Biofuels: A Sustainable Future Beyond Fossil Fuels?

The debate on whether biofuels can replace fossil fuels is ongoing. Biofuels are promoted as a low-carbon alternative to fossil fuels, with the potential to reduce greenhouse gas emissions. However, there are concerns about their environmental impact, and they are more expensive to produce than fossil fuels.

Biofuels are derived from organic matter, such as food products like corn, or non-edible, fibrous parts of plants. They can be categorised as first, second, and third-generation biofuels. First-generation biofuels are produced from food or animal feed crops, while second-generation biofuels are derived from non-food feedstocks, such as energy crops and agricultural residues. Third-generation biofuels, such as biodiesel from microalgae, are still in the research and development phase.

Biofuels have the potential to reduce greenhouse gas emissions and remove excess carbon dioxide from the atmosphere. For example, a study found that growing switchgrass, a leading candidate for next-generation biofuels, on lands transitioning away from crops or pasture has climate benefits comparable to reforestation. Additionally, technological advances like carbon capture and storage could further enhance the climate benefits of biofuels.

However, there are several drawbacks and challenges associated with biofuels. One of the main concerns is the impact on food prices and food security. Biofuels can increase food prices and reduce food availability, particularly for vulnerable populations. Biofuel production may also have negative environmental impacts, including conflicts between land for fuels and food, water scarcity, loss of biodiversity, and nitrogen pollution through excessive fertiliser use.

Furthermore, biofuels are more expensive than fossil fuels due to lower energy density and higher production costs. The energy return on investment (EROI) for biofuels is lower than that of petroleum, which means they provide a lower net energy gain. Biofuels also have higher transport costs due to their corrosive nature, which makes pipelines unsuitable for their transportation.

Overall, while biofuels have the potential to reduce greenhouse gas emissions, there are concerns about their environmental and economic impacts. As a result, biofuels may be more suitable as a niche market option rather than a large-scale replacement for fossil fuels.

Biofuels can reduce greenhouse gas emissions and remove excess carbon dioxide from the atmosphere

The transportation sector is responsible for about 27% of anthropogenic emissions of carbon dioxide (CO2), the chief greenhouse gas behind climate change. Biofuels have been proposed as a relatively quick and easy fix to a large part of the carbon problem. However, some studies have claimed that biofuel production releases more carbon than the fuels themselves save.

The benefits of biofuels

Biofuels can be differentiated according to key characteristics, including feedstock type, conversion process, technical specification of the fuel and its use. Biofuels produced from food or animal feed crops are referred to as first-generation biofuels. Since first-generation biofuels are produced through well-established technologies and processes, they are also known as conventional biofuels.

First-generation biofuels can, on average, have lower greenhouse gas (GHG) emissions than fossil fuels, but the reductions for most feedstocks are insufficient to meet the GHG savings required by the EU Renewable Energy Directive (RED). However, if no land-use change (LUC) is involved, they can reduce greenhouse gas emissions.

Second-generation biofuels, derived from non-food feedstocks such as dedicated energy crops, agricultural residues, forest residues and other waste materials, have a greater potential to reduce emissions, provided there is no LUC.

Third-generation biofuels, derived from microalgae, do not represent a feasible option at present due to their high GHG emissions and energy-intensive production. However, microalgae can be grown on non-arable land and in wastewater, saline or brackish water, and they grow extremely rapidly.

The drawbacks of biofuels

There are concerns that wider deployment of biofuels could lead to unintended environmental consequences. Some studies have shown that reductions in GHG emissions from biofuels are achieved at the expense of other impacts, such as acidification, eutrophication, water footprint and biodiversity loss.

The use of first-generation feedstocks, such as corn, has become a contentious issue due to competition with food production and concerns over diverting agricultural land into fuel production. A growing demand for agricultural produce risks an increase in deforestation and use of land with a high biodiversity value, as well as associated usage of freshwater, fertilizers and pesticides, with negative consequences for the environment.

LUC related to biofuels can occur in two ways: direct (DLUC) or indirect (ILUC). DLUC refers to the direct transformation of previously uncultivated areas into croplands for biofuel feedstock production, while ILUC occurs when additional demand for biofuel feedstock induces displacement of food and feed crop production to new land areas.

