本論文以此目標研究IGCC發電廠製造合成天然氣之程序設計暨最適化系統整合，研究中主要以合成天然氣每小時產量10,000公斤與複循環動力發電量12 MW為設計目標，整個系統包含六個製程： (1) 煤炭前處理； (2) 煤炭氣化； (3) 酸氣處理； (4) 化學遷移反應； (5) 甲烷化反應； (6) 複循環發電系統。最後再將程序最適化導入系統中，使得系統能源能較充分的被利用。程序最適化分析後吾人可得：(1) 在Bypass比設定為0.35時兩階段化學遷移反應進料溫度分別為290℃與180℃下，可控制生成物H2/CO莫耳比為3； (2) 在進料H2/CO莫耳比為3時，甲烷化反應操作溫度在240℃時，可得最大甲烷莫耳分率0.936，沉積碳質量流量由18,020降為16,220 kg/hr。論文中主要使用化工製程模擬軟體Aspen Plus進行程序合成與設計，最適化的部分則併入Aspen Simulation Workbook軟體以進行程序整合。
Recently, there is no denying the fact that people like to be eco-friendly, which means being kind to the environment. Therefore, people have started to reduce the use of nuclear energy and coal-fired power for these years. Hence, natural gas will certainly be the main power resource in the future. Unfortunately, the supply of natural gas from foreign countries to Taiwan will be difficult in a foreseeable future. As a result, we have set the process of producing natural gas from an integrated gasification combined cycle (IGCC) power plant to solve this problem. Not only would it solve the issue of providing a constant, supplemental source of natural gas but it also would reduce the pollution of coal power.
For this reason, the goal in this thesis which is researching IGCC power plant with the process of producing natural gas in optimization. Moreover, producing 10,000 kilogram per hour of natural gas and earning 12 MW power is our base-case design situation. There are six processes involved in the whole system: (1) raw coal pretreatment (2) coal gasification (3) acid gas treatment (4) shift reactions (5) methanation (6) integrated power system. In addition, we have set the process, which is optimum, into the IGCC system; it would use the resource from this system sufficiently. In other words, in this system, the efficiency will be better than before. After process optimization, we found: (1) By setting the bypass ratio as 0.35 and controlling the two-stage shift reaction feeding temperatures at 290oC and 180oC, respectively, we are able to obtain a H2/CO ratio of 3. (2) When controlling the H2/CO ratio of 3 and maintaining the methanation reactor’s temperature at 240oC, we are able to obtain a mole fraction of methane as 0.936 and reduce the deposit carbon from 18,020 to 16,220 kg/hr.
In this research, simulation program Aspen Plus is used to carry out the process synthesis and design. Additionally, Aspen Simulation Workbook is utilized to implement the process optimization.