Urban Waste as a Source of Energy for our Plants

At our plant in Salto de Pirapora, in the countryside of São Paulo, we were the first in the country to use part of unrecycled urban waste as an energy source for cement production. This process, called Refuse-Derived Fuel (RDF) co-processing, is widely used in North American and European countries and was introduced in Brazil in 2018, thanks to our pioneering initiative.

Urban waste is a global challenge. Brazil produces more than 78 million tons of urban waste annually, according to calculations by the Brazilian Association of Public Sanitation and Special Waste Companies (Abrelpe, for its initials in Portuguese). Approximately 41% of the garbage collected in the country is improperly disposed. RDF co-processing is a viable alternative to reduce the impact of urban waste, reduce the volume of garbage sent to landfills and transform part of this waste into energy for cement production.

In 2018, we started an unprecedented program in the cement industry in Brazil, transforming part of the garbage collected in Piracicaba and Sorocaba (in the countryside of São Paulo) into energy for the production of cement. In 2018, during the testing period for licensing, the Salto de Pirapora plant in São Paulo used 17,900 tons of RDF, resulting in a 5.3% petroleum coke substitution rate. In 2019, the unit received a permanent environmental license to use RDF. The plant has the capacity to process 65,000 tons/year.

"This technology offers environmental, social and economic benefits to both the company and the communities where we operate. Co-processing reduces the emission of greenhouse gases, reduces the volume of waste that ends up in landfills and contributes to the circular economy by enhancing the recycling chain and offering better working conditions to cooperatives, thereby generating employment and income. And we also help cities to properly dispose of urban waste," said our general manager of alternative fuels, Eduardo Porciúncula.

In the last four years (2016-2019), we invested R$ 47 million in co-processing at the Salto plant, which included equipment modernization and adaptation. In the next four years, we estimate another R$ 167 million investment.

The RDF process – Recyclable materials are sorted and sent to recycling centers. What is NOT recyclable and has energy value (example: Styrofoam, used pizza boxes, chip bags, chocolate wrappers and other used packaging), but would otherwise be sent to landfills, is now transformed into energy in our cement plants, replacing fossil fuels and reducing CO2 emissions. The remaining (organic) waste can be reused in other technologies, such as composting.

In addition to the Salto unit, our plants in Rio Branco do Sul (PR), Cuiabá (MT), Sobral (CE) and Brasília (DF) are also advancing in projects for the disposal of urban waste as an energy source. Salto de Pirapora (SP) is the only plant already operating with a permanent license. Considering these four plants, we estimate that we will be co-processing about 130,000 tons of urban waste annually, transforming it into energy in our cement kilns.

Since 1991, we have been pioneers in the use of alternative fuels in Brazil. The first type of waste we used was tires, and since then the company has been researching new materials that can replace petroleum coke as fuel in the cement manufacturing kilns, a process called co-processing.

In Brazil, 14 of our plants are co-processing or licensed to operate on alternative fuels. Our Brazilian operations use different types of biomass (such as rice hulls, wood chips, babassu coconut, sawdust and açaí pits) as fuel. In addition to biomass, we also co-process used tires and other types of industrial waste. In 2018, the company achieved a thermal substitution rate of approximately 30%.

In all, in 2018, we used 854,000 tons of biomass, tires and waste, resulting in a reduction of 521,000 tons of CO2 emissions, the equivalent of a truck driving 4,500 laps around the earth. This energy substitution prevented the use of 195,000 tons of petroleum coke. In other words, we avoided the production, transportation and use in our kilns of approximately 1,200 truckloads of this fossil, imported fuel.

Did you like this story? Watch our video.