Rhode Island's Smart Choice
Posted by Robert Rapier on June 7, 2006 - 10:04am
Topic: Alternative energy
Tags: automobile, compressed natural gas, ethanol, gtl, natural gas, peak oil [list all tags]
Another fuel to power your car arrives in R.I.
Some excerpts from the article:
May 24--WARWICK -- Hate the gas-guzzling SUV? Worried about greenhouse effects and smog? Fearful that we'll someday run out of oil? Rhode Island's eco-conscious, your day has come.Environmentalists have long offered the benefits of compressed natural gas vehicles as a solution to all of these problems. The engines burn immaculately clean. Vehicles powered by CNG produce only 10 percent of the carbon monoxide and particle discharge of gasoline-powered engines, and half the nitrogen oxides. Carbon dioxide discharge is reduced by 30 to 40 percent.
The fuel, which is primarily methane, is cheaper than gasoline -- at T.F. Green, the natural gas will retail for $2.69 for the equivalent of one gallon -- and natural gas-powered cars get better mileage.
According to the Natural Gas Vehicle Coalition, there were 130,000 natural gas vehicles operating in the United States and 5 million worldwide as of last year.The states have been the leaders in buying them: In 2005, Governor Carcieri signed an order mandating that 75 percent of all new state vehicles purchased use some sort of alternative fuel -- CNG, hydrogen, ethanol, biodiesel, or others. Rhode Island chose to use CNG.
"Initially, Rhode Island invested very heavily into natural gas," said David R. Sheldon, principal engineer with the Department of Administration's Environmental Compliance Unit.
While the gasoline-powered Civic GX gets an average highway mileage in the high 20s, the CNG version will average in the mid 30s, officials said.
I have long maintained that converting vehicles to natural gas (NG) makes more sense than converting that NG to diesel via the gas to liquids process (GTL) or ethanol via the corn to liquids process. Note that Brazil, which we immediately associate with ethanol, has over 8 times the CNG fleet of the U.S., despite having a population 100 million less than the U.S.
Consider the options for NG. If we convert it to diesel, we are going to consume about 40% of our initial BTUs in the conversion process, as shown here. But, since the diesel engine is around 35% more efficient than the combustion engine, we have an approximate wash. We will get around the same ultimate fuel efficiency from directly burning the natural gas as we will from processing it into diesel. (But, of course the advantage of GTL is the ability to develop stranded gas reserves).
If we convert it to ethanol, the BTUs in and out are close to a wash. According to the 2002 USDA study Estimating the Net Energy Balance of Corn Ethanol, it takes 77,228 BTUs of fossil fuel inputs – primarily natural gas - to make 83,961 BTUs of ethanol (and a BTU co-product credit of 14,372 BTUs). This is a gain of 8% for fossil fuels in and ethanol out, or a gain of 27% if we include the co-products. But to earn that modest energy gain we mine the topsoil, apply herbicides and pesticides – some of which end up polluting waterways, and we have to build an ethanol refinery.
Also note that the Union of Concerned Scientists report that CNG vehicles “achieve green house gas emission reductions in the range of 5 to 25 percent compared to conventional passenger gasoline vehicles.” The above article from the Providence Journal reported a 30-40% reduction in carbon dioxide emissions. Corn ethanol is reported by Daniel Kammen (the Berkeley ethanol advocate interviewed on the recent 60 Minutes piece on ethanol) to achieve a reduction of 10 or 15 percent over gasoline in terms of greenhouse gas production. So, natural gas is at least as good as ethanol with respect to greenhouse gas emissions, but probably better as a whole for the environment when you consider the environmental aspects of corn farming.
Natural Gas Sources
As I indicated in my essay on XTL, the estimated 3,000 trillion cubic feet of stranded natural gas is enough to produce 300 billion barrels of fuel. However, if we were to burn this gas directly in CNG vehicles, instead of converting it into fuel via the GTL process, we could expect that stranded gas to provide the energy equivalent of over 500 billion barrels of fuel. At current world energy usage rates of 84 million barrels/day of oil, that is enough BTUs to supply us for over 16 years. Consider that if ¼ of the world’s BTUs came from stranded natural gas, the stranded natural gas could contribute to the world energy portfolio for over 60 years at today's consumption rate. Also remember, we are only talking about stranded reserves. There are another 3,200 trillion barrels that are not considered to be stranded.
However, if you are concerned about global warming, as I am, converting all of that natural gas into carbon dioxide may not be too appealing. Fortunately, natural gas can also be renewable if we make if from biomass. Natural gas is created by the anaerobic decomposition of biomass. It can be made from sewage sludge, municipal solid waste, or biomass crops grown specifically for that purpose.
