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.

No comments
The Engineers' Choice Awards highlight some of the best new control, instrumentation and automation products as chosen by...
The System Integrator Giants program lists the top 100 system integrators among companies listed in CFE Media's Global System Integrator Database.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
Learn how to increase device reliability in harsh environments and decrease unplanned system downtime.
This eGuide contains a series of articles and videos that considers theoretical and practical; immediate needs and a look into the future.
Learn how to create value with re-use; gain productivity with lean automation and connectivity, and optimize panel design and construction.
Machine design tips: Pneumatic or electric; Software upgrades; Ethernet advantages; Additive manufacturing; Engineering Leaders; Product exclusives: PLC, HMI, IO
Industrial wireless cyber security: More complex than black and white; IIoT at the I/O level; Process modeling; Cyber security research
Robotic advances: Software, form factors; System-based ROI; Embedded control; MES and information integration; SCADA and cyber security; Position sensor; Controller, I/O module
Learn how Industry 4.0 adds supply chain efficiency, optimizes pricing, improves quality, and more.

Find and connect with the most suitable service provider for your unique application. Start searching the Global System Integrator Database Now!

Drilling for Big Data: Managing the flow of information; Big data drilldown series: Challenge and opportunity; OT to IT: Creating a circle of improvement; Industry loses best workers, again
Pipeline vulnerabilities? Securing hydrocarbon transit; Predictive analytics hit the mainstream; Dirty pipelines decrease flow, production—pig your line; Ensuring pipeline physical and cyber security
Cyber security attack: The threat is real; Hacking O&G control systems: Understanding the cyber risk; The active cyber defense cycle