Reviewer Comments - EERE

2011 Algae Platform Review – Reviewer Comments
Reviewer Comments are direct transcripts of commentary and material provided by the Platform’s
Review Panel. They have not been edited or altered by the Biomass Program.
Reviewer: 7
The project could benefit from specific quantitative goals based on commercial requirements for the
process and the economics. The extent of the technology survey that has been completed by the team is
not clear.
Presenter Response
Many of these comments are addressed above. Regarding the emphasis on batch digesters vs. larger scale
semi-continuous digesters, that is a useful comment and we will do as much work at the larger scale as
time and materials allow. However, our work at the smaller scale will provide much higher throughput
and therefore the testing of many more variables. We believe that this approach will allow for better
optimized digestions and maximize the output of useful data. The cost of enzymatic treatments, if they are
shown to be effective, will be modeled. Recent advances in the production of low-cost enzymes for
lignocellulosic ethanol processes suggest that such options may be affordable. We apologize if the
presentation did not adequately convey the justification for this work. As noted above, when considering
a process that currently is predicted to reduce algal lipid costs by $2.22 per gallon, it is important that the
underlying assumptions be tested. Co-products are essential to an economically viable process, and any
potential producer weighing the various options will want to make decisions based on actual data rather
than assumptions.
As discussed above, the possible need for co-feedstock will be an important outcome. We plan to use
relatively defined co-feedstocks for initial studies (primarily cellulose), but may be able to test alternative
low-cost materials. Regarding a question about recylcing of the AD sludge, we believe that sludge recycle
may be problematic. Current scenarios focus on the liquid fraction of the effluent. Regarding a suggestion
that algal residues simply be burned for power generation, anaerobic digestion for biogas/biopower has
several advantages over a simple combustion scenario. In particular, the drying step required before
combustion adds very significant costs and energy consumption to the process. Also, nutrient recycle
would be more difficult; combustion of this high-protein feedstock would likely release much of the
nitrogen as NOx, making recycle difficult and resulting in air pollution issues. Specific quantitative goals
are discussed above under Project Approach.
Project: 9.1.2.2 Sandia National Laboratories
Title: Pond Crash Forensics
Presenter: Todd Lane
Presentation Date: Friday, April 08, 2011
Criteria Avg Score Std Deviation Count
Approach 6.00 1.41 7
Progress 5.86 1.36 7
Relevance 6.00 1.93 7
Critical Success Factors 5.43 1.59 7
1. Project Approach
The project performers have implemented technically sound research, development, and deployment
approaches and demonstrated necessary results to meet their targets
The project performers have identified a project management plan that includes well-defined milestones
and adequate methods for addressing potential risks.
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