title: Potential application of gasification to recycle food waste and rehabilitate acidic soil from secondary forests on degraded land in Southeast Asia.
abstract: Gasification is recognized as a green technology as it can harness energy from biomass in the form of syngas without causing severe environmental impacts, yet producing valuable solid residues that can be utilized in other applications. In this study, the feasibility of co-gasification of woody biomass and food waste in different proportions was investigated using a fixed-bed downdraft gasifier. Subsequently, the capability of biochar derived from gasification of woody biomass in the rehabilitation of soil from tropical secondary forests on degraded land (adinandra belukar) was also explored through a water spinach cultivation study using soil-biochar mixtures of different ratios. Gasification of a 60:40 wood waste-food waste mixture (w/w) produced syngas with the highest lower heating value (LHV) 5.29 MJ/m(3)-approximately 0.4-4.0% higher than gasification of 70:30 or 80:20 mixtures, or pure wood waste. Meanwhile, water spinach cultivated in a 2:1 soil-biochar mixture exhibited the best growth performance in terms of height (a 4-fold increment), weight (a 10-fold increment) and leaf surface area (a 5-fold increment) after 8 weeks of cultivation, owing to the high porosity, surface area, nutrient content and alkalinity of biochar. It is concluded that gasification may be an alternative technology to food waste disposal through co-gasification with woody biomass, and that gasification derived biochar is suitable for use as an amendment for the nutrient-poor, acidic soil of adinandra belukar.
authors.affiliation: NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, 138602, Singapore; Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore.
authors.forename: Zhanyu
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore.
authors.forename: Shun Kai
authors.initials: SK
authors.lastname: Koh
authors.affiliation: NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, 138602, Singapore.
authors.forename: Wei Cheng
authors.initials: WC
authors.lastname: Ng
authors.affiliation: Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543, Singapore.
authors.forename: Reuben C J
authors.initials: RC
authors.lastname: Lim
authors.affiliation: Department of Biological Sciences, National University of Singapore, 14 Science Drive 4, 117543, Singapore.
authors.forename: Hugh T W
authors.initials: HT
authors.lastname: Tan
authors.affiliation: NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, 138602, Singapore; Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore.
authors.forename: Yen Wah
authors.initials: YW
authors.lastname: Tong
authors.affiliation: School of Mechanical Engineering, Shanghai Jiaotong University, #800 Dongchuan Rood, Shanghai, 200240, China.
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Dai
authors.affiliation: Bioplas Energy (Asia Pacific) Pte Ltd, 9 Tuas South Street 15, 637077, Singapore.
authors.forename: Clive
authors.initials: C
authors.lastname: Chong
authors.affiliation: NUS Environmental Research Institute, National University of Singapore, 1 Create Way, Create Tower #15-02, 138602, Singapore; Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, 117585, Singapore. Electronic address: chewch@nus.edu.sg.
authors.forename: Chi-Hwa
authors.initials: CH
authors.lastname: Wang
mesh_terms: D001210:Asia, Southeastern; D018533:Biomass; D002606:Charcoal; D005502:Food; D065928:Forests; D005740:Gases; D027741:Ipomoea / Q000254:growth & development; D059027:Recycling / Q000379:methods*; D012037:Refuse Disposal / Q000379:methods*; D012846:Singapore; D012987:Soil / Q000737:chemistry*; D014329:Tropical Climate; D014934:Wood / Q000737:chemistry
chemical_list: D005740:Gases; D012987:Soil; C540010:biochar; D002606:Charcoal
keywords: Acidic soil; Adinandra belukar; Biochar; Food waste; Gasification; Water spinach