FAQ

 

What is co-processing?

Co-processing is a globally recognized technology through which waste is treated in energy intensive industries such as cement. It helps in solving societal waste challenges responsibly and in an environmentally sustainable manner. Co-processing completely destroys waste materials through high temperatures and long residence time. The 3 Ts - Time, Temperature and Turbulence in cement kilns provide an extremely high destruction removal efficiency (DRE) for all waste types.

During co-processing, the mineral part of the waste replaces primary mineral materials (such as limestone, clay or iron) and the combustible part provides the energy needed for clinker production. As a result, 100% of the waste input is recycled and recovered without producing any residue. The technology is referred to as co-processing because the process of cement manufacture occurs parallely with safe destruction of the waste materials at the high temperatures and long residence time existing in cement kilns (or other industrial processes).

What happens to waste when it is co-processed in cement plants?

Co-processing of waste in cement kilns ensures complete disposal of waste in a safe and environmentally sustainable manner. During co-processing, the mineral part of the waste replaces primary mineral materials (such as limestone, clay or iron) and the combustible part provides the energy needed for clinker production. As a result, 100% of the waste input is recycled and recovered without producing any residue.

What makes cement kilns suitable for waste co-processing?

Cement kilns are ideally suited for safe and sustainable management of waste through co-processing due to their specific properties including:

  • High temperatures and long residence time which are in all cases more than 3” > 1100 °C. This allows for complete destruction of waste.
  • Self cleaning process since the environment is alkaline with lime representing > 60% in mass
  • Double valorization: organic gets completely destroyed and the ash gets incorporated in the final product.

It is thus a zero residue waste management option. Co-processing of waste leads to neither any untoward emissions nor detrimental effects on the final product. It is thus a zero residue waste management option. Co-processing of waste leads to neither any untoward emissions nor detrimental effects on the final product.

What is pre-processing?

Pre-processing is the concept of converting a wide variety of waste materials into a homogeneous mix of defined characteristics. It involves shredding, blending, drying, impregnation and other mechanical operations.

How is the cement quality maintained while co-processing waste?

All waste streams are accepted for co-processing only after complete analysis. This helps us determine the waste compatibility with the quality and process requirements of cement manufacturing as well as environmental compliance.

Additionally characteristic evaluation of every incoming waste truck is done which ensures that the physical and chemical characteristics of waste are known. The different streams are then mixed and homogenized in a proper recipe, in line with the quality requirements of the cement kiln, in the state- of- the- art pre-processing facilities employing trained man-power. Continuous quality checks on clinker and cement are undertaken to ensure that only the finest quality product is manufactured.

Why is co-processing in cement kilns the preferred choice for waste management?

Co-processing ranks higher in the waste management hierarchy compared to disposal based waste management options of land filling or incineration. It is a comprehensive, cost effective and win-win solution. Co-processing completely destroys waste materials through high temperatures and long residence time. Incineration and landfill both leave behind a residue while co-processing is a zero residue technology. Co-processing also utilizes any resource and energy value inherent in the waste and thus contributes to a regenerative circular economy. Therefore it is a more environmentally sustainable alternative to landfilling and incineration for waste that has been mixed, polluted or cannot be recycled for technological or economic reasons.

Is co-processing an accepted technology globally?

Co-processing as a waste management option has been in practice and evaluated for more than 40 years globally. Co-processing activities are endorsed by several international bodies and framed by specific regulations, standards and environmental permits to ensure enhanced environmental and safety standards. It is an approved technology by Basel Convention for disposal of all kinds of hazardous and other wastes. Trials conducted in cement kilns spread across the world have confirmed that wastes do not impact the cement kiln emissions or the product in any adverse manner.

Co-processing is fully recognized by many countries such as India, Mexico, Brazil, US, Europe and many others. In its recent communication, The European Commission advised Member States to take a long-term perspective and consider co-processing as an important lever for circular economy.

What impact does co-processing of waste have on emissions of a cement-kiln?

Many studies and trials around the world have shown that waste can be safely destroyed in cement kilns without having any impact on the emissions. This can be achieved due to the high temperatures, long residence times and alkaline environment existing in the kiln.

