the size of the chamber (12.5.25, 50 and 60%).
- Using the red iron oxide and hydroxide to remove the carbon dioxide which are put in the air filter which is used to purify the air from carbon dioxide where the red iron oxide is followed by calcium hydroxide.
4- Different velocity (1.6, 2 and 2.5 m / s) is used for air flow through the biomass oven to choose the best velocity. That allows the heat exchange with agricultural products in the drying chamber to be higher air temperature. It also allows to the heat exchange with the material to be dried and the exchange of lost moisture to be hot air.
5- The onions are dried after cutting to different thickness slices (2, 4, 6 and 8 mm), which have the primary moisture content (87.9%) on a wet basis.
6- Using two methods to put the onion slices inside the drying chamber. The onion slices, in one and two layers, are put in exchange with the spaces between each two slices in one layer.
Evaluation of the performance of the Biomass Oven with the following measurements:
1- The temperature of agricultural waste is measured in the combustion chamber.
2- The increase in the temperature of air pushing with different velocities from the combustion chamber to the drying chamber was measured.
3-Studying the drying properties of onion slices in different treatments lead to knowing the relationship of moisture content with time, drying rate and drying efficiency.
4-Evaluating the quality of dried onion slices by the sensory evaluation with a group of arbitrators in the Department of Food Industries Faculty of Agriculture Menoufia University which have experience in this filed and their number is ten.
5-Choosing the mathematical model which describes the drying curves of onion slices in this oven.
6- An economic study was done on drying onion slices in this oven.
After the experiments and various previous treatments, the most important results obtained were:
1- The best corncobs quantity according to the size of the combustion chamber was 25% where the highest increase in temperature of air input the drying chamber is 14.5 Co, in the least time is 120 minutes and the least carbon dioxide amount is 490 ppm.
2- The air velocity flow which gives the highest increase in air temperature passing in the drying chamber is 2.5 m/s.
3- The use of chemical materials in the filters to reduce the percentage of carbon dioxide in the drying chamber air and increase the temperature at an average of 4.5 Co is higher than the use without them in filters.
4- The drying time of the dried onion slices in the thickness (2, 4, 6 and 8 mm) is (6.75, 7.58, 8 and 8.4 Hours) for one layer. The drying time of the dried onion slices in the thickness (2, 4, 6 and 8 mm) is (7.3, 8.33, 9 and 9.5 Hours ) for two layers
5- The drying rate (0.116, 0.165, 0.17 and 0.202) gm/min for onion slices (2, 4, 6 and 8) mm for the falling period at one-layer. The drying rate (.016, 0.177, 0.182 and 0.3) g/min of onion slices (2, 4, 6 and 8) mm for two-layers.
6- Statistical analysis shows that the thickness of 6 mm is the best one for quality dried onions.
7- The best mathematical model that describes the drying curves is Page s model.
8- The economic analysis shows that the thickness of 6 mm with two layers achieves a net profit higher than that of one layer.
9- The economic study in the Biomass oven for drying shows the highest net profit compared with the other drying methods by other researchers.
Biomass oven, thermal oven and microwave oven achieve a net profit (131.6, 43.69 and 89.69) pounds/kg respectively.
THE FINAL CONCLUSION:
- The study recommends using a biomass oven for safely dispose from agricultural waste.
- The Biomass oven can be used to dry agricultural products when using a 25% from combustion chamber volume, where it is given the highest temperature increase.
- It is recommended to use the Biomass oven to dry onion slices with thickness 6 mm with two layers.
- The researcher is recommended to expand from biomass energy using as alternative energy to achieve the highest profit from agricultural waste.