Activated carbon injection to reduce mercury emissions by 90%
Lehigh Southwest Cement Company has found a way to cut mercury emissions by as much as 90 per cent. The cement company’s new system uses activated carbon injection, a method that traps mercury within cement rather than releasing it into the air. The system takes mercury, a natural component of cement production, and binds it with limestone particles, essentially trapping the mercury inside the finished cement product. The company also announced it will install a continuous monitoring system in the fall so that emissions can be better analysed in real time. This system will help the company to adapt to the new EPA standards of the US Environmental Protection Agency. The standards will limit American cement companies’ mercury emissions to 55 pounds per 1 million tonne of clinker.
Teijin’s initiatives towards carbon neutrality
Teijin Group provides innovative solutions for enhanced quality of life
As climate change has a large impact on the global society and economy, industry, governments and academia are making efforts to reduce environmental impact including greenhouse gas (GHG) emissions through energy conservation, green energy and lifecycle assessment (LCA).
As a people-focused company, the Teijin Group provides innovative solutions for enhanced quality of life and works to minimise any negative impact on the environment or society through its business activities. Teijin considers environmental management to refer to management that reduces the environmental impact over the entire product life cycle, including all processes from material procurement to production, product use and disposal.
With raised targets for reducing CO2 emissions, Teijin’s long-term environmental targets have been adapted to an ambitious level of 30% reduction. With a further target of reducing the portion of emissions that accounts for over two-thirds of the overall supply chain emissions by 15%. Establishing achievable targets while also being ambitious has been key for us in leading the way to a carbon-neutral future. The Teijin Group’s targets for GHG emissions are now officially validated as Science Based Targets (SBT) as the first Japanese chemical manufacturer. The objective of SBT is to help achieve the Paris Agreement’s goal of limiting global temperature rise to well below two degrees Celsius above pre-Industrial Revolution levels, which is expected to significantly reduce the risks and impacts of climate change.
Teijin established a method for calculating CO2 emissions during the manufacture of Tenax carbon fibres, which has made it possible to conduct Life Cycle Assessment (LCA) of all carbon fibres offered by Teijin. By doing so, Teijin became the first company in the industry to be able to achieve this. Not only calculates its own manufacturing processes, but Teijin also evaluates the carbon footprint of its customers’ manufacturing process with this method.
Teijin Aramid, a core aramid business of the Teijin Group headquartered in the Netherlands, has improved the carbon footprint of its para-aramid product called Twaron by 28% compared to 2014 according to the applicable ISO standards 14040 and 14044. The benefit of using Twaron can be calculated economically and environmentally by the Customer Benefit Model (CBM) developed by Teijin Aramid.
Teijin is also at the cutting edge of what is possible to exceed demands in our ever-changing world. Providing solutions to help reduce vehicle weight, which in turn helps reduce gas emissions and improves overall fuel performance, means we are impacting countless journeys around the world. Teijin Automotive Technologies’ has one of these solutions called TCA Ultra Lite, a 1.2 specific gravity ultra lightweight sheet moulding compound formulation that uses glass fibre reinforced plastic (GFRP). Carbon fibre reinforced thermoplastic (CFRTP) Sereebo is another example. Conventional carbon fibre-reinforced plastic (CFRP) that utilises thermosetting resins requires several minutes to several hours to mould, making it unfit for components used in mass-produced automobiles. However, by making use of thermoplastic resins, we have been able to significantly reduce these moulding times. This has allowed Teijin to establish the world’s first mass-production technology that is able to mould CFRP in only one minute.
In addition to this, the Teijin Group’s fibres and products converting company Teijin Frontier offers apparel manufacturers numerous products that help reduce CO2 emissions, including ECOPET, a recycled polyester fibre that utilises used PET bottles and fibre scraps as raw materials, and SOLOTEX, which uses plant-derived ingredients for a portion of its polymers.
Teijin Frontier has also developed a system to calculate CO2 emissions within the polyester fibre manufacturing process, thereby enabling the implementation of LCA. It will gradually expand the scope of its operations to cover more textiles, including those used for weaving and dyeing, while working with its partner companies to evaluate the entire life cycle of polyester fibre products.
