07 Jun
A decade has just now ended and we’ve got in to a brand new year 2020. One of the biggest challenge our mother earth facing today is climate change. The earth is getting more than two (2) degrees warmer every year, Amazon has burnt, bush fires in Australia is wreaking havoc, Middle East, Africa and some parts of our South East Asia is witnessing rages of war, large scale deforestation, massive industrialization at the emerging economies are leading to global warming, greenhouse gas emissions and major depletion of flora and fauna at an alarming rate.
The table below shows the total global emission as 36153 MTCO2 as per the 2017 data and the share of emissions across the world where China, US and India were seen as the major three contributors leading the pack. Globally the large and heavy industries with no or low substitutes (like cement/concrete) are facing the major challenges to reduce the emissions and positively contributing towards making a greener planet earth.
Carbon Emissions Around the world
Contrary to the flip side mentioned above there are also opportunities for growth and development in terms of technology, infrastructure, human capital, innovations and various disruptions happening across these spectrums. And industries like Cement which is in the core sectors of any country’s economy is a classic case of dichotomy wherein at one hand it provides the very basis of development, building & infrastructure, real estate, housing, logistics etc. and on the other hand contributes to Co2 emissions having a major environmental impact. Today globally 30 bn. MT of cement based materials like concrete, plasters. mortars, concrete, tiles, bricks etc. is produced and consumed annually. After food and water cement is the third most item of human usage across the globe. Cement being the large global industry faces the toughest climate challenge since it has got very low substitution. Ever since Portland cement is invented in 1924 or even before that when lime and brick dusts were used in construction cement forms a major ingredient in concrete thus being responsible for the Co2 footprint. Presently cement contributes around 5-7% of the global Co2 emissions after fossil fuel and was one of the major agenda for discussion during the Paris climate change talks in 2019.
The cement industry if we take the example of India have been consciously making efforts to work around the challenges of reducing Co2 emissions. Ever since the industry was deregulated in 1989 it has progressed a lot towards making lesser carbon footprints in terms of many a disruption which has happened in production, sourcing MIC (mineral ingredients and constituents), raw materials and in pollution control measures. The industry over the years have migrated from wet process plants to semi dry process and finally to dry process plants which does the preheating of raw meal (mixture of limestone, shell, alumina, bauxite etc.) before it enters the kiln (furnace) for making clinker which is the main raw material for manufacturing cement and thus contributes to reducing the energy consumption and costs in terms of coal usage. Alternate fuels (like rice husk, soya hush, lime sludge, red mud tyre chips, rubbers, plastic, polythene, ETP sludge, waste oil etc.) or AFR as it is known is also now being extensively used these days to increase the thermal substitution rate (TSR) and in turn reduce Co2 emissions. The major breakthrough in fact happened when the industry started moving from producing Ordinary Portland Cement (OPC) to blended cements like Portland Slag Cement, to Portland Pozzolana cement (PPC) and to very recently Composite cement which uses more cementitious materials (also known as Mineral Ingredients and Constituents-MIC) like fly ash, slag which replaces the clinker usage without diluting the strength, quality and durability aspect in cement and concrete. The blended cement (Portland Slag Cement) got produced in Germany way back in 1885 and made it’s beginning in India in 1951. The Portland Pozzolana cement (PPC) is comparatively came in vogue during the last two decades as gargantuan volume of fly ash generated by the thermal power plants posed a real environmental hazard and need to be mitigated. Further research and development has brought us the Composite cement which makes use of both fly ash and slag along with clinker as per BIS (Bureau of Indian Standards) specifications. Alternatively, in many a sites or in RMX (Ready Mixed Concrete) batching plants these MICs (say, Fly Ash and /or Slag) is mixed with Ordinary Portland Cement to make durable concrete. Currently approx. 60% of India’s cement production is blended cement which is cost efficient and environment friendly cement, reducing carbon footprint and many harmful emissions, conserving depleting limestone reserves and fossil fuels and mitigating soil pollution and erosion. Moreover, to successfully dispose of several thousand tonnes of blast furnace slag generated by the country’s steel plants and the huge fly ash generated by the thermal power plants is a huge challenge which was also effectively mitigated by using it in producing blended cement and thereby achieving the dual objectives of its successful disposition and substituting it against the clinker (limestone) which is a precious resource and expected to last for not more than 40-50 years unless new deposits are found out and permitted to make use of. The efficiency & emissions are the two major midterm goal for the industry at present and both positively contributes to lessen the industry’s adverse impact on the environment. There are various other disruptions happened within the industry worth mentioning is like replacing bag filters by ESPs (Electro Static Precipitators), usage of LD slag (Linz Donawitz process), usage of pet coke, use of high efficiency boilers in captive power plants, closed circuit mill & vertical roller mill (VRM) to ensure better grinding and control of dust particles inside the mill, reduction in fossil fuel consumption through Waste Heat Recovery System (WHRS), solar power plants and alternate fuels is immensely contributing to high energy efficiency and to effectively control emissions.
Cement as a product (making a transition from commodity to product and therefore brand) is highly logistics driven and we could see that both clinkerization and grinding units near to raw material and MIC sources and thus involves a major amount of transportation of inbound raw materials and outbound dispatches of cement inventory to various warehouse, depot, project sites and to various end customers including RMX plants, Large Buyers and individual house builders. And these gives opportunity for green transportation like using of waterways to move cement and clinker, split manufacturing units near Grinding Units (MIC & Market), palletization, mobile silo and mobile packers etc. to make it near to the market (thereby reducing the transportation footprint, cycle) and thus reducing the diesel emissions to a large extent.
Although a modest beginning is already made and continuing however the magnitude of the challenge is quite big. The industry captains as a responsible corporate citizen is making relentless efforts to make quick wins’ in terms of using the supplementary cementitious materials (SCMS) for making more and more blended cements, investing in research and development to come out with green concrete, self-healing and self-compacting concrete etc., encouraging sustainable construction in terms of design, use of eco-friendly materials and robust construction practices to supplement our efforts sustainable and get going.
