Ready-mix concrete segment is banking on the government’s environmental initiatives to take off from the present level of activity in a big way.
The construction industry has a significant role in the India’s development and it contributes about 8-10 per cent to the gross domestic product (GDP) of the country on an average. There are issues like scarcity of labourers, particularly skilled ones, in typical construction sites. In smaller towns, people use site mixes, resulting in cement and dust pollution in the locality. The pollution control agencies becoming stringent and are not allowing one to conduct site mixes enables ready-mix concrete (RMC) units to proliferate, but only in urban areas.
They are yet to make their presence felt in the construction sites in semi-urban and rural areas, where the people are not apprised of the benefits of RMCs yet.
Developing nations like India need to have faster construction with high quality assurance, durability and a pollution-free environment, which can be achieved only with RMC.
Given the government’s thrust towards infrastructure development and housing for all initiatives in the recent years, construction activity is expected to pick up pace in the times to come. Even the low per capital consumption of cement in the country at 180 kg per annum, with concrete accounting for 60 kg, is giving hope that the RMC industry has a lot of scope to expand from the present level. Per capita cement consumption in China is close to 2,000 kg per person per annum.
The cumulative current RMC capacity is estimated at 60,000 cu.m/hr, with a relatively comparative spread of commercial and dedicated batching plants across India. RMC demand also has increased at a CAGR of 4-5 per cent," says Atul Desai is ED & CEO of Prism Johnson (RMC India Division). However, owing to inadequate awareness and soft government norms, conversion from site mix is at a very negligible pace especially in small towns and rural areas.
The RMC segment is concentrated in a few urban pockets of the country. Mumbai and Delhi alone constitute close to 45-50 per cent of total consumption in West and North respectively, whereas Bengaluru and Hyderabad put together constitute about 45 per cent of total consumption in South. Going further, tier-II and tier-III cities may catch up soon, and the concentration of capacities is expected to gradually rise in such cities too.
Key demand centres of western and southern regions are the most favourable markets for RMC business. Mumbai, Nagpur from West and Chennai, Hyderabad and Amravati from southern region are among the top ranked cities for RMC business attractiveness.
Mumbai leads the city-wise attractiveness list. Construction of multiple metro rail corridors, coastal road, trans harbour sea link and Mumbai-Nagpur Expressway to name a few projects may boost RMC demand in times to come, says Desai.
Overall economic slowdown since 2017 impacted commercial and industrial construction, combined with sluggish residential real estate activity and resulted in moderate rise in RMC market at an average of 4-5 per cent to reach an estimated Rs 215 billion (58 million cubic meters) in 2015-16, from Rs 184 billion (50 million cubic meters) in 2012-13. "This growth is anticipated to increase to 6-8 per cent CAGR touching close to Rs 300 billion (81 million cubic meters) by 2020-21. The growth in RMC demand may be primarily attributed to government-infused spending in infrastructure and expected demand from affordable housing," says Desai.
Real estate currently accounts for 60-65 per cent of RMC consumption with residential real estate occupying the majority share of 38-42 per cent. Further, while infrastructure constitutes about 32-35 per cent of RMC demand, industrial and commercial construction constituted about 26-28 per cent of the total RMC consumption in 2016-17.
RMC penetration, measured as the proportion of cement consumed in commercial RMC to total cement consumption in India, is expected to increase to 10 per cent by 2020-21 from the current 7 per cent on the back of healthy demand growth, increased usage in infrastructure projects and penetration of RMC plants in tier-II/ tier-III cities, consistent quality requirements, stringent project timeline, and higher focus on safety and quality norms amongst others, says Desai. RMC penetration in India has gradually risen with increasing acceptability and usage of higher grade of concrete; however, the current levels are very low compared to other developed economies such as USA, Europe and China where it is above 65-70 per cent. The biggest demand drivers for the country’s RMC and batching plant segments will be the government’s large-scale infrastructure and housing for all scheme. These infrastructure projects include the Bharatmala Pariyojana, Sagarmala, the Smart Cities Mission and the Pradhan Mantri Awas Yojana, and affordable housing. The government initiatives on the dedicated freight corridors have also provided opportunities for setting up new RMC plants across the country. With rapid urbanisation, the Indian construction industry has witnessed a major move towards complex architectural structures in commercial buildings, elevated driveways, coastal highways, bullet trains, etc., which may further fuel the demand for high performance concrete.
