title: Sustainable use of biofuel by recycling ash to forests: treatment of biofuel ash.
abstract: The influence of treatment techniques on leaching properties of alkaline species from biofuel ash is investigated in this paper. Ash samples from combustion of biofuels in a circulating fluidized bed and grate-firing combustion plants are studied. The samples are treated using three different treatment techniques; self-hardening, thermal treatment, and hardening bythe addition of binding materials. Nontreated and treated samples are evaluated for the leaching properties of the alkaline compounds and, furthermore, are characterized with respect to both physical and chemical characteristics. The results show the influence of treatment techniques on the physical structure and leaching characteristics of alkaline species. Results also indicate that ash samples show different behavior when treated with different methods, i.e., the influence of treatment technique on controlling the leaching properties is highly dependent on the initial chemical composition of ash. It was also found that there is an interaction between leaching of limited and easily soluble species, e.g., calcium and potassium leaching. Therefore, to control the leaching rate of alkaline species from ash, the characteristics that correlate the leaching properties of both easily and limited soluble species need to be adjusted.
authors.affiliation: Forest Products and Chemical Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden.
authors.forename: Maryam
authors.initials: M
authors.lastname: Mahmoudkhani
authors.forename: Tobias
authors.initials: T
authors.lastname: Richards
authors.forename: Hans
authors.initials: H
authors.lastname: Theliander
mesh_terms: D000468:Alkalies / Q000737:chemistry; D001674:Bioelectric Energy Sources; D002118:Calcium / Q000737:chemistry; D003246:Conservation of Energy Resources; D004787:Environmental Pollution / Q000032:analysis; D006358:Hot Temperature; D019216:Metals, Heavy / Q000737:chemistry; D011188:Potassium / Q000737:chemistry; D017640:Silicates / Q000737:chemistry; D012995:Solubility; D053260:Soot / Q000737:chemistry*; D014197:Trees
chemical_list: D000468:Alkalies; D019216:Metals, Heavy; D017640:Silicates; D053260:Soot; D011188:Potassium; D002118:Calcium