Abstract Many geothermal power plants require systems for steam washing and treatment of non-condensable gases (NGCs). Steam washing is an early-stage unit and the NCG treatment is performed before the reinjection. The paper describes the potential methods for those parts of the process and evaluates the approach of scrubbers and the associated models. The first model is developed for the steam washing scrubber, which eliminates the dissolved solids from the extracted steam. The energy analysis, steam loss, and the efficiency of removal are investigated and potential approaches to the H2S removal process are discussed. The second model is dedicated to the packed-bed acid-gas scrubber, which efficiently reduces the H2S content of NCGs before the reinjection into the reservoir. This model is a rate-based approach that considers all the reactions in parallel. Also, a comprehensive model for the sizing of the scrubbers is proposed. The case study is a binary geothermal power plant, designed for the area of Larderello, in which the extracted steam consists of 25 ppm dissolved solids. The power plant design includes the NCG reinjection system, having about 0.3% of H2S content. The design parameters are found to achieve solid removal efficiency higher than 90%, thus abating the dissolved solids in the steam to less than 3 ppm by the first scrubber. The performance of the selective H2S removal treatment is optimized by identifying the best operating parameters for the effective removal of the H2S and keep the CO2. The selectivity is calculated in various conditions considering recycle-ratio, caustic solution temperature, and caustic solution concentration. The configuration of the second scrubber is optimized with an H2S removal efficiency of about 99.96 percent, with a selectivity index around 10.

中文翻译：

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为 Larderello 地区设计的全回注地热发电厂的气体净化工艺

摘要 许多地热发电厂需要用于蒸汽洗涤和处理不可凝气体 (NGC) 的系统。蒸汽洗涤是一个早期单元，在回注之前进行 NCG 处理。该论文描述了流程中这些部分的潜在方法，并评估了洗涤器的方法和相关模型。第一个模型是为蒸汽洗涤洗涤器开发的，它可以从提取的蒸汽中去除溶解的固体。研究了能量分析、蒸汽损失和去除效率，并讨论了 H2S 去除过程的潜在方法。第二个模型专用于填充床酸性气体洗涤器，可在回注到储层之前有效降低 NCG 的 H2S 含量。该模型是一种基于速率的方法，它并行考虑所有反应。此外，还提出了洗涤器尺寸的综合模型。案例研究是为 Larderello 地区设计的二元地热发电厂，其中提取的蒸汽包含 25 ppm 的溶解固体。电厂设计包括 NCG 回注系统，其 H2S 含量约为 0.3%。发现设计参数可实现高于 90% 的固体去除效率，从而通过第一洗涤器将蒸汽中的溶解固体减少到 3 ppm 以下。通过确定有效去除 H2S 和保持 CO2 的最佳操作参数来优化选择性去除 H2S 处理的性能。考虑到循环比、苛性碱溶液温度、和苛性碱溶液浓度。第二个洗涤器的配置经过优化，H2S 去除效率约为 99.96%，选择性指数约为 10。