Development of Biofuels and Future Prospects

#Biofuel is produced from renewable biological materials such as ethanol from corn starch, corn straw, perennial grasses, woody biomass, and algae, or diesel fuel from soybeans. Currently available biofuels are extracted from sugar crops (sugar cane, sugar beets), starch crops (corn, potatoes), oil crops (soybeans, sunflower, rapeseed), and animal fats. During the fermentation process, sugars and starches are converted into bioalcohols, including ethanol (the most widely used), butanol, and propanol. Oils and animal fats can be processed into biodiesel. Most vehicles manufactured after 2000 can use gasoline/ethanol blends containing up to 15% ethanol (by volume).

Replacing fossil fuels with biofuels can reduce some of the undesirable environmental impacts of fossil fuel production and use, including emissions of conventional pollutants and greenhouse gases, depletion of inexhaustible resources, and dependence on unstable foreign suppliers. Demand for biofuels can also increase farmers’ incomes. However, the production and use of biofuels also has disadvantages, including the need for land and water resources as well as air and groundwater pollution. Depending on the source material and the production process, biofuels can cause even more greenhouse gas emissions in energy equivalent than some fossil fuels.

Over the past 20 years, the production and use of biofuels has increased significantly, as evidenced by the charts from the EPA.

Let’s look at the data from the U.S. (as the global leader that produces more than 45% of all biofuels in the world) for the last two decades on the production, consumption, imports, and exports of biofuels:

History

Wood can rightfully be considered the first biofuel on the planet. For example, in Tanzania, it still accounts for about 70% of energy produced. Of course, developed countries have long moved away from wood as primary source of energy. It is an exhaustible resource, which means that if we cut down trees too quickly, we will naturally run out of energy. Such a crisis took place in England in the 16th and 17th centuries. There used to be huge forests there. An old proverb said that in England a squirrel could cross the whole country without touching the ground. But to smelt steel, it was necessary to spend charcoal. At that time, 50?kilograms of charcoal were needed to produce 1 kilogram of steel. And to get charcoal, you had to collect a lot of wood and burn it. Thus, the English cut down almost all economically viable forests. Because of this, around the beginning of the 17th century, iron smelting fell sharply in England. They began to import iron from Sweden and Russia. This continued until the discovery of the next source of energy, coal, which allowed the English industrial revolution to ignite with renewed vigor.

Later, a similar situation developed with coal. England had huge reserves of coal, and at one time, they reckoned there would be enough of it for three thousand years. But in 1865, the economist William Stanley Jevons published a book called The Coal Question; An Inquiry Concerning the Progress of the Nation, and the Probable Exhaustion of Our Coal Mines. He argued that coal consumption was increasing at a rate of 3% a year and that England would run out of coal by the end of the 20th century. History proved him right: there are now only six large mines in England whereas during Jevons’s time there were 3,000.

What Came After Wood

After wood came oil. In the late 19th century, Rudolf Diesel used vegetable oil in his engine, and it worked. The efficiency of the oil-fueled engine was first appreciated in shipbuilding: beginning in 1903, many ships were equipped with such engines. At the 1900 Paris Exposition, the German engineer demonstrated his engine powered by peanut oil. Diesel, a visionary, was already advocating for biofuels at that time, supporting the use of natural vegetable oils.

In 1912, the first diesel locomotive was produced; then, during World War I, submarines appeared that were designed to be propelled by diesel motors. The first diesel engines were too bulky, so it took some time to start using them in the automobile industry. 1923 marked the first time when a diesel engine was put in a truck, and 13 years later, Daimler-Benz AG produced the first diesel-powered passenger car, Mercedes-Benz 260-D.