Dust Control: Balancing Health and Sustainability
With governmental norms for reduction of dust emissions and technological advancements for dust control, the Indian cement industry is geared up to reduce the environmental and health hazards of dust emissions and to make cement processing more sustainable.
Dust emissions from cement plants can have significant environmental and health impacts, as well as affecting nearby communities. Cement plants generate dust during the production process, which can include raw material grinding, blending, preheating, kiln processes, clinker cooling and cement grinding.
Dust emitted from cement plants is a significant environmental and health concern in India, where the cement industry is a major contributor to air pollution. According to the Central Pollution Control Board (CPCB), the cement industry is one of the top five polluting industries in India, and dust emissions are a major contributor to this pollution. To address this issue, the Indian government has set emissions standards for the cement industry under the National Ambient Air Quality Standards (NAAQS) and the Environment Protection Act (EPA). The standards set limits on particulate matter (PM) emissions, which include dust particles, from cement plants.
The Indian cement industry has also implemented measures to reduce dust emissions such as using modern filters and control technologies, optimising production processes and providing training to employees on dust control practices. However, despite these efforts, the industry still faces challenges in meeting emissions standards, particularly for smaller, older plants. To further address the issue of dust emissions, the Indian government has launched initiatives such as the National Clean Air Program (NCAP) and the Swachh Bharat Abhiyan (Clean India Mission), which aim to reduce air pollution and improve environmental cleanliness.
“We have addressed fugitive emissions in the clinker tunnels at the cement plant where the clinker is stored in the silos and a lot of dust comes out when it is discharged onto the conveyor belts. Conventionally cement plants have used back filters which are connected to exhausts located besides the discharge point, but it is common knowledge that these systems were not entirely effective, resulting in a lot of dust in the tunnels. It also made it very difficult to get maintenance done in these tunnels because anyone who enters would have to breathe dust and that is a health hazard,” says Venkatesh Ravula, CEO, DCL Bulk Technologies.
DUST EMISSION HAZARDS
Dust hazards are a significant concern in Indian cement plants due to the high levels of dust generated during production processes. Exposure to cement dust can have negative health effects on workers, including respiratory issues such as bronchitis and asthma, as well as skin and eye irritation. Some of the major sources of dust hazards in Indian cement plants include raw material handling, clinker production, and cement grinding processes. Dust can also be generated during maintenance activities such as cleaning, repair, and replacement of equipment.
To address these hazards, Indian cement plants have implemented a variety of measures, including using personal protective equipment (PPE) such as respirators, dust masks, and goggles, as well as installing dust collection and control systems. In addition, training programs for employees on the safe handling and control of dust are often provided. The Indian government has also established regulations and guidelines to protect workers from dust hazards in the workplace. The Factories Act, 1948 and the Mines Act, 1952 set standards for occupational health and safety, including measures to control dust emissions and protect workers from exposure to hazardous materials.
“For achieving effective prevention and control of potential fugitive emission sources in cement manufacturing plants, specific requirements along with guidelines have been evolved by the central government. For the Indian cement industry, the Ministry of Environment Forest and Climate Change has notified the norms for reduction of dust emission from cement plants, which includes Particulate Matter, SOx and NOx. The notification clearly defines the limits for above mentioned emissions, particulate matter should be <30 milligram, SOx should be <100 milligram, NOx should be <1000, 800, 600 milligrams. It depends on the age of the plant or we can say that on the commissioning date of the plant,” says Anil Gupta, Technical Head – Nimbahera Plant, JK Cement.
It is important for Indian cement plants to prioritise the implementation of dust control measures and training programmes to protect the health and safety of their workers and nearby communities.
FILTRATION TECHNIQUES AT CEMENT PLANTS
Cement plants use various types of dust filtration equipment and techniques to control dust emissions and improve air quality. Some of the common methods used include:
- Bag filters: Bag filters are commonly used in Indian cement plants to capture dust particles from the production process. These filters consist of bags made of fabric material that trap dust particles as air passes through them.
