Biofuel

Fuels produced from plants are considered to be biofuels. Biofuels are mainly ethanol and sometimes butanol, which whilst being a better fuel, is actually much harder to obtain from plants than ethanol. Both ethanol and butanol are alcohols produced from crops by fermentation of sugars that are present within the crops. Plants such as wheat, corn, sugar beets, sugar cane, molasses and any other sugar or starch containing plants can be used for biofuels, even potatoes. During ethanol production an enzyme is used to break down the starches in the crops into sugars, then fermentation of sugars occurs followed by distillation and drying. In 2010, global biofuel production was at 105 billion liters and provided almost 3% of fuels required for road transport. Most of the ethanol is produced in Brazil although USA also does not lag far behind.

Ethanol itself is lower energy fuel than petroleum per unit volume however it does prove to be more efficient and hence more environmentally friendly in this sense. Ethanol can actually be used in petrol engines instead of petrol if it is mixed with petrol where up to 15% of the fuel can be ethanol. Although larger fuel volumes by approximately 30% are required when ethanol becomes involved, the price of biofuel currently remains lower than that of pure petroleum.

However not everything is so pretty and shiny with biofuels. As with many new technologies, lack of research suggest that it remains uncertain whether it takes more energy to produce biofuels than is recovered. The distillation process requires a very high energy input for heat as well as energy being required for farm equipment, cultivation, planting, fertilizers, pesticides, herbicides and fungicides, which are all made from oil, when growing the crops for biofuels. Irrigation systems, harvesting, transport, fermentation and drying all also require further energy inputs (Russo, 2008).

The other dark side of biofuels that is known as an ongoing debate called food energy and environment trilemma (Butterbach-Bahl, 2013). This debate is about crops grown on fields and farms for biofuels threatning food supplies. It has not been properly investigated whether there is sufficient land available to produce the crops needed in sufficient amounts for common biofuel use by the general public.

Some other difficulties may arise in the cultivation of biofuels such as the process of plant growth being highly seasonal in many regions of the world and climate dependent hence not all countries would be able to implement it. Also disease and insects may destroy crops and sometimes these things get out of hand potentially leaving the human population starving for oil and without energy supply if there was no other energy back up available.

Ethanol has also shown to be corrosive for today’s oil infrastructure such as piping networks and ships thus it would require infrastructure adjustments and replacements and thus investment if it was to become a global energy source (Savage, 2011).  It also produces less energy than petroleum as shown by figure 1 below but research is currently under way to try and find an easy, cheap and environmentally friendly way to either synthesize butanol and other larger hydrocarbons from ethanol or to ferment these large hydrocarbons directly from the crops themselves.

Figure 1.

Source: Savege, 2011.Energies available from biofuels compared to traditional fuels.

Finally, vegetable oil has also been recognized as a source of fuel when burned. This is because it contains fatty oils. The fatty oils are also produced by palm trees and soya, so research into these plants is also currently being done as well as algae which are also believed to be a good potential source of biofuel. Some studies such as the one by Savage, 2010 actually argue that the only viable and efficient biofuel that can be produced will be from algae as it can be affordable in large enough volumes for biofuel to become the new global energy source.

Some studies suggest that biofuels could provide up to a quarter of global transport fuel by 2050 but this is highly debatable and would require a lot of research, investment and new technologies to be invented for the myth to become reality. There is currently a lack of evidence to show that biofuels are associated with lower GHGs emissions than fossil fuels when the full life cycle of their production and combustion are considered. However the governments of more than 35 countries have already established policies promoting the use of biofuels which is especially evident in Brazil, USA and countries within the EU (Butterbach-Bahl, 2013). So in conclusion, whilst biofuels sure do seem a cleaner option of energy production than non-conventional oil, we can only hope that enough research is done into the area before it becomes our new reality and yet again we dup ourselves into something that we can no longer get out of such as the irreversible anthropogenic global warming that we have created by the combustion of fossil fuels.

