1. Division of Biomass Technology and Chemistry; Swedish University of Agricultural Sciences; SE 901 83 Umeå Sweden
2. Centre of Biomass Engineering; China Agricultural University; No.2 Yuanmingyuanxilu, Haidian Beijing 100094 China
3. National Energy R&D Centre for Nonfood Biomass; China Agricultural University; No.2 Yuanmingyuanxilu, Haidian Beijing 100094 China