VOA慢速英语2014 美国公司从垃圾提取天然气（在线收听）

AS IT IS 2014-06-13 Companies Make Gas from Garbage 美国公司从垃圾提取天然气

The future in energy production is here.  And some of the materials used to supply the energy may surprise you!  Companies have developed a way to turn plant wastes and other garbage into fuel.  It has been called one of the most promising technologies in alternative energy.  And the process is expected to become more common this year.

The American-based company Fiberight is taking the lead in this new form of energy production.  Truck loads of garbage are sent to Fiberight’s test plant in southern Virginia.  Randy Garrett heads the plant.  He says old vegetables, cardboard boxes and other wastes become something much more valuable through the work done at the factory.

“What we’re doing is taking a, that (what was) originally headed for a landfill, half of this material is going to be processed for the conversion of biofuel such as ethanol.”

Ethanol makes up about 10 percent of America’s fuel supply.  Nearly all of it comes from corn, the food known as maize in some countries.  Critics say this creates competition between food and fuel, and raises food prices.  Environmentalists say farmers are using more land to plant corn crops.  They also say farmers are using more fertilizers and products for killing insects.  They say this creates more pollution. 

But Fiberight does not depend on corn to produce fuel.  Randy Garrett says the garbage is loaded into a huge pressure cooker.

“That converts your paper, your cardboard, banana peels, any organic fibers, it converts it to a pulp.  That pulp is what we’re after for our energy-fuel conversion.”

The material that comes out of the cooker is mostly cellulose, a substance that can be made into sugar.  The sugar can then be turned into ethanol.

In 2007, President George W. Bush signed a law that required increasing amounts of ethanol in U.S. gasoline.  One goal of the law was to support production of new kinds of fuel.  The energy created from plant material would produce fewer environmentally harmful gases than those from oil-based fuels.

This year, several other fuel production plants are expected to start making ethanol from the cellulose in corn stalks, wheat straw and other plant material.

Madhu Khanna is an agricultural economist at the University of Illinois.  She says making cellulosic ethanol turned out to be harder than expected.

“We know how to do that in a lab.  The main problem is doing that in a continuous way, cost-effectively on a large scale.”

Ethanol production from cellulose has yet to meet expectations.  However, this year could be the turning point.  But Madhu Khanna says our cars may limit how much the industry can grow.

“Even if we can begin to produce this cost-effectively, we need to be able to consume it as well.”

Only a few models of automobiles can operate on high-ethanol fuel.  Without more of them, there is only so much gas from garbage that will sell.