In Pursuit of Greener India
Cement production is characterised by an extremely high-temperature combustion process (up to 20,000°C flame temperature), necessary for heating and fusing the raw materials. The traditional fossil fuels most commonly used in this combustion process are coal, heavy fuel oil or gas. Substitution of these fossil fuels by alternative, waste derived fuels is a common practice in the cement industry, in many parts of the world. The nature of the production process makes it eminently suitable for this purpose - by ensuring full energy recovery from various wastes under appropriate conditions. Any solid residue from the waste then becomes a raw material for the process and is incorporated into the final cement clinker. Sometimes, waste can also be used to substitute raw materials in the process, thereby also conserving the natural resources generally used in the manufacture of cement.Why is this issue important?
Waste is an important issue for society - as an example, Europe alone produces more than 350 million waste tyres per annum. Recycling and disposal options for many waste materials and industrial by-products are often limited - used tyres is but one example. Where recycling is not possible, incineration or landfill is the most common disposal practice available for many wastes. However, by using waste as an alternative fuel or raw material in the cement-making process, there are benefits for society as well as to the cement maker. For many cement companies in India, it represents an important business opportunity, because it reduces fuel costs and CO2 emissions. By dealing safely with wastes that are often difficult to dispose of in any other way, cement manufacturers are able to provide an important service to society.
India can achieve 25 per cent thermal substitution rate (TSR) by 2025. In comparison to global standards, the country is far behind, as in many countries the substitution is 60-100 per cent. The main differentiator is the waste characteristics and the lack of support by the required agencies for generating a good segregated quality waste. This long term plan of achieving 25 per cent substitution rate, is as it is very challenging.
Why achieving 25 per cent substation rate is a challenge, is very well explained by Milind Murumkar, Advisor - AFR, Vicat India Group. The main challenges faced by any cement manufacturer in use of Alternative Fuels & Raw Materials (AFR), which can be classified into four.
Managements 'will' to use and improve the AFR utilisation in its plants. Which means, creating a suitable environment and commitment in their people to achieve the targeted short and long term plans. Initially no one is willing to bring and use waste - which may have strong or unpleasant odour, may be difficult to handle, store and use - from other industries in their plant. Management thus needs to build and develop the infrastructure in a manner that it can use all types of industrial wastes be it solids, semi-solids or liquid.
Secondly, skill development and infrastructure is important, as AFR utilisation requires special skills in cement plants. In this case, engineers need to be properly trained to understand the waste characteristics, raw material and fuel characteristics; and the point of dosage in the kiln. This is mainly due to the fact that while using higher quantities of wastes in cement plants, process stabilities are maintained, which may otherwise affect the quality of product and production levels. A cement plant has to know its raw material composition and fuel composition to decide on the types of waste that can be used in their system and accordingly decide on the feeding points of different types of waste that need to be co-processed.
Murmukar further enlightens the regulatory requirements. There are specific rules and guidelines for hazardous waste during transportation, storage and usage, that the cement plants have to comply with, while using hazardous materials. The equipment and storage area etc., needs to be selected based on the availability of waste and the plants for next 10-15 years. Here Murumkar's advice is to have proper market data mapping and long term agreements with the waste generators to build trust and confidence in them.
Lastly, understanding waste and waste generators, is the most challenging factor. It is necessary to understand the pain points of the waste generating industry and work on providing a total solution for managing their waste in an environmental friendly manner. Business success depends on having a good 'win-win' model between the cement plant and the waste generating industry. Waste generators need total solution for the different wastes generated. The success in utilisation of different types of waste in cement plant lies in having co-processing ability for providing total solution to the generating industry.
AFR for Greener India
As rightly simplify by UltraTech officials, the advantages of co-processing of alternate fuel in cement plant ranks higher in the waste processing hierarchy. This is because, high flame temperature (2,000°C) - ensures complete destruction of harmful pollutants. Residence time of combustion gases above 1,000°C in excess of three-four seconds - ensures complete destruction of pollutants. Plus, a complete destruction of organic compounds. Importantly, co-processing of AFR in cement ensures total neutralisation of acid gases, sulphur oxides and hydrogen chloride, by the active lime in the kiln load, in large excess to the stoichiometry. And, for the betterment of environment, there will be no production of by-products such as ash or liquid residue from gas cleaning.
