- In Bihar, the brick industry consumes the most coal after thermal power plants. It also contributes significantly to air pollution.
- Since 2016, the Bihar state government has been pushing for kilns to adopt the zigzag design that helps in reducing pollution.
- However, the state government’s initiative has hit many roadblocks due to a lack of capital and monitoring, among other challenges.
Brajesh Kumar’s skilled hands move with rhythmic precision as he shovels coal into the roaring brick kiln. With swift, practiced motions, he removes the hot lid of the furnace using an iron rod and pours in coal. Dark clouds gather, hinting at impending rain. Brajesh is racing against time to complete his work before the kiln must close for the monsoon. His colleague, Rajendra Paswan, assists him in this urgent task. This scene unfolds in Dobhi, a town in Bihar’s Gaya district, where the race to bake bricks before the rains is in full swing.
Both Brajesh and Rajendra have been working at this kiln for almost a decade. During this time, they have seen many changes.
“This kiln is different. Now, the bricks are arranged differently,” Brajesh says, as he advises against walking over the bricks. “If you walk over the bricks, you may trip and fall.”
“This type of kiln is called a zigzag,” explains Shyam Satish Kumar, a kiln clerk, who is standing near Brajesh. “Here, the bricks are placed diagonally so that less smoke comes out while cooking. This technique has been adopted to reduce pollution. There is a good distance between the bricks, which helps the coal burn completely.”
The zigzag technique of stacking bricks was implemented at Shivam Bricks, where Brajesh and Rajendra work, in 2018. Converting the kiln to zigzag design was done at a cost of Rs. 12 lakhs.
The change has been a result of the Bihar government’s efforts to reduce pollution caused by the brick industry. The government has been pushing kiln owners to adopt the zigzag design to reduce pollution and the design has been adopted by kilns throughout Bihar.
S. Chandrashekhar, Member Secretary, Bihar State Pollution Control Board, tells Mongabay India, “We collected data on the brick industry for the first time in 2015. It then emerged that there are 6,500 brick industries in Bihar, which cause significant pollution. The brick industry in Bihar consumes the most coal, after thermal power plants. The industries not only pollute the air but also consume fertiliser-rich topsoil and underground water.”
The zigzag design was initially adopted in brick kilns in 2016 to curb pollution. “In 2018, the Patna High Court ordered the adoption of zigzag technology in all brick industries. Subsequently, in 2022, based on an order from the Ministry of Environment, Forest and Climate Change, it was decided that this technology would be adopted in all the kilns across the country,” says Chandrashekhar.
By 2022, 60 percent of the brick kilns in Bihar had adopted this less polluting design. Currently, about 82-85 percent of brick kilns are using the zigzag technology. “With the help of this technology, coal consumption has reduced by 30 to 40 percent, and a reduction of up to 75 percent in carbon and other emissions has been observed,” he said.
Designing zigzag kilns
The zigzag kiln design is a technique for firing bricks in which zigzag paths, characterised by sharp turns in alternating directions, are used to pass hot air through the raw bricks, improving heat transfer and efficiency.
The bricks are arranged to form a chamber about two metres long, which forces air to travel in a zigzag pattern, approximately three times as long as a straight line. This increases the length of the airflow path, enhancing combustion and heat transfer rates. As a result, a more uniform temperature is achieved across the cross-section of the kiln. Through this method, bricks are baked more effectively with less coal. Coal burns completely when it comes in contact with sufficient oxygen, which also reduces pollution.
Sharing the story of the transformation in his kiln, Arvind Kumar, the owner of Shivam Bricks, says, “Twelve years ago, we used to make bricks in an iron chimney. At that time, eight lakh bricks were manufactured annually. The number of bricks has increased, but the cost is also increasing significantly.”
Explaining the cost of implementing the zigzag design in his kiln, he said, “A mechanic came from Moradabad who knew how to make a zigzag kiln. His fee alone was Rs. six lakhs. It then took about one lakh bricks to build it,” he says. “The government had asked to remove the iron chimney and install a fixed chimney. It cost a lot to do that and then once again, the order came to install a zigzag chimney. It cost a lot to demolish it and rebuild it.” However, he accepts the importance of less coal consumption and the reduction in pollution.
“We started using better coal after installing the zigzag technique. Due to this change, the number of good quality bricks has increased, and coal is also being spent less,” Arvind says.
Creating jobs but eroding the environment
The brick industry employs around 8 million workers annually across the country, playing a vital role in providing employment in this unorganised sector. There are about 1.5 lakh brick kilns in the country, according to various estimates. A 2016 analysis by New Delhi think tank Shakti Sustainable Energy Foundation noted that the brick industry produces about 150-200 billion bricks annually and uses about 350 million tonnes of fertile topsoil a year. Another study by the organisation, in 2012, noted that 90 percent of the raw material, or soil, for brickmaking comes from agricultural land, while 10 percent is obtained from riverbeds. This uncontrolled use of agricultural soil is causing a loss of approximately 5,500 acres of fertile farmland every year, which, otherwise, could produce 7,000 tons of rice.
The brick manufacturing sector contributes 8-14 percent of air pollution in the Indo-Gangetic plains, which is also known as the ‘Brick Belt’ of India.
