Sample Analysis of Material Chemistry
Coal gasification is the process of transforming coal from a solid or liquid form into a gaseous state. This process has been utilized, to varying degrees, since the late 1700s when it was discovered that heating coal to a high temperature would produce a combustible gas. This gas had the useful properties of being able to be combusted for energy, as well as produce byproducts that could be used to make products like metals, plastics and specialty chemicals. Coal gasification typically involves heating coal to high temperatures (generally greater than 800 degrees Celsius) in a gasifier.
The gas that comes off of coal gasification, referred to as “syngas,” is usually composed of the following primary components: Carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), and methane (CH4). This gas, which looks and smells like natural gas, can be easily combusted for energy production and is, in some cases, burned to produce steam, which can be used to spin turbines in an electricity generation plant.
The chemical structures of the components of syngas can vary significantly, depending on the type of coal and the process used to gasify it. The primary components of the raw gas coming off of coal gasification are determined through material chemistry analysis. The goal of a material chemistry analysis of coal gasification is to evaluate the various components of the gas by measuring the concentration levels of each component, the purity of the components and their overall chemistry.
When conducting material chemistry analysis, typically a sample of the syngas is taken and then subjected to a variety of tests, including gas chromatography and mass spectrometry. The analysis will provide detailed information on the composition, composition range, and impurities present in the gas.
Gas chromatography can be used to analyze the syngas components. The technique separates the components of a gas or vapor and measures their relative abundance by passing the sample through a stationary phase. The stationary phase may include a silica-based liquid or a porous polymer.
Mass spectrometry is an analytical technique that can create an “ionization spectrum” from a gas sample by separating the component elements or molecules by their mass-to-charge ratios. The spectrum allows the quantitative analysis of individual gas components, and can show very small differences in the organic makeup of the gas.
Material chemistry analysis is also used to evaluate other factors present in a sample of syngas, including moisture content, sulfur-containing compounds, trace metals and organometallic compounds.
In conclusion, material chemistry analysis of coal gasification is an important tool for evaluating the composition, composition range, and impurities present in the gas. The results of the material chemistry analysis can indicate how viable a gasification process is and whether or not it is operating effectively in terms of its production of syngas components. This information can help engineers make decisions about how to process the gas and how it should be used.