The Challenge of Biofuel Production

The problem we face currently is that we do not have enough land where we could grow crops from which vegetable oil would be produced so that we could provide our society with automotive biofuels. Furthermore, if we start planting palm trees, soybeans, or rapeseed in order to produce fuel, we will not have enough land to grow food. This problem, food vs. fuel, is very serious. The goal is to produce biofuels in such a way that they do not compete with food production in any way. This would be the second and third generations of biofuels. Straw, wood, and various agricultural waste can be used to produce the same types of biofuels as from food crops.

Biofuels are derived from renewable natural sources such as plants. They have the potential to reduce our dependence on limited fossil fuel reserves and reduce the risk of climate change.

The biofuel trend is now taking root in the world, aiming to reduce greenhouse gas emissions into the atmosphere, which heat up the planet. But are biofuels really that safe, or are they merely part of the political games played by advanced countries?

As we already mentioned, biofuels are usually produced from agricultural crops. The two main types of biofuels are ethanol (made from corn and sugar cane) and biodiesel (made from palm fruits, soybeans, and rapeseed).

Converting food into biofuels has side effects; it is tantamount to trying to reduce greenhouse gas emissions by reducing food consumption. Unfortunately, this leads to higher prices for foods made from crops that are used to produce biofuels. Essentially, we are turning food into fuel (as pointed out by G. David Tilman of the University of Minnesota).

The second problem is that much of the land in Europe, North America, and Asia is already used for agriculture, so we are beginning to expand into the tropical regions of Brazil and Indonesia where there are still places to plant crops. But when farmers cut down tropical forests to grow crops, as many greenhouse gases are emitted as in fossil mining, irreparable damage is done to the ecosystems, and wildlife is killed. The only sensible option, according to ecologists, is to grow crops for biofuels on abandoned agricultural land and in areas not covered by natural ecosystems.

Of course, even if we convert every grain and every fruit in the world into biofuel, this will only cover about 12% of the total fuel consumption, which is a noticeably low percentage. It is important to understand that a complete switch to biofuels is a political narrative, and many politicians around the world are speculating on the topic of phasing out fossil fuels amid rising oil prices or growing tensions between energy importers and exporters, even though this may not be possible in the near future.

Thus, the first generation of biofuels produced from the crops that can be used for food production is a dead-end development path.

The first and second generations of biofuels are an attempt to use existing capacities because building an industry from scratch in the capitalist world is very difficult and expensive; it is much better to use existing technologies to produce alcohol and vegetable oils. These are precisely the technologies that the first and second generations use.

A potential solution is to use cellulose instead of corn kernels to produce ethanol. It is much more affordable than, say, growing corn, and it takes much less time and energy to produce. Cellulose is the most abundant organic molecule on the planet and the main ingredient in plant cell walls. The problem is that the cellulose molecule, which is covered by a strong protective shell, is difficult to split. Creating ethanol from cellulose involves first separating this protective shell and then splitting the entire cellulose molecule into glucose molecules. Only after this process can the fermentation of glucose into ethanol begin. Scientists are currently researching special bacteria and fungi to find the best way to break down cellulose for use in biofuels.

But the third generation of biofuels is a completely new thing. The process of making them is based on photosynthetic microalgae. They use the energy of light to absorb carbon dioxide from the air and produce organic compounds. Microalgae are very small — 1 to 10 micrometers in diameter — but can produce very large amounts of lipids inside their cells. These lipids have a long hydrocarbon chain; they can be isolated and processed into biofuel. The advantage of this process is that these microalgae do not need to grow roots, leaves, and so on, that is, they are just cells with lipids inside. They grow very fast, and they can be harvested quite easily. This, of course, is a very promising solution. This kind of fuel is perfect, although the method of its production is quite labor-intensive and expensive.

What does the process of producing third-generation biofuel look like? First, we need to grow microalgae. Then their biomass has to be harvested. We can just take it as it is, put it in a machine, and raise the temperature and pressure. Hydrocracking will occur, and a bio-oil fraction (a type of biofuel, i.e., fuel obtained from raw materials of plant origin) will be released, which we can refine at a conventional refinery. There is another option: we can separate some fraction from microalgae biomass and convert it into biofuel chemically. And there are a lot of such technologies.

