Sustainability synergies and trade-offs considering circularity and land availability for bioplastics production in Brazil.

Alongside the concerns of waste management, plastic production represents a future problem for managing greenhouse gas emissions. Advanced recycling and bio-based production are paramount to face this challenge. The sustainability of bio-based polyethylene (bioPE) depends on the feedstock, avoiding stress on natural resources. This work discusses Brazil's potential to meet future global bioPE demand by 2050, using sugarcane as feedstock and considering environmental sustainability for production expansion. From the assessed 35.6 Mha, 3.55 Mha would be exempt from trade-offs related to land use change (dLUC), biodiversity, and water availability. The scenario with the highest circularity efficiency would require 22.2 Mha to meet the global demand, which can be accommodated in areas with positive impacts in carbon stocks, neutral impacts in water availability, and medium impacts on biodiversity. Here, we show that dropping demand is essential to avoid trade-offs and help consolidate bioPE as a sustainable alternative for future net-zero strategies.

Supplying the ethanol demand for 2030 in Brazil as a land-based climate change mitigation alternative: Implications on greenhouse gases emissions.

Transitioning from a fossil-based to a bio-based economy is crucial to climate action and achieving neutrality in greenhouse gas (GHG) emissions. Biofuel production is an essential land-based GHG mitigation alternative. However, it raises concerns about biodiversity conservation, competition with food production, and net GHG emissions associated with direct land-use change (dLUC). This study aims to assess how the location and conversion routes influence GHG emissions for sugarcane expansion in Brazil to supply ethanol demand projections for 2030. A consistent and significant reduction in GHG emissions is achievable by implementing a strategy that prioritizes the spatial distribution for ethanol biorefinery expansions based on georeferenced life cycle emissions, including dLUC emissions associated with sugarcane production. Because of conservative zoning for sugarcane expansion, dLUC emissions are not an overriding factor, representing less than 9.1 % of the total GHG mitigation potential. Despite that, accounting for georeferenced dLUC emissions when prioritizing expansion facilities leads to spatial differences. Regarding conversion routes and land requirements, using cellulosic biorefineries could meet future projected demand based on sugarcane production from 3.1 million hectares, mostly in currently degraded pastureland. Conventional refineries would require 5.5 million hectares to meet the same demand of 71 billion liters. Despite the 77 % higher land demand to produce the same volume of ethanol, conventional refineries with straw recovery could be considered if electricity generation is a priority. This study illustrates how Brazil can achieve GHG mitigation targets while attending to future energy demand and protecting areas with high biodiversity.