Benefits of AFR is it produces overall environmental benefits by reducing releases to air, water and land. It also, maximises the recovery of energy while ensuring their safe disposal. Since, most of the cement plant use coal as a fuel, AFR definitely stands a chance to substitute coal, with savings made through resource conservation and associated CO2 emissions.
Meanwhile, one must understand that not every waste is suitable. In addition, according to Holcim, manufacturers must ensure that they do not impact product quality nor increase their atmospheric emissions by using a particular waste. At the same time, a key objective of AFR use is to achieve reductions in CO2 emissions. Meanwhile, stakeholder debate continues over the use of AFR in cement kilns. Some stakeholders are concerned about potential health or environmental impacts from the handling and combustion of alternative fuels. Others are concerned that product quality could be compromised. It has also been claimed that the use of waste and by-products as fuels actually perpetuates the production of these wastes, by offering a legal, cost-efficient solution to disposal.
However, other stakeholders are pleased by the 'win-win' possibilities of cutting GHG emissions and disposing of wastes by using AFR. It is therefore a challenge for cement manufacturers to manage stakeholder expectations and provide assurances to demonstrate their responsible use of these waste materials.
Use of alternate fuels for TSR is a financial viable intervention with very good internal rate of return (IRR). It also depends on the type of waste proposed for usage and technical intervention. Many Indian cement plants have successfully implemented these options and substituted fossil fuel significantly. The payback period generally varies between two-four years.
Meanwhile, AFR is certainly beneficial in terms of earnings for the company (Refer Earning Benefits on page no 44). If managed properly, to have a blend of commodities and industrial waste in terms of TSR and thermi cost reduction, the benefits will be substantial. Unless AFR co-processing has a good economic viability, its long-term sustenance cannot be ascertained. The entire economic model needs to be such that the Rs/thermi is lower than that of fossil fuels.
Consistent supply and uniform quality are main constraints in utilising AFRs - for example, tyre carbon black. The cost of the carbon black depends upon the cost of waste tyres in the domestic market and import conditions. Due to high demand for waste tyres, the cost of carbon black is increasing and hence its adulteration too. There should be long term agreement with the manufacturers directly with clear quality parameters, thereby the traders can be avoided and can sustain the supply as well as quality. However, the essence of the agreement shall be the price factor with regards to the coal price. Regulatory authorities need to standardise all waste to streamline market operations.
Also, there is no existing standard for NOx from kiln Only SPM standard is 50 mg/Nm3 for new plants and 100 mg/Nm3 for old plants. NO2 standard from 1-1-2016 and SPM standard from 1-6-2016 for cement kiln will be 800 mg/Nm3 and 30 mg/Nm3, respectively. Now, most of the cement manufacturers have deployed online monitoring system and commissioned in plants stacks for monitoring SPM, SO2 and NOx. The online monitoring system has already started and likely to help manufacturers in controlling emissions while firing different type of AFRs.
Present Policy Framework
The Indian Waste Management policy frame-work, notified in 2016 is well designed for sustain-able waste management. It gives due recognition to co-processing. Its salient features are following.