Non-Conventional Oil

As mentioned preciously, with conventional oil running out fast and prices for crude oil increasing, the society is quickly trying to find new methods of obtaining energy. One of such methods is extraction of the same crude oil raw product from non-conventional oil. The difference between conventional and non-conventional oil is that crude oil is much harder to recover from non-conventional oil requiring much higher costs both financially and environmentally so the question remains as to whether it is worth it. The other method of obtaining energy is renewable and nuclear energy, which I shall discuss further on in my blog with all implications and advantages. I have already written a blog post about one of the non-conventional oil recovery methods from shale oil in detail and this is a more a more general post about other non-convectional oil that is out there and is being actively researched. Non-conventional oil includes oil from oil shale, oil sands, GTLs (gas to liquids), tight oil and biofuels. I shall also look at biofuels in more detail in my next post but I decided to do a more general post about all other types of non-conventional oils first because biofuel is in between being classed as non-conventional oil and renewable energy. My blog after non-conventional oil is going to explore renewable energy so I thought putting a post about biofuel in between non-convectional oil discussion and other biofuels was a good idea.

Oil sands are extra heavy crude oil or crude bitumen that is trapped in unconsolidated sandstone. These are still hydrocarbons thus forms of crude oil yet they are extremely dense and viscous making exrraction difficult, expensive and generally not possible using conventional oil extraction techniques. Some deposits, which are shallow enough, such as those found in Anthabasca oil sands can be extracted using conventional oil extraction techniques however most must be recovered using strip mining or the oil made to flow into wells using complex in-situ technologies. The more complex methods require more energy and water for the recovery of oil sands thus increasing costs yet again both monetary and environmentally. Furthermore the deposits may be contaminated by heavy metals such as nickel and vanadium as well as sulfur which mean separation after extraction is required increasing the costs of recovery. The deposits are found worldwide although the two most important, biggest and easiest to recover deposits are Athabasca Oil Sands in Alberta, Canada and the Orinoco heavy oil belt in Venezuela. Regardless of all its disadvantages, oil sands production is projected to increase very singnificnatly in the next 20 years although Canadians warn that the production rates are very slow and insignificant on the global crude oil production scales (Miller, 2013).

Tight oil is crude oil that is contained in petroleum formations of low permeability- often shale or tight sandstone. Tight oil is not the same as oil shale which is produced synthetically from oil shale. Tight oil requires hydraulic fracturing and often uses the same horizontal well technology as that which is used in shale gas production. One of the problems with tight oil is that its formations are heterogeneous and hence they vary widely over small distances thus it is very hard to predict the amount of oil that can be recovered from one well let alone a reservoir which potentially makes investments into these projects unattractive. Furthermore the production of tight oil requires at least 15-20% natural gas in the reservoir pore space to be able to drive the oil towards the borehole out the reservoir. It is located all over the world in such countries as Russia, USA, China, Australia, Argentina, Libya, Venezuela, Mexico, Pakistan, Canada and Indonesia thus could present a solution for each country’s own recovery of this product when conventional oil is exhausted. Some studies and news forums suggest that a $150 billion investment is going to be made into the tight oil industry in North America in 2015 (Mills, 2008).

GTLs and as well as CTLs (coal-to-liquid) are already being produced in small volumes as very expensive substitutes to conventional crude oil. They are expected to increase the contribution to the global energy font in the future. The four main conversion technologies used for the production of unconventional oil this way are Fischer-Tropsch process, Mobil Process, Belgius process and Karrick process. However natural gas requires high transportation costs thus many known yet remote fields are not yet being developed but the on-site conversion to liquid fuels are making energy recovered this way available under current economic conditions and large plants for coal to liquid conversions are currently being built in China. There are also some plants where gas-to-liquid conversion occurs found in such countries as Malaysia, South Africa and Qatar. Although the processes are highly inefficient in both scenarios and very large quantities of coal and gas are required to provide significant contributions to tatal liquid supply. Also environmental concerns remain a worry as the conversions generate high amounts of CO2, which is then released into the atmosphere. CO2 is a GHG and hence its emissions have significant impacts on global warming.