- Electrostatic precipitators (ESPs): ESPs are another type of dust filtration equipment used in Indian cement plants. They use an electrostatic charge to attract and trap dust particles.
- Cyclones: Cyclones are a type of mechanical separator that can be used to remove larger dust particles from the air. They work by creating a cyclonic effect that causes particles to be separated from the air stream.
- Wet scrubbers: Wet scrubbers are used in some Indian cement plants to capture and remove dust particles from the air. They work by spraying water onto the particles, causing them to stick to surfaces and be removed from the air.
- High-efficiency particulate air (HEPA) filters: HEPA filters are highly efficient filters that can remove up to 99.97 per cent of particles as small as 0.3 microns. They are commonly used in cleanrooms and other sensitive environments.
In addition to these filtration techniques, Indian cement plants also use various operational and maintenance practices to reduce dust emissions, such as regular equipment cleaning and maintenance, optimising production processes to reduce dust generation, and providing training to employees on dust control practices.
“Modern mining equipment is deployed with dedicated dust separation systems. Electric/hydraulic equipped mining machinery is also being used to minimise the dust. The cement industry has been modernised by introducing specific dedusting equipment used in the production, transport, and storage processes. The installation is equipped with specific filters (bag filters or electrostatic filters). This has reduced the flue gas emission and amount of dust released into the atmosphere. The main dedusting machine is the state-of-the-art bag filter, which is available and guarantees a maximum emission of 10 mg/Nm3,” says Pankaj Kejriwal, Whole Time Director, Star Cement.
“Truck mounted road/area sweeping machines are also operated to clean the dusty area. High pressure water spray systems are used to clean the tyres of vehicles moving inside the plant to minimise the fugitive dust emission,” he adds.
DUST CONTROL NORMS IN INDIA
The Indian government has established norms and regulations to control dust and fugitive emissions from cement plants. Some of the key norms include:
- National Ambient Air Quality Standards (NAAQS): The NAAQS set by the Central Pollution Control Board (CPCB) establish limits on air pollutants, including particulate matter (PM) emissions, from all industries, including cement plants.
- Environment Protection Act (EPA): The EPA provides guidelines and regulations for controlling emissions from industries, including the cement industry.
- Cement Industry (Prevention and Control of Pollution) Rules, 2013: These rules set specific emission limits for cement plants in India. For example, the rules specify that PM emissions should not exceed 30 mg/Nm3 for dry kilns and 50 mg/Nm3 for wet kilns.
- Ministry of Environment, Forest and Climate Change (MoEFCC) guidelines: There are guidelines for the installation of pollution control equipment in cement plants, including bag filters, electrostatic precipitators and wet scrubbers.
- State pollution control boards: State pollution control boards are responsible for enforcing the norms and regulations related to dust and fugitive emissions at cement plants.
Cement plants in India are required to comply with these norms and regulations to minimise their impact on the environment and public health. Failure to comply can result in fines, legal action and suspension of operations.
Exposure to cement dust may lead to health hazards for workers like respiratory issues, and skin and eye irritation.
It is important for cement plants to prioritise reducing dust emissions to protect both the environment and nearby communities from potentially harmful effects. The future of dust emission in the Indian cement industry is likely to see a continued focus on reducing emissions to improve air quality and protect public health. The industry is under increasing pressure to adopt cleaner technologies and more sustainable production processes, and there is a growing demand for environmentally friendly cement.
To meet these challenges, Indian cement plants are likely to adopt a range of strategies and technologies to reduce dust emissions, such as using low-emission fuels, implementing more efficient production processes, and investing in advanced dust filtration and control technologies. There is also likely to be increased focus on recycling and reusing waste materials to reduce environmental impact.
The Indian government is also expected to continue to play an active role in regulating dust emissions from the cement industry. This may include strengthening existing regulations and standards, as well as developing new policies and initiatives to encourage the industry to adopt more sustainable and environmentally friendly practices.