- These are based on the principle of Sustainability rather than disposal
- Waste generator is required to manage his waste respecting the Waste Management Hierarchy and SPCBs are required to authorise the same. (Rule 4, HWM)
- A facility is required to obtain authorisation from SPCB for receiving, storing, handling, transporting and pre-processing of wastes based on the availability of compliant infra-structure to handle them safely. (Rule 6, HWM)
- Co-processing in cement plant is to be implemented based on the compliance to prescribed emission standards. Co-processing trial of any waste is not required anymore to receive authorisation for its co-processing. (Rule 9, HWM)
- Interstate movement of wastes for recycling or co-processing is to be implemented by intimation to the respective SPCBs. (Rule 18, HWM)
- Pre-processing centers to be developed rather than landfill sites
- Convert SCF to RDF (Rule 15 (v), SWM)
- For wastes recycling / utilisation (Rule 5.1 HWM)
- Segregated Combustible Fraction (SCF) having calorific value >1500 Cal / gm to be sent to cement plant for co-processing (Rule 21.2, SWM)
Social and Environmental Security
Different kinds of wastes that get generated during agricultural, industrial or municipal acti-vities pose severe environmental concerns to the society and can cause substantial damage to the environment in case they are not managed properly. All these wastes that may be hazardous or non-hazardous, can be co-processed in an envi-ronmentally sound manner in the cement kilns.
As per the new Waste Management Rules 2016, Government of India has abolished the earlier practice of granting waste by waste permit system. This system, says Ulhas Parlikar, Deputy Head, Geocycle India, ACC Ltd, "was in practice prior to the notification of these rules in which, the permit for undertaking co-processing of a waste used to be granted based on the review of the results of the co-processing trial of that particular waste."
"This action MoEFCC has implemented because the cement kiln co-processing has been demonstrated as an environmentally sound and ecologically sustainable solution for waste management," he added. To achieve this, according to Parlikar, environmentally compliant management of the wastes, proper control on inputs, process, output and emissions is required by way of implementing necessary facilities and process control measures.
The new Waste Management Rules 2016 have mandated that the permission for co-processing of all kinds of wastes can be granted by State Pollution Control Boards (SPCBs) based on the availability of the prescribed infrastructure in the plant to handle wastes in an environmentally sound & occupationally safe manner and while undertaking co-processing, compliance to the emission standards notified by MoEFCC for cement kilns undertaking co-processing. The Central Pollution Control Board (CPCB) has already prepared a circulated a draft of the pre- and co-processing guideline illustrating specific requirements to the stakeholders and is in the process of publishing the same after accommodating stakeholder comments.
Target: 25% TSR
Currently, the Indian cement industry's average TSR is around four per cent, whereas the TSR in few countries are as high as 60 per cent (Austria, Germany). Now, with above stated challenges, it is a matter of interest to see how India will reach the set target of 25 per cent or more of TSR by 2025. A few is outlined by V Kannan, Counsellor, CII - Godrej Green Business Centre. The Government has already included necessary policy changes for adopting co-processing in the country. Further, capacity building on new rules and proper implementation of the rules will substantially increase co-processing levels in the country.
Under the Swachh Bharat Mission (SBM) and smart cities programme, management of municipal solid waste management (MSW) through sustainable practices is very vital. The new SWM rules also advocate source segregation of waste to channelise the waste-to-wealth by recovery, reuse and recycle. In addition, all industrial units using fuel and located within 100 km from a solid waste-based refuse derived fuel (RDF) plant shall make arrangements within six months from the date of notification of these rules to replace at least five per cent of their fuel requirement by RDF so produced. That apart, non-recyclable waste having calorific value of 1,500 K/cal/kg or more shall not be disposed of on landfills and shall only be utilised for generating energy either or through refuse derived fuel or by giving away as feed stock for preparing refuse derived fuel. And lastly, high calorific wastes shall be used for co-processing in cement or thermal power plants. Cement plants also working on various initiatives like pre-processing platforms, utilisation of hazardous waste, tie ups with urban local bodies to utilise MSW as a fuel increases TSR levels.
For experts to achieve the target there is an urgent need to implement necessary policy level reforms that are emission monitoring and infrastructure based. Further, there is a need for the cement industry to implement necessary facilities for waste handling, storing, pre-processing and feeding in the kiln. There is also investment required for creating facilities for monitoring and control of emissions. Further, the legislative process needs to bring the material in the market. For example, although, large quantities of tyres are replaced every year in the country, the same is not visible in the waste market. This is because there is no defined regulatory system in place to collect and divert them in the waste market. Once they become visible in the waste market, they will be available to the cement industry for disposal through co-processing.
