Mono-dimensional and two-dimensional models for chemical looping reforming with packed bed reactors and validation under real process conditions
Mono-dimensional and two-dimensional models for chemical looping reforming with packed bed reactors and validation under real process conditions
复制标题
使用填充床反应器进行化学循环重整的单维和二维模型以及在实际工艺条件下的验证
DOI：
10.1039/d2se00351a
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发表时间：
2022
影响因子：
5.6
通讯作者：
Argyris P
中科院分区：
文献类型：
--
作者：
Argyris P
化学链重整（Chemical looping reforming，简称CO2重整）是一种新兴的氢/合成气生产技术，与CO2捕集相结合。填充床反应器广泛用于制氢工业中，因为它们优选用于高压操作，并且描述它们的操作的数学建模对于它们的设计非常重要。在这项研究中，一个一维（1-D）和二维（2-D）模型已被开发来描述化学链重整过程中的填充床反应器（CLR-PB）的动态操作。研究中的反应器（L：400 mm ID：35 mm）包含轴向放置的热电偶套管（OD：6.35 mm）以监测横跨反应器床的6个点的温度和440 g NiO/CaAl 2 O 4氧载体（OC）。这两个模型都得到了验证，与实验结果非常吻合。在热电偶套管温度和气体成分突破方面进行了建模和实验结果之间的比较，其中2-D模型以高精度捕获热电偶套管温度记录，而1-D模型提供的结果低估了2.5%。尽管如此，预测的平均床温呈现出的差异限制在1-D到2-D模型的估计值低1%。床和热电偶套管之间的温差已经达到>180 °C的值，因此如果没有适当考虑，也会导致安全操作方面的问题。在氧化过程中，床内的温度甚至高出181 °C，强调了模型在反应器正确设计和安全操作中的重要性。1-D模型，由于计算时间显著降低（比2-D快21倍），已被选择用于在一系列氧化操作条件下进行测试（500-600 °C，1-5 bar，10-40 NLPM，10-20% O2），还原（600-900 °C，1-5 bar），使用H2、合成气和富含CH 4的还原剂和干重整（700-900 °C，1-5巴），特别是在固体转化率高的高温条件下和在类似于预期的工业。
Chemical looping reforming (CLR) is an emerging hydrogen/syngas production technology, integrated with CO2 capture. Packed bed reactors are widely used in the hydrogen production industry as they are preferred for high pressure operation and the mathematical modelling describing their operation is very important for their design. In this study, a one-dimensional (1-D) and a two-dimensional (2-D) model have been developed to describe the dynamic operation of chemical looping reforming processes in packed bed reactors (CLR-PB). The reactor under study (L: 400 mm ID: 35 mm) contains an axially placed thermowell (OD: 6.35 mm) to monitor the temperature across the reactor bed at 6 points and 440 g of NiO/CaAl2O4 oxygen carrier (OC). Both models have been validated presenting very good agreement with the experimental results. The comparison between modelling and experimental results has been carried out in terms of thermowell temperature and the gas composition breakthroughs, with the 2-D model capturing the thermowell temperature recordings with high accuracy, while the 1-D model delivered results that underestimated it by 2.5%. Nonetheless, the predicted average bed temperature presented a difference limited to 1% lower estimation of the 1-D to the 2-D model. The temperature difference between the bed and the thermowell has achieved a value of >180 °C thus resulting also problematic in terms of safe operation if not properly considered. with temperatures during oxidation being higher even by 181 °C inside the bed, emphasizing the importance of the model in the proper design and safe operation of the reactor. The 1-D model, due to the significantly lower computation time (∼21 times faster than 2-D), has been selected to be tested against a range of operating conditions for oxidation (500–600 °C, 1–5 bar, 10–40 NLPM, 10–20% O2), reduction (600–900 °C, 1–5 bar) with H2, syngas and CH4-rich reducing agents and dry reforming (700–900 °C, 1–5 bar), delivering results with good agreement especially under high temperature conditions where solid conversion is high and under conditions which resemble the expected industrial ones.