Comment by semi-extrinsic | Hacker News Reader

Comment by semi-extrinsic | Hacker News Reader

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I know Equinor publishes quite detailed numbers from their operations:

https://sustainability.equinor.com/climate-tables

The headline figure is maybe to compare 11.4 mill. tonnes CO2e emissions from "Scope 1 + Scope 2" (direct emissions from the company plus indirect emissions because they buy electricity and stuff), versus 243 mill. tonnes CO2e from Scope 3 (emissions from people burning the hydrocarbons sold).

If that figure is correct, you can add 1.6 percent to the car tailpipe emissions figures to account for production and refining etc.

But this is an oil & gas company that tries very hard and is among the best in the world for minimising emissions from production and refining. I would not be surprised if gasoline from US shale oil is more than an order of magnitude worse.

>EROI values for our most important fuels, liquid and gaseous petroleum, tend to be relatively high. World oil and gas has a mean EROI of about 20:1 (n of 36 from 4 publications) (Fig. 2) (see Lambert et al., 2012 and Dale, 2010 for references). The EROI for the production of oil and gas globally by publicly traded companies has declined from 30:1 in 1995 to about 18:1 in 2006 (Gagnon et al., 2009). The EROI for discovering oil and gas in the US has decreased from more than 1000:1 in 1919 to 5:1 in the 2010s, and for production from about 25:1 in the 1970s to approximately 10:1 in 2007 (Guilford et al., 2011). Alternatives to traditional fossil fuels such as tar sands and oil shale (Lambert et al., 2012) deliver a lower EROI, having a mean EROI of 4:1 (n of 4 from 4 publications) and 7:1 (n of 15 from 15 publication)

https://www.sciencedirect.com/science/article/pii/S030142151...

So the major difference between your numbers and the ones I cited, is that EROI is just "energy in versus energy out" and it does not change favorably if you do carbon capture or use renewables or whatnot.

Whereas if you compare CO2 emissions, you can do these things and in theory get down to zero emissions from production and refining of gasoline.

you are right -- EROI and emissions are different. If you add in things like carbon capture, emissions go down but energy-in goes up. Would it make sense to extract and refine gasoline with net-0 emissions if it took more energy than you get out in gasoline? _maybe_, but I don't think its a clear yes!

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