Hey I found an idea mentioned here that I think would be quite interesting to try. I started looking into syngas concepts and found that it readily reacts at 2-400 degrees with catalysts that convert it to Methane/SNG and DME. My Idea is to create a process that uses zeolite to filter the nitrogen from the air concentrates it then sends the oxygen to the gasifier to be reactted. From there the gas gets filtered and collected with a compressor at 200psi in a large vessel. From there it is heated to the reaction temperature and hydrogen is injected from an h2 generator. Then it passes through either catalyst and the product is collected at the end either with a CNG compressor or a fuel tank. I think this would be a realistic and simple process once the basics are created. DME would be able to be used for deisel s and cng for gassers.
While DME is very promising replacement for dino disel fuel, its production is not very favourable in energy efficiency point of view. I was interested in the topic for a while and found some resources worth to read.
Direct Dimethyl Ether Synthesis.pdf (663.9 KB)
This one is particularly good, since it discuss chemistry, production process and material balances as well. Another important thing is that process is based on CO:H ratio 1:1 which is very close to wood gasification. At least it could be achievable with good gasifier design and fuel selection. One may try to do own maths if it is worth to build something similar.
Thanks for the information. I will look. I know that many synthetic processes can be more expensive than it is worth. But it seems that it may become more feasible very soon.
Where did you get the combination of temperature of 2400 degrees and pressure of 13 bar for DME synthesis?
In the document shared by Kamil, these parameters are slightly different: a temperature of about 300 degrees Celsius and a pressure of 50 to 90 bar. The same Fischer-Tropsch process requires pressures of up to 30 bar (for an iron catalyst) and temperatures of up to 300 degrees Celsius.
Or did you mean the temperature range from 200 to 400 degrees? If this range is in degrees Celsius, then everything seems to fit, but you indicate the pressure in psi in your message, then we can assume that these 200-400 degrees are still in Fahrenheit.
And why bother removing nitrogen from the air if you need to produce hydrogen for the reaction? Then maybe it’s better to take oxygen from the decomposition reaction of water?
Your message also doesn’t say anything about a synthesis gas generator, but without it, no synthesis reactions will work. Will it be charcoal or firewood? The fact is that for synthesis you need a very stable composition of the incoming raw materials. You will have enough headaches in catalytic chemistry even without a floating synthesis gas composition. For example, I would love to see your beautiful solution to the problem of oxygen blowing into a hot gasifier!
And, most likely, you should focus your efforts not on the simplicity of the process, but, as Kamil very correctly noted, on increasing the energy efficiency of this process. Without solving this problem, everything else is just an expensive game of chemistry.
No offense intended, but this successful pilot plant flow diagram, from the PDF link provided by @KKubu, looks complicated and a good way to hurt yourself, physically and financially.
There are simpler and more effective ways to utilize wood gas, producer gas.
You said long story short, @MikeR
Then the factors of Scale of Productions. And the prices willing to pay for the end usages have a tremendous differences in what can; and does, get done.
Actual done Fischer-Tropsch that has been done as one example. Natzi Germany WWII. Much later done to a limited extent in the late Aprartide era in South Africa.
Once the God of Wars is loosed then effective war quality fuel is the driver of the processes.
But even then; and since; could it be done to fuel a civilian economy?? No.
Another example. Nuclear reactor power for ocean ships. Early on done in military submarines first. Then military aircraft carriers and large cruisers.
A few civilian cargo ships were done. Then fizzle, no more.
I think even the Soviets did a couple of Ice breakers with nuke power too. Quasi-civilian.
Why not anymore? Far too of high of all of the total cradle to grave true costs. Too Expensive.
So national-war effort maybe . . . for DME and SNG.
DIY personal use to replace your gasoline, diesel, propane??? Never going to happen using highly variable “dirty” wood as an input stock base. And the gas maker for wood breathing in highly oxygen diluted atmospheric air. “Contaminated” with 70% nitrogen and other trace gases.
Just use the wood more directly for engines running as the 1940’s Germans and Europeans learned that they had to.
And we here do again now. Woodgas and charocoal gas is Very DIY doable.
No it was in centigrade. The pressure was just for low pressure storage of raw gas and is in psi, I should have made it more clear.
My understanding is that there is a soviet design for a wood fueled gasifier using oxygen instead of air. Removing the nitrogen will remove the problem of having an inert gas taking up heat and space in the reaction making it more efficient. Injection of hydrogen later would help with generating methane and hopefully have the least amount of unreacted gas. It also allows for possible hydrocarbon use. There is some new research using nickle, zinc, alumina and a couple other catalysts for the catalyst. I am just trying to get the usability of gasifiers up vs having to add 400lbs of materials and let alone fuel to a vehicle.
Yevgen kolyvan of Ukraine has made a very lightweight raw wood gasifier. He claims a total system weight of 40kg. It hangs off the rear bumper of his Opel Kadett.
Looking at his system I believe his weight claims. Very tidy unit system.
When l get more time l will get back so Fischer-Tropsch for sure. This was my graduation project so l alredy have a few experiances. The reaction works under low pressures, as low as ambient, and the catalyst can be easyly made at home.
My idea is to run it in paralel with a generator, to power the compressor, and to use the gases after the first pass. No need to worry about reaction efficiancy then, the gases dont go to waste but make electricity and heat. The whole thing then becomes wery simple.
FTS produces mainly straight alkanes wich are a bad petrol base. Low octane rating, about 60-80 if l remember right. But the diesel is excelent and thats what l aim for.
The only trouble with FTS might be that it require twice as much of hydrogen as carbon oxide. But you are expert, so you most probably has the knowledge how the low hydrogen content in syngas may affect the reactions in FTS.
Have you tried producing methane, this is one of my goals. Easy-to-use in a vehicle with CNG kits.
These are some of the articles i am basing my ideas on. It makes more sense I believe to develop fuels that my vehicles can run straight away. There are others discussing this quite frequently now. It seems go be a great opportunity to develop.
How did you produce your own catalyst?
Why? Methane is no better thain woodgas. It doesent liqify and is hard to compress. You want longer chain hidrocarbons, wich are alredy liquid in ambient conditions.
The goal is to have nano iron particles on some sort of support, with a bit of spices to promote the reactions.
If l remember right l mixed iron nitrate with diatom earth and disasotiated it to form iron hidroxide. The brown mess is an absolute pain to filter but once it did l baked it at high temperature to form iron oxide and thats it. Before the first use thugh it has to be activated with pure hydrogen. This reduces the oxide to pure iron but after that it must never touch oxigen again.
I thought this was interesting. If someone could get a bench setup working it would be a big step forward.
Search: Direct Synthesis of Dimethyl Ether from Syn-gas over Cu-based Catalysts
I can buy a compressor that will work with methane as well as computers programed to run modern equipment. Thats the benefit to Methane. I also can have a methane digester and compress gas from that as well. Thats why I was looking at it. I also looked at compressing wood gas but it seemed unless used right away you would get component separation from the hydrogen and the CO.
youtube search: woodgas storage tank
I don’t think there will be any component separation. Tar and soot used to be collected from the bottoms of big gasometers before wwii, but that would be a benefit. Many people have stored woodgas in tanks, without loss of pressure, for long periods of time.
Main issue with compressed woodgas storage is hydrogen making steel components brittle over time.
A gasometer or gas bag are the safest methods for storage.
To go for CNG, anaerobic digestion as a methane source is much more favourable than methanation of woodgas. Also processing of biogas into biomethan is much more easier. The only issue would be with feedstock, because with low quality your production would not pay off.