The 120,000 brick kilns scattered across South Asia release huge amounts of greenhouse gases and black carbon into the atmosphere. Commonly known as soot, black carbon is the second biggest global warming pollutant after carbon dioxide; it affects health and visibility and accelerates the melting of Himalayan snow and ice. The brickmaking process is highly energy- and labor-intensive. In South Asia, bricks are mostly hand-molded and then baked in fixed chimney bull's trench kilns (FCBTKs). In recent years, mechanized brick making plants and other varieties of kilns have been introduced, such as tunnel kilns, the Hoffman kiln, the modified FCBTK, the zigzag, and the vertical shaft brick kiln technology (VSBK). Earlier attempts to introduce mechanized brick making and brick baking had not been successful because of operational and adaptability problems.
Most FCBTKs emit thick black smoke that contains pollutants (carbon monoxide, carbon dioxide, black carbon, sulphur dioxide, nitrogen oxides) and fine particulate matter, which present serious health hazards to surrounding communities, causing human illnesses and destroying animal and plant life.
After the 2015 Nepal earthquake, The International Centre for Integrated Mountain Development (ICIMOD), along with FNBI and MinErgy and with support from the Climate and Clean Air Coalition (CCAC), published an engineered design manual for zigzag brick firing. (CheRN also supported this initiative separately.) The manual became popular with brick kiln owners as the technique improved brick quality and reduced coal consumption considerably. It also lowered emissions. Many entrepreneurs from Nepal and other South Asian countries are eager to learn zigzag brick firing for improved business, environment, and health.
Bidya Banmali Pradhan, Programme Coordinator