Physical Properties of Wheat Straw Varieties Cultivated Under Different Climatic and Soil Conditions in Three Continents

Abstract

Over 500 million tonnes of wheat straw are produced annually worldwide, the majority of which are burnt in the field causing significant environmental and health problems as well as serious traffic accidents in addition to loss of a valuable resource. Wheat straw is abundantly available and renewable and can be used as an energy source in gasification and combustion systems. Proper understanding of the physical properties of wheat straw is necessary for utilizing these materials in thermochemical conversion processes. Wheat straws were collected from Egypt (Africa), Canada (North America) and Guyana (South America) and ground using medium size Wiley Mill. The physical properties (moisture content, particle size, bulk density and porosity) of wheat straws were determined using standard procedures. The moisture contents of wheat straws were in the range of 5.02-7.79%. The majority (56.87-93.36%) of the wheat straws particles were less than 0.85 mm and the average particle sizes were in the range of 0.38-0.69 mm. The average bulk density of the wheat straws were in the range of 97.52-177.23kg m^-3. A negative linear relationship between the bulk density and the average particle size was observed for the wheat straws. The average porosity of the wheat straws were in the range of 46.39-84.24%. A positive linear relationship between the porosity and the average particle size for the wheat straws was also observed. The wheat straw varieties collected from different countries had different physical properties due to variations in climatic conditions, soil type and used fertilizer. Also, significant differences were observed among the varieties grown under same climatic and cultivation conditions.