Effluent gas from shift converters in hydrogen plants refers to the gas that is emitted or released as a byproduct of the conversion process used to produce hydrogen gas. Shift converters are an essential component of hydrogen plants, which are facilities that produce hydrogen through the steam reforming of hydrocarbons or the gasification of carbon-containing feedstocks such as coal or natural gas. In these processes, the feedstock is reacted with steam to produce a mixture of hydrogen (H2), carbon monoxide (CO), and carbon dioxide (CO2). The shift converter then uses a chemical reaction to convert the CO into H2 and CO2, resulting in an effluent gas stream that contains a mixture of these gases.

The effluent gas stream from a shift converter may also contain other gases, depending on the specific process and the type of feedstock being used. For example, if natural gas is used as the feedstock, the effluent gas stream may contain methane (CH4), ethane (C2H6), and other hydrocarbons in addition to H2, CO2, and trace amounts of CO. On the other hand, if coal is used as the feedstock, the effluent gas stream may contain a higher percentage of CO2 and other impurities, such as sulfur compounds and particulates.

Proper management and treatment of effluent gas streams from shift converters is important for several reasons. First, these gases can have negative environmental impacts if they are not properly managed. For example, the CO2 in the effluent gas stream is a greenhouse gas that contributes to climate change. In addition, other gases in the effluent gas stream, such as sulfur compounds, can cause air pollution when they are released into the atmosphere. Second, effluent gas streams from shift converters are subject to regulatory requirements, which vary depending on the location of the hydrogen plant and the specific pollutants present in the effluent gas stream.

One way to manage and treat effluent gas streams from shift converters is to capture and store the CO2. This can be done through a process known as carbon capture and storage (CCS), which involves separating the CO2 from the other gases in the effluent gas stream and then injecting it into underground storage reservoirs. CCS is a proven technology that has been used for decades to reduce CO2 emissions from power plants and other industrial facilities. However, it is expensive and requires significant infrastructure, including pipelines and storage reservoirs, which can be challenging to develop in some locations.

Another way to manage and treat effluent gas streams from shift converters is to treat the gases to remove any pollutants before releasing them into the atmosphere. This may involve using scrubbers or other technologies to remove sulfur compounds and other impurities from the effluent gas stream. In addition, the effluent gas stream may be further processed to separate out individual gases or to remove trace contaminants. This can be done through a variety of techniques, such as cryogenic separation or chemical absorption.

In addition to CCS and gas treatment, there are several other approaches that can be used to manage and treat effluent gas streams from shift converters in hydrogen plants. For example, some hydrogen plants use a closed-loop system in which the effluent gas stream is recycled back into the shift converter, allowing for more efficient use of the feedstock and reducing the amount of gas that needs to be treated or released into the atmosphere. Other hydrogen plants use a combination of approaches, such as CCS and gas treatment, in order to meet regulatory requirements and minimize environmental impacts.

Overall, effluent gas from shift converters in hydrogen plants is an important issue that requires careful management and treatment in order to minimize negative environmental impacts and meet regulatory requirements.