Are Biofuels Any Better Than Fossil Fuels?

Are biofuels any better than fossil fuels?

Are biofuels any better than fossil fuels?

Check out this answer from Consensus:

Biofuels present a complex picture of benefits and challenges. While they offer potential for reduced GHG emissions and dependence on fossil fuels, their production can lead to significant environmental and health impacts. The sustainability of biofuels is highly situational and dependent on factors such as feedstock type, production methods, and land use practices. Further research and development are needed to optimize biofuel production for maximum environmental and health benefits.

 

The quest for sustainable and environmentally friendly energy sources has led to the exploration of biofuels as an alternative to fossil fuels. Biofuels, derived from biological materials, are considered renewable and have the potential to reduce greenhouse gas emissions. However, the debate on their overall sustainability and environmental impact is ongoing.

Environmental Sustainability of Biofuels

Biofuels are promoted as a low-carbon alternative to fossil fuels, potentially reducing greenhouse gas (GHG) emissions from transport1. Life cycle assessment (LCA) studies have shown that first-generation biofuels can have lower GHG emissions than fossil fuels, provided there is no land-use change (LUC)1. Second-generation biofuels generally have a greater potential to reduce emissions, while third-generation biofuels are not currently a feasible option due to higher GHG emissions1. However, biofuels’ production can lead to other environmental impacts such as acidification, eutrophication, water footprint, and biodiversity loss1.

Land Use and Carbon Debt

The production of biofuels can create a “biofuel carbon debt” when natural ecosystems like rainforests and grasslands are converted for biofuel crop production2. This conversion releases significantly more CO2 than the annual GHG reductions provided by displacing fossil fuels2. Biofuels made from waste biomass or grown on degraded lands can offer immediate GHG benefits without incurring a carbon debt2.

Economic and Energetic Costs and Benefits of Biofuels

Biofuels should provide a net energy gain, environmental benefits, be economically competitive, and not reduce food supplies3. Biodiesel from soybeans yields more energy than invested in its production and has lower environmental pollutants compared to ethanol from corn grain3. However, neither biofuel can replace a significant portion of petroleum without impacting food supplies3.

Environmental Aspects in Transportation

Biodiesel is considered eco-friendly and is a suitable candidate for diesel engines4. It has advantages over gasoline and petroleum diesel due to its lower emissions of toxic particulates and greenhouse gases4.

Political and Economic Impacts of Biofuels

Biofuel policies aim to promote the use of renewable fuels, create jobs, improve business efficiency, and protect the environment5. Biofuels can reduce dependence on imported petroleum, thereby reducing political and economic vulnerability5.

Microalgal Biofuels

Microalgal biofuels are a third-generation biofuel and are considered a sustainable energy source due to their high oil-producing capability6. They are renewable, non-toxic, biodegradable, and environmentally friendly6. The integration of wastewater treatment with biofuel production using microalgae has made this option more attractive and cost-effective6.

Environmental Costs and Benefits of Energy Crops

Lignocellulosic biofuels offer reduced environmental impacts and avoid conflicts between food and energy production7. Diverse mixtures of native prairie species may provide greater net energy gains and environmental benefits than monoculture energy crops7.

Health Impact Assessment of Biofuels

The production of biofuels can have health impacts, with biofuels showing a statistically significant lower carcinogenic impact than fossil fuels8. However, the production of certain biofuels may result in higher impacts of respirable inorganic compounds than fossil fuels8.

 

Are biofuels any better than fossil fuels?

Tom Richard has answered Near Certain

An expert from Pennsylvania State University in Resources Engineering, Ecology, Environmental Science

From a CO2 perspective, biofuels are a good idea, but they can be a really great idea if managed well.

First – a bit of chemistry. Biofuels are made from biomass, and about half the mass of biomass is carbon. Photosynthesis uses solar energy to turn gaseous CO2 into the solid and liquid carbon-based molecules that make up plants. When plants decay, that carbon returns to the atmosphere as CO2.