According to the company Gas Separation Technology, between 450 and 650 billion cubic feet per year of methane leeches out of landfills into the atmosphere. This is the energy equivalent of around 75-100 million barrels of oil, floating up into the atmosphere each year. While this is only equivalent to about 1% of U.S. oil demand, according to the EPA methane is 21 times more potent as a greenhouse gas than carbon dioxide. By capturing some of this landfill gas, we can make a small contribution toward our energy requirements while trading methane emissions for carbon dioxide emissions. That’s a good potential source of natural gas, and 395 landfill energy projects are already in place, demonstrating the feasibility of the technology.
Of course we are going to need more methane than we can get from landfills. As I mentioned above, we can generate methane from sewage sludge, any waste source of biomass, or from crops grown specifically for methane generation. It is unlikely that we will be able to generate enough methane to maintain our current levels of consumption, but with a major conservation push, methane can be a nice fraction of the energy pie.
EROI
Ah, but what about the EROI? That’s an obvious question, and I don’t have a good answer. I simply haven’t found a good energy analysis. But due to the fact that biogas consists mostly of methane and carbon dioxide, and carbon dioxide has a much higher solubility in water than methane, the separation should not have a high energy requirement. If anyone knows of any literature on this, I would be interested in reading it.
Footnotes
Note that I have used methane and natural gas interchangeably. Natural gas consists primarily of methane (~92-97%), but natural gas from gas wells can contain nitrogen, carbon dioxide, hydrogen sulfide, ethane, propane, and even trace longer chain hydrocarbons.
Finally, I want to note that the article above says that the price of NG right now is $2.69 for a gasoline gallon equivalent (GGE). To put that in perspective, a gallon of ethanol on the CBT today closed at $3.41, and is around $3.70 in California on the spot market. On a GGE basis, this would be $5.00-$5.50 a gallon – twice the price of the NG.
cynus,
Yeah, I recently suggested using NG and or Propane in the"off demand" summer monthes and was pretty much kicked around here for saying it.
My argument is still this: If you are going to use nat gas in transportation, (and it it's available, we will) it is better to take out the massively expensive and environmentally damaging middle steps, that is, using nat gas fertilizer to grow corn for ethanol and waste it PLUS waste water and topsoil....or waste nat gas in the tar sand industry, and create a mightmare in carbon release and wasted water and wasted prestine landscape, or, waste nat gas in assisting coal to liquid, AND waste water and create carbon release.....finally, you just have to say, IS IT NOT FAR MORE EFFICIENT AND ENVIRONMENTALLY RESPONSIBLE TO BURN IT DIRECTLY IN TRANSPORTATION AND LEAVE ASIDE THE HUGE DAMAGE. (CAPS for emphesis and not for shout)
Due to the North American problem on nat gas production, i.e. peak nat gas, we would have to be very clever not to just waste it, however, and look for ways to reduce electric demand/heating demand in homes and business to free up enough without sending nat gas prices out of sight and then being in no better shape then before.
I have my doubts on this, being clever has not been a hallmark of American energy use.
Roger Conner known to you as ThatsItImout
That is exactly correct. We are already using natural gas, and will continue to do so, on inefficient schemes like ethanol production. It would be far more efficient to burn it directly.
RR
BTW, I picked up your comment on screen names the other day ... and yours is a lot more obscure to me than mine is to you. :-) !!!
The CNG vehicles drive pretty much like normal cars. The drawback is limited range. Maybe 150 miles, which means 75 mile radius, assuming a round trip. That's enough for many trips, but not for all. Wouldn't be too much of a pain, except it's not easy to find places to refuel.
And the range is seriously impacted by load. Much more so than with gasoline-powered vehicles. If you've got more than one person in the car, have heavy equipment in the trunk, or run the air conditioner, the range drops sharply. Takes some getting used to.
Good info. Thank you.
Electric vehicles were deemed 'impossible': now the streets of London are full of them (built in Bangalore, retail for £8000 each).
And the roads are full of Toyota and Honda hybrids which are electric vehicles (at urban speeds).
In the early days of automobiles, the steamer car looked like a real competitor. To kill them off, the internal combustion engine makers had to pull some very dirty tricks (commissioning articles about car boilers exploding), the Stanley brothers were very uncommercial, and there was an outbreak of foot and mouth disease one summer (closing all the cattle and horse troughs, so no water to refill). A steamer would probably run CNG much more efficiently than an ICE car?
The key was all these alternatives were to some extent 'purpose built'.
Whereas CNG vehicles are simply converted ICE vehicles.
I wonder if by actually building from the ground up a CNG vehicle, we could get much improved performance and range?
However, my question is, if you burn methane, do you end up with the same impact with respect to GHG compared to simply letting it flow unburned up into the atmosphere?
