Advanced BioFuels USA

by Ross Mazur and Joel Braden (Sustainable Fuels Consulting LLC/Biofuels Digest)  …Carbon-neutral Electricity

• • For all of us whose product is sold in an LCFS or RFS-2 market, carbon-free electricity could bring additional value (see B.O.T.E. profitability analysis below). Although most biorefinery processes don’t generally have a substantial base electric demand, co-location might make electric process heat (as opposed to natural gas process heat) more attractive. Further, partnering with the nuclear developer might provide the opportunity for negotiating wholesale REC pricing. It also gives boasting rights for not contributing to distribution line losses (either viewed as system inefficiencies or wasted electricity).
• Carbon-neutral, Low-cost Heat
  • Nuclear power plants are in essence heat plants that commonly generate electricity using Rankine steam cycles. These steam cycles are designed to optimally reduce enthalpy of the heated steam fed into the turbine. This produces byproduct low-grade heat in the form of low-quality steam or condensate. If you have a biochemical process that requires a steady supply of low-temperature heat, this waste heat might have value to you. Otherwise, the waste heat might be of little use.

Alternatively, many nuclear facilities throughout history (described in greater detail below), have designed facilities to use heat and steam (in the case of LWR’s) for multiple applications (such as desalination, in addition to electricity generation). The impact of a biorefinery on a planned power generation facility will vary depending on the biorefinery base heat demand as compared with the scale of the reactor. If your process would only require 1% of the high-quality steam generated, this would just cause the turbine to operate nominally lower on the generation curve. However, if your facility required 15% of the high-quality steam generated, this might mean a different turbine (whose generation curve peak is at 85% of that the currently planned turbine) would need to be selected.

Regardless, it would likely be important to develop relationships earlier to make use of this opportunity. Once designs are finalized and facilities are built, it might be difficult to convince an owner or utility to retrofit the system with your heat-sink facility and introduce technical risk.

If able to secure high-quality steam, this carbon-free heat could in theory also be used to dry wet feedstocks.

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Large-scale nuclear facility construction requires lots of concrete and steel, and changes land use and albedo of a large land area. Even with a 60-year operating life, this yields a non-zero CI score. The US median CI of Gen II nuclear power is 12 g-CO2/kWh – one of the lowest in stationary power generation, only beat by wind, having a CI of 11 g-CO2/kWh, (as compared with 820 g-CO2/kWh from coal). We would anticipate lower CI’s for Gen IV reactors. Further, the capacity cost of electrical power generation and H2-kg/day generation for nuclear might be greater than for solar or wind with a PEM-electrolyzer for H2 production. Because of this, it might be best to co-locate with a nuclear facility rather than develop one yourself.   READ MORE