Viability of some African agricultural by-products as a feedstock for solid biofuel production

As a source of renewable energy, agricultural by-products after pre-processing and cleaning in post-harvest lines can be used as a feedstock for the production of pellets or briquettes. This can be achieved by determining the physicochemical properties of the by-products. Groundnut pods, maize cobs and the husks of rice, millet and sorghum were considered, and their properties were determined, which were then compared with the standard properties of pellets and briquettes to ascertain their viability as a feedstock for the pellet or briquette production. The by-products were transported from Nigeria to the Czech Republic and the research was carried out at the Department of Technological Equipment of Buildings, the Faculty of Engineering, Czech University of Life Sciences Prague. The moisture content, ash content, calorific value, nitrogen content and sulfur content were the properties considered of the by-products. Groundnut pods and maize cobs with a calorific value of 17.48 MJ·kg–1 and 16.25 MJ·kg–1, an ash content of 3.46% weight and 1.79% weight, a nitrogen content of 1.24% weight and 0.44% weight and a moisture content of 7.92 weight and 7.56% weight, respectively, were discovered to fulfill all the requirements for graded non-woody pellets A. With the exception of rice husks and millet husks, which were discovered to have high ash contents and low calorific values, all the by-products fulfilled the standard requirements for one or more grade of pellet/briquette. They can, therefore, be used as a good feedstock for pellet or briquette production.