I don't know the current opinions on how those two factors balance out, but I expect it won't be a simple answer given the radically different paths these two chemicals take through the world, and the complexity of the reactions they are involved in (especially CO2).
but USA is pretty much at peak gas. Production has been flat for 5 years now ?
Any extra demand is going to cause havoc on the price of NG.
What needs to be built is the import infrastructure. New England is increasing the capacity of the Nova Scotia plant, and bringing the gas over the border to fuel the power plants.
The world has the gas, just not in the right places.
but USA is pretty much at peak gas.
LNG will continue to grow, and will continue to bring gas into the U.S. We can use this gas inefficiently to produce ethanol or diesel, or we can burn it directly.
As far as causing havoc on energy prices, diminishing sources of all kinds of fossil fuels are going to play havoc on all fossil fuel prices, except for maybe coal (for a while).
RR
I for one would rather cope with a gasoline shortage (I can forego a lot of driving in the winter) than a natural gas shortage ( I rather not forego keeping warm in the winter).
While burning CNG as automotive fuel has some benefits re reducing greenhouse gas, I'm not convinced it's a good idea.
By the way, the amount of methane that can (and often is) produced by the anaerobic digestion of sewage sludge is usually barely enough to run some of the on-site equipment at the sewage treatment plant. While this is a good thing, it hardly represents a new source of energy in the conventional sense.
And many of the larger landfills in the US and EU are already recovering methane from landfills and mostly using it on site or for highly localized usage. However, methane recovery from small (often poor constructed) landfills) is usually not considered economically feasible.
A heat pump will meet the heating needs of most houses (open question of how the electricity to power it is generated, if by gas, then we haven't solved the problem*).
there isn't a 'freeze in the dark' danger from using gas for transport purposes. Not at least in the next 20 years.
The key is to get the least CO2 per unit of energy produced. There is the energy cost of LNG ((about 20% of the energy in the LNG I think) but that is still a better tradeoff than GTL, Tar Sands etc.
*it's entirely feasible to have the electric power generation capacity of pretty much any developed country 30% by renewables- -be it wind, tidal, etc. You need a baseload which is 100% reliable (probably nuclear), plus technologies for smoothing peak demand (eg the utility shuts off air conditioning at peak) and, again, there are huge efficiency savings which can be realised (just redesigning the 'instant on' features on tvs, pcs etc. could save 5% of consumption).
Regardless, we're talking big effort and cost, with just about every house being custom. I'd be concerned about the moisture/vapor issues in a retrofit application also. As the housing market falls apart, and the equity in everyone's homes drops significantly, where is the money going to come from to do this?
There's no doubt you can build this way, and if I were building a home now that's how I would go. But we didn't build this way in the US, and it does not seem feasible to change it in a short time period now.
Somebody told me: blown-in cellulose insulation. I doubt that's the general solution, because:
Naw. I'd say the 'solution' is to construct a lattice on the OUTSIDE of the home and use polyureathane, then cover with stucco.
If you can gut the inside, polyureathane on the inside.
No matter what is done, one should plan on putting in an air excanger.
Thank you for mentioning polyurethane. I did a number of industrial & commercial buildings with spray urethane roofs back in the late '70's. Many of those structures have had no heating costs whatsoever since. They stay cool in the summer too.
It is just astonishing to me that informed people (most everyone on this board is, I believe, much better informed than average) still ponder blown cellulose.
Industrial buildings are a little easier to work with than residences. If you spray insulation over a 250,000 sq. ft. roof the building is insulated and other factors don't much matter. You just made a cave.
I have no favorite link to recommend but googling "passivhaus' (Germans waay ahead on this as they contemplate supply disruption) or simply 'passive house' you will see that a zero heating bill is no fantasy.
On new construction passive is already completely cost-effective. On older structures it will vary a lot, most owners are going to do it because they believe in it or believe energy prices are going up
My biggest question would be whether American contractors can work meticuously and thoroughly enough to make the passive house concept work. Back when I was in it the on-site urethane production was technically problematic to say the least. Most all the contractors working with the stuff should simply have bowed out and found something else to do. Instead they went ahead and made millions of squares of godawful problems. Ruining the business.
- windows oriented wrt sun angles to allow winter heat gain and daylighting
- minimize windows with no direct sunlight to avoid winter heat loss
- trombe walls behind glass that heat up during the day and release heat at night
- overhangs or brise-soleil to prevent summer heat gain
- non-solar walls built into hills or berms
- cross-ventilation or clerestory windows for low-to-high ventilation
Most of this is best planned in advance.My Northern Ohio house was built in 1997 with 2x4 construction and R-13 for the walls, which is the minimum requirement. I'd love to go to a higher R rating, but you really need 2x6 construction.
