Ethanol from Wood Gas??
Posted 06 April 2009 - 07:03 PM
Posted 27 August 2010 - 03:17 AM
Researchers are using traditional Fischer Tropsch catalysts for the C-C chain building, and Co, Zn, type catalysts for the -OH termination step. However, the selectivity of ethanol is highly sought after and there are many exotic catalysts and research fronts to optimize for solely ethanol. However there is much success in procuring mixed lower chain alcohols and mixed higher chain alcohols within a range of C +/- 2.
At the temperatures and pressures needed for these catalysts, water gas shift reactions can occur which potentially cycles the potential water product back to equilibrate to oils or alcohols.
Posted 01 February 2011 - 11:53 AM
He uses 3:1 aluminum-nickel (available as 'Hyalite 16' apparently) to catalyze a natural gas-steam reaction in a first vessel @500C to produce syngas which is then cooled/condensed. Then the syngas is separated and fed at pressure into a second vessel with a 4:1 copper-zinc catalyst @ 200-250C. This will supposedly produce liquid methanol after separating and cooling the reaction products. Anyone heard of this before?
Posted 17 June 2011 - 01:37 AM
Yes, this book is an excellent starting point. Well worth the read. It looks like methane happens much quicker. The technology is not too difficult. there is a problem with gat to liquid xfer, I'd like to know if pyro-oil can be used.
Posted 01 October 2011 - 10:12 AM
The target is to convert 1 tonn of organic waste into 100 US Gallsons Ethanol. This is achived by a ultra high temepartur plasma reactor (>5000°C), then after cooling down (heate recovery, stem-generator, steam turbine, gene-set) the gas passes a sequence of scrubbers, finally feed to bacteria clostridium carboxidivorans which produce Ethanol. The Ethanol is earned abfter a destillation process.
Posted 14 October 2011 - 03:29 AM
In the case with ethanol from syn gas this could be done via biological routes (enzymes or bacteria) or catalytic routes (transition metals, etc.).
Comparing these two routes, it seems that there are two ways to look at specific efficiency of the conversion here. While the biological routes seem to have higher carbon conversion rates due to their high selectivity. However with most biological processes, they tend to be picky and require sensitive environmental controls, are subject to contamination by other strands, and are very slow processes.
The catalytic process happen much quicker, usually at some pressure, and temperature (~250C). But it seems that most of the catalytic technologies are not as selective.
It seems like most of these catalysts not only create ethanol but also have side products such as methanol, butanol, and propanol.
Most of the time these reactions create water according to the reaction below.
2CO + 3H2 > C2H3OH + H2O
These processes whether biological or otherwise, still the combining of two carbons to create not only an ethanol molecule but one water molecule. At higher temperatures in the presence of catalytic constituents the water undergoes the water gas shift and can be available to build more ethanol molecules or its sisters (methanol, butanol, propanol). Biological processes seem to be more selective but have more water as a product, since the water does not under go water gas shift.
Separating water from ethanol requires a significant amount of energy to get to fuel standards. This is a major factor in the overall efficiency of the whole process.
These technologies are developing day by day as more research is being funded these days. If anyone knows of any specific technologies that are producing different results, post!
Posted 09 May 2012 - 01:03 AM
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