It is critical to lift veil of secrecy around use of refuse-derived fuel in cement plants

In the last three months, I have had discussions on the use of refuse-derived fuel (RDF) in cement companies with several plant officials, RDF suppliers and industry experts. While the cement companies were very open to discussion regarding the limitations on the use of municipal waste as RDF, most of them displayed apprehensions about sharing data on how much coal they have been able to substitute using RDF produced from municipal waste. 

However, most officials maintained that they regularly submit this information to the regulatory authorities, primarily their respective state pollution control boards and Central Pollution Control Board. 

RDF is a high-calorific-value fraction of municipal solid waste (MSW), obtained by conventional separation systems. It is shown to be used for co-processing in cement kilns for energy recovery. Replacing or supplementing fossil fuels or mineral resources with waste in an industrial process is called co-processing. 

Read more: Are combustibles derived from legacy waste dumpsites opportunity or challenge?

The most recent thermal substitution rate (TSR) for cement companies is available to the public, but no one knows what percentage of sustainable alternative fuels were used to replace fossil fuels or how different alternative fuels, such as RDF, helped reach this TSR.

Our interest in the usage of municipal waste in the form of RDF to replace coal for energy requirements for cement manufacturing stems from the huge quantity of this waste available to us and its potential to successfully replace coal and bring down sector emissions. Co-processing of waste in cement kilns provides an environmentally sound and sustainable option to municipalities as well. 

Though information on RDF use in cement plants is difficult to obtain as long as the government does not lift the secrecy by sharing this information in the public domain, I will attempt to highlight some of the sector concerns by sharing expert insights from my discussions and site visits.

Quality and quantity issues

Most of the cement companies that I spoke with have engaged third-party suppliers to procure RDF, or in most cases, segregated combustible fraction (SCF), which is  the less processed version of RDF. Several of these plants are in the process of ramping up their alternative fuel and raw materials (ARF) facilities, but the uncertainty regarding the continuous and adequate supply of RDF by the vendors continues to grapple with them.

For instance, Wonder Cement Plant in Nimbahera, Rajasthan has a SCF storage space of 1,500 square metres that can handle 5,000 tonnes of waste. However, the plant is supplied approximately 300 tonnes per day, which is way less than the input feed based on which they have planned and designed their systems.

Aside from the logistical issues, the quality of the waste that the cement plants receive is another major concern. The Central Public Health and Environmental Engineering Organisation, technical wing of the Ministry of Housing and Urban Affairs, issued guidelines in October 2018 on the use of RDF in industries and specified grades to be used for co-processing in cement kilns. But the RDF suppliers hardly adhere to that. 

Read more: India is all set to go for its first waste-to-hydrogen project

The plants claimed they are supplied with non-homogenous waste with above 30-50 per cent moisture and 30-40 per cent ash content. The plant operators must strictly control both moisture and ash levels, as they can interfere with the production of cement and result in significant losses for the business. 

Cement plants frequently experience breakdowns of the shredders installed on their property to size-reduce waste that they receive as a result of processing non-homogeneous waste. Cement companies, such as Prism Cement Plant in Satna, Madhya Pradesh, have imposed a pro-rata penalty on SCF vendors based on calorific value and moisture content to prevent plant malfunctioning and cement quality deterioration due to poor waste quality. 

An alternative fuel and raw materials (ARF) facility being built at Prism Cement Plant in Satna, Madhya Pradesh. Photo: Anubha Aggarwal / CSE

Transportation factor

Another issue that needs to be worked on more is the transportation of this waste from the handler sites to the cement plants. The cement companies are procuring waste from a distance of 500-1,000 kilometres.

“A truck full of coal is equivalent to nine trucks of waste supplied to the cement factories in terms of calorific value”, a plant official told the New Delhi-based think tank Centre for Science and Environment (CSE). This implies an enormous escalation of freight on the roads. 

On the other hand, the ‘third parties’ or waste handlers who provide SCF to the cement plants face different sets of challenges. Saurabh Agnihotri has been in the business of managing and handling municipal waste for several years. He runs a firm in Udaipur, Rajasthan, called Trashonomy Pvt Ltd which handles approximately 150 tonnes of municipal waste on a daily basis. 

Agnihotri claimed that his staff has suffered medical injuries on multiple occasions despite the use of personal protective equipment, as the waste handled by them is often contaminated with bio-medical waste such as syringes and has sharp objects like glass shards, etc. 

The officials in charge of the solid waste management division more often than not do not have any prior experience in the field, some of the waste handlers told CSE. This results in them taking stop-gap measures to deal with the challenges presented to them instead of adopting a long-term planning approach. 

It is clear from the series of interviews and site visits that stakeholders involved are working in isolation rather than in an enabling ecosystem, which will aid in overcoming some of the challenges presented above. The private cement plants are reluctant to directly deal with the municipalities because of their ‘laidback’ and ‘bureaucratic’ approach. 

“The municipalities we have worked with have not shown enough interest or were reluctant to arrange for the SCF loading, transport and unloading logistics, thus making it economically unviable for their businesses to handle it all,” a plant official shared. 

Municipal authorities’ primary concern is to get the ‘burden of waste handling’ off their shoulders by involving third parties. There does not seem to be any scrutiny on whether the waste is being disposed of by the third parties as disclosed by them as per the signed agreements. 

Read more: Green coal: Can it tackle twin challenges of reducing emission, waste management?

Third-party waste handlers have learned to navigate the ‘strict’ terms and conditions set up in the agreements they have signed with the municipal authorities. Most of them point-blank refuse to guarantee the quality of waste they deliver to the plant site for the simple reason that the quality of waste picked by them is usually mixed waste and beyond a certain point, manual labour is not enough to segregate this waste. 

Most of these facilities are medium-scale enterprises and do not have the resources to send their samples for lab testing before each delivery. “Funds being made available in contracts are not sufficient to meet the growing needs of collection workers. Because of the paucity of finances, often plant operations and maintenance get delayed, disrupting the entire supply chain,” a vendor said. 

Overall, the sectoral experts are of the opinion that the cement plants will get on board for RDF consumption in their plants, as it also makes economic sense to them as long as the RDF provided is of quality that does not compromise the quality of their product or harm their equipment. What is now required is for the municipalities to identify vendors who are technically competent instead of prioritising the commercial value of their operation, they opined. 

Subscribe to Daily Newsletter :

SUPPORT US

We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.