In fact, this industry is quite fragmented with unorganised segment cornering a major share of the cake. The top five RMC players are holding a market share of close to 35-40 per cent. And rest of the concrete requirement is being fulfilled by local players, said an industry source.
Majority forward integrated players with nation-wide business reach constitute organised segment, which maintains high standards of products, backed by accredited laboratories and research and development.
"Whereas, unorganised players are the local standalone ones, who cater to regional demand with smaller capacities thriving on moderate profitability. Prices are generally lower and product offerings are standard replicated ones. Desired standards and quality are rarely implemented. Safety is a big concern. Grades widely used are replicated and on-the-job training is usually carried out," says Desai.
A lot of regulations and structural changes like implementation of the Real Estate (Regulation and Development) Act (RERA), and GST that have happened in the recent past will encourage the industry to continue its growth streak. So, there is going to be much more level-playing field for major players as well. However, Desai feels that proactive measures from the government like setting stringent and well-defined QA/QC and safety norms to discourage site mix, single window clearance for RMCs and designated green zones for RMCS in urban centres would go a long way in increasing the growth of RMCs in future.
– BS SRINIVASALU REDDY
The main task in cement production is improving sustainability
Prakhar Shrivastava, Head – Corporate Quality, JK Cement Limited, discusses the smart use of supplementary cementitious materials to improve cement production and make cement manufacturing more integral to a circular economy.
What are supplementary cementitious materials? Tell us more about their nature
Supplementary Cementitious Materials (SCM) are materials that are obtained from other industrial waste as by-product and none have their own/individually hardened properties but contribute by grinding with clinker or blending with Ordinary Portland Cement (OPC) through hydraulic and/or pozzolanic activity. These waste products are used as supplementary cementitious materials so that the maximum utilisation of wastes is possible. SCM play a significant role in increasing the workability of the product and enhance the serviceability or durability, thus, decreasing the permeability, aiding in pumpability and finishability.
Typical SCM are flyash, slag, silica fume, natural ashes, rice husk ash, burnt shale, metakaolinite, calcined clay and natural pozzolana i.e., volcanic glass, etc. Among them, flyash and slag are widely used by cement industries for production of PPC and PSC.
Flyash or pulverised fuel ash is formed during combustion of coal from coal-fired electric and steam generating plants and obtained by electrostatic or mechanical precipitation of dust like particles from the flue gases. Earlier, it was recognised as an industrial waste but now has become an important industrial by-product.
Steel slag, a by-product of steel industries, formerly referred to as ground, granulated blast-furnace slag, is a glassy, granular material formed when molten, iron blast-furnace slag is rapidly chilled – typically by water sprays or immersion in water – and subsequently ground to cement fineness.
Tell us about the supplementary cementitious materials and their composition used by your organisation?
Supplementary cementitious materials are soluble siliceous, alumina-siliceous or calcium alumina-siliceous powders used as partial replacements of clinker in cements or as partial replacements of portland cement in concrete mixtures.
At JK Cement, we manufacture Portland Pozzolana Cement (PPC) from all our plants with addition of flyash up to 35 per cent and PPC in premium category with 20 per cent flyash to promote usage of only blended cement to fulfil customer requirements by achieving equivalent strength properties of OPC (Ordinary Portland Cement). At our south India plant in Muddapur, we also manufacture Portland Slag Cement (PSC) with the addition of slag at approximately 65 per cent, meeting all the internal product quality norms.
In our plants, flyash is sourced from different thermal power plants in accordance to the quality, cost and suitability criteria of the plants. Similarly, slag is sourced from steel plants located in Karnataka and Goa. The typical chemical composition and quality requirements as per Indian standards of flyash and slag are mentioned in the table:
Does the use of supplementary cementitious materials impact the process of cement manufacturing?
Impact of SCM can be categorised in two aspects i.e., challenges and benefits. Below are the few challenges faced during the process of cement manufacturing.
- Major SCM are available across the country, such as, dry flyash and pond ash; however, less availability of dry flyash directly connected with thermal power plants (TPP) operation.
- Though there is abundance of pond ash, the major concern in its usage is the high moisture content and coarser size, which creates constraint of jamming, leading to lower production, higher power consumption, blended cement quality and slower production.
