Southerly by David Haywood

Here's a question:
- has anyone looked at the efficiency difference between making biofuel from wood and simply burning the wood in a power station?

Rich:

Yes, I have done so (along with other scenarios). I don't have the figures to hand, but the conclusion is exactly as you would expect -- it's much better to burn the wood directly if you want to produce electricity.

The point is, however, that NZ can't use unmodified wood to meet our energy requirements in our existing transport infrastructure. For that you have to convert the wood into something like bioethanol (conversion into biomethanol and biodiesel is also possible, of course).

I'll be away from my computer for the next week or so -- but feel free to chat amongst yourselves...

From the Diversa Press release

Statements in this press release that are not strictly historical are "forward-looking" and involve a high degree of risk and uncertainty. These include statements related to...Diversa's ability to discover and develop enzymes designed for cost-effective wood biomass conversion. Such statements are only predictions, and the actual events or results may differ materially from those projected in such forward-looking statements.

In other words 'We have an idea, we don't know if it will work'. It seems a bit early to be saying we can use wood based ethanol to replace tranport hydrocarbons when they have not got wood based ethanol working yet...

I'm sure almost anything is better but what of the pollutants from the process & end product - any ideas on that?

NZ sustainable energy on the horizon that's fantastic

Andrew is pretty much right. Jim Watson from Genesis Bio has been banging on about this kind of thing with willows – it only needs a bit more money he keeps saying and we could be 100% self sufficient. There are still major hurdles.

They are usually a bit quieter when it comes to fuel costs. MED has an NZIER study on their site and EECA has others. The consensus is that ethanol in any form is not competitive as yet.

Only the Minister of energy thinks there is a potential New Zealand supply on the horizon, that’s apparently why he mandated it without consulting anyone. The Stephen Tindall part owned Lanzatech think they can grow corn in the Waikato to make it – making a nonsense of Parker’s claim that local biofuels wouldn’t compete with food production. Even then it is only economic with a 50 cent/litre tax break and a guaranteed market. Tindall got a big shiny medal in the recent QB honours interestingly enough.

One pollution problem is VOCs, which can lead to haze issues due to photochemical processes, particularly in summer. That can also mean your engine could run rough in hot weather.

Of course they don’t mention the 30% lower fuel economy of ethanol (funny that) and that you shouldn’t use it in boats or aero fuel.

The Genesis willow operation raised some issues besides the production of ethanol from woody biomass.
In the UK, where they do coppice willow for biofuel (direct combustion, not ethanol), they mix species in order to reduce potential damage from bugs/fungus and other biological nasties as chemical control is too expensive - the Genesis approach is to pick one variety and monocrop, which leaves them open to this risk.
The byproducts they will extract, like wood sugar, are also produced by China - any guesses who will control the price?

On the corn/food production point, I think a lot of the production in the Waikato is for stockfood (could be wrong) and so you could say that human food production will not be affected...

Apparently I'm still at my computer tonight...

Andrew Stevenson wrote:

It seems a bit early to be saying we can use wood based ethanol to replace tranport hydrocarbons when they have not got wood based ethanol working yet...

Just to clarify, I certainly wasn't saying that. To quote my conclusion:

While it's perhaps a little too early to declare 'mission accomplished' on the transport energy front...

It's my understanding that the Diversa process works fine to produce ethanol -- but it's the cost of the enzymes that's the problem. Scion believes that this can eventually be significantly reduced in a mass production context.

insider outsider wrote:

Of course they don’t mention the 30% lower fuel economy of ethanol (funny that)...

I think you're a little confused here. It's only a lower "fuel economy" on a volumetric basis -- and that's because ethanol's volumetric energy density is only about 2/3rds that of petrol. The ratio of work output to chemical potential energy (i.e. the efficiency) is still approximately the same for ethanol as for petrol when used in an internal combustion engine.

The reason that Scion, etc. don't make a big deal of the difference in volumetric energy density is because they do their cost calculations on a per joule basis, not a per litre basis -- which is entirely sensible.