Understanding this chemistry, there are thus several ways that the CO2 from biofuels can be better than fossil fuel CO2 emissions: 1) if the rate of photosynthesis is acellerated (by planting fast-growing plant or trees, fertilizing the biomass crops, etc.); 2) if the types of plants grown increase soil carbon content (terrestrial carbon sequestration); 3) if the source of the biomass for the biofuels was already destined to decay to CO2 (as is the case for organic wastes, crop residues, logging residues, etc.); 4) if some of the CO2 that is a byproduct of biofuel processing is captured and turned into plastics or other biomaterials, or pumped deep into the earth (carbon utilization, or geologic sequestration – one Illinois biofuel plant is sequestering a million tons of CO2 a year) ; and 5) if the biofuel combustion is more efficient than fossil fuel at producing useful energy per unit CO2 emitted (this would be true for ethanol if cars were designed for ethanol’s high octane levels, but sadly they are not – and many other bioenergy systems are not as efficient as they could be).

Photosynthesis will be the key to reducing the already excessive levels of CO2 in the atmosphere. Biofuels are one way to take advantage of the power of photosynthesis, and so are biochemicals, bioplastics, wood-based materials, and rapidly growing forests. For any of these systems, it is important to follow the carbon: How efficient is the photosynthesis, and how fast is the decay? How much carbon is being sequestered in the soil, or in deep geology? How much is tied up in long-lived biomaterials? How much CO2 is emitted relative to fossil fuel alternatives? Designing systems that give good answers to all of these questions will help us achieve a sustainable world.

 

Are biofuels any better than fossil fuels?

Barry Solomon has answered Likely

An expert from Michigan Technological University in Renewable Energy

Biofuels are better than fossil fuels only if they are grown sustainably, at a rate to sequester carbon dioxide (CO2) from the atmosphere to match the CO2 emissions they generate when consumed. This however, does not always happen, and the production of biofuel crops or feedstocks, whether from trees, other plants or agricultural crops, can lead to indirect emissions in other locations. In addition, the production of biofuel crops is much less energy efficient and the resulting fuel has lower energy density than fossil fuels. Finally, some conventional air pollutants from biofuel such as ethanol and biodiesel, especially nitrogen oxides and volatile organic compounds, are higher than from the combustion of gasoline and conventional diesel fuel. Thus, there is not a clear answer to the question “Are biofuels any better than fossil fuels?” in all cases.

 

Are biofuels any better than fossil fuels?

Ben McNeil has answered Near Certain

An expert from UNSW Sydney in Oceanography, Climatology, Marine Science

Yes of course they are! Although biofuels release carbon when burnt just like fossil-fuels (coal, oil & gas), there is a world of difference on the impact of atmospheric carbon dioxide. The growing of biofuel crops have taken up carbon dioxide from the atmosphere to form the biomass over the preceding months to years – so when the biomass is burnt – it has no net impact on atmospheric carbon dioxide. In reality, this process is not exactly 100% (but near enough). Burning of fossil fuels however are unlocking organic carbon in the ground from millions of years ago (when they formed) so any carbon burnt from fossil fuels will immediately elevate atmospheric CO2 levels. From a wider environmental perspective (biodiversity, non-co2 pollution etc) it is debatable, however in relation to carbon & climate, biofuels are alot better. They also provide one of the only ways of potentially creating negative carbon emissions (see points 7,8 & 9 here: https://www.carbonbrief.org/explainer-10-ways-negative-emissions-could-slow-climate-change).

 

Are biofuels any better than fossil fuels?

Patrick Hallenbeck has answered Likely

An expert from Université de Montréal in Microbiology

Basically it is all about the Earth’s carbon cycle. Over hundreds of years, the carbon dioxide concentration in the atmosphere can be kept at a quasi-equilibrium through biological activities of consumption (photosynthesis) and production (plant decay). Biofuels merely add a short term loop to this cycle since their combustion releases CO2 that was very recently captured through plant photosynthesis. Fossil fuel use releases CO2 that was removed from the atmosphere millions of years ago. This fossil CO2 is overwhelming the processes that help maintain the quasi-equilibrium as seen by the increasing levels of CO2 in the atmosphere.

