carnej1 Hmmmm..... nothing I've posted was intended to support the contention (pro or con) that DME as an economical alternative to conventional diesel fuel.
Hmmmm..... nothing I've posted was intended to support the contention (pro or con) that DME as an economical alternative to conventional diesel fuel.
The economics of DME as a diesel fuel may depend on factors other than cost per BTU. I suspect that a diesel engine running on DME will emit dramatically fewer particulates than diesel engines running on more conventional fuels. What I don't have a clue about is whether use of DME will reduce NOx emissions - if there is a significant reduction, then using DME may end up being less expensive overall than using conventional fuels. There was a PowerPoint slide show from someone at UPRR describing the difficulties with installing emissions control systems on locomotive engines.
Having said that, I'm probably at least as much in the dark about the actual economics of DME as a diesel engine fuel.
I have no intetion of sparring with anyone. I work for a companyi n that field and really want to read about it since I haven't heard about it before. My sarcasm was intended to be funny because the logic that gets politicians elected astounds me.
ndbprr I'd like a reference for that please. Since CO2 is already oxidized to its limit (burnt) it sounds more like a plan to free up the oxygen for reuse and capture the carbon. I still think it will be highly energy intensive and not a fuel that will be justifed based on cost of production but then I have trouble using logic and not being politicaly correct in my analysis or life. .
I'd like a reference for that please. Since CO2 is already oxidized to its limit (burnt) it sounds more like a plan to free up the oxygen for reuse and capture the carbon. I still think it will be highly energy intensive and not a fuel that will be justifed based on cost of production but then I have trouble using logic and not being politicaly correct in my analysis or life. .
Hmmmm..... nothing I've posted was intended to support the contention (pro or con) that DME as an economical alternative to conventional diesel fuel. It is entirely possible that the aforementioned scheme is "pie in the sky" rather than technically/economically practical. My understanding of the CO2-to-Methanol/DME proposal was that it intended to acheive Carbon Sequestration just as you stated.
In other words If you are interested in having a political debate over alternative fuel use or climate change you'll have to find somebody else to spar with......
"I Often Dream of Trains"-From the Album of the Same Name by Robyn Hitchcock
I have read of proposals to capture the CO2 emissions of coal burning powerplants (and coal-to-liquids plants) and use it as feedstock for DME production. I am aware that there are considerable technical hurdles to overcome in doing this...
Would anyone care to wager that this wasn't all started by a press release from the developer/manufacturer? Naturally, they would emphasize the, "Look at how 'green' we are," and quietly gloss over the crass financial realities.
The best alternative fuel we have today is coal, delivered to locomotives through high-voltage catenary at commercial AC frequency...
Chuck
Why convert coal to coal gas (ICCG process already scratched by the DOE as to expensive) then make a secondary product which takes even more energy. Now you need to add the cost of sulfur removal from the coal which is where ICCG costs went out of site and casued it to be scrapped. Somebdy can claim the cost to make the stuff is x cents per gallon but when all the costs are figured in there is a reason it is theoretical. Ethanol even with all the subsides we are putting into it is still more expensive than gasoline as it gets 2/3 the mileage. People look at the pump price and think it is a good deal. For a direct gasoline comparison add 50% of the pump price to the cost to equal gas mileage and it doesn't look so good. Guess we should plan to hide more costs with tax dollars for that to be viable.
Jim,
From what I've read, the feedstocks for producing DME are either methanol or carbon monoxide and hydrogen. The classic methanol production method is destructive distillation of wood (hence the moniker "wood alcohol"), which implies that it might be produced from anything that has a high cellulose content. Carbon monoxide and hydrogen are typically the first products from gasifying coal - might make more sense to produce DME than "coal to liquid" synthetic diesel fuel, especially if DME is cleaner burning.
I'm not a big fan of using crop based ethanol.
Erik,
Even if it makes a 'pretty decent' diesel fuel, the bottom line is what does it cost to produce? If the cost is too high, or it takes more BTU's of energy to produce than one gets out of the process; then it is a losing game.
Ethanol production right now only results in about a 7% average 'gain' in BTU's after adding up the fuel to plant/harvest/transport the corn to the ethanol plant. And it has driven the cost of corn sky high(checked out the cost of your cereal). Here in SE Minnesota(corn belt) we have farmers planting corn from 'fence line to fence line'. Soybean product has suffered due to the higher prices that can be gained from corn production, Further west of here, other grains have suffered as well. Depending on 'who' you talk to, if we planted corn on all the production land available; we still would only be able to produce 25-35% of our energy needs.
Energy needs for the nation need to be balanced between several options.
Jim
Modeling BNSF and Milwaukee Road in SW Wisconsin
With a cetane number of 55, DME would make for a pretty decent fuel for diesel engines. One interesting aspect of DME is the lack of a carbon-carbon bond, which may significantly reduce the amount of soot produced - much of which comes from acetyline being produced as part of the combustion of hydrocarbons.
Using DME would require some changes to the injectors, I rather doubt that DME is as good a lubricant as ordinary diesel fuel.
Wikipedia is certainly not the most reliable source out there but here's the entry:
http://en.wikipedia.org/wiki/Dimethyl_ether
http://en.wikipedia.org/wiki/Methanol_economy
OK but what does it cost to make? How much heat is needed in the process and does it burn its own product? You don't gain energy in any process. The process always uses energy to make the product. Having an idea can make you rich but may not be the cheapest solution orthe easiest since diesl fule can be had anywhere in the country
The Energy Conversions inc. website mentions this as a technology that company has in development. This is the same company that manufactures diesel-to-natural gas conversion kits for locomotives. I understand that DME (which is produced from Methanol) makes a high quality synthetic diesel fuel...........
Moneynews.com carried a promotional piece on Alternative Fuel Technologies, LLC and work on dimethyl ether (DME) as a greener, and less costly to produce fuel similar to LPG. DME would seem to have application for railroad motive power.
If you missed it, "Rohr Turbos for sale" has been an interesting companion thread in Forums>Passenger discussing recuperated gas turbine power and fuel efficiency.
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