After Gutenberg

According to the DoE (U.S. Department of Energy), via Green Car Congress, there are renewed efforts by NGVTF (Natural Gas Vehicle Technology Forum) “to develop and deploy commercially competitive natural gas engines, vehicles, and infrastructure,” to include hybrid natural gas vehicles. In the GCC post, Mike Millikin mentions 2 ideas for engine development that have been featured by this blog in past posts:

• Develop engine technology optimized for hydrogen-natural gas blended fuel; and

• Develop NGVs with HCCI (Homogeneous Charge Compression Ignition) engine technology.

Running compression ignition on alcohol is one approach to a sustainable range extender. Using DME (di-methyl ether) is another, although probably less acceptable approach. Yet another approach is to modify the combustion engine to run on natural gas.

After Gutenberg previously has favored the idea of natural gas range extenders for serial plug-in hybrid vehicles, in urban settings where reduced emissions are of special interest, and when waste to biogas is a source of fuel. Albeit this blog’s approval has been reluctant since 1) an internal combustion engine requires modification to run on natural gas, which adds to the cost of already more expensive electric propulsion; and 2) the energy density of natural gas is less than other combustible fuels.

With Peak Natural Gas modifying combustion engines to run on natural gas would seem ill-advised. On the other hand, when biogas can be cleaned sufficiently cheaply and burned in an internal combustion engine, the range extender is clean and sustainable, although more expensive. Clean defined herein as a minimum requirement that the range extender generate 120 CO2 g/km or less.

And, it bears repeating that ICE-powered generator sets can be operated within an optimum range, whereas a challenge to current HCCI engine technology is a problem with unsatisfactory emissions when operating ranges frequently change, something that is necessary with ICE-powered vehicles. Furthermore, while it adds to the manufacturing cost of such a platform, a micro turbine APU (Auxiliary Power Unit) could be especially well-suited to serial electric drive because of a consistent high temperature feed to the HCCI range extender.