I was told that adding blown-in cellulose insulation to increase the R factor is not an option for my situation.
You could furr out your inside walls and add rigid insulation between the furring, but it would affect all your door and window casings, and it would leave your rooms that much smaller.
You could also put EIFS (Exterior Insulation and Finish System) on the outside of your house. EIFS is basically fake stucco over rigid insulation boards. It isn't cheap, but it would add insulation without sacrificing interior area. I suppose you could put clapboard or shingles over the rigid, too.
The material with the highest R value is aerogel, nearly 10 per inch. If there was an economical process to make aerogel, then we could have 2X4 construction with R35 walls.
R-values tell you very little. Applied seamlessly as exterior insulation 2 inches of urethane at R-14 outperforms R-60 pink. In walls you would never need that much. When I hear of an R-13 wall that needs upgrading I know its a leaky drafty wall full of gaps and penetrations
'normal' expansion is 100X. A slow rise foam is .10 a LBS more expensive (chemical sold in 1100 bls sets) and needs a threaded intermix chamber. ($310)
better know where interior moisture will be displaced to
hence the comment about the air exchange unit.
And in a fire burning urethane is toxic/fatal. But your house is already full of urethanes and no one thinks of this one
Part of the reason for the air exchange - the toxic load from all the outgassing chemicals yields the 1970's "sick building syndroime'
Applied seamlessly as exterior insulation 2 inches of urethane at R-14 outperforms R-60 pink.
Damn water vapor migration.
Combustion products are unavoidably among the worst. One more reason to prefer exterior insulation. Sprayed foam covered with heavily sand-filled acrylic paint can be made to look like stucco & the sand acts as fire retardant.
When I did this a quarter century back we were flying blind, going thru the Binks catalog looking for what might work. It's so easy now, the problem being the contractors don't know nothing and the customers are looking for guidance to guys who would as soon screw up a job of cellulose.
I never tried slow foam but I would bet that it can be determined and forceful as it does it's 10 to 1 thing & I would still be super-cautious with overfill. Not for DIYer.
More than most things urethane insulation works spectacularly well when you let it work the way it works and wreaks havoc when you ask it to defy the laws of physics.
My experience with homeowners, property managers, architects , mostly tells me that they are clueless and respond to anything but physics. Forget gaps in insulation, I routinely find large holes in roofs, usually left behind by someone who never finished a job. And the owners ask "Should we do something about that?" When you look at an attic with R-90 hyperinsulation, Prius and hybrid Highlander in the drive, and a wide open 4 by 6 foot opening at the peak of the roof you just wonder. In that case they had replaced the drywall in an upstairs bedroom 3 times (as the Mexicans laughed) and had never understood why their heating bills were so high.
When energy prices rose, the solution handed down was deeper studs, thicker batts and R-Max sheathing, not passive solar.
When I designed my house, I put in a wall of south windows. The sun shines on my red concrete floor, which also has heat pipes in it. Very toasty place to sit on a winter day!
The radiant pipes use water heated with a standard Sears hot-water heater at night. The electricity is used off-peak, and is generated by wind turbines up in Wyoming. So my house actually puts out no CO2 emmissions.
I really had to think about this plan, since everybody else around here was just buying natural-gas furnaces back in the '90s.
But guess what? My house is cheaper to heat now that the price of gas has gone up.
Buildings I did back when, the new owners come in, they've got the number to call if a problem develops with a drain or a flashing. They look at a roof on their industrial building that has worked 20 years with no significant hitch, they see that the boiler has been removed to make floor space, they notice that it's 95 degrees outside and 75 degrees inside with no A/C and they think OMIGOD I am the alcoholic brother-in-law physical plant manager and I don't understand this! This is a tech time-bomb waiting to explode! Better get rid of it before I screw up worse! And I'm at yeah, go ahead, try to remove it, every inch is glued down and as soon as you start I never have to talk to your silly face again.
Look at how the Germans or the Japanese do it. They don't have standards based on materials specs, they have standards based on performance. If I was not personally putting every scrap of material in place I would never vouch for the performance of a building based on specification. Look back at my previous post: R-90 fibreglass in place, 4 foot by 6 foot section of roof ridge open to sky. If the contractor was liable if the building did not perform you would not see this constantly. Americans do not like to sweat details and think they do not have to. They don't have to.
On the other hand you see guys coming up with clever stuff to get millions of BTUs of solar heat gain and then it all flies right back out the window. Cause the window is open.
I have no idea when anyone will get serious about conservation of heating fuel but am entirely certain 90% of what we burn is wasted. In post peak world I don't know if people will get smart or freeze. They don't need to freeze, the investments are not large, but they may.