Lactic acid production is highly affected by the fermentation pH. The need for neutralizing agents and the salts produced during fermentation have a significant impact on the overall process performance. Changing the neutralizing agent and allowing lower pH fermentation can improve the process profitability. This work investigates the impact of fermentation parameters and evaluates the process economics of alternative downstream processing designs to produce lactic acid. The results show that low-pH fermentation (pH = 3.86) was profitable (internal rate of return, IRR > 10%) at a fermentation yield of 0.97 g/g sucrose. Decomposing the salt subproduct to reduce the environmental burden associated with gypsum disposal has a significant impact on the economic performance, resulting in a lower IRR than the other designs. Although the salt decomposition process has a high energy demand, it is compensated by the savings obtained in the downstream processing, thus resulting in a similar overall energy demand when compared to conventional reactive distillation. A novel process configuration with ammonium sulfate subproduct shows potential for 3 p.p. higher IRR and up to 30% lower fuel demand in comparison with the conventional process. Therefore, alternative downstream processes could drive low-pH fermentation to outperform the conventional process without any neutralizing agent.

This Opinion highlights several successful cases of biofuel technologies recently described by the IEA Bioenergy Intertask Report on Lessons Learned. The report discussed the potential of biofuels to contribute to a significant market supply, thus replacing fossil fuels and mitigating global warming, and it underscores the challenges in expanding biofuel production and replicating successful models between countries and regions. Based on the lessons learned from conventional, established technologies, the authors analyzed policies, feedstocks, products, technologies, economics, environmental concerns, social aspects, scalability, and ease of implementation and replication in different countries or regions. There are blending mandates in place around the world to foster the use of biofuels. Dependence on the availability and price fluctuations of crop feedstocks may limit biofuel production in certain circumstances. Legal restrictions on using food crops as feedstocks present obstacles to scaling up production. Temporary constraints related to feedstock costs and availability, as evidenced by changes and postponements of biofuel blending mandates in various countries (particularly during the COVID‐19 pandemic) also pose challenges. Technological hurdles exist for advanced biofuels that implicate premium pricing. Still, 2G ethanol from sugarcane meets very strict feedstock requirements with a carbon footprint so low that only electric vehicles charged in Norway could have life‐cycle GHG emissions at the same level as a 2G ethanol‐fueled combustion engine car. The authors evaluate whether and how much electrification could contribute to advance the decarbonization efforts in different countries. Drawing from these observations, the authors express their viewpoints to assist researchers and policymakers in the energy sector in formulating viable approaches to combat the climate crisis.