UC Berkeley ERG PhD candidate Dan Sanchez has a new paper (gated) out on the optimal size of bio-refineries. The research suggests that smaller might be better when it comes to biomass energy production: the key results (summarized in the chart below) show that the optimal bio-refinery size could only 10-30 MM gal/yr (the world's largest oil refineries produce over 1B gal/yr).
This finding has interesting implications for CDR, especially for biomass energy with carbon capture and sequestration (BECCS). Currently, CO2 pipeline infrastructure is very limited in the US (also across the world). This infrastructure works well for current CO2 consumption needs, as it brings CO2 from a few major underground natural reservoirs to a few major enhanced oil recovery operations, where the CO2 is used in the oil extraction process. A 2010 report on the CO2 pipeline infrastructure required for carbon capture and sequestration (CCS) suggested that this "few to few" pipeline-to-sequestration system is likely to persist as more CCS projects come online, under the theory that CCS projects will be located at clusters of big fossil power plants that can share pipeline capacity.
But if we need to also have significant BECCS capacity come online in the near future, and optimal BECCS capacity sizes are small, we might also have to build out considerable amounts of additional pipeline infrastructure to service all of these facilities. At an average cost of $50,000/in. diameter-mile, new pipelines are not cheap.