Lignite also known as brown coal is a type of coal with a high level of moisture content and a relatively low percentage of carbon. Although as a lower grade of coal, it is far less efficient when burned in its crude form due to the great amount of smoke output and low heat yield. Despite this, there is a way to bring lignite’s efficiency closer to that of the other three types of coal and also make it more friendly to the environment by a process known as briquetting.