The future of biofuels

Biofuels offer both advantages and disadvantages in terms of environmental, economic and social sustainability. On the one hand, reduction in GHG emissions, energy security and rural development are the most important drivers for biofuels globally. On the other hand, there are concerns related to increasing biofuel production, such as upward pressure on food prices, the risk of increased GHG emissions through DLUC and ILUC, as well as the risks of degradation of land, forests, water resources and ecosystems.

To encourage the sustainable development of biofuels, regulatory policies such as the RED and the US Renewable Fuel Standard (RFS) stipulate various sustainability criteria, including life cycle GHG emissions. Despite the existing evidence, the outcomes of LCA studies are highly situational and dependent on many factors, including the type of feedstock, production routes, data variations and methodological choices.

Plant-based biofuels can play a key role in reducing greenhouse gas emissions and removing excess carbon dioxide from the atmosphere. Growing these crops in certain landscapes offers net climate benefits compared to other land use options. Technological advances like carbon capture and storage could result in biofuels producing several times the benefit of other land use options.

Biofuels are a common source of renewable energy in the US

Biofuels are advocated as a cost-effective and environmentally benign alternative to petroleum and other fossil fuels, particularly within the context of rising petroleum prices and increased concern over the contributions made by fossil fuels to global warming. However, critics express concerns about the scope of the expansion of certain biofuels because of the economic and environmental costs associated with the refining process and the potential removal of vast areas of arable land from food production.

Biofuels can be classified into four generations, namely first, second, third, and fourth based on their sources and production of various biomaterials. First-generation biofuels are derived from two types of edible feedstock, namely starch-based (e.g. potato, corn, barley, and wheat) and sugar-based (e.g. sugarcane and sugar beet) feedstocks. The main advantages of first-generation raw materials are the availability of crops and comparative simple conversion processes. However, using edible food crops for biodiesel production reduces the food supply.

Second-generation biofuels, such as lignocellulosic or carbohydrate biomass, are derived from non-edible plants and do not require agricultural land. Cellulosic biomass comprises various chemical compositions such as cellulose, lignin, and polyose. Lignocellulosic-based biofuel production processes have the potential to lower GHG emissions, boost the economy, and aid energy security.

Third-generation biofuels are produced from algal biomass and waste oil. The advantages of using third-generation biofuels include higher growth and productivity, no agricultural land required, higher oil content, and less impact on food supply.

Fourth-generation biofuels are derived from genetically modified algae that accumulate high lipid and carbohydrate content to improve biofuel yield. The raw materials used for fourth-generation biofuel production are microalgae, macroalgae, and cyno-bacteria.

Biofuels are more expensive than fossil fuels

Biofuels are generally more expensive than fossil fuels. The price of biofuels is influenced by many factors, such as the availability and price of raw materials, the technology and scale of production, subsidies and incentives, and market demand and competition.

Higher production costs

Biofuels have a higher production cost compared to fossil fuels. This is due to the lower energy density of biofuels, which means that more fuel is required to produce the same amount of energy. In addition, biofuels have a lower energy return on investment (EROI), which measures the net energy gain of a fuel compared to the total energy used in its production. Biofuels have an EROI of 5.5, while petroleum has an EROI of 16. This lower EROI contributes to the higher cost of biofuels.

Higher transport costs

The transport of biofuels is also more expensive than that of fossil fuels. Biofuels are corrosive and can cause cracking in steel pipelines, so they are typically transported by truck or rail, which can increase transport costs by a factor of three to five compared to pipelines. This is particularly relevant for regions that are distant from the main biofuel production areas, such as the Northeast states in the US.

Higher feedstock prices

The rising price of feedstocks, such as cereals, vegetable oils, used cooking oil, and animal fats, has contributed to the higher cost of biofuels. Biodiesel costs are currently 70-130% higher than petrol and diesel on the wholesale market, depending on the crop used. This price difference is expected to increase further due to the rising prices of feedstocks.

Negative impact on food prices

The demand for biofuels can also drive up food prices. Biofuels can compete with food production for resources, leading to higher prices for agricultural products. For example, over 40% of US corn is used to produce ethanol, which has contributed to sharp increases in food prices. Additionally, the demand for soybeans for biodiesel production has increased the price of soybeans, which are used in a wide range of food and industrial products.

