The selection criteria for fuel gas components in sulfur recovery

In the recycling of coal chemicals, selecting the effective components of fuel gas is an important step. As potential sources of fuel gas, the feasibility of raw gas, shift gas, and purified gas, along with the impact of sulfur recovery catalysts, are key factors in the evaluation process. I. Selection of effective components for fuel gas and feasibility analysis: Raw coal gas – Characteristics: Raw coal gas is obtained directly from the coal gasification process; it contains high levels of CO and H2, as well as small amounts of CH4 and other hydrocarbon gases. It may also contain impurities such as sulfides and nitrides. Feasibility: Since crude gas contains a large amount of combustible components (such as CO and H2), it has potential as a fuel gas. However, due to its high impurity content, particularly sulfides and nitrides, using it directly as a fuel gas may have adverse effects on equipment and the environment. Therefore, purification is required before use. Characteristics of shifted gas: Shifted gas is obtained through a catalytic reaction between CO in raw gas and water vapor, resulting in the formation of CO2 and H2. The reformate gas has a relatively high H2 content and a reduced CO content; it may also contain small amounts of CO2 and other impurities. Feasibility: H2 in the reformate gas is an efficient fuel, and its combustion products are water, resulting in no pollution. However, the CO2 content in the reformate gas may affect its combustion performance. Furthermore, if the catalyst performance is poor or the operating conditions are inadequate during the conversion process, the converted gas may still contain a certain amount of CO and other impurities, requiring further purification. Characteristics of purified gas: Purified gas is gas that has been processed through a series of purification processes such as desulfurization, denitrification, and dust removal, resulting in a reduced level of impurities; its main components are H2, CO2 (which may have been removed), and small amounts of CH4, among others. Feasibility: Using purified gas as a fuel gas is highly feasible, as it has a low impurity content, stable combustion properties, and causes minimal adverse effects on equipment and the environment. However, the cost of purified gas is relatively high due to the need for additional purification equipment and operating costs. II. The impact of sulfur recovery catalysts In the coal chemical industry, sulfur recovery is an important step. Sulfur recovery catalysts play a key role in the sulfur recovery process. The impact of fuel gases from different sources on sulfur recovery catalysts is mainly reflected in the following aspects: sulfur content: The sulfur content in the fuel gas directly affects the activity and lifespan of the sulfur recovery catalyst. Fuel gas with a high sulfur content can cause catalyst poisoning or deactivation, thereby reducing sulfur recovery efficiency. Impurity components: Other impurities in the fuel gas (such as nitrides, dust, etc.) may also have an adverse effect on the sulfur recovery catalyst. These impurities may cover the catalyst surface, reducing its activity ； Or it may react with the catalyst to produce products that are unfavorable for sulfur recovery. Operating conditions: Operating conditions such as the temperature and pressure of the fuel gas can also affect the performance of the sulfur recovery catalyst. For example, excessively high temperatures may cause the catalyst to sinter or become deactivated ； Too low a pressure may reduce sulfur recovery efficiency. In summary, when selecting the effective components of fuel gas for recycling in coal chemical industries, it is necessary to take into comprehensive consideration the characteristics and feasibility of raw gas, shifted gas, and purified gas. At the same time, attention must also be paid to the content of sulfur and other impurities in the fuel gas, as well as the impact of operating conditions on the sulfur recovery catalyst. Through appropriate selection and processing techniques, efficient utilization of resources and environmentally friendly development can be achieved in the coal chemical industry.