绿氢之心：过程气体分析（中英文）

氢（H2）是当前能源转型讨论的关键因素之一。它是宇宙中最常见的元素，但仅以结合态存在。气态下，氢比空气轻约14倍，燃烧后无残留。H2 具有高能量密度，因此非常适合替代煤炭或天然气等化石燃料。由于它在自然界中主要以结合态存在，因此需要将其从载体中释放出来。例如，水（H2O）的电解过程可以实现这一目标。如果电力来自可再生能源，称之为“绿色”氢；如果是天然气的主要成分甲烷（CH4），则可以通过蒸汽重整或热解获得。重整过程会产生副产品二氧化碳（CO2）（蓝色氢），而热解过程则会产生一氧化碳（CO）（绿松石色氢）。这两种物质都可以进一步加工成原材料，或通过碳捕获和储存（CCS）技术进行储存。

由于密度极低，产生的 H2 极易挥发，这使其运输到用户手中非常具有挑战性。气态 H2 可以通过管道运输。液态 H2 可以通过隔热油罐车或油罐车运输给消费者；在这种情况下，不可忽略的波动率是不可避免的。此外，H2 具有脆化材料的特性，所有工厂组件的使用寿命和设计都必须考虑到这一点。在生产“绿色”氢气时尤其如此，生产商不仅需要确保生产现场有足够的“绿色”电力，而且还要确保有充足的优质水源。

Hydrogen (H2) is one of the key factors in the current discussion on energy transition. It is the most common element in the universe, but only exists in bound form. In gaseous form, it is around 14 times lighter than air and it burns without leaving residues. H2 has a high energy density and is therefore well suited as a substitute for fossil fuels such as coal or natural gas. Since it is predominantly only present in bound form in nature, it needs to be released from its carriers. This is achieved, as an example, in the case of water (H2O) by electrolysis. If electricity is generated from renewable sources, we speak of 'green' hydrogen - or in the case of methane (CH4), the main component of natural gas - by steam reformation or pyrolysis. Reformation produces CO2 (blue hydrogen) as a by-product and in the case of pyrolysis CO (turquoise hydrogen). Both substances can be further processed as raw materials or stored by carbon capture and storage (CCS).

The H2 produced is extremely volatile because of its very low density, which makes its transportation to users very challenging. In gaseous form, transport by pipeline is conceivable. In liquefied form, hydrogen can be transported to the consumer in insulated tankers or tank trucks; in this case, non-negligible fluctuation rates are inevitable. In addition, H2 has the property of embrittling materials, which must be considered in the service life and design of all plant components. This is especially the case when it comes to the production of 'green' hydrogen when producers need to ensure that not only sufficient 'green' electricity is available, but sufficient, good quality water is available at the production site.

电解器中会发生什么？

What happens in an electrolyser?  

电解器的核心是一个圆柱体（电解模块），其中两个腔室由膜隔开。每个腔室包含一个电极（阳极/阴极）。模块通常由不同的制造商以统一的输出尺寸制造。为了达到所需的系统输出，一定数量的模块被组合成所谓的堆栈。目前使用两种工艺：AEL电解（碱性电解）和PEM电解（质子交换膜）。这两种工艺各有优缺点。PEM工艺特别适用于波动性能源（风能和太阳能）。简而言之，PEM电解器的操作可以描述如下：将预热的至少达到饮用水质量的水送入两个腔室。工作温度需要在50-80°C之间。通过施加电压，水被分解成H2和H2O成分。这会从9千克H2O中生成1千克H2。阳极侧为氧气，阴极侧为氢气，它们分别通过热交换器和气体分离器分离。根据整个装置的具体任务，氧气会被释放到环境中或用于其他用途（例如用于废水处理）。

The core of the electrolyser is a cylindrical body (electrolysis module) in which two chambers are separated by a membrane. Each chamber contains an electrode (anode/cathode). The module is usually made by the various manufacturers in a uniform output size. To achieve the desired system output, a certain number of modules are combined into a so-called stack. Two processes are currently in use: AEL electrolysis (alkaline electrolysis) and PEM electrolysis (proton exchange membrane). Both processes have their advantages and disadvantages. The PEM process is particularly compatible with fluctuating energy sources (wind and sun). Simplified, the operation of a PEM electrolyser can be described as follows: Preheated water, of at least drinking water quality, is fed into the two chambers. The operating temperature needs to be between 50-80°C. By applying a voltage, it is split into the constituents H2 and H20. This produces 1 kg of H2 from 9 kg of H2O. On the anode side - the oxygen, and on the cathode side - the hydrogen are each removed via heat exchangers and gas separators. Depending on the task of the overall plant, the oxygen is released into the environment or used elsewhere (e.g. for wastewater treatment).

