生命週期評估應用於台灣燃煤發電廠之碳捕獲與碳封存的政策環境影響評估

Abstract

以煤、石油、天然氣為主的化石能源佔據了當今人類能源消費結構的主體地位，由此造成大氣中溫室氣體含量的逐漸增高，導致全球氣候變暖，對人類的健康安全的生存和社會經濟的可持續發展造成了嚴重的威脅。 碳捕獲與封存技術(Carbon Capture and Storage, CCS)被看做是解決全球氣候變暖問題的最為重要的手段之一，然其發展一直爭議不斷，主要體現在CCS技術造成的環境衝擊以及安全風險問題。CCS發展的主要阻礙則是政策支持不足，加之公眾對該技術理解貧乏。因此，制定CCS的相關政策十分重要，對政策做環境影響評估也必不可少。 政策環境影響評估(Strategic Environmental Assessment, SEA)是一個程序性方法，需要有效的環境評估工具，才達到環境評估結果。而生命週期評估(Life Cycle Assessment, LCA)即是一種量化且具系統性思維之環境管理工具，其針對一個產品(或服務)自搖籃至墳墓等不同生命階段之能資源投入與污染物排放進行盤查，並使用衝擊評估模式進行產品生命週期之環境衝擊評估以做為環境化設計與決策之參考。當生命週期評估與政策環評在相同的系統邊界之下，可全程評估及系統化分析政策方案的環境衝擊，非常適合應用於政策環評衝擊分析階段與替代方案的選擇。 本研究以2025年作為評估基準年，評估CCS是否適合與台灣燃煤發電廠進行配套施行，基準方案為對台灣的傳統燃煤發電廠的燃煤機組不採取任何措施，替代方案為對台灣的傳統燃煤發電廠的燃煤機組配置CCS。使用生命週期評估工具Simapro8.1對基準方案與替代方案各階段的投入產出進行盤查分析後，再經ReCiPe3.0評估模式量化其潛在衝擊，再將結果以對應至政策環評說明書規範中之作業評估矩陣表，提供決策者環境面之量化資訊。 生命週期評估方法配合矩陣表使用可將各評估項目中衝擊結果以量化方式具體呈現，在環境衝擊方面也可以涵蓋許多評估項目。生命週期評估可以適合應用於政策環評衝擊分析階段。 結果顯示，替代方案在氣候變遷、顆粒物形成、陸域酸化和氣候變遷生態系統四個衝擊類別具有衝擊減量的正面效益，並隨發電技術增加而減量程度增高（亞臨界衝擊最大，超臨界次之，超超臨界最小）；但在資源使用、臭氧消耗、人體毒性、光化學氧化物、水域毒性，優養化等類別造成更高的衝擊。 基準方案的衝擊結果為9.07E+09，替代方案的衝擊結果為8.51E+09，即燃煤電廠配置CCS後，總衝擊只減少了6.22%。台灣是否要將燃煤發電廠配置CCS作為減碳手段之一值得慎重考慮。

Fossil fuels-Coal, oil, natural gas, occupy the dominant position of the current human energy consumption structure, resulting in the gradual increase in atmospheric concentrations of greenhouse gases, which will cause global warming. It will bring a serious threat to human health and sustainable economic development. Carbon capture and storage technologies, CCS, is regarded as one of the most important method to solve the global warming problem. However, the development of this method has always been in controversy, which mainly focus on the environmental impact and safety risks brought by CCS. And the main obstruction of the develop-ment is the lack of policy support and the poor public understanding of CCS. There-fore, it is of great significance to establish relevant policies, on which environmental impact assessment is also absolutely necessary. Strategic environmental assessment is a routinely method, which needs effective environmental assessment tools to achieve solid results. Lifecycle assessment, which is just a quantitative and system thinking environmental management method, examines on the resource investment and pollutant discharge of one product or service at vari-ous life stages from the beginning to the very end. Concise assessment mode is taken use of in this thesis to do the environmental impact assessment on the lifecycles of the product, further as a reference of environmental designs and decisions. When lifecycle assessment and strategic environmental assessment are under the same system bound-aries, environmental performance evaluation and systematical analysis on the envi-ronmental impact of the policy and strategy, which is quite suitable during the stage of environmental impact assessment and for the selection of alternatives. The year of 2025 is set as the baseline year in this thesis to evaluate whether CCS is suitable for coal-fired power plants in Taiwan to carry on. And the baseline plan is taking no efforts on core-fired units in traditional Taiwanese coal-fired power plants, while the alternative is applying CCS on the core-fired units. Lifecycle assessment tool Simapro8.1 is used at first to perform inventory analysis on the input and output of each stages of the two schemes. Then pattern quantification of the potential im-pacts was accomplished by ReCiPe3.0. In the last, this work corresponded the results to the project evaluation matrix in the specification and instruction of the strategic en-vironmental assessment, providing quantized environmental information for policy-makers. The results shows the alternative scheme has positive effects on the reduction of four impact categories, climate change, particle formation, land acidification and cli-mate change ecosystems. And along with the improvement of power technologies, the reduction effect grows, that subcritical has the maximum impact, supercritical takes the second place, and ultra-supercritical has the minimum impact, while causing larger impacts within the aspects of resource usage, ozone bleaching, human toxicity, photo-chemical oxidant, aquatic toxicity and eutrophication. The impact result of the baseline plan is 9.07E+09, and the alternative plan is 8.51E+09, which means the impact is only reduced by 6.22% after applying CCS technologies. Under the precondition of regardless of the economic factors and secu-rity risk, whether allocating CCS to coal-fired power plants in Taiwan or not is a ques-tion for policy-makers to solve.