With respect to long-term subsidies: I think everyone agrees that in an agricultural country like NZ we simply can't afford to subsidize agriculture. Biofuels (on a meaningful scale) will sink or swim on their cost-effectiveness. This is obviously dependent on the manufacturing cost of the biofuel, but also the cost of the fossil fuel competitors, and any carbon tax (or similar) that may be applied to fossil fuels. I suspect a lot of biofuels people are expecting both rising oil prices and carbon levies. And they might be right.

I'd guess that the Minister of Energy is expecting the same thing, and wants to encourage biofuel development in NZ on this basis.

Andrew

I'm not confused at all. When I buy my fuel by the joule and put it in an ethanol specific vehicle, then you might have a point. Unfortunately I buy it by the litre and that new car is a long way off for the vast majority, so the point stands.

How successful have NZ govt ministers been in picking the long term oil price in the past? I have a bad feeling in my wallet.

Yeah Andrew, you're talking crap about doing energy cost calculations on a per joule basis. It doesn't matter how much energy actually costs, it only matters how much the litres will cost you.

That's why water is such a good fuel -- the litres cost you hardly anything!

[**insider outsider**: to put it another way, you may think you're buying your energy on a per litre basis -- but that's only because volume is a convenient way of measuring energy in a liquid fuel such as petrol. However, this doesn't hold up when you're doing a cost comparison of fuels of different volumetric energy densities. In this case, it makes sense to consider $/Joule not $/litre. So it would be completely silly if Scion et al were doing their cost comparisons on a per litre basis -- that's why they don't talk about "fuel economy" (i.e. litres per 100 km travelled). It's not a conspiracy of silence, as you seem to be implying!]

David, first off best of luck with your other bio based production/genetic engineering experiment

I did read your conclusion and agree with it as far as it goes. What I was trying to communicate (and obviously failing) was that it appears premature to talk about preparing a roadmap for the path to an ethanol future when (to mangle the metaphor) the we're still not able to say if the vehicle we are going to drive in will run properly.

An enzyme is a catalyst ie it is unchanged by the reaction whose rate it accelerates. It seems reasonable to assume that once you have enough catalyst for a reactor, you don't need much more after that then to top up what is lost as product is removed. So the cost of your enzyme production would seem to be a small part of the total operation which are dominated by feedstocks, labour, capital and energy. These costs, combined with the sale price of the products will determine the profitability of the process.

OK maybe I'm wrong and the pesky proteins cost more then diamonds, or they can't be seperated from the reaction products and are lost or destroyed. But it seems from a process engineering point of view that its more the enzyme effectiveness, or how fast it can do the job, compared to the other cost factors thats the main issue rather then the cost of the enzyme itself.
So the whole edifice appears to depend on tweeking the enzyme effectivness, which "involves a high degree of risk and uncertainty"

In what form are Scion planning to produce the ethanol, hydrous or anhydrous? This will have a significant impact on costs and markets for the product. Brazil use hydrous ethanol for flexi fuel vehicles, but Anchor in NZ appear to make more money out of fine anhydrous ethanol produced from whey.

[**REPLY**: okay, I see what you're saying now. Dr Stuthridge told me that the enzymes were the key to reducing costs for the process. Unfortunately, I don't know if this implies that they are consumed in the process, or if they need 'faster' enzymes, or if Diversa charges an arm and a leg to recover their original R&D costs. I should have asked. If I have time, I'll try to find out -- DH]

My wife also prefers joules.

Ah but David, I am a consumer, and I am interested in the case as it affects me not the business case for a potential producer or energy balance modeller. When you invent a water powered car, then the cost of water might be relevant. As a consumer I am more interested in the price I pay for fuel and how far it takes me.

My parallel reality is that fuel is priced by volume, my fuel tank capacity is based on volume not energy content, I measure fuel economy by comparing volume consumed by distance travelled, fuel taxes are by volume. Unless everything I have read is wrong, in my world if I put a ethanol blend in my car - all things being equal - I am going to go fewer kms in my vehicle than if I put in straight petrol in a ratio proportionate to the ethanol content.

And as the ethanol content is likely to make the fuel a higher price than pure petrol, I am going to get a double whammy. However I will now be able to sleep content in knowing that I was better off in terms of joules.

PS My "they" was undefined and was not aimed at Scion at all. They are welcome to do their business case numbers based on joules. I was more referring to the various cheerleaders who oversell the wonders of ethanol and biodiesel and conveniently ignore the known downsides.