- Additional feeding systems are required.
- Challenges of further grinding of abrasive/harder to grind materials such as coarser pond ash, GGBS, copper slag.
- It may increase the cost of the product especially where some SCM are more expensive than cement. i.e., the availability of SCM.
- SCM used for the clinkerisation process required high grade limestone to maintain the desired quality of clinker which affects the mine life.
What are the key advantages of using supplementary cementitious materials in the cement manufacturing process?
The key advantages of using supplementary cementitious materials are:
- Increased clinker substitution; reduces CO2 emission per ton of cement production.
- Reduces use of fossil fuel per ton of cement production.
- Increases the life of limestone mines.
- Reduces consumption of thermal and electrical energy.
- Reduces water consumption.
- Reduces generation of garbage materials at the location, which in turn leads to clean India.
How does the use of supplementary materials increase the profitability of the cement manufacturing for your organisation?
SCM play a vital role in increasing the profitability of the cement manufacturing; with the addition of SCM during cement production, it enhances the overall cement capacity. All our plants are using SCM which are available nearby to plant location. We are investing a lot at locations where SCM are available at a lower cost value and hence reducing the overall cost of cement as compared to clinker cost. Also, these SCM help in reducing the power consumption per ton of cement due to increase in cement volume. Another benefit is the increased cement volume that results in intangible benefit by increasing limestone mine life and conserving natural resources of compendious materials.
Tell us about the quality standards and checks implemented for the final product made using supplementary materials.
The Indian standards have been framed to define the quality of SCM by BIS. Each SCM has a specific Indian standard with specific quality norms like for pulverised fuel ash (IS 3812 Part-1), slag (IS 12089), calcined clay pozzolana (IS: 1344-1981 (Part-II) etc. According to IS specification; internal quality standards have been specified to monitor the SCM quality and these quality specifications are specified in the purchase order for vendor reference. A structured and systematic approach is made to check the SCM quality by the quality control department and all test results are recorded in SIT formats.
In order to make different grade products following checks have been implemented
- Has established a distinct location/yard/silo for proper storage of SCM and to avoid contamination.
- Different hoppers are assigned for each type of material storage and to introduce during the manufacturing process.
- For controlled and calculated addition; weigh feeders are installed.
- For each process or step, quality norms have defined and organised the monitoring and testing in stipulated frequency as per IS requirement.
- Prior to dispatch and release of product in market or to customer the prescribed quality testing performed for quality reassurance.
Tell us about the role of technology in deciding the proportions of supplementary cementitious materials.
Today, the main task in cement production is improving sustainability by reducing emissions. This is achieved by promoting the use of green fuels that lower the conventional fuel consumption and by utilising the alternative raw materials i.e. SCM while producing reliable products at a competitive cost for the construction industry. Less clinker and more SCM is the challenge for the cement industry. The control and optimisation of clinker and cement reactivity is one important key to reach these targets. A problem today is that clinker and cement reactivity are not quantified at cement plants, except by slow and indirect methods like compressive strength testing.
XRF and XRD studies are valuable to understand the composition. However, quantitative XRD does not directly assess the reactivity of SCM. Recently isothermal heat flow calorimetry techniques have been suggested as a new analytical tool for process control and deciding the proportion of SCM in cement.
Recently, the beneficiation or processing of flyash has become hugely important. Flyash Beneficiation Technology or process converts waste from coal-fired power stations (pulverised fuel ash or flyash) by separating the constituent minerals to generate a range of sustainable, environment-friendly products with unique physical and chemical characteristics.
What are the major challenges you face while using supplementary materials for cement manufacturing?
The major concern is availability in terms of quality and quantity; the second factor is cost because the overall cost depends on the distance between the generation unit to the cement manufacturing plant which eventually impacts the cost of cement.
Constantly the SCM demand is increasing and the availability of good quality SCM is very limited and on high cost, the high moisture content of slag and pond ash creates operational challenges. The quality of SCM, largely influenced by the existence of high quartz, heavy metals, alkalis and the fineness that determine the quality of cement. Indian flyash is more crystalline compared to what is generated in other countries and the ratio of formers (SiO2,+Al2O3+Fe2O3) to network modifiers (Na2O+K2O+CaO+MgO) in the Indian flyash is very high and imbalanced.
