Refining

Refining crude oil into gasoline takes energy. But how much?

From this page: http://tonto.eia.doe.gov/dnav/pet/pet_pnp_capfuel_dcu_nus_a.htm
We can see that in 2008 american refineries used:
711 billion cubic feet of natural gas
43000 tons of coal
42.7 billion kWhr of electricity purchased from the grid
327 million barrels of oil products ( non-gasoline refining leftovers )
98.8 billion pounds of steam purchased

From this source we find the conversion efficiency of electric power generating stations ( in 2005/2006) . www.npc.org/Study_Topic_Papers/4-DTG-ElectricEfficiency.pdf
At that time the average BTU/kWh for US coal was 10,410
The top 20 US coal plants averaged 9400 BTU/kWhr
The best available technology for a new coal plant was 7757 BTU/kWhr
The average US NG plant was 7920 BTU/kWhr
A typical NGCC ( natural gas combined cycle ) plant is 6800 BTU/kWhr
And the best available NGCC technology is 6333 BTU/kWhr

Back to our consumpton numbers… if instead of using that energy to refine crude oil into gasoline, we used it to generate electricity, how much would we get?

The natural gas could generate 90 billion kWhr with average gas plants.
And 107 billlion kWhr using the best NGCC plants.
The coal can produce 107 billion kWhr using average coal plants, or 139 billion kWhr using the most advanced coal plants.
I couldnt find data on electrical generation from petroleum products, so I’m going to take the average of coal and NG ( the average plants ). Thus the 327 million barrels of oil products can produce 235 billion kWhr of electricity.
Lastly the energy used to generate the steam could instead generate 13 billion kWhr of electricity.
Add all that up and you get a low value of 488 billion kWhr and a high value of 533 billion kWhr.

In 2008 the total number of vehicle miles driven was 2921 billion.
The Tesla Roadster is about 88% efficient charging and there is about 8% transmission loss per 500 miles. At 80% charging efficiency and 4 miles per kWhr, the 488 billion kWhr would move EVs a total of 1561 billion miles.

Yes we could supply the energy we need to drive EVs more than 50% of the miles we drive in a year from repurposing the energy we use just to refine gasoline.

This does not even cover the energy that we use to extract crude oil and transport gasoline to the consumer.

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One response to “Refining

  1. Good approach. One complication is that refineries produce a range of products and only a fraction of the energy used can be attributed to gasoline production. Also the the configuration of the refinery matters. US cracker refineries might actually use quite a bit of fuel on the margin to increase gasoline production. If gasoline requirements drop, cracking could be possibly taken back and that may have a surprising impact on “refinery fuel and loss”.
    – Alfred

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