Just as the real estate industry begins to embrace environment-friendly technologies in building homes and buildings, the same pro-environment bug has bitten one of its raw materials suppliers —- the cement industry.
Local cement manufacturers are coming up with their own means to cut the carbon footprint of their products, which according to studies, contribute to about 4 percent of carbon emission globally.
Roland van Winjen, chief operating officer of Holcim Philippines, Inc., said companies are also busy trying to reduce the environmental degradation resulting from the production of cement.
“When we produce clinker, you have to imagine (this) picture: A wonderful mountain, green, that is blasted apart and over the 20 to 25 (year) lifetime of the cement plant, is completely diminished. After that, the material we get from the mountain we burn. For that, we use lots and lots of energy, mainly coal, which is also not green. At the end of the process, we have clinker that it is ground to become cement where we use lots and lots of electricity,” said Van Winjen.
Carbon emission, a major contributor to global warming, occurs in the manufacturing of cement when limestone is burnt to produce clinker, the raw material in the production of cement. To produce clinker, limestone is heated with around 1,500 degrees centigrade of heat, using mostly coal which also emits carbon.
Efforts to reduce carbon emission from cement ranges from finding alternative materials to use for fuel, educating the public of the more efficient way to use cements, and introducing alternative cement products that use less clinker, among others.
A study by the Lawrence Berkeley National Laboratory (Berkeley Lab) based in the University of California, shows that “the average intensity of carbon dioxide emissions from total global cement production is 222 kg of C/t of cement.”
Concrete is the second most used material in the world next to water. And as places grow and improvement is characterized by development activities, cement consumption to create concrete will not diminish.
In the Philippines, cement production is seen at 21.2 million metric ton of kiln capacity, with demand projected to hit up to 28.5 million metric tons.
There are 17 manufacturers of cement in the Philippine, the biggest of which are Holcim and LaFarge Cement Services (Philippines) Inc., comprising 63 percent of total capacity as of end-2010.
LaFarge Philippines for some time has been marketing their “Fly ash cement” with considerable success. This general purpose cement, marketed under the type 1P or the blended category, uses less clinker content than the traditional Portland cement while allowing the company to recycle its coal by-product produced in the burning process of coal.
Cirilo Pestano, vice president for corporate communications of LaFarge (Philippines) said the marketing of fly ash is met with favorable response since it has been launched in the market in 2001.
Don Lee, president of LaFarge (Philippines) earlier said the company is trying to expand the source of fly ash in the Philippines to take advantage of the planned construction of coal-fired power plants in the country.
“Adding cementitious materials such as fly ash and slag in the cement mix reduces the need for clinker. It is during the clinker manufacturing process that the most carbon dioxide is emitted as we burn coal in order to reach the high process temperatures required to produce clinker. Within our manufacturing process, Lafarge is aggressively pursuing the reduction in carbon footprint in two key ways: by minimizing the production of clinker by developing and selling blended cements with more environmentally friendly cement additives,” said Pestano.
LaFarge’s fly ash cement is the only product of its kind sold as a general purpose cement, same with Portland cement, with competing companies having their own blended cement but is marketed as a masonry type of cement, used mostly for finishing jobs in construction works.
“The Philippine market has generally accepted the use of blended cement which is a tacit acknowledgement of its advantages: durability and workability. This is the reason why more than two-thirds of the market has converted to blended/cementitious cement. However, there are still many opportunities to produce “greener” cements with higher additions of various types of cement additives that provide for different types of concrete performance,” said Pestano.
Holcim’s van Winjen, however, said cement cannot be called “green” technically, given that the manufacturing of cement “involves extraction of mineral resources, and requires a lot of coal, which releases carbon dioxide.”
“But what is perhaps relevant is not the ‘greenness’ of the product, but the application. Concrete (with cement as main ingredient) has qualities (such as thermal mass and fire-resistance) which allows for sustainable construction solutions if rightly applied,” he said.
Van Winjen said educating cement users about the proper and efficient use of cements in their work helps a lot.
“In this part of the world, there is still low awareness on the urgency of protecting the environment. Very few people know about the benefits of sustainable construction and correct cement application. In addition to low awareness, there is less application knowledge and the building material users tend to be conservative. These aspects lead to the fact that it’s not always that the best cement product is used in terms of value for money and the environment,” he said.
Holcim has its own less-clinker content cement marketed under the masonry type.
But much of cement manufacturers’ carbon reduction initiatives fall more into activities when initially producing clinker.
Van Winjen said cement producers are “increasingly” using alternative fuels and raw materials in manufacturing, while implementing co-processing so as to reduce wastes in its processes.
“Through co-processing… we are able to process waste streams in our cement kilns, thus allowing for the safe and effective disposal of many types of wastes, including industrial wastes. This is supplemented by a careful maintenance program to ensure that our equipments are at optimal performance, thus allowing for more efficient energy consumption,” said Van Winjen.
LaFarge also implemented a mechanism to capture unspent energy in the clinkering process to produce electricity. The company is likewise using biomass as alternative fuel for its manufacturing activities.
” Lafarge’s associated company, Republic Cement Corp., has installed a waste heat recovery (WHR) system at the Republic Teresa plant. A lot of heat is produced during the cement production process. However, only a small portion of this heat is being used for raw material and coal drying. Most of the heat ends up being wasted, then vented directly into the atmosphere,” said Pestano.
“The WHR project involves the installation of a 4.5-megawatt capacity turbine at the Teresa plant to capture and utilize most of the waste heat to generate electricity, the first of its kind in the Philippine cement industry,” Pestano added.
Van Winjen said cement production consumes 100 kilowatts of electricity per ton manufactured.
These efforts are complemented with other initiatives to maintain the lower carbon emission of plants in its processes.
Van Winjen said Holcim is “the first company to put continuous monitoring of emissions.”
Holcim’s continuous emissions monitoring systems ensure that emissions are within permissible levels set by company and the Clean Air Act.
LaFarge Philippines meanwhile has partnered with World Wildlife Fund (WWF) Philippines for its environmental programs and together have commissioned a life cycle analysis (LCA) study that will measure the carbon footprint of the production of blended cement versus ordinary Portland cement.
“Based on the initial LCA results, using blended cement will reduce the carbon footprint by approximately 30 percent,” said Pestano.
Van Winjen said cement companies are likewise involved in the reforestation of areas mined for limestone. At other times mined areas are used for land development purposes.
With demand for cement still on the rise, Van Winjen said that cement companies will have to continue working to reduce their contribution to carbon emission.
“Concrete compared to other building material options is extremely well-positioned when it comes to elements important for sustainable development and sustainable construction. While its ingredients may not be green, concrete itself is a very important help for you architects and constructors to work towards green buildings. It is strong and durable, energy efficient and recyclable,” said Van Winjen.
“The demand for this product is also not expected to go away… The demand for concrete is not going down and will continue to rise driven by the emergence of megacities here in Asia,” he added.
So for now what companies like Holcim can do is “reduce our energy consumption and replace coal with alternative fuels, and find building materials that do not take away mountains and use so much energy,” according to van Winjen.