Depending on the source of coal that varies from mine to mine impacts the composition of flyash like bituminous coals, sub-bituminous and lignite coal determine the flyash colour, fineness and other radicals. Among all SCM, flyash is mostly used in cement plants and as thermal power plants (TPP) are the source of flyash, the present availability of coal and its high cost is a major concern for TPP operations that is affecting the flyash generation. The availability and sources of slag in India are limited, which are affecting its usage in blended cement. Except for flyash and slag, other SCM availability is very less and not too economical.
How does the use of cement made of supplementary materials impact its carbon footprint?
We have committed to achieving our SBTi goal by cutting our GHG emissions according to climate science and as a Global Member of GCCA, by pledging for UNFCCC’s ‘Race to Zero Campaign’ to achieve Net Zero Carbon by 2050.
Clinker manufacturing is responsible for 80 per cent of the carbon emissions and supplementary cementitious materials reduce the clinker content in cement to a great extent without compromising the quality of the product. JK Cement’s green vision is to deliver a sustainable product to meet the stakeholder’s demands while taking several measures that can reduce CO2 emissions in the clinker manufacturing process. This can be achieved by using different types of alternative fuels, RDF/MSW, biomass fuels etc. and various industrial waste such as raw mix components like red mud, GCP dust, iron sludge, zinc slag etc.
Supplementary cementitious materials such as flyash, slag, waste gypsum and industrial waste are the crucial components of JK Cement’s business strategies for conservation of the mineral resources which enables us to produce sustainable construction materials in terms of low embodied carbon at a competitive cost. This has transformed our operations by setting up a benchmark for achieving the best sustainable business practices in the industries and producing Green Certified Cement.
Tell us about the impact of cement made with supplementary materials on the construction and allied industries.
As the construction sector is incessantly challenged by the growing societal demands for safer and cost-effective infrastructures, more and more environment-friendly products and processes must be developed and adopted into our industrial practice. Although supplementary cementitious materials are one of the most used construction materials worldwide, there are still some major concerns about their sustainability and durability.
Firstly, the production of concrete is releasing large volumes of carbon dioxide into the atmosphere, one of the greenhouse gases attributable to
climate change. Secondly, even though cementitious materials are very versatile and robust they may suffer from various deteriorative processes, leading to shortened service life, and consequently, intrusive or expensive costs for maintenance and repair.
To meet the expectations of consumers, demanding more durable, less labour and service intensive materials at a competitive price, numerous new composite materials and technologies have been developed over the last couple of decades including blended cements with Supplementary Cementitious Materials (SCM).
Some of the positive impacts are summarised as follows:
- The use of supplementary cementitious materials in construction not only improves the mechanical property of cement matrix but also reduces its impacts on the environment.
- Blended cement helps to reduce the damage to the concrete from alkali-silica reaction and provides higher resistance to chloride ingress thus reducing the risk of reinforcement corrosion.
- Mitigating sulphate phase formation, which takes place when sulphates found in seawater and some soils react with tricalcium aluminate in concrete.
- Some of the allied industries have started making limestone bricks, AAC blocks, hollow blocks, flyash bricks which are not only considered as green products but also reduce the cost of construction works.
How do you foresee the future of the global cement industry in terms of using alternative materials for cement manufacturing and running the race of decarbonisation?
The production of Ordinary Portland Cement (OPC) is continuously declining, with a simultaneous increase in the production of blended cement like PPC, PSC, and Composite Cement based on flyash and granulated blast furnace slag. SCM are increasingly used to minimise cement-related CO2 emissions and increase plant efficiency from an economic and environmental perspective.
At present, blended cements have a greater share (73 per cent) in comparison to ordinary portland cement (27 per cent). Other cement formulations such as Portland Limestone Cement (PLC) and Limestone Calcined Clay Cement (LC3) are also at different stages of development in India.
In recent years, globally and in India several research has been conducted for the development of environment-friendly and less CO2 emission cement i.e., Calcium Sulfo-Aluminate Cement, Reactive Belite Cement, Alkali Activated Cement etc., that is found to be more energy-saving, less carbon intensive and optimises waste-utilisation. Further studies were carried out on carbon capture storage and usage, zero emission mining, oxyfuel combustion in kiln etc. If these solutions become economically viable, they may contribute to a considerable reduction in CO2 output from the cement industry.