Overall, while the Indian cement industry faces significant challenges in reducing dust emissions, there are also many opportunities for innovation and progress. With continued investment in new technologies and sustainable production processes, the industry can help to create a cleaner, healthier and more sustainable future for all.
Automation can provide real-time monitoring of emissions
Anil Gupta, Technical Head, JK Cement Works, Nimbahera, discusses the adverse effects of dust emissions on human health and the environment and how use of advanced filtration systems, automation and other technology solutions can help reduce it.
What are the key areas where dust emission is prominent in cement manufacturing?
Cement manufacturing unit consists of various sections such as mining, crusher, raw mill, kiln, coal mill, cement mill, packing plant, etc. However, the key areas where dust emission is highly prominent are dump hoppers of limestone and additive crusher, raw material storage yards, feeding circuits of clinker and cement raw material, packing and loading area, raw mill bag house, cooler ESP, coal transport and grinding circuit, cement mills bag house and CPP stack.
What are the measures taken to control the dust emissions at a cement plant?
We have two types of dust emissions:
- Stack or vent duct: From process operation and have fixed point of release.
- Fugitive dust: Dust that is generated or emitted from open air operations or at material transport point (emissions that do not pass through as stack or vent).
To control both the types of dust emissions in a cement plant, following measures are taken:
- Installation of de-dusting bag filter.
- Installation of bag house and electro static precipitator.
- Installation of water spray system in yard area.
- Enclosure should be provided for all unloading operations, except wet materials like gypsum.
- The pathways in the coal yard for vehicle movement should be paved.
- Accumulated dust shall be removed / swept regularly and water the area after sweeping.
- Air borne fines extracted from the clinker cooler shall be separated and sent to the last possible destination directly, if possible.
Tell us about governmental regulations and compliance for dust emissions.
For achieving effective prevention and control of potential fugitive emission sources in cement manufacturing plants, specific requirements along with guidelines have been evolved by the central government. For the Indian cement industry, the Ministry of Environment Forest and Climate Change has notified the norms for reduction of dust emission from cement plants, which includes particulate matter, SOx and NOx. The notification clearly defines the limits for above mentioned emissions, particulate matter should be < 30 milligram, SOx should be
< 100 milligram, NOx should be < 1000, 800, 600 milligrams. It depends on the age of the plant or we can say that on the commissioning date of the plant.
Some relaxation is there in the SOx limit. It should be 700 and 1000 milligram with more pyretic sulphur presence in limestone deposit. In cases where SPM concentrations exceed the prescribed limit, necessary corrective measures in terms of improving the controls shall be taken and action taken records of improvements carried out be maintained.
Tell us about the role of dust collectors in cement production.
A dust collector is a system used to enhance the quality of air released from industrial processes by collecting dust and other impurities from air or gas. It is designed to handle high-volume dust loads. A dust collector system consists of a blower, dust filter, a filter-cleaning system, and a dust receptacle. It is distinguished from air purifiers, which use disposable filters to remove dust. It may be of single unit construction, or a collection of devices used to separate particulate matter from the process air. It is also used as an air pollution control device to maintain or improve air quality.
A dust collector also helps to increase productivity as when dirt, dust and debris collect on equipment, it can make its way inside, interfering with the mechanics of the equipment. This can lead to slower machines and broken equipment. Compromised machinery constantly needs attention and repairs. Dust collectors remove this risk, allowing your machinery to work at optimal performance.
Where is the collected dust discarded?
The environmental concerns related to cement production, emission and disposal of dust is becoming progressively significant. Cement kiln dust (CKD) is fine-grained, particulate material chiefly composed of oxidised, anhydrous, micron-sized particles collected from electrostatic precipitators during the high temperature production of clinker. CKD so generated is partly reused in cement plant. No dust is discarded in the environment except stack dust. However, Stack emitted dust is discarded in an environment which is under the limit of governmental norms.
What is the impact of dust emission on the environment in and around?
