Just when I thought my sequence of blogs on making ethanol as a biofuel was complete, I found another option that involved two major projects in the US (Range Fuels and Enerkem) and, in my opinion, should never have been considered.  Both first made synthesis gas by gasifying biomass, a technology that is reasonably well-developed. As an example, in the mid 1970s Union Carbide operated a 200 t/day plant at South Charleston, West Virginia, although it is unclear how many continuous hours were operated. The Purox gas typically contained about 26% hydrogen, 40% CO and 23% CO₂, and some source of additional hydrogen (and a significant additional cost) appears to be required.
 
So, assume you have syngas and want to make fuels. What next? Most analyses would select one of three obvious routes that are deployed commercially: Fischer Tropsch (FT), methanol, and short alcohols, which is an abbreviated FT route. However, from what I can make out, these two investments elected to propose to make ethanol the hard way. They both started off by making methanol (and Enerkem apparently has four plants operating that are technical successes) and I love the next step, for personal reasons noted below. They propose to react methanol with restricted amounts of CO to make acetic acid/methyl acetate. All acetic acid is then converted to methyl acetate in a further step. The methyl acetate is then hydrogenated to make a methanol/ethanol mix, from which methanol is recycled and ethanol produced. After huge investments, neither venture could convince the market this is economical. While the jury is still out, it appears that these ventures will not produce ethanol.
 
 My question is, why was this alternative route to ethanol not rejected on theoretical grounds prior to the loss of so much money? Maybe I am perverse, but shouldn't a simple analysis have suggested "too many steps to compete with the single step process?" In my opinion, hundreds of millions of dollars could have been saved simply by an hour of sound theoretical analysis. The reason I wrote my first ebook, and I started this blog, is to try to convince that theory is not confined to abstractions or marathon computations. Thinking first can be productive, and it is cheap!
 
Now to round off a little personal note to explain a comment above . When I was a first year student, I undertook extra reading, and not the usual sort. Accordingly, when I got the question in a test, "Convert an alcohol to an acid with one extra carbon atom" I could not resist writing down  "R-OH  + CO  -> product", and listed a catalyst, a temperature and a pressure. Yes, I know what they wanted, but I was strong on alternatives even then. This got zero marks, so I protested. "You can't do anything like that," they explained. Now that was not satisfactory. "According to Paul Karrer," I replied, "IG Farbenindustrie used this to make thousands of tons," then I added, "He is a reputable chemist, isn't he?" (He was one of the 1937 Nobel Prize winners in chemistry.)  Rather grumpily, they had to agree he was, but they did not give me any marks because you could not do that in the lab, and when I looked as if I might question that, they added, "at least in glassware". That was not specified in the question, but I did not care. I had made a point.