Looking Beyond the Low Hanging Fruits
With the Net Zero targets looming in the near future and an imminent problem of emissions to contend with, the Indian cement manufacturing sector should no longer be satisfied with doing the bare minimum. Looking at innovative solutions, breakthrough technologies, automation and artificial intelligence, and most importantly, a change in mindset, is the need of the hour.
There is no denying the fact that cement being the second most consumed material after water in the world in terms of quantity, and by virtue of its inherent conversion process from limestone to clinker, the amount of CO2 emission from cement alone (7 per cent of all emissions) is one quarter of all industry emissions put together. Even in dollar terms the maximum CO2 per dollar of revenue industry-wide shows cement taking the top spot at 6.9 kg of CO2 per dollar.
The process of cement making has majorly two areas – raw material resources and clinker and cement manufacturing, where the emission needs to be segregated into its constituent elements, both from the point of view of energy consumption and also in terms of CO2 emissions. While two-thirds of the emissions stem from the calcination process, which is where the bulk of the thermal energy is consumed, the raw material extraction to feed generates negligible amounts of emissions and the cement grinding from clinker and logistics makes the bulk of the remaining emissions. The total emissions of 925 kg per tonne of cement production leaves a staggering 4 billion tonnes of CO2 generation each year, as the world produces 4.2 billion tonnes of cement annually.
The pathways through which the industry has progressed so far can be seen in the following areas:
- Energy Efficiency
- Alternative Fuel
- Clinker Substitutes
- New Technologies
- Alternative Building Materials
If one goes into the analysis of each of these levers that the cement industry is currently using, the first three have remained the low hanging fruits where most of the attention and energy had been diverted to. These top three levers have so far fetched about 25 per cent of the CO2 emission reduction possibility into 2050, with energy efficiency showing a possibility of 7.2 per cent, alternative fuel a possibility of 10.5 per cent and clinker substitution 7 per cent. However, the investments needed for these and the abatement cost per tonne of CO2 would look very different for each. For example, alternative fuel would still need disposal cost, carbon capture and storage as well and the investments for these would make this category the highest in terms of abatement cost. The following table gives this as follows among all the levers:
So far, the cement industry has focused on the low hanging fruits, mostly clinker substitution after working on efficiency improvement levers, where the abatement costs were negative, giving economic benefits to the cement makers. Driven by the country’s landfill laws and pollution control norms, some of the advanced countries have outright rejected use of coal and PetCoke in cement kilns, replacing that with alternative fuel and biomass. However, these have to go through the abatement cost of Carbon Capture and Storage, which has been so far very high. Let us go through each category and see what is the current stage of development of these areas of focus.
Efficiency Improvement: The last step change for cement kiln technology was in the case of dry process replacing the wet process, thereafter the recent advancement has happened in the use of electrical energy instead of thermal energy for the kiln conversion process. This has been put to commercial use but till we use renewable energy in kilns, this does not give any advantage in terms of overall gain in emission. The replacement cost of thermal to electrical could be very high as well, so the future electrification of kilns, depends on use of renewables that must be part of a stable grid power, which raises many actions to be taken.
Clinker Substitution: Maximum gains have happened so far in reduction of emission by adopting various means to replace clinker with fly ash, slag etc., but the future could actually have very little of this available as generation of electricity moves to the renewable mode and the steel companies adopt more of the green technology that would generate far less waste eventually from the process.
Alternative Fuel: The availability of alternative fuels depends largely on the development of local supply chains that must wade through a number of constituencies like the local municipalities for the municipal wastes and the development of logistics systems have a lot to be desired. The only hope remains the use of biomass, which is the highest growing segment. The investments here include not only the platforms but also avenues of de-chlorination, etc.
Carbon Capture Use and Storage (CCUS): This method isolates and collects CO2 from industrial emissions and either recycles it for further industrial use or safely stores it underground. Once captured, a wide variety of potential uses for CO2 could be possible, such as in the production of glass, plastics, or synthetic fuels. Though carbon-capture technologies do exist commercially, they are utilised in very few plants—one example being natural-gas plants. Therefore, the progress of extensive decarbonisation will not only depend on the economic viability of storing and sequestering the carbon but also on the availability of CO2 marketplaces, through which the captured CO2 can be sold.
