A process synthesis and global optimization framework is presented to determine the most profitable routes of producing liquid fuels from natural gas through competing technologies. Chemical looping is introduced into the framework for the first time as a natural gas conversion alternative. The underlying phenomena in chemical looping are complex and models from methods such as computational fluid dynamics are unsuitable for global optimization. Therefore, appropriate approximate models are required. Parameter estimation and disjunctive programming are described here for modeling two chemical looping processes. The first is a nickel oxide based process developed at CSIC in Spain; the second is a iron oxide based process developed at Ohio State University. These mathematical models are then incorporated into a comprehensive process superstructure to evaluate the performance of chemical looping against technologies such as autothermal reforming and steam reforming for syngas production. The rest of the superstructure consists of process alternatives for liquid fuels production from syngas and simultaneous heat, power, and water integration. Among the various case studies considered, it is shown that chemical looping can reduce the break-even oil prices for natural gas-to-liquids processes by as much as 40%, while satisfying production demands and obeying environmental constraints. For a natural gas price of $5/TSCF, the break-even price is as low as $32.10/bbl. Sensitivity analysis shows that these prices for chemical looping remain competitive even as natural gas cost rises. The findings suggest that chemical looping is a very promising option to enhance natural gas-to-liquids processes and their capabilities.

提出了一种过程综合和全局优化框架，以确定通过竞争技术从天然气生产液体燃料的最有利途径。首次将化学循环引入框架作为天然气转化的替代方案。化学循环中的基本现象很复杂，并且来自诸如计算流体动力学之类的方法的模型不适合全局优化。因此，需要适当的近似模型。在此描述了用于对两个化学循环过程进行建模的参数估计和析取编程。第一个是西班牙CSIC开发的基于氧化镍的工艺。第二种是俄亥俄州立大学开发的基于氧化铁的工艺。然后，将这些数学模型合并到一个综合的过程上部结构中，以针对诸如合成气生产的自热重整和蒸汽重整之类的技术评估化学循环的性能。上层建筑的其余部分由工艺替代品组成，这些工艺替代品由合成气生产液体燃料，同时进行热，电和水集成。在所考虑的各种案例研究中，表明化学循环可将天然气制油工艺的收支平衡油价降低多达40％，同时满足生产需求并遵守环境约束。对于5美元/ TSCF的天然气价格，收支平衡价格低至32.10美元/桶。敏感性分析显示，即使天然气成本上涨，这些用于化学循环的价格仍具有竞争力。