ethanol

Fuel from Corn Waste

June 27, 2025 By EarthWise Leave a Comment

A substantial amount of corn is grown in this country for the purpose of producing ethanol. The value of doing so is debatable for many reasons. Nevertheless, the majority of the corn crop is grown for food. But along with all that corn, there is corn stover. Stover is the dried stalks, leaves, and other plant parts that remain in the field after the corn itself has been harvested. Corn stover is the largest quantity of biomass residue in the United States. Around 250 million tons of it is produced annually and the majority of it is left unused. Some is used for animal feed and other purposes and has monetary value, but much of it goes to waste.

Scientists at Washington State University have developed a way to produce low-cost sugar from stover that can be used to make biofuels and other bioproducts.

Corn stover is an abundant and cheap source of biomass, which holds great potential as a source of energy and valuable chemicals. The challenge is to overcome the high cost of processing stover whose complex structural molecules like cellulose and lignin need to be broken down.

The new process uses potassium hydroxide and ammonium sulfite to convert stover into a sugar. It is a mild-temperature process that allows enzymes to break down the cellulosic polymers in stover into sugar, which can then be fermented into biofuels. The resulting sugar from the process would be cost-competitive with low-cost imported sugars. The researchers estimate that their patent-pending process could produce sugar that could be sold for as low as 28 cents per pound.

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Scientists discover a new way to convert corn waste into low-cost sugar for biofuel

Photo, posted August 30, 2012, courtesy of Idaho National Laboratory Bioenergy Program via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar on farmland

June 4, 2025 By EarthWise Leave a Comment

New studies have found that devoting a small percentage of U.S. farmland to producing solar power would benefit both the country’s energy system and its farmers.

Currently, about 46,000 square miles of farmland – about the area of Pennsylvania – is being used to grow corn to make ethanol. One study looked at the impact of using some of this land for solar power instead of corn ethanol.

Not much of all this farmland is close enough to electrical transmission lines to be practical for utility solar power. In fact, only about 1,500 square miles fits the bill. But if even this small fraction of the corn growing land was used instead for solar power, it would generate as much energy each year than from all of the farms growing corn for fuel.

Solar installations on farms are helpful for farmers as well. The land beneath the panels can be used to grow wildflowers that attracts the bees, wasps, and other insects needed to pollinate crops in the nearby fields. In addition, the solar arrays provide a steady income stream for farmers.

In some places, farmers can earn substantially more from leasing their land for solar than from growing crops. But a study of farms in California suggests that the best option is to do both. Farmers who both grow crops and host solar arrays can have more financial security than those who do just one or the other. The income from solar arrays is pretty predictable and is paid throughout the year. Income from crops can drop off from, for example, a seasonal drought, or from extreme weather events.

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To Help Growers and the Grid, Build Solar on Farmland, Research Says

Photo, posted June 9, 2016, courtesy of Matt Lavin via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Airplanes, corn, and groundwater

January 11, 2024 By EarthWise Leave a Comment

The aviation industry wants to slash its greenhouse gas emissions. One proposed strategy is to replace ordinary jet fuel with ethanol. Ethanol in this country mostly comes from corn. The airlines are enthusiastic about the idea; corn farmers are enthusiastic about the idea. Ethanol suppliers are obviously enthusiastic about it. But is it a good idea?

Today, nearly 40% of America’s corn crop is turned into ethanol. Twenty years ago, the figure was around 10%. The massive growth was the result of mandates for ethanol augmentation of gasoline for environmental reasons.

But the environmental benefits of corn ethanol have always been controversial at best when all the energy factors are considered. But apart from that, a very serious issue is that corn is a water-intensive crop, and it can take hundreds of gallons of water to produce a single gallon of ethanol. As the climate warms and corn crops expand, groundwater in many corn-growing areas is being increasingly depleted and groundwater provides half our drinking water and meets far more than just the needs of corn farmers.

Corn farmers and ethanol producers see the rapid growth of electric vehicles as a threat to their lucrative business of supplying the auto fuel industry. The ambitious goals of the airline industry to reduce its emissions would likely require nearly doubling ethanol production.

