Sugarcane Biogas Bets on Waste as Raw Material

“…what was previously waste is now considered an input for a new process, providing better use of our main raw material: sugarcane.”

Victor Machado is the planning and business intelligence manager at Raízen Geo Biogás, undergraduate in production engineering from PUC – Rio de Janeiro and holds an MBA in finance from the Federal University of Rio de Janeiro.

Raízen Geo Biogás is a joint venture between Raízen and Geo Energética. Raízen holds an 85% stake in the undertaking.

Victor Machado, planning and business intelligence manager at Raízen Geo Biogás


AgriBrasilis – How is biogas produced? What are its characteristics as a renewable fuel?

Victor Machado – The production of biogas is made from a biological process in which biodigesters convert the organic matter from the filter cake and vinasse – sugarcane by-products generated during the sugar and ethanol production process – into methane and CO2. Next, there is a desulphurization process to remove sulfur and then there is the possibility of purification to produce biomethane or send it to motor generators, transforming it into electricity.

After extracting the biogas, the vinasse and cake processed in the biodigesters are also used in the production of fertilizers, a ‘turbinated’ fertilizer, rich in potassium, phosphorus and nitrogen.

AgriBrasilis – Why has the use of biogas shown accelerated growth in Brazil? What is the share of biomethane?

Victor Machado – In economic and sustainable terms, it is a market with great potential. We understand that biogas has an energy power capable of strategically contributing to the national power grid, by considerably reducing waste, and betting on waste as a raw material.

With the same amount of sugarcane, for example, it is possible to increase power generation by up to 50%, without increasing the planted area. That is, with a thousand tonnes of sugarcane we managed to produce 50 MWh, using the straw and bagasse burning as fuel. The gas from the filter cake and vinasse biodigestion gives us an additional 25 MWh, that increases the potential for generating electricity by 50%.

As biogas serves both for power generation and for the production of biomethane, it is highly connected with the circular economy system, considering that this technology takes advantage of all waste from production processes to generate new products.

Because it has a chemical composition similar to that of natural gas, except it comes from renewable sources, biomethane can replace natural gas, diesel, LPG or fuel oil, reducing direct emissions of greenhouse gases by more than 90%.

Both solutions contribute directly to the environment and help to decarbonize the Brazilian power grid and several production chains.

AgriBrasilis – What is the relationship between biogas and the production of second-generation ethanol? What is the role of the circular economy in this context?

Victor Machado – Second-generation ethanol (2GE), like biogas, is an important alternative to increase biofuel production. Using sugarcane bagasse as raw material – biomass extracted from sugarcane processing and the production of first-generation ethanol (1G) and sugar –, 2GE has the potential to increase our ethanol production capacity by around 50%, without increasing the cultivation area.

The 2GE production process also generates vinasse, a residue that will be used to produce biogas, increasing the potential for circularity and the use of all by-products from the bioparks. This makes the entire process even more sustainable, as we maximize the reuse of waste and inputs used in our operations. In other words, what was previously waste is now considered an input for a new process, providing better use of our main raw material: sugarcane.

AgriBrasilis – Raízen hopes to build biogas production units at all its plants over the next ten years. What will it be used for? Is it possible to replace all natural gas, diesel and LPG with biogas?

Victor Machado – Once purified, biogas has the same characteristics as natural gas (96.5% methane). Therefore, it can also be used, in the form of biomethane, as a substitute for diesel as fuel for cars, tractors and trucks.

We have a clear project to lead the country’s energy transition by offering a complete portfolio of renewable energy solutions. In 2020, Raízen inaugurated the largest biogas plant in the world, produced with agro-industrial waste, located next to the Bonfim Bioenergy Park, in the city of Guariba, State of São Paulo. This unit generates power from sugarcane by-products.

In 2022, we also announced the construction of our second biogas plant, the first dedicated to the production of renewable natural gas (biomethane). This plant will be installed in the Costa Pinto bioenergy park, located in the city of Piracicaba, State of São Paulo. Investments in this and other technologies reinforce Raízen’s position as one of the pioneering companies in the use of waste from industrial processes for renewable power generation on a commercial scale.

AgriBrasilis – Who are Raízen’s partners in this expansion program?

Victor Machado – We seek to contribute with more sustainable solutions for our customers and partners. For this, we have a joint venture with Geo Energética, a company from State of Paraná that produces biogas and green hydrocarbons derived from sugarcane, Raízen Geo Biogás. A pioneer in the use of waste from industrial processes to produce renewable energy on a commercial scale, Raízen holds an 85% stake in this joint venture.

Production from the biomethane plant at Costa Pinto Biopark has already been fully sold to Yara Brasil Fertilizantes, Scania and Brazil’s Volkswagen. These are long-term contracts, in which biomethane will be used in the production of hydrogen and green ammonia, in the case of Yara, and to supply Scania and Volkswagen factories, allowing a reduction of greenhouse gas emissions of more than 90%, when compared to the fossil alternative.

Raízen’s goal is to offer a complete portfolio of renewable energy solutions to our customers. We currently have three 2GE plants under construction, attached to the Bioenergy Parks Bonfim, in the city of Guariba, Univalem, in the city of Valparaíso, and Barra, in the city of Barra Bonita, all in the interior of the State of São Paulo, and we have already announced another five units. Our first Raízen 2GE plant is located in city of Piracicaba, State of São Paulo, and has been in operation since the 2014/15 harvest.

 

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