再生能源與環境友善的廢棄物處理方案，是現代社會發展重要的課題，生質能氣化技術可能是同時解決兩個問題的解方，該技術可以在缺氧的頂空環境下，將生質物或廢棄物進料轉換成生物炭、生質油脂與合成氣，並搭配ㄌ聯產系統將合成氣進一步轉換成熱能、電能。
本研究使用生命週期評估研究方法，為一台以廢棄木棧板作為進料的燃木生質氣化機進行評估，由於該系統同時可以做為廢棄物處理方案與產能設備，因此本研究假設了兩項情景進行評估，其功能性單位分別為一公斤廢氣木棧板進料、一度電能產生。為了比較生質能氣化系統的表現，本研究也將評估結果與替代廢棄物處理方案、產能系統進行比較。本研究也使用敏感性分析研究方法，來評估生物炭最終處置、熱利用效率、尾氣排放濃度放大倍率如何影響整體的生命週期評估結果。
根據生命週期評估結果指出，燃木生質氣化機主要環境衝擊來自於汽電共生系統的尾氣排放，而環境效益則主要來自於系統的電能能源回饋，兩者相加後，較常見的環境衝擊指標如全球暖化潛勢 (Global warming, GW) -0.937822 kg CO2 eq、平流層臭氧消耗 (Stratospheric ozone depletion, SOD) -2.72x10-07 kg CFC11 eq 都呈現負值，十八項環境衝擊指標中僅有臭氧形成-人類健康危害 (Ozone formation, Human health, OFHH)、臭氧形成-陸域生態系危害 (Ozone formation, Terrestrial ecosystems , OFTE) 與陸域酸化 (Terrestrial acidification ,TA) 三項指標為正值，分別為 0.009578 kg NOx eq 、0.009648 kg NOx eq 與 0.000951 kg SO2 eq，顯示該系統在考量能源回饋的效益後，實際上是環境衝擊相當小的技術；比較性生命週期評估結果指出，不管以廢棄物處理方案或產能技術來看待氣化系統，整體來說，氣化系統所造成的環境衝擊皆比其替代方案來的小，是相當值得投資發展的技術選項；敏感性分析結果指出，為生物炭尋找更合適的最終處置、加裝空氣汙染防制設備，或許不是最佳化系統所需達成的優先任務，加裝水循環熱交換系統、尋找台灣合適的廢熱利用方式，或許才是現在的主要目標。
在得到氣化系統是相當環境友善的結論後，本研究也進行了廢棄物背景調查，以調查可能幫助氣化系統於台灣廣泛發展的替代進料；根據調查結果指出，除了現有的木材類廢棄物以外，稻殼、稻蒿與禽畜糞廢棄物都是相當具有潛力的生質廢棄物進料選項。

Gasification is a potential solution for renewable energy and eco-friendlier waste treatment. The life cycle assessment (LCA) results of the gasification system indicate that the main environmental impacts come from the emission of the combined heat and power (CHP) unit, while the environmental benefits primarily stem from the energy recovery of electricity. After accounting for all impacts and benefits, environmental impact categories such as Global Warming (-0.937822 kg CO2 eq) are all negative. Except for Ozone Formation, Human Health, Ozone Formation, Terrestrial Ecosystems , and Terrestrial Acidification , all other environmental impact categories are negative. Comparative LCA results demonstrate that the gasification system outperforms incineration and landfill systems in 16 out of 18 environmental impact categories, with lower impacts observed in 15 out of 18 categories. This suggests that gasification may result in lower environmental impact compared to other alternative systems.
The sensitivity analysis reveals that the fate of ash has minimal influence on the overall LCA results due to the low ash generation rate. Additionally, the magnification factor of flue gas concentration only affects four impact categories, mainly attributed to the NOx emissions from the CHP unit. To optimize the environmental performance of the gasification system, the utilization of waste heat should be prioritized.
Finally, background investigations on alternative candidate feedstocks suggest that poultry litter, rice husk, and rice straw are potential options. These feedstocks exhibit a stable generation rate and have been extensively researched as suitable materials for gasification.

1. EMBER. World electricity generation by source. 2022; Available from: https://ember-climate.org/data/data-explorer/.
2. Fan, Y., J. Klemeš, and S.R. Wan Alwi, The Environmental Footprint of Renewable Energy Transition with Increasing Energy Demand: Eco-cost. Chemical Engineering Transactions, 2021. 86: p. 199-204.
3. Ramos, A., et al., Environmental and socio-economic assessment of cork waste gasification: Life cycle and cost analysis. Journal of Cleaner Production, 2020. 249: p. 119316.
4. Funke, A. and F. Ziegler, Hydrothermal carbonization of biomass: A summary and discussion of chemical mechanisms for process engineering. Biofuels, Bioproducts and Biorefining, 2010. 4(2): p. 160-177.
5. Qian, K., et al., Recent advances in utilization of biochar. Renewable and Sustainable Energy Reviews, 2015. 42: p. 1055-1064.