It is also important to understand the properties and chemistry of the waste materials that we are co-processing in the kiln (analyze all waste before pre- and/or co-processing). Once the waste inputs are properly controlled through systems and processes employed by Geocycle, it can be ensured that there is no untoward impact on emissions.

What measures are implemented to ensure that the waste does not have an impact on soil and groundwater in areas around the facility?

Geocycle ensures that proper storage arrangements are made available for all waste. Geocycle’s state-of-the-art facilities are fully compliant having all safety provisions including full-fledged waste testing laboratory, sealed concrete flooring with geo-membrane, rainwater- collection drains, fire detection, alarm & suppression system, internal and external odour suppression systems. Spill control and response kits are also available throughout our facilities. Safety audits, area monitoring and soil/groundwater monitoring are conducted to ensure that no contamination takes place.

Will handling of wastes affect the health of employees and surrounding communities?

No, co-processing has been proved to be a safe treatment option. No cases of any adverse health impacts have been reported in any of the places across the world where co-processing has been going on for quite some time. It is a zero residue technology, meaning that there are no discharges or waste residues left behind after waste is co-processed.

Additionally, the waste management operations respect all LafargeHolcim health and safety rules. Geocycle is proactively managing all risks involved in its operations through its dedicated risk management program called ACert.

Geocycle employees are well protected through the hierarchy of controls approach. All waste materials are analyzed in specialized laboratories in order to ensure that they meet the specifications related to quality, health and safety, and environment. A stringent control of the waste input, continuous monitoring of the most important emission parameters, adequate operational controls and a regular and transparent reporting to the authorities ensures that our surrounding communities can be assured of a clean and safe environment.

Will the waste trucks passing through the community generate odour and pose a spillage and health risk?

All precautions are taken during transportation of waste be it through Geocycle’s own vehicles or third party transporters. Waste is packaged properly to contain odours and spillage while transporting. Care is taken in choosing appropriate trucks which would control spillage if any. The drivers are trained in safe material transportation.

Geocycle also carries out transporter engagement and training to sensitize our transport partners and enable them to raise their safety standards. Undertaking all precautions as per relevant regulation means that chances of spillage and odour are remote.

How do local communities benefit from co-processing in cement kilns?

All precautions are taken during transportation of waste be it through Geocycle’s own vehicles or third party transporters. Waste is packaged properly to contain odours and spillage while transporting. Care is taken in choosing appropriate trucks which would control spillage if any. The drivers are trained in safe material transportation.

Geocycle also carries out transporter engagement and training to sensitize our transport partners and enable them to raise their safety standards. Undertaking all precautions as per relevant regulation means that chances of spillage and odour are remote.

How does co-processing of waste reduce CO2 emissions?

Co-processing reduces CO2 emissions since the energy value of the waste (if any) is recovered in the cement kiln helping to substitute fossil fuels that would otherwise have been used in the cement process. If these wastes would have been incinerated or landfilled, it would have led to corresponding GHG emissions. The below figure explains how waste co-processing in cement kilns reduces these emissions:

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Can all wastes be co-processed?

A wide range of waste material is suitable for co-processing, including hazardous and non hazardous industrial waste, sorted municipal waste and agricultural residues. However, a strict list of ‘banned waste’ is adhered to. The reasons for the same include risk of excessive emissions, health and safety provisions, negative impact on kiln operation, or the observation of the general waste hierarchy principles.

Banned wastes not to be pre-processed or co-processed:

  • Radioactive waste
  • Asbestos-containing waste
  • Explosives and ammunition / weapons
  • Anatomical medical waste

Banned wastes not to be co-processed:

  • 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

These wastes however can be co-processed after pre-processing to remove the banned portion of the waste.

What kind of expertise does Geocycle have in the waste management field?

Since the 1970s, Lafarge and Holcim have pioneered the co-processing of waste materials in cement kilns. The companies have developed innovative and tailored industrial and municipal waste management solutions for a wide range of customers for decades. Geocycle leverages this rich experience to offer highly specialized waste management services.

LafargeHolcim and Geocycle have a long-term commitment to their waste management activities. This includes ongoing investment, development of expertise and knowledge in the field, as well as long-term cooperation with customers and partners. We have a dedicated team of 2,000 people globally with significant experience in the waste management sector.