結果發現利用焚化飛灰製作成環保紅磚原料之製程中，磷酸的使用對環境所造成的環境負荷最大、其次是電力的使用。而針對此結果，本實驗提出使用廢磷酸來取代磷酸的使用建議，且經過假設模擬後發現，可以大量的減少環境負荷。最後比較一般紅磚、環保紅磚及第二代環保紅磚的單點得分後可發現，一般紅磚的分數為3.77E-03 Pt、環保紅磚的分數為4.05E-03 Pt，兩者僅相差了2.08E-04 Pt，兩者相差十分接近，本結果完全顛覆了外界對飛灰資源化的觀感，在此之前普遍認為飛灰資源化為高耗能、對環境衝擊大，但整體來看，其實差距不大，而日後若能使用廢磷酸來穩定重金屬，此製成的第二代環保紅磚，其分數便少於紅磚為3.44E-03 Pt，因此對環境相對最友善，因此可作為日後研發的方向。
The recovery is the best way to the management of municipal solid waste incinerator (MSWI) fly ash. However, we have to consider that the whole environmental load affected by recovery process for fear of causing more environmental problems after solving the problem of fly ash. Thus, if the Life Cycle Thinking could be introduced at the initial stage of research and full-scale simulated assessment, we might have a clear direction and improved skill for fly ash recovery to reduce the whole environmental load. In this study, Life Cycle Assessment was applied to simulate the environmental influence of in-plant recovery of fly ash and the Life Cycle program “Simapro” was adopted to perform this study. The technology assessed here was the recovery of fly ash for green brick manufacture which was developed from our research team. The improvement project was presented after the assessment and comparison of traditional bricks, green bricks and 2nd green bricks.
The results indicated that the use of phosphoric acid has the biggest environmental load in the process of green brick manufacture and power was the next. Therefore, waste phosphoric acid was suggested for the substitute in the experiment and we found that it can reduce environmental load substantially. Finally, comparing with traditional brick, green brick and 2nd green brick, we found that single score of traditional bricks was 3.77E-03 Pt, the green brick was 4.05E-03 Pt. The difference between these two was only 2.08E-04 Pt. Before the assessment, people usually considered that the recovery of fly ash was high-energy consumption and high impact to environment. However, the results showed that recovery of fly ash didn’t spend much more than the traditional process, and further, if waste phosphoric acid was adopted for substitute in the production process of 2nd green brick, the single score was reduced to 3.44E-03 Pt which was less than the single score of traditional brick. Therefore, the process of 2nd green brick was the friendliest technology to environment that could be the further direction of research in the future.