- AFR substitution increased from less than 1% to more than 4% in 2016.
- Recognition for co-processing in the policy framework.
- >45 cement plants started co-processing in their production units.
- Few state pollution control boards like Gujarat and Tamil Nadu, developed specific action plan & implementation schedule to promote co-processing.
- >12 cement plants set up pre-processing facilities to convert non-homogeneous waste in to AFRs.
- LCA (Life Cycle approach) is considered as a part of manufacturing process and extended producer responsibility.
Vicat's proven track record
Vicat operates two plants in India as Kalburgi cement plant and Bharti cement plants, with an annual capacity of around 8 mtpa, to produce quality cement since 2009. Since the inception the focus was on utilisation of AFR material in both the plants and presently, Vicat could achieve TSR of around 20 per cent.
The journey started with substitution rate of around 5 per cent in 2012 and in last five years it has reached to a level of 20 per cent. The initial start-up was on utilisation of easy to use AF materials like biomass, segregated non-recyclable plastic waste etc. Presently, the company can co-process different types of waste like industrial wastes (hazardous and non hazardous), tyre derived waste, plastics derived waste, derived waste from MSW segregation process, animal waste, waste from windmill sources etc. The company also offers cradle to grave solution for different sectors like pharmaceutical industry, FMCG, tyre sector and municipal corporations for segregated MSW, food and beverage industries etc.
Understanding the main factors that led to this improvement in usage of AFR in Vicat will help the Indian cement industry have an introspection of their processes and preparedness for improving AFR utilisation in their plants.
INCOME ITEMSEXPENDITURE ITEMS
1.Sale price of Waste
2.Savings in cost of waste management due to co-processing
3.Reduction in the liability costs1.Tipping Fee for waste management
3.Pre-processing cost to convert waste into AFR
1.Tipping Fees from waste generator
2.Substitution benefit derived due to use of AFRs1.Waste identification
3.Handling and storage
4.Pre-processing cost to convert waste to AFR
6.Fuel usage impact
7.Interest and Depreciation costs etc.
ACC: Leader in waste Management
The use of AFR essentially serves to move away from dependence on fossil-based fuels and other mineral resources.
In 2016, the company succeeded in co-processing 379,520 tonnes of AFR, achieving a TSR of 3.22 per cent. Following the commissioning and stabilisation of two pre-processing platforms and a third under execution, ACC expects the TSR percentage to increase in the long run, enabling company to cut its footprint even further.
ACC has taken the lead in providing safe waste management solutions to major waste generating industries and organisations. The core objectives of value creation, customer service and technical excellence together drive the company's initiative towards providing sustainable waste management solutions under the brand name - Geocycle. A key challenge posed on environment today that is a cause of major concerns about the health and safety of all citizens comes from the enormous volumes of municipal waste being generated in our cities and towns. Recognising this problem, the company is extending the scope of its waste management solutions to developing safe and sustainable solutions for the efficient disposal of municipal wastes. In the course of providing waste management solutions to municipalities, ACC also seek to reduce reliance on traditional fuels.
ACC has increased co-processing of RDF and non-recyclable SCF of MSW in its facilities enabled by large scale investments in R&D made for the safe utilisation of these waste streams. ACC, in this case, is working with state governments and waste management agencies such as in Goa on a MSW Landfill Remediation Project, the first-of-its-kind project in India, wherein ACC received and co-processed around 4,800 tonnes of RDF at the Wadi plant in 2016.
ACC redoubled its endeavours in lobbying, advocacy and capacity building to achieve greater technical and legal recognition for co-processing technology in line with accepted international standards.
"Banned wastes" not to be pre-processed or co-processed:
Explosives and ammunition / weapons
Anatomical medical waste
"Banned wastes" not to be co-processed (These wastes however can be co-processed after
pre-processing to remove the banned portion of the waste):
Electronic fraction of electrical and electronic waste (e-waste)
Whole batteries as a targeted material stream
Waste of unknown or unpredictable composition, including unsorted municipal waste