Know your alternative gasses
In my discussion of home producer gas appliances, Kevin Chisholm pointed out that I had misused some terminology in the interest of trying to add variety to my prose. (Such is a hazard in this business, and I have been called on it a few times before.) In the headline I used the term bio-gas to refer to the product from the wood gasification process. While this does describe what wood gas is since it comes from bio material, the term bio-gas (with or without the hyphen) is normally reserved for something more specific.
Bio-gas is better used to describe the product from digesters that is generated by sewage, rotting plant material, and cows. A more accurate description would be anaerobic digester gas (ADG) which is mostly methane. Sometimes the term bio-methane is also used.
The generators discussed in this case make wood gas, which is primarily a mixture of carbon monoxide and hydrogen. It also contains carbon dioxide, methane, various tars, nitrogen, and probably a few other trace substances. It’s basically the same thing you get taking a drag on a cigarette, which is why they’re so good for you.
Sometimes the term producer gas is used interchangeably with wood gas, although that may have a slightly more specific connotation. Coal gas, as the name suggests, uses a different feedstock and produces different proportions of components.
One term that has re-emerged in recent discussions is synthetic gas (syngas) which generally describes a purer mixture of hydrogen and carbon monoxide without the tars and other components. It is still usually produced by gasification of organic material but at a higher temperature and under more controlled conditions. This can be used as a feedstock for ethanol and synthetic gasoline processes.
The University of Arkansas agricultural folks have published an interesting discussion of gasification that goes into greater detail as to the processes involved. It has enough detail to get into issues like energy balance but without being too technical. For example, the wheat straw from one acre could replace 410 pounds of propane.
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Annual Salary Survey
Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.
There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.
But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.
Read more: 2015 Salary Survey