Assessment of biomass pellets and briquettes technologies by rough sets theory

Since biomass briquette/pellet technology has been at the initial stage of development in China, the good and bad are intermingled for technical level, its comprehensive evaluation becomes more complicated and uncertain. Rough Sets Theory is an effective tool in dealing with vague and uncertainty information. A new comprehensive evaluation model based on Rough Sets Theory has been proposed in this paper, in which the evaluation of weighting coefficient has been transformed into calculation of the importance of attributes, so it can effectively avoid subjectivity about the weighting coefficient in fuzzy comprehensive evaluation. Another contribution to the paper is that a new attribute reduction algorithm by constructing generalized decision table has been presented in the paper, which effectively reduces the computational complexity and increases reduction efficiency during reduction. Finally, the model has been applied to comprehensive evaluation of listed-technology in China. The results show that appropriate priority to the promotion of the technology is mechanical piston pelletizing technology, stickiness felted pelletizing technology, hydraulic piston pelletizing technology, double rollers pelletizing technology, and annulus die and pressing roller pelletizing technology in turn.