lignito

Lignito, commonly referred to as lignite or brown coal, is the lowest rank of coal. It forms from peat that has been buried and subjected to relatively low temperatures and pressures, typically in shallow basins. Compared with higher-rank coals, lignito has a high moisture content and a low carbon concentration, which results in a lower energy density.

Key properties include a soft, crumbly texture and a dull, brownish-black appearance. Moisture can comprise roughly 30–60% of its weight, and the carbon content is generally around 25–35% on a dry basis. As a result, the calorific value of lignito is relatively low, and the energy content as fired is even lower due to the moisture.

Geologically, lignito is younger than higher-rank coals and tends to form in peat-rich environments where rapid burial limits decay. It occurs in numerous coal basins around the world and is a major energy resource in some countries, particularly in Europe (notably Germany, Poland, and the Czech Republic) as well as parts of Russia, China, the United States, and Australia.

Uses and processing are dominated by electricity generation in coal-fired power plants and, in some regions, district heating. It is less suitable for residential heating due to its high moisture content and lower heat output. Upgrading options (such as drying or briquetting) are limited by cost and technical factors.

Environmental considerations include higher carbon dioxide emissions per unit of energy compared with higher-rank coals, substantial moisture-related efficiency losses, and typical mining and land-reclamation impacts associated with coal extraction.