Simulation Results for “Integration of Plant and Microbial Oil Processing at Oilcane Biorefineries for More Sustainable Biofuel Production” Publication

Themes: Conversion, Sustainability

Keywords: Life Cycle Assessment, Modeling, Software, Technoeconomic Analysis

Citation

Cortés-Peña, Y.R., Woodruff, W., Banerjee, S., Li, Y., Singh, V., Rao, C.V., Guest, J.S. June 9, 2024. “Simulation results for ‘Integration of Plant and Microbial Oil Processing at Oilcane Biorefineries for More Sustainable Biofuel Production’ publication” Zenodo. DOI: 10.5281/zenodo.11536864.

Overview

Simplified flowsheets of the (a) direct cogeneration (DC), (b) integrated co-fermentation (ICF), and (c) integrated co-fermentation and recovery (ICFR) configurations with microbial oil production. In all configurations, either sugarcane or oilcane is crushed to release the juice, the oil in the fermentation effluent is recovered through a three-phase decanter centrifuge, and a heat exchange network (HXN) integrates heating and cooling of process streams to decrease utility demand. In the DC configuration, the bagasse is sent directly to the boiler to produce heat and power. In the ICF and ICFR configurations, the bagasse is pretreated with liquid hot water, hydrolyzed with cellulases, and co-fermented with the juice. In the DC and ICF configurations, the oil in the cell mass is recovered mechanically with a screw press after drying. In the ICFR, the oil in the cell mass is recovered by centrifugation after cellulosic pretreatment with the bagasse.

Oilcane—an oil-accumulating crop engineered from sugarcane—and microbial oil have the potential to improve renewable oil production and help meet the expected demand for bioderived oleochemicals and fuels. To assess the potential synergies of processing both plant and microbial oils, the economic and environmental implications of integrating microbial oil production at oilcane and sugarcane biorefineries were characterized. Due to decreased crop yields that lead to higher simulated feedstock prices and lower biorefinery capacities, current oilcane prototypes result in higher costs and carbon intensities than microbial oil from sugarcane. To inform oilcane feedstock development, we calculated the required biomass yields (as a function of oil content) for oilcane to achieve financial parity with sugarcane. At 10 dw% oil, oilcane can sustain up to 30% less yield than sugarcane and still be more profitable in all simulated scenarios. Assuming continued improvements in microbial oil production from cane juice, achieving this target results in a minimum biodiesel selling price of 1.34 [0.90, 1.85] USD∙L⁻¹ (presented as median [5th, 95th] percentiles), a carbon intensity of 0.51 [0.47, 0.55] kg CO₂e L⁻¹, and a total biodiesel yield of 2140 [1870, 2410] L ha⁻¹ year⁻¹. Compared to biofuel production from soybean, this outcome is equivalent to 3.0–3.9 as much biofuel per hectare of land and a 57%–63% reduction in carbon intensity. While only 20% of simulated scenarios fell within the market price range of biodiesel (0.45–1.11 USD∙L⁻¹), if the oilcane biomass yield would improve to 25.6 DMT∙ha⁻¹∙y⁻¹ (an equivalent yield to sugarcane) 87% of evaluated scenarios would have a minimum biodiesel selling price within or below the market price range.

Data

Zenodo – Includes baseline and target fermentation performances and detailed reports

GitHub – BioSTEAM biorefinery for canes.

Related Publications

Integration of Plant and Microbial Oil Processing at Oilcane Biorefineries for More Sustainable Biofuel Production