The maximum concentration of hydrogen that can be commingled with or blended in natural gas has been a topic of discussion for many years. The reasons for blending hydrogen with natural gas are mainly twofold: to improve the renewable content of natural gas and to utilize the existing natural gas pipeline infrastructure for hydrogen distribution. This paper aims at addressing these issues by proposing an optimization model that considers blending hydrogen generated through a “power-to-gas” (PtG) technology pathway with natural gas. This paper develops a deterministic mixed-integer nonlinear programming network pressure-flowrate optimization model that captures the interaction between natural gas pipeline systems and the impact of hydrogen injections across multiple pipeline connections in the natural gas grid. A stochastic model is subsequently developed. The optimal quality/concentration of hydrogen in the natural gas pipelines and the optimal location of PtG units are realized while minimizing system-wide capital and operating costs. The design decisions obtained for the deterministic model differ from the stochastic model; the design decisions for the stochastic model varies across the different uncertainty realizations.

中文翻译：

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管网中天然气与氢气混合的集成设计和运行优化

可以混入或混入天然气中的最大氢浓度多年来一直是讨论的话题。将氢气与天然气混合的原因主要有两个方面：提高天然气的可再生含量，并利用现有的天然气管道基础设施进行氢气分配。本文旨在通过提出一种优化模型来解决这些问题，该模型考虑将通过“动力天然气”（PtG）技术途径产生的氢气与天然气混合。本文建立了确定性的混合整数非线性规划网络压力-流量优化模型，该模型捕获了天然气管道系统之间的相互作用以及天然气网格中多个管道连接处注氢的影响。随后建立了一个随机模型。实现了天然气管道中氢气的最佳质量/浓度和PtG装置的最佳位置，同时使系统范围的资金和运营成本降至最低。确定性模型获得的设计决策与随机模型有所不同。随机模型的设计决策在不同的不确定性实现中会有所不同。