Léda N. Gerber

Target Cultivation and Financing Parameters for Sustainable Production of Fuel and Feed from Microalgae

Production of economically competitive and environmentally sustainable algal biofuel faces technical challenges that are subject to high uncertainties. Here we identify target values for algal productivity and financing conditions required to achieve a biocrude selling price of

Geoengineering, marine microalgae, and climate stabilization in the 21st century

5 per gallon and beneficial environmental impacts. A modeling framework--combining process design, techno-economic analysis, life cycle assessment, and uncertainty analysis--was applied to two conversion pathways: (1) fuel only (HTL), using hydrothermal liquefaction to produce biocrude, heat and power, and (2) fuel and feed, using wet extraction to produce biocrude and lipid-extracted algae, which can substitute components of animal and aqua feeds. Our results suggest that with supporting policy incentives, the fuel and feed scenario will likely achieve a biocrude selling price of less than

Algal biofuel production for fuels and feed in a 100-ha facility: A comprehensive techno-economic analysis and life cycle assessment

5 per gallon at a productivity of 39 g/m(2)/day, versus 47 g/m(2)/day for the fuel only (HTL) scenario. Furthermore, if lipid-extracted algae are used to substitute fishmeal, the process has a 50% probability of reaching

Demonstrated Large-Scale Production of Marine Microalgae for Fuels and Feed

5 per gallon with a base case productivity of 23 g/m(2)/day. Scenarios with improved economics were associated with beneficial environmental impacts for climate change, ecosystem quality, and resource depletion, but not for human health.

Integration of deep geothermal energy and woody biomass conversion pathways in urban systems

Society has set ambitious targets for stabilizing mean global temperature. To attain these targets, it will have to reduce CO2 emissions to near zero by mid-century and subsequently remove CO2 from the atmosphere during the latter half of the century. There is a recognized need to develop technologies for CO2 removal; however, attempts to develop direct air capture systems have faced both energetic and financial constraints. Recently, BioEnergy with Carbon Capture and Storage (BECCS) has emerged as a leading candidate for removing CO2 from the atmosphere. However, BECCS can have negative consequences on land, nutrient, and water use as well as biodiversity and food production. Here, we describe an alternative approach based on the large-scale industrial production of marine microalgae. When cultivated with proper attention to power, carbon, and nutrient sources, microalgae can be processed to produce a variety of biopetroleum products, including carbon neutral biofuels for the transportation sector and long-lived, potentially carbon-negative construction materials for the built environment. In addition to these direct roles in mitigating and potentially reversing the effects of fossil CO2 emissions, microalgae can also play an important indirect role. Because microalgae exhibit much higher primary production rates than terrestrial plants, they require much less land area to produce an equivalent amount of bioenergy and/or food. On a global scale, the avoided emissions resulting from displacement of conventional agriculture may exceed the benefits of microalgae biofuels in achieving climate stabilization goals.