Coal breaker remaining. The sorting by size is particularly important for anthracite coal. In order to burn efficiently, air must flow evenly around anthracite. Subsequently, most anthracite coal is sold in uniform sizes. In the 1910s, there were six commercial sizes of coal (with the smallest size having three subsets): Coal pieces smaller than in size were considered "culm," and unable to be separated from the impurities (and thus useless). The grade of coal ranged from a low of 5 percent impurities for steam or broken coal to a high of 15 percent for pea-size coal and its subsets. Coal breakers were
Carbon capture and storage could have a significant effect on their phase behaviour and could pose a significant threat of increased corrosion of pipeline and well materials. In instances where impurities exist, especially with air capture, a scrubbing separation process would be needed to initially clean the flue gas. According to the Wallula Energy Resource Center in Washington state, by gasifying coal, it is possible to capture approximately 65% of carbon dioxide embedded in it and sequester it in a solid form. Broadly, three different configurations of technologies for capture exist: post-combustion, pre-combustion, and oxyfuel combustion: Carbon dioxide can be separated out of air