so, it is economically less expensive, but what does the energy balance look like?

it sounds like they can use any biomass (not just grains, like fermentation-based ethanol), so they may have a better energy balance than the current norm.

I tend to notice terms like 'once perfected'. The tag on the table says actual yield but the number is estimated. Maybe there is a reason that GM enzymes, acids and high pressure reactors are needed in the proven processes.

Shaun -

Iogen efficiency = 70/114 = 61%
Syntec efficiency = 114/230 = 50% ("once perfected")

Ergo, while the syngas route may be cheaper per unit of end product, it requires more feedstock to deliver the same amount of ethanol. As long as that feedstock is biomass that actually does get renewed, there is no net CO2 release from the process + fuel combustion either way. Note, however, that Syntec is also looking at NG, coal bed methane and other non-renewable feedstocks.

Cervus -

chapter 3 of the following document outlines the various chemical synthesis processes for producing the various isomers of butanol. In particular, note that it is apparently possible to produce butanol from ethanol via several intermediary products, but that overall yield per unit of biomass is probably unattractive:

http://dsir.nic.in/reports/techreps/tsr107.pdf

Here's more detail on how ethanol is produced from syngas:

http://spitswww.uvt.nl/web/telos/documents/rapportbioethanol.pdf

It's better, but still not good enough to even replace gasoline.  We'd have to do much better to replace all motor fuel, and far better still to replace all the various uses of petroleum.

Well, at least somebody got it right! I've always suspected that cellulosic or grain to ethanol is an inefficient process. Gasification is much simpler and more efficient. But, they still ain't got it all right! With the syngas containing H2 and can be easily turned into methane, why not just stop there and use the H2 and methane as transportation, home, and power generation fuels? H2 for local transportation and immediate use without requiring long-term storage. Methane is for long-distance transportation, long-distance exportation via pipeline or LNG tankers, or long-term storage which we already have all the infrastructure designed for natural gas. For diesel application, make DME.

I question the EROI comment.  From the above, the EROI improvment is only about 60%; I'd call that considerable, but not dramatic.  Considering that the input material is waste, it's not clear how much energy to allocate to its production; there's clearly a lot of room for fudging, or shenanigans, there.

Rafael,
Syngas already contains CO, thus you've got all the carbon needed. Plus methane (CH4) requires more hydrogen than carbon anyway, so you've got a lot of excess carbon from cellulosic biomass. Convert some amount of syngas to liquid hydrocarbons, if you will, but leave some H2 and methane left for those who just wanna to run their cars with H2 or methane, and pay less for the cost of renewable fuel while help reducing pollution.

NBK-Boston, Eng-Poet,
Heat energy required to heat the biomass to 815 degrees C is entirely recyclable by steam turbine with 40% efficiency into electricity, same efficiency as a coal burning power plant. So, one can consider this free heat. This, in contrast to the low-temp heat energy required to distill the fermented product into anhydrous ethanol, that has little recycling value.

Enzymes required to break down the cellulose into simple sugars so far are still very expensive, pushing the cost of cellulosic ethanol much higher than grain ethanol. Gasification does not require enzymes, nor much processing of the raw feedstock.

Ergo, while the syngas route may be cheaper per unit of end product, it requires more feedstock to deliver the same amount of ethanol.

No, the opposite is the case. Remember, the syngas route can exploit everything -- starches, cellulose, hemicellulose, fats, proteins, and (very importantly) lignin. The enzymatic processes can't do anything with lignin.

I suspect the problem with the syngas route is that it's not economical on a small scale, particularly if you need an oxygen-blown gasifier.
I understand gasifying biomass is also somewhat problematic, in that the slag is more corrosive than the slag from gasified coal.

This leads to the natural question: why are they gasifying biomass instead of coal? Coal is cheap and plentiful and coal gasifiers are well understood. Are they trying to exploit government subsidies for biomass-based ethanol?