Compared to conventional crops, microalgae can produce an order of magnitude more biofuel because, as we already mentioned, they do not need to synthesize roots, branches, and leaves; they are just small cells. Moreover, they grow very fast; it takes just a couple of weeks to grow microalgae whereas conventional crops grow over an entire season.

In the future, new kinds of biofuels could really make a difference. Environmentalists say that breakthrough technology is now being developed to extract biofuels from almost any type of plant, which would really help reduce the harmful effects of human activity on the planet, since the waste from such production could be used as fertilizer for the soil.

Biofuel and the Conventional Engine

Why don’t engines run on alcohol alone? Because alcohol as a fuel has a corrosive effect. In addition, the low saturated vapor pressure and high heat of vaporization of alcohol make it almost impossible to start a gasoline engine if the ambient temperature falls below +10?°С.

It is believed that an alcohol content of about 10–15% has no effect on the corrosiveness of the fuel and does not harm the power system of an ordinary, purely gasoline car. That is why in many European countries the presence of 5% alcohol in gasoline is not even declared to the consumer; it just goes without saying. By the way, in developed countries, those 5% of alcohol are required by law and are added to gasoline as a harmless substitute for the environmentally dangerous additive called MTBE (methyl tert-butyl ether).

American researchers from the Energy & Environmental Research Center (EERC) at the University of North Dakota and the Minnesota Center for Automotive Research (MnCAR) conducted several types of tests with cars, which were fueled with various concentrations of bioethanol, with alcohol content ranging from 2% to 85%, and tested according to HWFET (Highway Fuel Economy Test) standards.

The question that worries many car owners is, “Is alcohol in fuel dangerous for the engine?”

Most problems associated with biofuels occur when switching from pure conventional fuel or during seasonal storage. A fuel system that has used only conventional fuel will have a thin layer of water at the bottom of the fuel tank. This water is sucked up by the fuel intake in very small amounts and passes through the fuel system without harming it. It is usually water droplets that cause the fuel line to freeze in cold weather.

Furthermore, over time, deposits of oxidation products and contaminants will form in the tank when the engine is run solely on pure fuel. These deposits will form even though the water layer is thin, but the engine system will remain stable.

When you add biofuel to the fuel tank, you are basically adding a new solvent. Ethanol will dissolve some of the deposits that accumulate over time, potentially reducing engine stability. That is why it is worth using fuel additives with detergent and anticorrosion properties.

According to Brian Kluge, Commodity Manager at Mercury Marine, a company that produces marine engines, all grades of gasoline, with or without the addition of ethanol, deteriorate (degrade) over time due to evaporation, the presence of water, and oxidation. However, ethanol can exacerbate this degradation process.

Mr. Kluge recommends the use of the following products:

·????????Cleaning agents that are added to fuel to remove deposits in the fuel tank and engine and which can be used for short-term cleaning or long-term maintenance (for example, the gel used in revitalizants is basically an active detergent component).

·????????Stabilizers that help reduce the rate at which fuel degrades and acquires a sour odor. Stabilizers contain corrosion inhibitors and are often used during seasonal storage or when fuel will not be consumed for a month or so.

·????????Alcohol-based antifreeze agents that combine with the fuel and lower the freezing point of the water present in the tank. For gasoline containing up to 10% ethanol (E10), antifreeze agents are not required.

Biofuels, the main types of which are bioethanol and biodiesel, are classified as renewable energy sources (RES) along with solar, wind, and hydropower. According to the Renewables 2016 Global Status Report, renewables outpaced fossil fuels for net investment in power capacity additions for six consecutive years. Annual investments in renewable energy until 2020 are estimated at $400–500 billion.

Consequently, we can conclude that in the near future we will see new ways of producing biofuels, and thanks to investments in this area, we will soon be able to get a better product that will replace fossil fuels.