In Tokamak exhaust processing system ,steam methane reforming reaction is expected to convert deuterium and tritium in the gaseous compounds to elementary gas , then the deuterium and tritium can be reclaimed . The method of Gibbs free energy minimization was employed to analyze the thermodynamic balance of steam methane reforming reaction .The effect of many factors ,such as reaction temperature ,reactants ratio ,pressure ,O2 ,CO2 ,H2 and CO ,was investigated .The appropriate reaction condition is as follows :The temperature is between 650 ℃ and 700 ℃ ,the pressure is 1 × 105 Pa ,and the ratio of water to methane is 1.5-2.0 .Moreover ,the presence of O2 or CO2 in reactants is favorable to lessen the yield of solid carbon and increase the conversion rate of hydrogen isotope . The presence of H2 does not affect the thermodynamic balance obviously , while CO increases solid carbon yield , which is a disadvantage to the reaction ,so it needs to be wiped off before reaction .%Tokamak裝置中的等離子體反應(yīng)一段時間后,需對產(chǎn)生的排灰氣進行凈化處理,以回收其中的氘氚。目前擬采用甲烷水汽重整反應(yīng)將化合態(tài)的氘氚轉(zhuǎn)化為單質(zhì)并回收。本文運用Gibbs自由能最小化方法,對應(yīng)用于等離子體排灰氣處理的水汽重整反應(yīng)進行熱力學(xué)分析,考查反應(yīng)溫度、原料比例、反應(yīng)壓力、O2、CO2、H2、CO等因素對反應(yīng)平衡的影響,確定了適宜的反應(yīng)條件,即反應(yīng)溫度范圍650~700℃,壓力1×105 Pa ,水碳比1.5~2.0。此外,原料氣中O2或CO2的存在有利于減少積碳的生成量,并獲得較高的氫同位素平衡轉(zhuǎn)化率;H2的存在對重整反應(yīng)的熱力學(xué)平衡無明顯影響;CO的存在會使積碳量增加,對反應(yīng)產(chǎn)生不利影響,在進入重整反應(yīng)器前應(yīng)將其去除。
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