Roger,

A co-generation scheme might significantly reduce if not eliminate the energy "lost" to the gassification process, especially if you adopt the attitude that "we were going to burn that coal anyway to turn it into electricity." There are still a few miscellaneous bits of energy accounting to take care of, including the energy value of the current uses of the biomass waste, but I'll assume for the moment that those items are small.

I'm still left with the problem that the infographic that goes along with this post does not indicate that the designers of this system actually intend to build it as a co-generation project. If this process goes anywhere commercially, I hope they have the good sense to try your proposal.

Moreoever, the infographic does indicate that there is a distillation step which takes place towards the end of this process, meaning that we cannot entirely get around that energy-consuming bottleneck. How distillation in this context compares to distillation of conventional or cellulostic-enzymatic ethanol is unclear. Whether lower-grade heat coming out of the gassification/steam electricity step can make a difference I cannot tell at the moment, but seems like a possibility -- a triple co-generation setup, if you will (biomass gassification, steam electricity, low-grade steam heat for distillation).

The biggest advantage here seems to be the ability to turn any mix of biomass waste into a reasonably useful fuel (ethanol), without having to fool around with costly and possibly narrow-spectrum enzymes or micro-organisms. Which is no small thing, but which doesn't mean that this process will automatically displace cellulostic developments, especially those aimed at markets where specific feedstocks can be grown to suit the needs of the enzymes or yeasts. Price out the processes using a higher figure for the coal and natural gas inputs (perhaps reflecting Rafael's carbon-tax approach, or perhaps reflecting higher prices due to higher demand) and see how things line up.

Combustion of wood to generate electricity is not economical per se. Combustion of wood wastes with heat utilization is currently the most economical way to get rid of this wastes. Due to moisture content and presence of oxygen atoms in the material, combustion temperature is lower then at combustion of coal or NG, and thermal efficiency of wood-fired boiler with steam turbine is about 30% vis 40% coal-fired. Currently standard method of combustion of wood wastes is co-firing on coal boilers with quantities about 5% of calorific input, thus retaining 40% efficiency. Alternative method of utilization is generation of biogas in anaerobic digesters (like at sewage treatment plants), but it is not widespread because of poor economics of the process. As any biological process, it can not decompose lignin, which constitute up to 40% of wood biomass. Same applies to cellulosic ethanol. Pyrolysis or gasification of biomass is accomplished by partial combustion of the material, thus sizable part of the biomass energy is wasted just to perform pyrolysis/gasification. Moisture content is critical to the economy of the process. All these methods of dedicated wood wastes combustion to generate electricity are not competitive (for local space heating it is economical and widely used) compared to coal burning.

Economics of the process changes dramatically when final product is liquid fuel, especially transportational quality – it is just way more expensive than fuel used to generate electricity. This is the core reason why cellulosic ethanol/butanol (can use wet organic wastes, but lignin content is wasted), or pyrolysis/singas (utilizes all biomass, but can work only on dry materials) path to convert biomass, first of all waste biomass, are economically appealing and are developing rapidly, with current oil prices especially.

Clean wood wastes, such as straw and sawdust, are way more valuable materials to make variety of construction panels and materials, instead to be combusted or even turned into liquid fuels. Thus two classes of organic wastes remaining to be converted to liquid fuel economically: wet wastes as corn stalks and alike to produce cellulosic ethanol/butanol, and dry bark/bark contaminated wood wastes to be used in singas conversion.

Rafael,
What I meant for methane production is actually not gasification, but pyrolysis, in which lower temp is used but fast transfer of heat to biomass and and less time at hot vapor phase, such that the carbon-carbon bonds break into short chain alkane such as ethane or methane, and hydrogen, and CO or CO2. If you gasify it all the way with high temp, then all the carbon-hydrogen bonds are stripped and all you've got is H2 and CO.