Environmental concerns

In addition to the economic impacts, there are also environmental concerns associated with biofuels. The production of biofuels can lead to land use changes, water scarcity, loss of biodiversity, and increased nitrogen pollution through the excessive use of fertilizers. These indirect emissions associated with biofuel production can result in higher life-cycle greenhouse gas emissions compared to fossil fuels.

Policy implications

The higher cost of biofuels has implications for policy and regulation. Mandates for the use of biofuels can lead to increased fuel and food prices for consumers. Therefore, it is important to carefully consider the economic and environmental impacts of biofuels before implementing policies that promote their use.

Biofuels are corrosive and cause cracking in steel

Biofuels, specifically ethanol, are known to cause stress corrosion cracking in steel. This phenomenon is observed in the storage tanks and pipelines used to transport ethanol. The propensity of ethanol to cause cracking in steel is dependent on its concentration in gasoline. According to Narasi Sridhar, vice president and director of the materials program at Det Norske Veritas, ethanol concentrations above 20% in gasoline can cause cracking in steel.

The Pipeline Research Council International and the U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration jointly funded research to find the cause of cracking of steel in ethanol from 2005 through 2012. The research found that dissolved oxygen in ethanol was responsible for the cracking.

Oxygen has two effects that cause the cracking of steel. Firstly, it protects most of the steel surface, which channels all the degradation to occur on isolated areas of steel that are highly stressed. Secondly, oxygen pushes the corrosion processes to occur faster in the unprotected portion of the steel.

The practical implication of this research is that it is now possible to prevent stress corrosion cracking without removing oxygen from ethanol, which is an expensive process. Sacrificial metals and inhibitors can be used to prevent cracking.

Biofuels increase food prices

The use of biofuels has been linked to an increase in global food prices. This is due to the pressure placed on food prices by the use of crops for fuel.

The Impact of Biofuel Demand on Food Prices

The demand for biofuels made from food crops, such as palm and rapeseed oil, has led to an increase in global food prices. This has been particularly notable in Europe and the US since the early 2000s, where policies have been implemented to cut the use of fossil fuels.

In response to criticism about the link between biofuels and rising food prices, the EU agreed to cap the use of food-based biofuels at 7% in 2015. This cap is currently being debated, with NGOs calling for a further reduction.

A study commissioned by BirdLife and Transport & Environment found that if the EU were to cut its use of food-based biofuels to zero, global vegetable oil prices, including palm oil, would be 8% cheaper, and global cereal prices would be 0.6% cheaper by 2030.

The Environmental Impact of Using Vegetable Oils for Biofuel

The environmental benefit of using vegetable oils, such as palm and rapeseed oil, to produce biodiesel is also being questioned. A report by The Royal Academy of Engineering found that some biofuels, such as diesel made from food crops, have led to more emissions than those produced by the fossil fuels they were meant to replace.

The Impact of Biofuel Production on Food Insecurity

The use of biofuels has been linked to increased food insecurity, particularly in developing countries. The UN Special Rapporteur on the right to food, Hilal Elver, stated that biofuels are "having a huge impact on accessibility of food because of price increase, especially in developing countries".

Biofuel production has also been linked to land grabbing and the heavy use of pesticides, further exacerbating food insecurity.

The Impact of Biofuel Feedstocks on Food Prices

The type of feedstock used to produce biofuels can also impact food prices. For example, soybean-based biodiesel is particularly land-intensive, taking five times more land than ethanol to produce the equivalent amount of biofuel energy.

The demand for soybean-based biodiesel has increased the price of soybeans, which has had a trickle-down effect on food prices as soybeans have a wide range of industrial uses.

The Impact of Biofuel Policies on Food Prices

Policies promoting the use of food-based biofuels have been found to lead to increases in food prices. An independent literature review considered over one hundred economic modelling studies of the potential impact of increased biofuel demand on prices. The review found that the size of the price increase resulting directly from biofuels varies depending on the study, feedstock, and size of demand. However, the overwhelming body of evidence shows significant price increases ranging from 16-171%/EJ biofuels produced, with EU vegetable oils having the highest impact.

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