Carbon-cured Cement: This technology injects CO2 captured during cement production to accelerate the curing process and ‘lock in’ CO2 in the end product. Current low-carbon cement technologies can sequester up to 5 per cent of CO2, with the potential of 30 per cent. In fact, 60 million tonnes of CO2 per year are projected to be stored via carbon-cured concrete in 2050.
Alternative Building Materials: In the years to come, alternative building materials could shift demand away from cement. To date, cross-laminated timber (CLT) has attracted the most attention. Made by gluing wooden panels and boards together, CLT is an adequately fire-resistant building material that can reach large dimensions. Its application has recently increased and includes projects in Canada, Japan, and Sweden. Assuming a 10 per cent replacement of concrete—and considering the CO2 captured in the wood has been abated—would reduce the overall cement footprint by 25 per cent, as even more
CO2 is captured than avoided by reducing the cement production.
Recycled Concrete: Use of recycled concrete and demolition waste is the new development especially in Europe with the sources of limestone becoming limited in the future.
The potential reduction of 50 per cent of the CO2 emissions by 2050 depends on the progress of carbon capture and storage systems and technologies, where we have a few start-ups who have come up with very different processes. For example, one start-up uses a lower proportion of limestone in its cement, which results in fewer process and fuel emissions; this company’s process also locks in additional CO2, which is added before the concrete cures. Adding CO2 makes the concrete stronger and reduces the amount of cement needed. Carbon-cured concrete could also use CO2 captured during cement production. Today’s methods could sequester up to 5 per cent of the CO2 produced during production, but newer technologies could sequester 25 to 30 per cent. Products such as carbon-cured concrete, positioned differently, could earn a ‘green premium,’ potentially giving companies an edge among environmentally conscious buyers and greater pricing power.
The Indian cement industry must move steadily to these new innovations, after making the maximum gains from the low hanging fruits. Innovation remains the key word and investments in innovation, including the mindset, for cement is the first step in this journey.
Indian cement industry is well known for its energy and natural resource efficiency
Dr Hitesh Sukhwal, Deputy General Manager – Environment, Udaipur Cement Works Limited (UCWL) takes us through the multifaceted efforts that the company has undertaken to keep emissions in check with the use of alternative sources of energy and carbon capture technology.
Tell us about the policies of your organisation for the betterment of the environment.
Caring for people is one of the core values of our JK Lakshmi Cement Limited. We strongly believe that we all together can make a difference. In all our units, we have taken measures to reduce carbon footprint, emissions and minimise the use of natural resources. Climate change and sustainable development are major global concerns. As a responsible corporate, we are committed with and doing consistent effort small or big to preserve and enrich the environment in and around our area of operations.
As far as environmental policies are concerned, we are committed to comply with all applicable laws, standards and regulations of regulatory bodies pertaining to the environment. We are consistently making efforts to integrate the environmental concerns into the mainstream of the operations. We are giving thrust upon natural resource conservation like limestone, gypsum, water and energy. We are utilising different kinds of alternative fuels and raw materials. Awareness among the employees and local people on environmental concerns is an integral part of our company. We are adopting best environmental practices aligned with sustainable development goals.
Udaipur Cement Works Limited is a subsidiary of the JK Lakshmi Cement Limited. Since its inception, the company is committed towards boosting sustainability through adopting the latest art of technology designs, resource efficient equipment and various in-house innovations. We are giving thrust upon renewable and clean energy sources for our cement manufacturing. Solar Power and Waste Heat Recovery based power are our key ingredients for total power mix.
What impact does cement production have on the environment? Elaborate the major areas affected.
The major environmental concern areas during cement production are air emissions through point and nonpoint sources due to plant operation and emissions from mining operation, from material transport, carbon emissions through process, transit, noise pollution, vibration during mining, natural resource depletion, loss of biodiversity and change in landscape.
India is the second largest cement producer in the world. The Indian cement industry is well known for its energy and natural resource efficiency worldwide. The Indian cement industry is a frontrunner for implementing significant technology measures to ensure a greener future.