Eng-Poet,
Imagine that eventually, most cars will be capable of 50-80 mpg combined. Then, we'll be able to meet gasoline demand with biomass, won't we? The technology for these high efficiency is here today. It just takes time to be adopted commercially, providing that gas prices will remain high. For home electricity, wind or solar will be best.

"the ICE is dead? NO, long live the ICE-electric hybrid" Especially if you run it with renewable H2 or Methane.

Of course gasification consumes heat input, and does not produce it. I certainly know that (cf. my comment about "having to burn this coal anyway..."), and I think Roger knows it as well. But the question he was addressing is how much heat does it *actually* have to consume -- that it, how much of the input energy is non-recoverable once you've turned your biomass into syngas.

The point is, though you may have to burn a whole pile of coal to heat up your load of biomass to something like 800 F (or whatever), by the very end of your process you need the liquid ethanol product to be no hotter than 100 F in order to safely load it and transport it. It seems likely, based on first impressions, that there is room somewhere in this process for a steep drop in temperature. That could be effected by simply venting the heat into the atmosphere, or it could be effected by running the hot syngas through a heat exchanger in order to cool it, and then having that heat exchanger dump the energy into a steam boiler. Which could then be used to run an electricity turbine. If you then take the view that we were going to burn coal to generate electricity anyway, the loss associated with the gasification process could turn out to be fairly low. You'd have to compare the electricity produced by this sort of "co-generation" with the amount that could be produces if you burned the same amount of coal in a standard electricity plant. There is at least a chance that the amounts could be rather close.

To the extent the chemical bonds in the resulting simple molecules (H2) embody more potential energy than the chemical bonds in the complex carbohydrate molecules of the input mass (which I think they do -- I recall from somewhere that reforming methane into H2 causes external energy to be "embedded" in the H2 molecules), we haven't lost anything, we've only moved the energy to an different place which also happens to be a pretty useful one. To the extent that we keep the temperature in the syngas conversion chamber up at high levels, we retain the ability to run an efficient thermodynamic engine -- to generate electricity say.

The key proviso is that there needs to be a stage in the syngas-to-ethanol process where the temperature of the working fluid can be quickly dropped from 800 F to perhaps 400 F or 200 F. That is the point at which a classic Carnot engine can make useful work out of this heat which we have already generated.

The key accounting trick is to think of a syngas-to-liquids cogeneration plant as a conventional power plant that needs to run anyway. Then, the only operating cost involved in the syngas conversion step is the cost associated with any additional fuel that needs to be burned to keep electricity production up to previous levels, plus the typcialy overhead costs of a syngas plant such as pumping, maintenance, etc.

The point is, gasification consumes thermal energy. But it does not need to "consume" all the thermal energy used to keep the operating temperature up.

I recall a landfill gas to hydrogen project along just these lines -- using concentrated solar energy as a (partial) heat input to support the endothermic reaction involved. To the extent you can effectively substitute solar for coal in this process, that makes perfect sense. But to the extent that you are still burning coal, the point remains that there are several useful pathways to extract useful energy products from the inputs, meaning that this proposition need not be much of a loser. Thermal input from coal can be embodied in the higher energy content of the H2 component of the syngas, and after gasification, the residual heat can be used to pre-heat the incoming mixture (your suggestion) or run a thermodynamic engine (Roger's suggestion). Or maybe even both (step from 800 to 200 in a boiler, step from 200 to 100 as a counterflow preheater). Specific engineering practicalities will dictate which is the superior plan in any given case. They will also determine whether we want to allow any of the biomass/syngas to be consumed to create thermal energy to promote the gasification of the remaining amount, or if we want to prevent that reaction and use only other thermal inputs. There are good reasons for prefering the latter. Biomass might be more expensive to acquire or scarcer than coal or solar power. In any event, I don't think anyone was suggesting that we allow some of the syngas flow to be diverted to electricity production. I think we were merely trying to say that electricity co-generation is one possible way to make effective use of residual waste heat that remains after biomass is successfully reduced to gas -- as you point out, there are certainly others.