The rub in biofuels production is in the amount of fuel, almost always fossil fuel, that must be used in their production. This of course reduces their net benefit and thus must be taken into account in determining if it makes energetic sense to produce a particular biofuel. For example, biodiesel production will use fossil fuels in the growing of the crops, transportation of the harvested crops to the production facility, and in the conversion of the crop to biodiesel since fossil fuel derived methanol is used. Energy accounting and some kind of carbon accounting is required to compare the production and use of this biofuel with other biofuels and with fossil fuels to make an accurate quantitative assessment.

 

Are biofuels any better than fossil fuels?

Clifford Goudey has answered Near Certain

An expert from Massachusetts Institute of Technology in Mechanical Engineering, Renewable Energy, Marine Science

Like anything biofuels can be done poorly. Corn ethanol is an example of where the energy in from fossil fuels and fertilizer can render and CO2 advantage to nil. Certain crops are better such as macroalgae (seaweeds) that can be farmed without the use of land, fertilizers, or fresh water. They are likely to become the dominant sourse of biomass for conversion to fuels. Is doing so these farms will absorb CO2 from the ocean thereby reducing ocean acidification. If placed appropriately these farms can also absorb the excess nutrients that are triggering dead zones.

 

Are biofuels any better than fossil fuels?

NAGARAJ BANAPURMATH has answered Likely

An expert from B.V.B. College of Engineering and Technology in Renewable Energy, Nanotechnology, Materials Science

Disclosure:

Biofuels are alternative options for petroleum based fossil fuels as they are renewable and carbon neutral. However the practical realization of these biofuels (biodiesels and alcohols) for both automotive traction and power generation needs suitable technological as well as societal interventions. This strategy should aim at inclusive growth of farm community and fine tuning of engine hardware to evolve as a cost competitive and sustainable option. The current research in biofuels has merged better combustion of SI mode coupled to higher thermal efficiency of CI engines through new generation concept of Reactivity Controlled Combustion Ignition (RCCI). The new genera of engines will operate on gasoline like fuel to improve combustion characteristics and harnessing the high efficiency operation of diesel mode, resulting in dramatic fall in bsfc (brake specific fuel consumption) and emissions.

 

Are biofuels any better than fossil fuels?

Bruce Dale has answered Near Certain

An expert from Michigan State University in Chemical Engineering

Depending on how they are produced, biofuels can be much better than fossil fuels. However, it is possible to do a really bad job of producing biofuels so that the environment is actually harmed. Here is a reference that shows how it is possible to achieve large environmental, economic and social benefits as a result of “doing biofuels right”.

dx.doi.org/10.1021/es5025433 | Environ. Sci. Technol. 2014, 48, 7200−7203

 

Are biofuels any better than fossil fuels?

Zumar Bundhoo has answered Likely

An expert from University of Mauritius in Environmental Engineering

Most biofuels are hydrocarbons, but not all (e.g. bio-hydrogen (H2), despite it being a biofuel). Biofuels are generated from biomass or waste materials and may consist of bio-ethanol, bio-diesel, biogas (mainly bio-methane), H2, etc. The question “are biofuels any better than fossil fuels” is a bit tricky. “Better” in what aspect? Cost, Environmental Impacts, Combustion Efficiency?

From an environmental point of view, the answer is Yes, Biofuels are indeed better than fossil fuels. All biofuels (only hydrocarbons considered here) generate CO2 upon combustion and could therefore be classified as generating greenhouse gas and contributing to global warming similarly to fossil fuels. However, it must be pointed out that these biofuels are produced from plant biomass which during their lifecycles are CO2 sinks. E.g. Biofuels (hydrocarbons) produced from agricultural residues generate CO2 upon combustion. However, during the plant lifecycle, CO2 is also absorbed. As such, whenever biofuels are considered, the net carbon cycle is Zero! It’s a closed carbon cycle…

With respect to cost, this will heavily depend on the technology employed to produce the biofuel… Is it a bio-chemical or thermo-chemical technique or other (in the case of transesterification for bio-diesel production)…?

For combustion efficiency, some studies have reported higher efficiency for bio-diesel as opposed to diesel. Likewise, the emissions from bio-diesel combustion are less harmful as opposed to diesel combustion…

 

Are biofuels any better than fossil fuels?