The cement industry is an energy intensive and significant contributor to climate change. Cement production contributes greenhouse gases directly and indirectly into the atmosphere through calcination and use of fossil fuels in an energy form. The industry believes in a circular economy by utilising alternative fuels for making cement. Cement companies are focusing on major areas of energy efficiency by adoption of technology measures, clinker substitution by alternative raw material for cement making, alternative fuels and green and clean energy resources. These all efforts are being done towards environment protection and sustainable future.
Nowadays, almost all cement units have a dry manufacturing process for cement production, only a few exceptions where wet manufacturing processes are in operation. In the dry manufacturing process, water is used only for the purpose of machinery cooling, which is recirculated in a closed loop, thus, no polluted water is generated during the dry manufacturing process.
We should also accept the fact that modern life is impossible without cement. However, through state-of-the-art technology and innovations, it is possible to mitigate all kinds of pollution without harm to the environment and human beings.
Tell us about the impact blended cement creates on the environment and emission rate.
Our country started cement production in 1914. However, it was introduced in the year 1904 at a small scale, earlier. Initially, the manufacturing of cement was only for Ordinary Portland Cement (OPC). In the 1980s, the production of blended cement was introduced by replacing fly ash and blast furnace slag. The production of blended cement increased in the growth period and crossed the 50 per cent in the year 2004.
The manufacturing of blended cement results in substantial savings in the thermal and electrical energy consumption as well as saving of natural resources. The overall consumption of raw materials, fossil fuel such as coal, efficient burning and state-of-the-art technology in cement plants have resulted in the gradual reduction of emission of carbon dioxide (CO2). Later, the production of blended cement was increased in manifolds.
If we think about the growth of blended cement in the past few decades, we can understand how much quantity of , (fly ash and slag) consumed and saved natural resources like limestone and fossil fuel, which were anyhow disposed of and harmed the environment. This is the reason it is called green cement. Reduction in the clinker to cement ratio has the second highest emission reduction potential i.e., 37 per cent. The low carbon roadmap for cement industries can be achieved from blended cement. Portland Pozzolana Cement (PPC), Portland Slag Cement (PSC) and Composite Cement are already approved by the National Agency BIS.
As far as kilogram CO2 per ton of cement emission concerns, Portland Slag Cement (PSC) has a larger potential, other than PPC, Composite Cement etc. for carbon emission reduction. BIS approved 60 per cent slag and 35 per cent clinker in composition of PSC. Thus, clinker per centage is quite less in PSC composition compared to other blended cement. The manufacturing of blended cement directly reduces thermal and process emissions, which contribute high in overall emissions from the cement industry, and this cannot be addressed through adoption of energy efficiency measures.
In the coming times, the cement industry must relook for other blended cement options to achieve a low carbon emissions road map. In near future, availability of fly ash and slag in terms of quality and quantity will be reduced due to various government schemes for low carbon initiatives viz. enhance renewable energy sources, waste to energy plants etc.
Further, it is required to increase awareness among consumers, like individual home builders or large infrastructure projects, to adopt greener alternatives viz. PPC and PSC for more sustainable
What are the decarbonising efforts taken by your organisation?
India is the world’s second largest cement producer. Rapid growth of big infrastructure, low-cost housing (Pradhan Mantri Awas Yojna), smart cities project and urbanisation will create cement demand in future. Being an energy intensive industry, we are also focusing upon alternative and renewable energy sources for long-term sustainable business growth for cement production.
Presently, our focus is to improve efficiency of zero carbon electricity generation technology such as waste heat recovery power through process optimisation and by adopting technological innovations in WHR power systems. We are also increasing our capacity for WHR based power and solar power in the near future. Right now, we are sourcing about 50 per cent of our power requirement from clean and renewable energy sources i.e., zero carbon electricity generation technology. Usage of alternative fuel during co-processing in the cement manufacturing process is a viable and sustainable option. In our unit, we are utilising alternative raw material and fuel for reducing carbon emissions. We are also looking forward to green logistics for our product transport in nearby areas.
By reducing clinker – cement ratio, increasing production of PPC and PSC cement, utilisation of alternative raw materials like synthetic gypsum/chemical gypsum, Jarosite generated from other process industries, we can reduce carbon emissions from cement manufacturing process. Further, we are looking forward to generating onsite fossil free electricity generation facilities by increasing the capacity of WHR based power and ground mounted solar energy plants.
We can say energy is the prime requirement of the cement industry and renewable energy is one of the major sources, which provides an opportunity to make a clean, safe and infinite source of power which is affordable for the cement industry.
