There is an urgent need to harness technology to reduce energy consumption in the process of brick-making in the country and its contribution to the pollution levels

A remarkable aspect of India’s economy is the significant contribution the construction sector makes. It is estimated that the property industry contributes around eight per cent of the GDP. This, not counting the ancillary business it fuels. The huge footprint of this sector is visible in the continuous construction activity you see everywhere. While this spells economic success and deserves to be encouraged with policy and economic incentives, some thought needs to be paid to the ecological aspect too.

The brick manufacturing sector could be an area worth looking at. India is the second largest producer of bricks, after China. The estimated production in India is close to 150 billion. The Indian brick industry is unorganised with small production units clustered in rural and semi-urban areas. It is believed that there are more than one lakh brick kilns in the country, with an annual turnover of over Rs. 1,000 crore.

“Brick-making is one of the major energy-consuming sectors,” laments Uma Rajarathnam, Head-Environment Practice at Enzen Global Solutions, an energy and environment consulting company. “About 25 million tonnes of coal and several million tonnes of biomass fuel are needed every year to run this industry. Coal consumption by the brick industry is approximately 10 per cent of the total coal consumption in the country. The share of energy in the total cost of brick production is 35 to 50 per cent. Therefore, some innovation and eco-friendly technologies can save brick-making companies a huge amount in production cost, and conserve energy at the same time,” she says.

Gas emission

The impact of brick-making on the environment is quite significant. “Low efficiency and high fuel consumption result in significant air pollution. In addition to the emissions from the chimney, the work environment is also polluted. Particularly in the dry summer months, the wind carries a lot of dust particles from brick kilns. Coal consumption in brick-making contributes to the greenhouse gases. In addition to air pollution, it also contributes to water pollution and degradation of soil quality due to top soil erosion,” adds Uma.

Energy efficiency through improved technologies and the use of fly ash can reduce fuel consumption and pollution levels. Fly ash entails a 30 per cent saving in fuel in firing as compared to traditional clay brick technology. Vertical shaft kilns, habla kilns and tunnel kilns are some of the improved options in brick-making.

Basically, there are two methods to improve production technology — one is a more energy-efficient kiln to produce burnt clay bricks, and the other is replacing burnt clay bricks with fly ash bricks which are manufactured without the use of thermal energy. Says Ingo Hofmaier, Director, Commercial & Managing Director, Weinerberger, an Austrian company into manufacturing of clay-based building materials including bricks and hollow blocks, “Wienerberger Porotherm clay block production plant uses the latest production technologies as we respect environmental aspects. You need to see the complete life-cycle of a product for an assessment.

When digging the clay, Wienerberger uses clay sourced from non-agricultural land (like clay tanks which need to be de-silted) which are mixed with secondary raw materials (e.g. fly ash, rice husk, granite dust, etc.). In the dryer, we use to a large extent recycled hot air from the kiln. The kiln itself is highly isolated to avoid loss of heat during firing. A significant reduction of energy consumption is the design of the product. With a void ratio of up to 60 per cent we also save 60 per cent of energy compared to conventional bricks,” he adds.

Barriers

Unfortunately, it is not quite as easy to bring in awareness on the need to improve the technology in the brick-making process. Many brick kiln owners don’t know the reasons for the relatively poor performance of the kilns, and the various technology options that can be used to improve performance. Lack of resources and skilled manpower is another reason why it is difficult to bring in technological advances in this sector.

A shortage of technology intermediaries for large-scale diffusion of technologies is yet another barrier. Only a small group of technology providers exist in this sector. These are either small private firms or government institutions. They have limited capacity in terms of reaching out to kilns scattered across the country.

“Clearly, environment-friendly technologies cost money and can only be absorbed if you have large production facilities. On the other hand, unit costs decrease with larger production quantities.

This is how the large manufacturers manage their competitiveness. On a larger scale, these eco-friendly technologies can also reduce costs. A large potential lies in the use of wastes and non-primary energy resources during production,” opines Ingo Hofmaier.

The brick industry is vital to the property industry. A significant amount of a project’s budget goes into this raw material.

This apart, the industry employs a large number of people directly and indirectly. It is, therefore, necessary to bring in technology and awareness to harness the potential of this industry further, and decrease its contribution to pollution levels.