Definition and Purity Standards of High-Purity Methane

High-purity methane refers to methane gas with a relatively high purity. Generally, methane with a purity of 99.99% or higher can be considered high-purity methane. In some more stringent applications, such as the electronics industry, purity requirements may reach 99.999% or even higher. This high purity is achieved through complex gas purification and separation technologies to remove impurities such as moisture, carbon dioxide, carbon monoxide, hydrogen, and other gaseous components.

Application areas of high-purity methane

In the electronics industry, high-purity methane is used as an etching gas and a raw material for chemical vapor deposition (CVD) in semiconductor manufacturing. For example, in plasma etching, methane is mixed with other gases to precisely etch semiconductor materials, forming tiny circuit patterns. In CVD, methane provides a carbon source for growing carbon-based thin films, such as silicon carbide films, which play a crucial role in improving the performance and stability of semiconductor devices.

Chemical Raw Materials: High-purity methane is an important raw material for the synthesis of many high-value-added chemicals. For example, it can react with chlorine to produce chloromethane compounds such as chloroform, dichloromethane, trichloromethane, and carbon tetrachloride. Chloromethane is a raw material for the production of organosilicon compounds, dichloromethane and trichloromethane are commonly used as solvents, and carbon tetrachloride was once used as a fire extinguishing agent, but its use is now strictly limited due to its ozone-depleting effects. Furthermore, methane can be converted into syngas (a mixture of carbon monoxide and hydrogen) through reforming reactions, and syngas is a fundamental raw material for the production of methanol, synthetic ammonia, and many other chemical products.

In the energy sector: While common methane (natural gas) is the primary energy resource, high-purity methane also plays a role in certain specialized energy applications. For example, in fuel cells, high-purity methane can be used as fuel, undergoing reforming to produce hydrogen, which powers the fuel cell. Compared to traditional fossil fuels, fuel cells using high-purity methane achieve higher energy efficiency and lower pollutant emissions.

Preparation of standard gases: High-purity methane can be used as a standard gas for the calibration of gas analysis instruments. For example, in a gas chromatograph, using high-purity methane standard gas of known concentration can calibrate the instrument’s detection sensitivity and accuracy, ensuring accurate and reliable analytical results for other gases.