Graeme,
Just winder if you read up on your beloved Red Rock.
They claim that they want to build a plant with a feed capacity of 175 kta woody biomass and produce 16 millions gallons (mixing units again to hide the reality) of naphtha, jet and diesel.
http://redrockbio.com/Technology.htmlThe process is our old and trusted FT using a reactor system from Velocys.
http://www.velocys.com/index.phpTwo problems come to mind.
1. Scale - this is a very small plant - in fact Bonsai
2. The Veloscys reactor has not ever been built commercially- yet
Previous attempt to scale FT have not been successful. The reported cost of the plant is $200 million.
Now a few maths. 16 million gallons of products is about 60 million litres with an average density of about 0.8. That gives us about 48 kta . As I said a Bonsai plant.. Base on current jet and diesel pricing of around $510 pmt and naphtha of $470 pmt the annual revenue can be expected to of the order of $24.5 million. Using a lower average density would actually make matter worse, and the average density might be lower.
Working out the operating expenses on such a small plant id difficult, but judging by the location and likely hefty personal costs it is perhaps wishful that they are going to make a huge profit. If they were to make 20% profit on the sales revenue, that would take 40 years to pay off the plant excluding any interest charges. On a capacity basis the installed cost works out at about $4166 pmt of plant capacity. Compare that with Shell Pearl $2933 pmt and FREE natural gas for 10 years.
Red Rock publish some interesting if not confusing data.
Feestock @ $22.5 / barrel BTU equivalent
Crude Oil @ $95 / barrel BTU equivalent
If we look at natural gas as an equivalent feed the BTU equivalent price of NG in the US is about $18-20 / barrel based on NG of $3.0-3.3 MMBTU.
In other words NG is cheaper and a whole lot easier to handle. Bearing in mind that this is woody biomass left over form wood harvesting it is also likely to contain a lot of contaminants which will need to be removed. This add cost and potentially fouls equipment.
So what do Red Rock know that the rest of the world does not. All I know is that past attempts on small volume FT plants have not borne fruit (Choren comes to mind). How many FT plants have been built in the US? Shell cancelled their proposed project. It remains to be seen if Sasol proceed with their even more costly plant.
Now let us look at the plant yield. 48 kta of products from 175 kta of feedstock . That is about 27.5% on purely mass basis. On a CV basis it is a little different
Biomass 14 MJ/kg heating value
Products 43 MJ/ KG heating value
Feed (175 million x 14) = 2450 million MJ
Products (48 million x 43) = 2064 million MJ
Looking at the conversion on heating value in/out we have 2064/2450 x 100 = 84%
That would appear to be optimistic, or my maths might be wrong. Dry wood typically has a CV of 16-18 MJ with hardwoods are the higher rage and softwoods at the lower range. I used 14 MJ/ kg as this could be realistically assumed for wood harvest waste and might even be optimistic. Moisture content is critical.
Using a value of 16 MJ/ Kg lowers the conversion to 73.7%.
Compare this with the Shell process (SMDS) then shell claim a theoretical thermal efficiency of 78% and that their process achieves 63% using NG feed. Source Myers Petroleum Refining Handbook 3rd edition 15.35.
I will leave readers of this post to draw their own conclusions. I know what mine are.