What are the current programmes run by your organisation for re-building the environment and reducing pollution?
We are working in different ways for environmental aspects. As I said, we strongly believe that we all together can make a difference. We focus on every environmental aspect directly / indirectly related to our operation and surroundings.
If we talk about air pollution in operation, every section of the operational unit is well equipped with state-of-the-art technology-based air pollution control equipment (BagHouse and ESP) to mitigate the dust pollution beyond the compliance standard. We use high class standard PTFE glass fibre filter bags in our bag houses. UCWL has installed the DeNOx system (SNCR) for abatement of NOx pollution within norms. The company has installed a 6 MW capacity Waste Heat Recovery based power plant that utilises waste heat of kiln i.e., green and clean energy source. Also, installed a 14.6 MW capacity solar power system in the form of a renewable energy source.
All material transfer points are equipped with a dust extraction system. Material is stored under a covered shed to avoid secondary fugitive dust emission sources. Finished product is stored in silos. Water spraying system are mounted with material handling point. Road vacuum sweeping machine deployed for housekeeping of paved area.
In mining, have deployed wet drill machine for drilling bore holes. Controlled blasting is carried out with optimum charge using Air Decking Technique with wooden spacers and non-electric detonator (NONEL) for control of noise, fly rock, vibration, and dust emission. No secondary blasting is being done. The boulders are broken by hydraulic rock breaker. Moreover, instead of road transport, we installed Overland Belt Conveying system for crushed limestone transport from mine lease area to cement plant. Thus omit an insignificant amount of greenhouse gas emissions due to material transport, which is otherwise emitted from combustion of fossil fuel in the transport system. All point emission sources (stacks) are well equipped with online continuous emission monitoring system (OCEMS) for measuring parameters like PM, SO2 and NOx for 24×7. OCEMS data are interfaced with SPCB and CPCB servers.
The company has done considerable work upon water conservation and certified at 2.76 times water positive. We installed a digital water flow metre for each abstraction point and digital ground water level recorder for measuring ground water level 24×7. All digital metres and level recorders are monitored by an in-house designed IoT based dashboard. Through this live dashboard, we can assess the impact of rainwater harvesting (RWH) and ground water monitoring.
All points of domestic sewage are well connected with Sewage Treatment Plant (STP) and treated water is being utilised in industrial cooling purposes, green belt development and in dust suppression. Effluent Treatment Plant (ETP) installed for mine’s workshop. Treated water is reused in washing activity. The unit maintains Zero Liquid Discharge (ZLD).
Our unit has done extensive plantations of native and pollution tolerant species in industrial premises and mine lease areas. Moreover, we are not confined to our industrial boundary for plantation. We organised seedling distribution camps in our surrounding areas. We involve our stakeholders, too, for our plantation drive. UCWL has also extended its services under Corporate Social Responsibility for betterment of the environment in its surrounding. We conduct awareness programs for employees and stakeholders. We have banned Single Use Plastic (SUP) in our premises. In our industrial township, we have implemented a solid waste management system for our all households, guest house and bachelor hostel. A complete process of segregated waste (dry and wet) door to door collection systems is well established.
Tell us about the efforts taken by your organisation to better the environment in and around the manufacturing unit.
UCWL has invested capital in various environmental management and protection projects like installed DeNOx (SNCR) system, strengthening green belt development in and out of industrial premises, installed high class pollution control equipment, ground-mounted solar power plant etc.
The company has taken up various energy conservation projects like, installed VFD to reduce power consumption, improve efficiency of WHR power generation by installing additional economiser tubes and AI-based process optimisation systems. Further, we are going to increase WHR power generation capacity under our upcoming expansion project. UCWL promotes rainwater harvesting for augmentation of the ground water resource. Various scientifically based WHR structures are installed in plant premises and mine lease areas. About 80 per cent of present water requirement is being fulfilled by harvested rainwater sourced from Mine’s Pit. We are also looking forward towards green transport (CNG/LNG based), which will drastically reduce carbon footprint.
We are proud to say that JK Lakshmi Cement Limited has a strong leadership and vision for developing an eco-conscious and sustainable role model of our cement business. The company was a pioneer among cement industries of India, which had installed the DeNOx (SNCR) system in its cement plant.