The situation is a powerful example of the tradeoffs that can arise as the world tries to make the transition away from fossil fuel. Even green solutions can have their own environmental cost and sometimes that cost may be too steep.

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Airlines Race Toward a Future of Powering Their Jets With Corn

Photo, posted September 2, 2007, courtesy of Rosana Prada via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Liquid Fuel From Sunshine | Earth Wise

July 6, 2023 By EarthWise Leave a Comment

A key goal of artificial photosynthesis research is to be able to produce a useful liquid fuel using only carbon dioxide, water, and sunlight in a single step. Such a so-called solar fuel would produce net zero carbon emissions and would be completely renewable.

Bioethanol has long been touted as a green alternative to fossil fuels, since it is made from plants rather than petroleum. But producing it takes up agricultural land that could be used to grow food instead and there are emissions associated with many aspects of the process by which plant mass becomes fuel.

Researchers from the University of Cambridge in the UK have developed a so-called artificial leaf that produces ethanol or propanol – usable liquid fuels – in a single step. They developed a copper and palladium-based catalyst that allows the artificial leaf to directly produce multicarbon complex chemicals. Earlier versions of artificial leaves could make simple chemicals, such as syngas, which would then require additional processing to turn into high-density fuels.

The new device produces liquid fuel from carbon dioxide and water simply by shining sunlight on it.

At present, the artificial leaf is a proof-of-concept device that exhibits only modest efficiency. The researchers are working to optimize the device’s light absorbers so that they can better make use of sunlight and to optimize the catalyst so that it can convert more of the sunlight into fuel. In addition, the device needs to be scaled up so that it can produce large volumes of fuel.

All that being said, it is an important step towards people being able to do what plants have been doing for millions of years.

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Driving on sunshine: clean, usable liquid fuels made from solar power

Photo, posted March 23, 2015, courtesy of Astro via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Corn Ethanol And The Climate | Earth Wise

March 29, 2022 By EarthWise 1 Comment

The Renewable Fuel Standard legislation, first passed in 2005 and updated in 2007, requires billions of gallons of renewable fuel to be added to the country’s transportation fuel supplies. It created the world’s largest biofuels program.

The standard was hailed as a major victory for the climate as well as a way to reduce our dependence upon foreign oil.

The intent of the legislation was to encourage various forms of renewable fuels – especially cellulosic ethanol from plant and wood fiber – to become an increasing part of the fuel mix. That has yet to happen. Instead, corn ethanol has been the backbone of the program.

Back in 2007, the EPA determined that ethanol from corn would lead to a 20% reduction in greenhouse gases compared to gasoline. But the next year, a study published in the journal Nature projected that corn ethanol would double greenhouse gas emissions over 30 years because demand for corn would drive farmers to plow up increasing amounts of carbon-rich forest and grassland.

A new study published by researchers at the University of Wisconsin, Madison, has again concluded that corn-based ethanol may actually be worse for the climate than fossil-based gasoline as well as having other environmental downsides. According to the study, since the fuel standard was passed, farmers have expanded corn production on nearly 7 million acres each year, causing the conversion of lands to cropland. The result is that the carbon intensity of corn ethanol could be as much as 24% higher than gasoline.

The issue is still being debated in Congress, but if these results are verified, the time has come to revamp the terms of the renewable fuel standard.

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Corn-Based Ethanol May Be Worse For the Climate Than Gasoline, a New Study Finds

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Photo, posted October 23, 2011, courtesy of the United Soybean Board via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Liquid Fuels From Carbon Dioxide | Earth Wise

January 5, 2022 By EarthWise Leave a Comment

Most of the world’s energy demands are still being met by burning fossil fuels, thereby releasing carbon dioxide into the atmosphere. The energy system is in the midst of a transition to renewable sources such as solar and wind power, but it will be quite some time before fossil fuels are only a minor part of energy production. To reduce global warming, it will be necessary to prevent the carbon dioxide from fossil fuels from entering the atmosphere by capturing it and either locking it away or making use of it.

