Second-generation biofuels are made from food, agricultural, and forestry waste biomass and are considered low-carbon.
May 12, 2022
In the energy transition towards a decarbonized future, second-generation biofuels are an essential asset. In their production process, wastewater disposal represents a critical issue and requires specific water treatment.
What are biofuels?
Unlike common fuels derived from fossil fuels, biofuels are produced from organic raw materials, such as biomass (corn, wheat, sugar cane, etc.) or vegetable oils. Biodiesel and bioethanol are just some of them.
Coming from renewable raw materials, they are potentially always available. Still, we must focus attention on their impact on the environment. Their use in industry has brought to light some of the limitations of first-generation biofuels, i.e., those coming primarily from agricultural or forestry products. In this case, using this material implies massive deforestation and high energy and water consumption. In addition, the production of some first-generation biofuels uses products whose cultivation takes away space and resources from growing food.
An effective response to the limitations of first-generation biofuels is second-generation biofuels. These are made from food, agricultural, and forestry waste biomass and are considered low-carbon. They drastically reduce CO2 emissions and do not compete with food production.
Second-generation biofuels are key in the decarbonization process undertaken by different states. For this reason, their market is evolving rapidly and is estimated to touch $59.4 billion by 2030.
“For second-generation biofuels, water is the cornerstone of the biofuel generation process; to be discharged requires specific treatment to remove a wide range of contaminants.”
The Cannon Artes experience
Water as a resource is a fundamental element in the production of biofuels.
For a well-known renewable diesel and jet fuel manufacturer, we supplied a water treatment plant designed to treat effluent from the pre-treatment units and acidic water from the conversion process units. The combined wastewater from these processes contains mainly organic acids, alcohols, aldehydes, ketones, and ammonia, which are highly polluting.
The unit provided includes:
- Pre-treatment with de-oiling system: consisting of a Corrugated Plate Interceptor (CPI) and a Dissolved Air flotation system (DAF), it aims to remove oil and suspended solids.
- Equalization tank: fed by de-oiled water, it smoothes out variations in COD concentration. The de-oiled and equalized water has a quality suitable for subsequent biological treatment.
- Biological treatment: this is the heart of the treatment process and happens via an MBR (Membrane Bioreactor) system; the step aims to achieve very high removal performance, equal to 98% of COD and BOD.
- Tertiary treatment: this process consists of a series of activated carbon filters for further water cleaning, particularly for removing phenols.
- Sludge treatment: sludge from primary and biological treatment will be thickened, dewatered, and disposed of outside the plant.
At the end of this process, the wastewater from biofuel production will have all parameters in line to be adequately discharged.