Eva-Mari Aro has answered Near Certain

An expert from University of Turku in Biochemistry

To mitigate climate change we should get rid of fossil fuels. This is because the fossil fuels are the result of “ancient” photosynthesis of plants and cyanobacteria.

During millions and millions of years, the plants and cyanobacteria have fixed CO2 from the atmosphere and after death, they have sedimented and accumulated as fossil fuels.

The use of fossil fuels now releases to atmosphere huge amounts CO2 that was fixed such a very long time ago and stored in the sediments.

Instead, biofuels contain CO2 that was fixed recently – using them as energy source is more carbon neutral. Approximately same amount that was fixed “yesterday” will be released “today”. Using biofuels, we do not release CO2 to the atmosphere from sediments where they have been stored for a long time.

However, production and use of biofuels also have their sustainability problems – but very different from those of the fossil fuels. We still have to develop more clean technologies based on photosynthesis principles.

 

Are biofuels any better than fossil fuels?

C N Hewitt has answered Near Certain

An expert from Lancaster University in Atmospheric Science

Biofuels are almost certainly “better” than fossil fuels with respect to atmospheric carbon dioxide, but they are almost certainly a “very bad” thing when it comes to food security. Currently, 22% of all the crop energy (expressed as kcal or J) grown in North America and Oceania is used as biofuel to produce 2% of its primary energy use. To produce sufficient liquid biofuel to meet 2013 global aviation energy needs would require human-edible crop inputs of ≈2100 kcal/person globally/day, assuming a 50% conversion efficiency of food energy to aviation fuel – in other words it would take almost as much food for current global aviation fuel as it does to feed the global population. Any increases in biofuel production will almost certainly put pressures on global food supply.

For details of this, please see: Berners-Lee, M., Kennelly, C., Watson, R. and Hewitt, C.N., 2018. Current global food production is sufficient to meet human nutritional needs in 2050 provided there is radical societal adaptation.  Elem Sci Anth, 6(1), p.52. DOI: http://doi.org/10.1525/elementa.310

 

Are biofuels any better than fossil fuels?

Jose Goldemberg has answered Likely

An expert from University of Sao Paulo in Environmental Science

There seems to be a lot of hype around the production of biofuels (bioethanol and biodiesel primarily) as a good, ‘green’ alternative to fossil fuels for generating energy and powering cars etc. However, aren’t they also hydrocarbons? And therefore wouldn’t burning them also produce CO2? What makes them so ‘green’ in this regard?

Biofuels are produced from vegetable oil (biodiesel) extracted from some agricultural products such as soybeans or (ethanol) from sugarcane or corn which grow through the effect of photosynthesis a process in which solar energy synthesizes carbohydrate molecules such as sugars from carbon dioxide (from the atmosphere) and water (from the soil) When burned, biofuels return CO2to the atmosphere which is reabsorbed in the next season when the agricultural product grows again. Biofuels are in principle renewables and solar energy in a liquid form

However on a life cycle basis the use of biofuels is not entirely carbon neutral because global warming is caused not only by CO2 emissions but also by other types of greenhouse gases like methane (CH4) and nitrous oxide (N2O). During combustion of hydrocarbons and biofuels some small amount of these gases are also emitted. There are also greenhouse gases emissions triggered by the soil management, in the production of fertilizers applied in the farmland, due the fossil fuel used in the transportation of inputs for the agricultural activity, as well as due transportation of harvested biomass to the biofuel factory. 

Detailed life-cycle calculation has been carried out and the result is a function of the type of biomass used as bienergy feedstock and in the way the agricultural and industrial practices are performed. In general, the conclusion is that for sugar cane, planted in areas not previously occupied by dense vegetation (like tropical forests), as well with the traditional industrial process, the amount of greenhouse emissions is 20 to 40% of the emission of an equivalent amount of fossil fuels. For maize, the result is in the range of 80 to 90%.

In addition to that being derived from agricultural products, biofuels do not have the pollutants that are found in fossil fuels which are mainly sulphur oxides and particulates. When burned fossil fuels throw such products in the atmosphere, being the primary source of smog and atmosphere pollution. The beneficial consequences of replacing gasoline with ethanol have been empirically verified by the improvement of the quality of the air in the city of São Paulo as the fraction of ethanol in the gasoline increases

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