Recent research at several Chinese universities has developed a novel electrocatalyst that efficiently converts CO₂ to liquid fuels containing multiple carbon atoms. The main products of the high-efficiency reaction are ethanol, acetone, and n-butanol. Previous electrocatalystic methods have mostly produced simpler hydrocarbons – namely, ones with only a single carbon atom. The fuels the new catalyst produces are much more useful.

The catalyst is made from thin ribbons of a copper/titanium alloy that are etched with hydrofluoric acid to remove the titanium from the surface. The process results in a material with a porous copper surface on an amorphous CuTi alloy. The substance exhibits remarkably high activity, selectivity, and stability for catalyzing the reactions leading to the production of the hydrocarbon fuels.

Converting carbon dioxide into liquid fuels would be advantageous because they have high energy density and are safe to store and transport. Apart from preventing carbon dioxide from entering the atmosphere, the process could also be a way to make use of excess energy produced by solar and wind generation by essentially storing that energy in the form of liquid fuels.

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Liquid Fuels from Carbon Dioxide

Photo courtesy of Angewandte Chemie via Wiley-VCH.

Earth Wise is a production of WAMC Northeast Public Radio.

An Incentive For Carbon Capture | Earth Wise

April 1, 2020 By EarthWise Leave a Comment

Convincing industries to reduce their carbon dioxide emissions has not been easy. Many approaches have been debated, including carbon taxes, carbon tax-and-trade schemes, and passing a giant Green New Deal. Most economists agree that putting a price on carbon is likely to be the most effective approach.

But there is already in place an adjustment to the US tax code that is more of a carrot than a stick. It is a tax credit that is designed to make capturing CO2 a financial winner for a number of high-emitting industries. The credit, called 45Q, was enacted in February 2018.

The 45Q credit earns industrial manufacturers $50 per metric ton of CO2 stored permanently or $35 per ton if the CO2 is put to use. An earlier credit for capturing carbon dioxide was limited to only $20 per metric ton and was capped at 75 million tons. Some large fossil fuel companies did make use of the earlier credit.

The new version does not have a cap, but to qualify, companies need to start constructing carbon-capture facilities within 7 years and have 12 years to claim their money.

Companies with emission-intensive operations are busy figuring out how to take advantage of the credit. These include cement makers, steel and power plants, corn ethanol producers, and ammonia plants.

Because the credit mandates that companies start constructing their carbon-capture facilities within seven years, most companies will tend to rely on mature technologies. But the tax credit should also drive demand for next-generation carbon-capture technologies, of which there are many under development. Saving lots of money on taxes is likely to lure US companies to capture carbon dioxide.

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45Q, the tax credit that’s luring US companies to capture CO2

Photo, posted October 2, 2014, courtesy of Sask Power via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Livestock And Sustainable Food Systems | Earth Wise

February 10, 2020 By EarthWise Leave a Comment

Animal-based agriculture has endured a great deal of criticism with regard to its contributions to climate change and its other environmental impacts. But its contributions to a sustainable food system are by no means all bad. In fact, livestock play important roles in sustainable, regenerative agro-food systems.

Animals’ natural biological processes enable them to consume plant and food residues that are either indigestible by humans, unpalatable to people, or are no longer sellable for various reasons, all referred to as IUUB biomass. There are many examples.

One dairy farm receives daily deliveries of apple waste from a processing facility that supplies apple slices for school lunches. Another local dairy gets three truckloads of vegetable and fruit discards, along with expired bread products, each week. No longer useful for consumers, these foodstuffs become feed for cattle rather than going to a landfill. Even the booming market for plant-based foods like artificial meat for consumers has generated a surge of processing byproducts that can be consumed by livestock.

On a national scale, livestock are consuming millions of pounds of otherwise unusable IUUB created in the production of products like soybean and canola oils, orange juice, ethanol, and more.

While the livestock industry needs to keep working to minimize its environmental impact and there are many reasons to eat less meat, livestock farming is an integral part of our agro-food systems. Farmers are embracing techniques to produce meat, milk and eggs as efficiently and sustainably as possible, minimizing agriculture’s climate-contributing footprint in the process.

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