Initiatives towards sustainable future
Sanjay Joshi, Chief Manufacturing Officer, Nuvoco Vistas Corp. speaks to Manufacturing Today about the company’s initiatives towards sustainability
The cement industry is known to be polluting and not friendly to the environment. On this background, what steps is Nuvoco taking towards sustainability and making manufacturing a greener product?
Not just in India, but globally, the cement industry has become aware of its carbon footprint, and has started to function in line with the Paris Climate Accord. Manufacturing companies across the world are now developing carbon capture technologies, which are being tested along with carbon cure clinkers during production of cement. The use of clinker factor reduction using GBBS, calcined clay, and fly ash has also emerged as a solution towards sustainable manufacturing.
At Nuvoco, we are committed towards enabling smarter and greener solutions to the construction industry. At our Construction Development and Innovation Centre (CDIC), we have developed Concreto Green, keeping in mind the long term environmental impact. Following in-depth research that highlighted that an alarming 54% of India faces high-to-extremely high water stress, Concreto Green was created to conserve a shrinking water table. It is manufactured with GBBS using 28% fly ash, which offers lower shrinkage and better workability with 25% less water as compared to other OPC 53 variants in the market. Additionally, it is able to provide durability and strength, with a high resistance to water penetration and chloride attacks. In a similar manner, our Duraguard range of cement is also manufactured using fly ash.
Please tell us about rainwater harvesting & water recycling initiatives at various plants?
In our constant endeavour efforts to reduce our water footprint and bring about sustainability, our primary focus and commitment has been on conscious best practices like rainwater harvesting, re-use of waste-water and water-recycling. Rain water harvesting pits have been created across our plants. At Arasmeta and Sonadih, we have used the empty mine pits as a proactive measure towards conserving water resources, which have led to an improvement in the groundwater levels. The harvested water is put to various uses like controlling the dust emissions in mines, spraying on haul roads, watering the plants and vegetation surrounding the mines area. At our Mejia Plant, a rain water harvesting pond has been constructed and the harvested rainwater has been channelized for use in the development of the greenbelt area. At the Jojobera Cement Plant, three rain-water harvesting pits have been commissioned towards the conservation of water. Rainwater storage has been developed and made available inside the plant area at the Chittor Plant. As part of their CSR drive, our Arasmeta and Sonadih plants have also undertaken work in the form of deepening of ponds in the surrounding villages to improve rainwater storage in the vicinity.
In addition to that, the recycling of discharge water from the sewage treatment plant (STP) has been put to good use by sprinkling on haul roads. As part of Nuvoco’s new initiative aptly titled, “War on Waste”, we have taken up an ambitious pledge to target a reduction of 5% water consumption at every plant we own. To aid this target, water meters have been installed at every possible juncture to monitor and make note of exact water flow and thereby reduce wastage out of usage. All the STP waste water is being regularly used for plantation purposes at all our plants.
Also, tell us about waste heat recovery system.
One of our major sustainability initiatives was to reduce emissions, which we were able to achieve through the waste heat recovery (WHR) systems being installed in our plants. What the WHR does is that it reutilises the heat which is being emitted from a cement kiln in the clinker manufacturing process, and converts it into electrical energy. This energy is then used to meet a portion of the energy requirements at our plants. We have invested in WHR systems across all of Nuvoco’s integrated plants, which began operations earlier this year; the installed capacity across our integrated plants is 30MW.
Can you please elaborate on use of waste and by products from power and steel plants?
Waste management is an important part of all our operations at Nuvoco, and at every step of the manufacturing process, care is taken to reduce leftovers and reuse materials. The addition of cementitious material (fly ash, ground blast furnace slag) in cement has greatly reduced our carbon footprint, as we are able to take the waste from another industry, and use it in cement production, making it a win-win for everyone. As a result of our efforts, today we have the highest cementitious material additions in the industry. We manufacture both PSC (Portland Slag Cement) and PPC (Portland Pozolona Cement; fly ash based), making it among the lowest CO2 emissions/ton of cement production within the sector.
How far the company has been successful in reducing energy consumption?
An important part of our sustainability goals is to reduce the energy we consume. We have focused on reducing our specific heat consumption (SHC) as well as specific power consumption (SPC) in the clinkerization and grinding units.
Over the last few years, we have taken various steps to reduce heat and power consumption, which include:
Installation of LED lights.
Installation of the latest Variable Frequency Drives (VFD).
Replacement of old inefficient fans by latest generation high efficiency fans.
Installation of high efficiency and modern coolers at Sonadih Cement Plant Line2 and Chittor Cement Plant to reduce SHC.
Compressed air and utility optimization.
Study of Computational Fluid Dynamics (CFD) in gas ducts.
Modification of ducts and implementation of the CFD action plans.
Productivity improvement of kiln and cement mills.
Use of alternate fuels and bio waste as substitute fuels.
Investment and implementation in energy reduction CAPEX.
What is the company’s sustainability vision?
An integral part of our vision at Nuvoco is to build and contribute towards a sustainable world through various means. To meet this goal, we are actively developing products that use fewer natural resources, and finding solutions for recycling waste materials like fly ash and slag. We are also working with the communities in which we operate, to ensure all-round growth and development through healthcare, education, infrastructure, and employability opportunities. For example, at our Arasmeta Cement Plant, a thick green belt all along the roads, colony, plant and mines has been developed under the Afforestation Programme. Similarly, we have undertaken extensive tree plantation drives at Sonadih, Chittor and Mejia. Over 22,000 trees have been planted under social forestry projects for developing the green land as part of Chhattisgarh Van Vikas Nigam (CRVVN) initiative of Hariyar Chhattisgarh. We have also planted 1000 trees as part of Harit Haryana Abhiyan in Government Primary and Secondary schools and have distributed 4000 plants/saplings to promote Social Forestry Programme in 15 villages of Latiyaboni Gram Panchayat.
We are also actively adopting renewable energy; with our plant at Chittor being powered by a 500kWp solar plant and we will start a 1MW plant at our Bhiwani plant by June this year. Small steps taken now can go a long way in helping us meet our sustainability goals, and besides incorporating them in core areas of our operations, we are also extending them to our townships. Here we have composting machines, and are working towards meeting our Zero Waste Discharge goal. In FY20, we could substantially reduce our water consumption by more than 40% with the installation of the WHR systems. We are now working towards reducing water consumption by an additional 5% in FY21 as well as increasing the green coverage in our plant and mines areas.