Stories tagged gasoline

Also in honor in of Bike / Walk to Work Week, this fun video asks the question: which is faster, a gasoline-powered motorcycle, or a yogurt-powered bicycle?

May
25
2008

The law of unintended consequences: Making ethanol to reduce carbon in the atmosphere is playing havoc with food prices.
The law of unintended consequences: Making ethanol to reduce carbon in the atmosphere is playing havoc with food prices.Courtesy swankslot

Well, probably neither. But ethanol – a type of fuel made from plants – has been causing a lot of controversy lately. We’ve talked about this here before.

Many people like ethanol. As the price of gasoline rises, ethanol becomes an economical alternative. We can grow it at home, and not have to buy it from foreign countries who may or may not be our friends. And using it as fuel does not add any extra carbon into the atmosphere.

The problem is, most ethanol today is made from food crops, like corn. The more food we turn into ethanol, the less there is to eat. This puts pressure on food prices, as do droughts and growing populations. Food riots have broken out in several countries, and some people are beginning to rethink the push toward ethanol.

(A rather more bleak assessment of the same phenomenon.)

However, not everybody sees this as gloom-and-doom. Here's a spirited defense of biofuels.

Dennis Avery, Director of the Center for Global Food Issues, argues that the push for ethanol is hurting the movement toward sustainable farming.

However, blogger Austin Bay argues that, while rising demand for ethanol is a factor in food prices, it is far from the only one, or even the most important.

A scientific convention right here in Minneapolis agrees, noting that the problem isn’t biofuel per se, but the use of food crops to make biofuel. If we used non-food crops, we would relieve some pressure on food prices. Furthermore, non-food crops like native prairie grass actually make better ethanol than corn does!

Ronald Bailey, science correspondent for Reason magazine, notes the effect of ethanol on food prices, and makes some suggestions for reversing the trend.

Scientists in Tennessee are working on just that, using switchgrass to make ethanol. Meanwhile, researchers at the University of Massachusetts are making progress towards turning switchgrass straight into “green gasoline” – a substance chemically identical to gasoline (unlike ethanol, which has some important differences.)

(We’ve discussed switchgrass on Science Buzz before.)

Researchers in Texas are working to make ethanol from sweet sorghum. This would reduce the need to use corn, but sorghum is used in syrup and other sweeteners, so it really wouldn’t solve the food-into-fuel problem.

Jun
19
2007

Pumping less: When the temperatures go up, the volume of fuel you gas you pump into your car goes down according to the "hot fuel" effect of physics. It could cost you between three and nine cents a gallon on hots this summer. (Photo by architeckt2)
Pumping less: When the temperatures go up, the volume of fuel you gas you pump into your car goes down according to the "hot fuel" effect of physics. It could cost you between three and nine cents a gallon on hots this summer. (Photo by architeckt2)
Just when we thought we were paying too much for gasoline these days, here comes some even worse news.

Depending on the air temperature at the time you fill up your tank, you might be getting less gas than what the pump is telling you. That difference could be costing us between 3 to 9 cents per gallon, with that loss factor going up as the temperatures go up.

Is this another example of oil companies ripping off consumers? Maybe a little bit. But it’s a lot of science – actually physics -- at play.

I was just reading a story in today’s Star Tribune about this phenomenon called “hot fuel.” Here’s quick summary on how it works.

The set industry standard for a gallon of gasoline is 231 cubic inches of the fluid at a temperature of 60 degrees. But as the temperature goes up, gasoline expands and it takes a larger amount of the fluid to create the same amount of energy.

Gas stations don’t take into account temperature changes at the fuel pumps. They pump the same amount of fuel as one gallon no matter what the temperature may be. And while that may result in a rip-off in summer time, when gasoline expands, consumers get a flip-side benefit in the wintertime, when gasoline pumped below 60 degrees actually contracts and you get more energy for your dollar at the pump.

Interestingly, the state of Hawaii back in the energy crunch of the 1970s recallabrated its gas pumps to reflect the volume of gasoline to be set at 80 degrees, a much more standard and uniform temperature there. At that temperature, a gallon of gas is actually 234 cubic inches.

There are some Congressional leaders asking for an investigation into this gasoline volume discrepancy. Oil companies, predictably, say that the cost of factoring in temperature changes in pumping gas will be too high.

Judging from the weather here in Minnesota, I’m not too hot in getting government involved into this. Judging that are temperature are under 60 more than they’re over that level, I think we’re getting a pretty good deal. But residents in the south and western U.S. are probably getting a bad deal out of the situation.

What, if anything, should be done about this gas situation? Share your thoughts here with other Science Buzzers!

May
31
2007

To good to be true? Maybe not. India’s largest car company is planning to start production on a car that runs on compressed air. An on-board tank would store over 3,000 cubic feet of compressed air. Released in small, controlled bursts, the air would push pistons to make the car go. Nothing burns, so there is no pollution, no greenhouse gas emissions, no use of gasoline.

The car has a range of 120-180 miles, about double what the best electrics now offer. Drivers will fill up at special compressors installed at filling stations. (The car also comes equipped with a compressor that can refill the tank if plugged in overnight.) Thus, “fuel” costs will come down to about 2.2 cents per mile.

The car saves energy in other ways:

  • Because there is no internal combustion – no gasoline burns in the engine, and it stays relatively cool -- you only need to change the oil every 31,000 miles or so. (In fact, you can use vegetable oil.)
  • As air expands, its temperature drops – in this case, to somewhere between 0 and 15 below. This cool air could be recaptured for the air conditioning system, saving even more energy.

The car does have some drawbacks. The top speed is 68 mph -- fine for tooling around town, but pretty weak for the highway. Also, to save weight, the car is made entirely of fiberglass and is glued together, rather than bolted. This kind of construction is not considered safe enough in the US. But if the air car is successful, it’s a good bet that car companies will look for ways to adapt this technology to the American market.

May
09
2007

It seems that everywhere I look, energy is in the news these days. Here are a few more stories that caught my eye recently.

Wind power

Delaware is considering building a massive windfarm in the waters off their Atlantic coast. Experts estimate this could generate enough energy to light 130,000 homes. But some people raise concerns about the damage this might do to migratory birds, ocean shipping, and the natural beauty of the view.

Nano solar panels

We’ve discussed how nanotechnology might revolutionize solar energy elsewhere on this blog. Now come word from Rice University of a breakthrough: an efficient means of creating molecular-sized semiconductors, an important component of high-efficiency solar panels.

Green fuel guide

Ethanol. Biodiesel. Hydrogen. Lots of new fuels are vying to replace gasoline as the automotive energy of the future. Popular Science magazine gives a run-down on the pros and cons of each.

All about CFLs

We’ve had a couple of threads here on Compact Fluorescent Bulbs and the advantages of replacing your regular bulbs with low-energy CFLs. For those who want to learn more, here’s a handy round-up, telling you everything you need to know about these bulbs.