6. Pandey, D., et al., Fly Ash From Poultry Litter Gasification – Can it be Utilised in Agriculture Systems as a Fertiliser? Energy Procedia, 2019. 161: p. 38-46.
7. Yen, C.-P., S.-Y. Zhou, and Y.-H. Shen, The Recovery of Ca and Zn from the Municipal Solid Waste Incinerator Fly Ash. Sustainability, 2020. 12(21): p. 9086.
8. Ayaz, M., et al., Biochar Role in the Sustainability of Agriculture and Environment. Sustainability, 2021. 13(3): p. 1330.
9. Jatav, H., et al., Importance of Biochar in Agriculture and Its Consequence. 2020.
10. Wang, J. and S. Wang, Preparation, modification and environmental application of biochar: A review. Journal of Cleaner Production, 2019. 227: p. 1002-1022.
11. Wang, M., et al., Review on utilization of biochar for metal-contaminated soil and sediment remediation. Journal of Environmental Sciences, 2018. 63: p. 156-173.
12. Oasmaa, A. and S. Czernik, Fuel Oil Quality of Biomass Pyrolysis OilsState of the Art for the End Users. Energy & Fuels, 1999. 13(4): p. 914-921.
13. Jacobson, K., K.C. Maheria, and A. Kumar Dalai, Bio-oil valorization: A review. Renewable and Sustainable Energy Reviews, 2013. 23: p. 91-106.
14. Zhang, Q., et al., Review of biomass pyrolysis oil properties and upgrading research. Energy Conversion and Management, 2007. 48(1): p. 87-92.
15. Hu, X. and M. Gholizadeh, Progress of the applications of bio-oil. Renewable and Sustainable Energy Reviews, 2020. 134: p. 110124.
16. Zacher, A.H., et al., A review and perspective of recent bio-oil hydrotreating research. Green Chemistry, 2014. 16(2): p. 491-515.
17. Briones-Hidrovo, A., et al., Environmental and energy performance of residual forest biomass for electricity generation: Gasification vs. combustion. Journal of Cleaner Production, 2021. 289: p. 125680.
18. Jeswani, H.K., et al., Environmental impacts of poultry litter gasification for power generation. Energy Procedia, 2019. 161: p. 32-37.
19. Siregar, K., et al., Life Cycle Impact Assessment on Electricity Production from Biomass Power Plant System Through Life Cycle Assessment (LCA) Method using Biomass from Palm Oil Mill in Indonesia. E3S Web Conf., 2020. 188: p. 00018.
20. Siregar, K., et al., Life cycle inventory of electricity production from biomass power plant system using life cycle assessment in Aceh Province, Indonesia. IOP Conference Series: Earth and Environmental Science, 2021. 749: p. 012061.
21. Ouedraogo, A.S., R.S. Frazier, and A. Kumar, Comparative Life Cycle Assessment of Gasification and Landfilling for Disposal of Municipal Solid Wastes. Energies, 2021. 14(21): p. 7032.
22. Martillo Aseffe, J.A., et al., The corn cob gasification-based renewable energy recovery in the life cycle environmental performance of seed-corn supply chain: An Ecuadorian case study. Renewable Energy, 2021. 163: p. 1523-1535.
23. Porcu, A., et al. Techno-Economic Analysis of a Small-Scale Biomass-to-Energy BFB Gasification-Based System. Energies, 2019. 12, DOI: 10.3390/en12030494.
24. Jeswani, H.K., et al., Environmental and economic sustainability of poultry litter gasification for electricity and heat generation. Waste Management, 2019. 95: p. 182-191.
25. Ademola, A.A., Comparisons of Incineration and Gasification Thermal Conversion of Municipal Solid Waste in Trinidad and Tobago. Procedia Computer Science, 2022. 203: p. 290-299.
26. dos Santos, R.G. and A.C. Alencar, Biomass-derived syngas production via gasification process and its catalytic conversion into fuels by Fischer Tropsch synthesis: A review. International Journal of Hydrogen Energy, 2020. 45(36): p. 18114-18132.
27. Koroneos, C., A. Dompros, and G. Roumbas, Hydrogen production via biomass gasification—A life cycle assessment approach. Chemical Engineering and Processing: Process Intensification, 2008. 47(8): p. 1261-1268.
28. Kumar Rajput, S., et al., Environmental Impact Assessment of Coal Gasification in Hydrogen Production. IOP Conference Series: Earth and Environmental Science, 2021. 795(1): p. 012029.
29. Yoo, Y.D., S.J. Lee, and Y. Yun, Synthesis of dimethyl ether from syngas obtained by coal gasification. Korean Journal of Chemical Engineering, 2007. 24(2): p. 350-353.
30. Yadav, P., et al., Environmental Impact and Environmental Cost Assessment of Methanol Production from wood biomass. Environmental Pollution, 2020. 265: p. 114990.
