Biorefinery: Diesel from Algae

Biomass is a renewable energy source that is available abundantly and can be stored and transported. It can be burnt directly to generate heat and power and it can be converted into fuels and chemicals. However, from an economic perspective these processes generally cannot compete with their fossil counterparts. A bio-refinery is an integrated concept aiming at full utilization of biomass, in which different fractions of biomass are converted in large-scale plants (economy of scale) or in standardized small-scale units (economy of numbers) into an economically optimal product slate. In this SIP, algae have been selected as feedstock for a sustainable biorefinery with “green” diesel (and kerosene) as the target product. Production of chemicals from algae is investigated in collaboration with groups at Wageningen University (WUR).

There are quite some challenges that need to be addressed before large-scale algae production for diesel becomes feasible. In this SIP, the potential of algae for fuel production is evaluated. The following research items are investigated in this SIP:

·	Chain analysis centered on the energy balance of the whole route.

·	Reactor engineering focused on new algae growth reactors minimizing energy consumption.

·	Separation of the algae solution into triglycerides, precursors for chemicals and a residue. Here, both physical and thermal/chemical methods (e.g. high-pressure treatment) will be studied.

·	Conversion of the residue by gasification (H₂ production) and pyrolysis.

·	Nutrient recycling. As algae contain ~ 10 wt% nutrients the proposed route is only feasible energetically if these can be recycled to a large extent.

The project involves process engineering, reactor engineering, separations and catalysis.