GM Volt Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
1,860 Posts
Discussion Starter #1 (Edited)
This study makes the very dubious assumption that methane sequestration techniques will not improve over the coming 100 years. We have seen similar propaganda techniques used against electric vehicles. Makes one wonder if Exxon or the Koch brothers paid for this research:

Natural gas vehicles worse for climate than diesel ones

Natural gas is widely hailed as cleaner than other fossil fuels, but new research says using it -- instead of diesel -- to power trucks and buses will likely exacerbate global warming over a 100-year period.

Diesel engines are relatively fuel-efficient while the natural gas infrastructure leaks more heat-trapping methane than federal or industry data suggest, says a study Thursday by 16 scientists from federal laboratories and seven universities including Stanford, Harvard and MIT .

"Fueling trucks and buses with natural gas may help local air quality and reduce oil imports, but it is not likely to reduce greenhouse gas emissions," lead author Adam Brandt,of Stanford said in releasing the findings. "Even running passenger cars on natural gas instead of gasoline is probably on the borderline in terms of climate."

Full article:
http://www.freep.com/usatoday/article/5452829

This article highlights that increasing atmospheric methane levels may be largely unrelated to natural gas extraction:

Ice-free Arctic in two years heralds methane catastrophe – scientist

A new paper in the journal Nature argues that the release of a 50 Gigatonne (Gt) methane pulse from thawing Arctic permafrost could destabilise the climate system and trigger costs as high as the value of the entire world's GDP. The East Siberian Arctic Shelf's (ESAS) reservoir of methane gas hydrates could be released slowly over 50 years or "catastrophically fast" in a matter of decades – if not even one decade – the researchers said.

Full article:
http://www.theguardian.com/environment/earth-insight/2013/jul/24/arctic-ice-free-methane-economy-catastrophe

Obama, auto industry more committed to vehicles that run on natural gas

Washington — President Barack Obama proposed new efforts to boost the number of cars and trucks that run on compressed natural gas — and the auto industry is showing increasing interest in the technology.

“One of the reasons why is natural gas — if extracted safely, it’s the bridge fuel that can power our economy with less of the carbon pollution that causes climate change,” Obama said in his State of the Union address. “Businesses plan to invest almost $100 billion in new factories that use natural gas. I’ll cut red tape to help states get those factories built and put folks to work, and this Congress can help by putting people to work building fueling stations that shift more cars and trucks from foreign oil to American natural gas.”

Full article:
http://www.detroitnews.com/article/20140129/AUTO01/301290108


In the 1970's:

"I'd like to buy the world a Coke
and keep it company"​

Today:

"I'd like to buy the world" (a Koch)
"and make it my company"​
:p
 

·
Registered
Joined
·
3,452 Posts
most of the thermal energy in cng comes from the carbon atom- the benefits on NG is that it is a domestic fuel, and can be used at very high efficiency in Combined cycle power plants, but in an otto cycle ICE it is really not much lower in CO2 output per ton/mile or passenger mile than liquid hydrocarbons.. It may very well be bad policy, driven by the desire to provide offsetting porkbarrel subsidies, to have the federal incentives that we currently do on CNG vehicles.
 

·
Registered
Joined
·
3,452 Posts
Paul - actually, NG emits about 25% less CO2 per BTU of energy release than gasoline. NG is mostly methane (CH4) and has a higher hydrogen/carbon ratio than gasoline (octane - C8H18). That's 4/1 compared to 18/8. This means more H2O is produced and less CO2 during combustion.

http://www.eia.gov/tools/faqs/faq.cfm?id=73&t=11
I agree with what you say, but you just reinforced my points.:
  • Most of the energy comes from the 1 carbon atom and
  • CO2 per ton mile is not about only combustion BTUs,
Otto cycle efficiency is reduced also as more steam is carried in the exhaust. Natural gas is a great power generation fuel because it can run at over 60% total energy conversion efficiency, but that same thing is not true in automobiles.

CNG is just not enough better for CO2 production in transportation to make it worth the subsidies it gets. And that is at the vehicle only, not including the methane leaks, which are the main topic of the recent released study, inherent in the production and delivery systems... We subsidize CNG vehicles mostly as a quid pro quo between natural gas production state Senators and corn production states Senators.
 

·
Registered
Joined
·
5,410 Posts
This study makes the very dubious assumption that methane sequestration techniques will not improve over the coming 100 years. We have seen similar propaganda techniques used against electric vehicles. Makes one wonder if Exxon or the Koch brothers paid for this research:




This article highlights that increasing atmospheric methane levels may be largely unrelated to natural gas extraction:








In the 1970's:

"I'd like to buy the world a Coke
and keep it company"​

Today:

"I'd like to buy the world" (a Koch)
"and make it my company"​
:p
 
1 - 5 of 5 Posts
Top