31. Li, H., et al., Biomethane Production Via Anaerobic Digestion and Biomass Gasification. Energy Procedia, 2017. 105: p. 1172-1177.
32. Akmalina, R. and M.G. Pawitra, Life cycle assessment of ethylene production from empty fruit bunch. Asia-Pacific Journal of Chemical Engineering, 2020. 15(3): p. e2436.
33. Mohammadi, F., et al., Life cycle assessment (LCA) of the energetic use of bagasse in Iranian sugar industry. Renewable Energy, 2020. 145: p. 1870-1882.
34. Dong, J., et al., Life cycle assessment of pyrolysis, gasification and incineration waste-to-energy technologies: Theoretical analysis and case study of commercial plants. Science of The Total Environment, 2018. 626: p. 744-753.
35. Kutin-Mensah, E.K., Life Cycle Assessment of Small-Scale Waste Gasification System in Vestmannaeyjar. 2021.
36. Pa, A., X.T. Bi, and S. Sokhansanj, A life cycle evaluation of wood pellet gasification for district heating in British Columbia. Bioresource Technology, 2011. 102(10): p. 6167-6177.
37. Puy, N., J. Rieradevall, and J. Bartrolí, Environmental assessment of post-consumer wood and forest residues gasification: The case study of Barcelona metropolitan area. Biomass and Bioenergy, 2010. 34(10): p. 1457-1465.
38. Bianco, I., D. Panepinto, and M. Zanetti, Environmental Impacts of Electricity from Incineration and Gasification: How the LCA Approach Can Affect the Results. Sustainability, 2022. 14(1): p. 92.
39. Panepinto, D., et al., Environmental Performances and Energy Efficiency for MSW Gasification Treatment. Waste and Biomass Valorization, 2015. 6(1): p. 123-135.
40. Astrup, T.F., et al., Life cycle assessment of thermal Waste-to-Energy technologies: Review and recommendations. Waste Management, 2015. 37: p. 104-115.
41. SpannerRe². Medium-scale wood gasifier from Spanner Re². [cited 2022; Available from: https://www.holz-kraft.com/en/.
42. International Energy Agency, I. Statistics: World Energy Balances 2018 Overview. 2018; Available from: https://www.iea.org/events/statistics-world-energy-balances-2018-overview.
43. Huijbregts, M.A.J., et al., ReCiPe2016: a harmonised life cycle impact assessment method at midpoint and endpoint level. The International Journal of Life Cycle Assessment, 2017. 22(2): p. 138-147.
44. Commission, E. The European Biochar Certificate (EBC). 2022 [cited 2022 12/22]; Available from: https://www.european-biochar.org/en.
45. Initiative, I.B. International Biochar Initiative. 2022 [cited 2022 12/22]; Available from: https://biochar-international.org/.
46. GOV.UK. Quality protocol: poultry litter ash (PLA) 2022; Available from: https://www.gov.uk/government/publications/quality-protocol-poultry-litter-ash.
47. Environmental Protection Administration, E.Y.E. Hazardous Waste Standard in Taiwan. 2020 2020/02/21 [cited 2023 01/09]; Available from: https://law.moj.gov.tw/LawClass/LawAll.aspx?pcode=O0050023.
48. Furutani, Y., et al., Current Situation and Future Scope of Biomass Gasification in Japan. Evergreen, 2017. 4: p. 24-29.
49. Environmental Protection Administration, E.Y. 事業廢棄物申報及管理資訊系統. 2022; Available from: https://waste.epa.gov.tw/RWD/Statistics/?page=Year1.
50. Tame, N.W., B.Z. Dlugogorski, and E.M. Kennedy, Formation of dioxins and furans during combustion of treated wood. Progress in Energy and Combustion Science, 2007. 33(4): p. 384-408.
51. Chiou, C.-R., J.-C. Lin, and W.-Y. Liu, The Carbon Benefit of Thinned Wood for Bioenergy in Taiwan. Forests, 2019. 10(3): p. 255.
52. Chang, K.-H., K.-R. Lou, and C.-H. Ko, Potential of bioenergy production from biomass wastes of rice paddies and forest sectors in Taiwan. Journal of Cleaner Production, 2019. 206: p. 460-476.
53. Naqvi, S.R., et al., Agro-industrial residue gasification feasibility in captive power plants: A South-Asian case study. Energy, 2021. 214: p. 118952.
54. Council of Agriculture, E.Y. 綠色國民所得帳農業固體廢棄物 2022; Available from: https://agrstat.coa.gov.tw/sdweb/public/common/Download.aspx.
55. Yoon, S.J., et al., Gasification and power generation characteristics of rice husk and rice husk pellet using a downdraft fixed-bed gasifier. Renewable Energy, 2012. 42: p. 163-167.
56. Parvez, A.M., I.M. Mujtaba, and T. Wu, Energy, exergy and environmental analyses of conventional, steam and CO2-enhanced rice straw gasification. Energy, 2016. 94: p. 579-588.