Research also shows that air pollution causes economic losses by reducing labour productivity and affecting the health of those associated with the industry.
Bihar, with around 6,000 kilns, produces approximately 18 billion bricks a year, according to the Shakti analysis, which also highlighted that the production of fired clay bricks consumes 2-4 million tonnes of coal per year and lead to emissions of 4-6 million tonnes of carbon dioxide (CO2) per year.
Murari Kumar Munna, the President of the Bihar Bricks Association, runs a brick kiln in the Begusarai district of Bihar. While talking to Mongabay, he explains the problems of kiln operators. “It is good that efforts are being made to reduce pollution, and kiln operators are cooperating on this, but kiln operators are facing many problems.”
“Many kiln owners are facing problems due to the rising price of coal and the shortage of soil and water. When demand for bricks decreases, one has to sell them after incurring losses.”
He suggested that if soil is given to the kiln operators while removing silt from the river or pond, then their problems can be reduced to some extent.
Chandrashekhar says, “We did not ask for any sudden changes. It would have affected both the construction and the labour market. We spent a lot of time and also conducted training meetings with brick kiln owners to adopt the zigzag technology.”
AI for brick monitoring
Brick kilns are also using technology to monitor kilns, which they could not do well so far because of lack of resources. The Bihar Pollution Control Board, in collaboration with the United Nations Development Program (UNDP) and Development Alternatives (DI), is monitoring the kilns using artificial intelligence technology called Geo AI.
The GeoAI platform, developed by UNDP and the RITES Lab at the University of Nottingham, uses machine learning algorithms and geospatial analysis to provide information about brick kilns.
With the help of this technology, 1,680 kilns were inspected in five districts in Bihar. Ninety-six percent of brick kilns detected by Geo AI were found at the detected location. Seventy-five percent were found to be operational, and 65 percent were identified by the AI algorithm as zigzag kilns. This accuracy improves by feeding more field data into the algorithm. Based on field observation, it was found that an average brick kiln produces 35,086 lakh bricks annually.
This technology has helped predict the locations of more than 47,000 brick kilns in the country’s Ganga plain with 96 percent accuracy.
Fly ash brick alternatives
Air pollution has decreased to some extent with the zigzag design of brick kilns, but the greenhouse gases they emit remain a problem. In Bihar, people are looking for alternatives to clay bricks.
Fly ash is one of the raw materials used to make bricks and cement. It is a byproduct of burning coal, such as in thermal power plants, and is a pollutant. But repurposing it into bricks is one way to use it more sustainably since its disposal is otherwise a major environmental concern. India’s coal-fired power plants generate approximately 196 million tonnes of fly ash annually and the government of India has been pushing for the effective use of fly ash to counter the issues with its disposal.
The 2016 analysis by the SSEF, the Bihar State Pollution Control Board, and Development Alternatives said that Bihar has 129 fly ash brick factories with a capacity of producing 300 million bricks annually. As of 2016, if operating at full capacity, they were estimated to save 67,000 tonnes of coal, 210,472 tonnes of carbon emissions, and 914,400 tonnes of soil each year.
“We want to reduce coal consumption in the future. Therefore, efforts are being made to promote fly ash bricks in Bihar. There are six coal-fired thermal power plants in Bihar, so there will be no problem with raw material for making fly ash bricks,” says Chandrashekhar. “A decade ago, there were only two fly ash brick manufacturing factories in Bihar, but now their number is around 600,” he said.
Sudhir Kumar, Vice President of Bihar Fly Ash Bricks Manufacturers Association, says the major problem with bricks made from fly ash is their lack of demand. “It is necessary to use it in government buildings; hence, this brick has become the standard brick for contractors but there is no awareness about it among common people.”
Sudhir Kumar considers the quality of bricks made from fly ash to be the main reason for the indifference of the common people. “Although bricks made from fly ash are chemically bonded and are better than clay bricks, due to the absence of any standards, poor quality bricks are being made at many places for contractors,” he says.
Suggesting a solution to this problem, he said that after setting standards for brick factories, common people would also look for better options.
Read more: Transforming Assam’s brick industry from red to green
In 2009, the Ministry of Environment, Forest and Climate Change ordered that thermal plants provide free fly ash and in 2017, the Bihar government ordered the use of 100 percent fly ash bricks in the construction of all government buildings. Now there are more than 600 fly ash factories in Bihar, up from about two a decade ago. However, there are challenges. Sudhir Kumar says that in recent years, fly ash is not available for free anymore. “Coal ash is the major raw material in fly ash bricks. It is made by mixing cement and sand in about 70 percent fly ash. Earlier, thermal power plants used to provide it for free, but now they no longer have such an obligation. Not only this, even if you want to buy it by paying money, there are difficulties in getting it because fly ash is the raw material for the cement industry. The government should have some quota of ash for the fly ash bricks factory,” he says.
This story was reported by Mongabay-India’s Hindi team and first published here on our Hindi site on August 16, 2024.
Banner image: A laborer at Shivam Bricks in Gaya, where zigzag technology was installed in 2018 to reduce pollution. Image by Manish Chandra Mishra/Mongabay.
Credits