In the past, cement dust spread out over large areas due to wind and rain and accumulated over the soil and plants. It has the potential to affect animal and human health adversely. Dust from cement factories adversely affects the forest ecosystem, soil enzymes, fungi and bacteria population within the vicinity of cement factories. Furthermore, it was shown that plant height, phytomass, net primary productivity, chlorophyll content, metabolites and yield were reduced in response to cement dust in the polluted areas.
After the 1990s, the cement industry did a lot of investment for dust control. Several modifications have also been carried out in the existing system to make the system more efficient. This can be achieved through the use of advanced filtration systems, alternative fuels, automation and other technology solutions. It is also important to monitor and report emissions to regulatory agencies to ensure compliance with environmental regulations. No significant impact has been observed in and around the cement plant.
Can dust emission be qualified as a health hazard at a cement plant?
Yes, dust emission can be qualified as a health hazard at a cement plant. Inhalation of cement dust can cause a range of respiratory problems, including bronchitis, asthma and silicosis, a lung disease caused by inhaling crystalline silica dust. Prolonged exposure to high levels of cement dust can also increase the risk of developing lung cancer.
To minimise the health risks associated with dust emissions, cement plants are continuously implementing measures to reduce the amount of dust generated during the manufacturing process. This is achieved through the use of advanced filtration systems, automation, and other technology solutions. It is also important to provide proper personal protective equipment (PPE) to workers and to ensure that they receive adequate training on the health risks associated with working in a cement plant.
How can automation and technology help in reduction of dust emissions?
Automation and technology are contributing in reduction of dust emissions in following ways:
- Real-time monitoring and control: Automation can provide real-time monitoring of emissions, which can help to identify and address potential issues before they become major problems. This can be achieved through the use of sensors and advanced data analytics.
- Optimised process control: Advanced process control technologies can optimise the cement manufacturing process and minimise dust emissions. This technology can help operators monitor and control the process in real-time, ensuring that emissions are kept to a minimum.
- Advanced filtration and scrubbing systems: Technology can improve the efficiency of filtration and scrubbing systems, such as bag filters and electrostatic precipitators. These systems can remove particulate matter and other pollutants from the air, reducing dust emission.
- Use of drones for inspection: Drones can be used to inspect hard-to-reach areas in the plant, such as the top of the kiln or preheater tower, without risking the safety of personnel. This can help to identify areas where dust emissions are high, and take corrective actions.
- Overall, automation and technology can help reduce dust emissions in cement plants by providing real-time monitoring and control, optimising process control, improving filtration and scrubbing systems and using drones for inspection.
Tell us about newer innovations that help reduce the dust missions and control it?
The cement industry has been under increasing pressure to reduce its environmental impact, especially concerning the emission of dust and pollutants. Here are some of the newer innovations that the cement industry is adapting to reduce dust emissions and control them:
- Use of Low-NOx Burners: The use of low-NOx burners in cement kilns reduces the emission of nitrogen oxides (NOx), which are one of the major contributors to air pollution. These burners help in reducing the temperature inside the kiln, which in turn reduces the formation of NOx.
- Installation of Bag Filters: Bag filters are used to capture particulate matter emitted during the cement manufacturing process. These filters are highly efficient and can capture up to 99 per cent of the particulate matter emitted from the kiln. This reduces the emission of dust and improves the air quality around the cement plant.
- Use of Alternative Fuels: Cement manufacturers are increasingly using alternative fuels, such as waste materials, biomass, and municipal solid waste, to power their kilns. These fuels emit less carbon dioxide (CO2) and other pollutants than traditional fossil fuels.
- Automation of Process Control: Advanced process control technologies can optimise the cement manufacturing process and minimise dust emissions. This technology can help operators monitor and control the process in real-time, ensuring that emissions are kept to a minimum.
- Introduction of Green Cement: Green cement is a new type of cement that is produced using environmentally friendly manufacturing processes. It can reduce carbon emissions by up to 80 per cent compared to traditional cement. Green cement can be produced using waste materials such as fly ash and slag, and can also be made using renewable energy sources.
Overall, the cement industry is making significant strides in reducing its environmental impact, particularly concerning dust emissions. These innovations are helping to improve the sustainability of the industry and protect the health of nearby communities.