Unless innovative technologies are developed or policies change, the U.S. is unlikely to meet some biofuel mandates under the current Renewable Fuel Standard by 2022, according to a new report from the National Research Council.

The council's study, which was requested by Congress, also says that producing future biofuels could have unintended environmental consequences because of fertilizer and water requirements and may not do as much to reduce greenhouse gas emissions as the government has estimated.

Click here for access to the full report, "Renewable Fuel Standard: Potential Economic and Environmental Effects of U.S. Biofuel Policy," which was released Oct. 4.

In USA Today, Phil Brasher reported:

The advanced fuels are supposed to be made from non-food feedstocks such as corn stalks, wheat straw, grasses and trees, all sources of plant cellulose. The Obama administration has been pushing the cellulosic fuels as a way of reducing U.S. dependence on foreign oil while creating thousands of rural jobs.

A 2007 law mandated that refiners use increasing amounts of the next-generation fuels starting in 2010, but production so far as fallen far short of relatively modest targets.

In 2012, the mandate calls for motorists to use 500 million gallons of cellulose-based fuel, but the government estimates that as little as 3.5 million gallons actually will be produced. By 2022, refiners are required to use 16 billion gallons annually.

But those targets can't be met "unless innovative technologies that unexpectedly improve the cellulosic biofuel production process and technologies are scaled up and undergo several commercial-scale demonstrations in the next few years," the study said.

Wallace Tyner, a Purdue University economist and co-chairman of the 15-member panel of experts who conducted the study, ticked off the list of major problems facing the biofuel industry: "It's a technology that's not known except that it's known to be expensive, a feedstock that's expensive, and a lot of uncertainty in many areas, including in government policy."

One of the biggest hurdles is the cost of raw material. Farmers will demand to be paid several times as much as the biorefineries can afford to pay them, the study found.

Ethanol industry groups criticized the report.

The Renewable Fuels Association said: “Global demand for energy continues to escalate yet this report chooses to focus with laser-like precision on the perceived shortcomings of conventional and next-generation biofuels.  Instead, we should be comparing the relative costs and benefits of all future energy options."

The association said it shares the committee’s view that "commercializing advanced and cellulosic ethanol technologies will require more policy certainty and a re-commitment to reducing oil import dependency.  The RFA has longed called for an extension of cellulosic ethanol tax incentives and a repeal of decades-old subsidies for the oil industry, totaling at least $4 billion a year in direct benefits."

The Environmental Working Group, meanwhile, said the report "underscores just how misguided and U.S. biofuels policy has become. It catalogs the environmentally damaging aspects of corn-based ethanol and also casts serious doubt on the future viability of so-called ‘advanced’ biofuels made from other sources.”