如何监控整个过程？

How do we monitor the process?

与大多数能源生产方法一样，氢气的生产过程必须进行分析监控。重点在于是否符合 LEL 和 SIL 规范。在所有生产过程中，萃取式气体分析是实现这一目的的首选分析方法。在样品气体进入分析仪之前，需要去除残留水分，以保护测量池并避免测量值失真。

As in the case of most energy production methods, the manufacturing processes of H2 must be monitored analytically. The focus here is primarily on compliance with LEL and SIL specifications. In all manufacturing processes, extractive gas analysis is the preferred analytical method for this purpose. Before the sample gas enters the analyser, the residual moisture is removed to protect the measuring cell and avoid falsifying the measured values.

样气泵 P2.2 O2 Atex

Sample Gas Pump P2.2 O2 Atex

基于数十年在气体分析领域提供和设计分析仪系统的经验，建议在这些应用中使用加压萃取预处理系统。其原理如下：

由于电解过程中样气中不太可能发现颗粒污染，因此只需设置简单的采样点即可，理想情况下每个模块的出口处均应设置采样点。样气由专用样气泵吸入，该泵还能够输送可能产生的冷凝物，并将其输送至在轻微过压下运行的样气冷却器。

Based on our decades of experience in providing and designing analyser systems in gas analysis, we suggest using a pressurised extractive conditioning system for these applications. In principle, this is constructed as follows:

Since no particulate contamination is likely to be found in the sample gas during the electrolysis process, simple sampling points are sufficient, ideally at each outlet of a module. From these, the sample gas is drawn in by a special sample gas pump, which is also capable of conveying any condensate that may occur and fed to a sample gas cooler operating under slight over-pressure.

样气泵 P2.4 H2 Atex

Sample Gas Pump P2.4 H2 Atex

确定所需流量时，必须考虑氢气侧较低的氢气密度，以便将其节流至分析仪上游的正确流量。如果生产过程中已有足够的压力和流量，则可以省去泵。水分在冷却器中分离，干燥的样气被送入分析仪。样气中的过压可防止外部空气进入，确保测量结果不受影响。同时，过压迫使冷凝物通过自动冷凝水排放装置排出系统。流量和过压由合适的装置持续监测。从抽气点经泵头到自动冷凝水排放装置的管道均采用不锈钢材质。建议采用相同的系统设计来监测同样积聚的氧气。由于氢气波动较大，建议采用通风良好的外壳来容纳监测系统。系统中使用的组件在制造过程中经过特殊工艺处理。其适用于 H2/O2 应用的部分已获得认证。

该系统设计将处理系统中的材料混合量降至最低，提供最佳的使用寿命，并确保测量结果的稳定性。

When dimensioning the required flow rates, the lower density of hydrogen on the H2 side must be considered so that it can be throttled to the correct flow rate upstream of the analyser. If there is already sufficient pressure and flow rate in the production process, the pump can be dispensed with. The moisture is separated in the cooler and the dry sample gas is fed into the analyser(s). The over-pressure in the sample gas prevents the ingress of external air and ensures unaltered measurement results. At the same time, the over-pressure forces the condensate out of the system via an automatic condensate drain. Flow and over-pressure are permanently monitored by suitable devices. The piping from the extraction point via the pump head to the automatic condensate drain is made of stainless steel. The same system design is recommended for monitoring oxygen that also accumulates. Due to the high fluctuation of H2, a well-ventilated enclosure is recommended to house the monitoring system. The components used in the system are subject to special procedures in the manufacturing process. Their suitability for the H2/O2 application is partially certified.

This system design reduces the material mix in the treatment system to a minimum, offers the best possible service life and ensures unaltered measurement results.

样气冷却器 TC-Standard H2/O2

Sample Gas Cooler TC-Standard H2/O2

样气冷却器 RC1.1 H2/O2

Sample Gas Cooler RC1.1 H2/O2

样气冷却器 TC-Midi H2/O2

Sample Gas Cooler TC-Midi H2/O2