2019 update - Emission section extended to include CCS capture rate #28
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OFR-IIASA
changed the title
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this lgtm, @volker-krey should confirm the addition/subtraction of technologies |
| - 85% | ||
| * - Liquid fuel production | ||
| - Fischer-Tropsch gas-to-liquids with CCS | ||
| - 90% |
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The capture rates for liquid fuel production from coal and gas seem very high to me given that a significant fraction of carbon remains in the liquid fuel. Are these relative to the carbon content of the input or relative to the output, excluding the carbon in the fuel?
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These are based on the output fuel. I took these numbers from the spread sheet derived by "eric", where the capture efficiencies are explicitly provided. So, syn_liq has an entry into CO2c of .539. syn_liq_ccs has an entry of 0.080 (therefore .459 is captured). The remainder .631 remains in the output fuel.
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Hi all,
Yes, this table also looks a bit unclear to me, especially regarding the liquid fuel production.
I'l probably drop by your office @OFR-IIASA to understand it a probably to make it clearer for an external reader. Afterwards I guess we could close and merge this PR.
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I had a closer look at this issue, using the example of coal methanol-to-gasoline with CCS (meth_coal_ccs in AFR for 2030). I can reproduce the 85% capture rate for the residual emissions, i.e. the emissions excluding the carbon that remains in the fuel produced. My suggestion would be to provide two capture rates with a clear definition in this table: (i) the current capture rate as a fraction of the process CO2 emissions and (ii) the capture rate relative to the carbon content of the feedstock. For the above example, the latter is about 55% as a significant share of carbon remains in the fuel. The former number is interesting from an engineering point of view and describes the efficiency of the capture process. The latter number is particularly relevant for the biomass-based CDR technologies as it describes the potential to sequester carbon from the atmosphere. Obviously for processes that produce carbon-free energy carriers like electricity of hydrogen the two are the same.
@OFR-IIASA Please add this second column with a clear definition. - Thanks.
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@OFR-IIASA @volker-krey since this has seen no activity in 4 months, I am going to merge it so that we can complete the “2019” update of the docs. I created a follow-up issue, #38, so that someone can be assigned to make this edit to the table. |
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