Sunday, October 9, 2011

The pressure of modern life

We often refer to ourselves as living in a pressure cooker. Modern lifestyles are fast paced and change is rapid. I do feel like I am living in an atmosphere that is above one bar and that bar is set high. Michael Jackson thought that immersing himself in a higher pressure oxygen chamber would bring him a long and healthy life. He forgot that propathol would not. Propathol sounds like a new biofuel that is a blend of Propane and Alcohol but it was an anesthetic that put Michael into Jackson Hole. Why am I blogging about pressure? Well to increase the pressure of the system requires energy to compress the contents of the system. Highly compressed natural gas can be used as a substitute for gasoline and is in my opinion one of the two best substitutes for gasoline, the other being diesel.

Some very smart folks out of British Columbia, Canada have devised an engine that operates on 95% compressed natural gas and 5% diesel and it is now being used in long haul trucks that carry heavy loads. This Canadian company is called Westport. Cummins the famous diesel engine company has teamed with Westport and is offering an 8.9 liter engine that is quite brilliant. The truck outfit with this engine may cost $60,000 to $80,000 more than a traditional diesel engine truck, but for long haul heavy load truckers the saving of switching to natural gas from pure diesel can be as high as $50,000 a year and the added cost will be paid back in just over a year. The fuel storage is either in the form of high pressure gas or preferably in liquefied natural gas. If liquefied natural gas (LNG) is used, the waste heat from the engine is used to vaporize the LNG and pressurization is achieved without turbocharging as the evaporation on the liquid causes an increase in pressure. As natural gas has 4 atoms of hydrogen for each carbon atom and diesel only has 2 hydrogen atoms for each carbon atom, this engine will have about 25% less CO2 per mile the truck travels.

This North American made engine, shows how good engineering can really make a difference and can be deployed with profits for the vendor, installer, and user of the system. Compare the 1 year payout to the 20 year payout on the Chevron Coalinga smoke and mirror system. Another small company, Langson Energy in Carson City, Nevada is testing an energy recovery system to capture the energy from high pressure pipeline natural gas when the gas pressure is let down and reduced at use points. Normally the potential energy of this high pressure gas is “wasted” by simply expanding the gas over a valve or regulator. The pressure can be reduced through an expander that then uses the rotary motion of the expander to drive a generator and some electricity can be derived from the potential energy stored in the compressed natural gas. The expected payout for these expander generators is between 4 and 5 years and the electricity is essentially generated in a “carbon free” manner. This shows that letting down the pressure of a system can be a good thing, likewise relieving the pressure of everyday life is also a great idea. Each of us should have an “expander” in our minds and that is precisely why I blog to let off steam.