Thus overall it seems clear that so far no technology is available to make recovery of oil and energy from non-conventional oil nor economically profitable nor environmentally friendly. No significant research has been performed yet as it would require a lot of investment so it is unlikely that these methods will take of on global scales any time in the foreseeable future until humanity gets desperate to obtain more oil and thus non-conventional oil can not currently be considered as a viable alternative to the conventional oil and energy we obtain from it.

Shale Oil

With the conventional oil supply potentially decreasing, non-conventional oil supplies are being explored as some of the alternatives. Some of the sources of non-conventional oil include oil shale, tight oil, oil sands, tight oil, GTLs (gas-to-liquids) and biofuels. In this blog post I shall discuss shale oil in more detail.

Oil shale is an organic-rich fine-grained sedimentary rock that contains kerogen from which liquid hydrocarbons known as shale oil can be produced. Shale oil is known as a non-conventional oil as it has to be produced from the oil shale rock rather than directly being pumped out from beneath the Earth’s surface. Shale oil has the potential to be a substitute for crude oil but currently the costs of production of shale oil from oil shale are both not economically viable and environmentally unsustainable. Kerogen is an organic byproduct in oil formation or rather not full formed crude oil however it was formed more than 500 million years ago at the same time when crude oil formation occurred. Formations of kerogen can be graded and there is a great range of grades of the formations with some being up to 100 gallons of oil per ton. However such a high grade is rare and the approximately average grade of kerogen is 40 gallons a ton (Youngquist, 1998).

Kerogen forms in shallow marine embayments or in lakes, ponds and swamps. When pressure and temperature rises during organic decay of fossil fuels, the fossils are converted into insoluble mixture of extrememly large organic hydrocarbons, which are known as kerogen. As the process continues and the temperature increases molecules break off forming crude oil however kerogen deposits are left behind. This was discussed in my previous blog post on oil formation. The generation of crude oil from kerogen occurs naturally over geological timescales under the Earth’s surface however it requires a particular oil window which in turn requires specific high temperature of 70-160C. It may start to become obvious that in order to convert kerogen extracted from oil shale, high temperatures are necessary thus the environmental implications could be devastating. By extracting shale oil from oil shale we are basically trying to finish crude oil formation artificially in the matter of days or may be months compared to the natural processes that take millions of years. Environmental implications shall be discussed further in this post.

Oil shale itself occurs in many parts of the world including Canada, many European countries, China, Russia, South Africa, Australia, Brazil so on every continent (Youngquist, 1998). This means that potentially oil shale could be a solution to when recoverable crude oil resources become particularly scarse and Russia together with the Middle East have a monopolized market of very high oil prices as oil shale deposits are found everywhere so with appropriate technology, virtually every country could produce oil from oil shale.

Oil shale is not seen as an ideal alternative firstly due to geological factors- only a few beds are thick enough to mine it efficiently. Also economic costs due to geological reason as oil shale strata are very often found very deep below the surface and thus mining is very expensive. Furthermore recovery methods also add difficulties as once it is extracted, the rock must be blasted and crushed in a processing plant followed by heating to produce shale oil from kerogen at very high temperatures. High temperatures are not environmentally friendly plus require energy input thus costly. Water must also be supplied to the site as an additional hydrogen atom, which is extracted from water, has to be added to kerogen to convert it into shale oil. This means that a water source needs to be nearby the plant with a plentiful water supply or water needs to be transported to the plant, which yet again adds further costs and environmental implications. Finally the amount of waste material from this process of conversion is very large and thus would require a disposal site and needs stabilization to it does not contaminate the surrounding as shale has undesirable mineral compounds, which rain leaches. (Youngquist, 1998).  This creates another negative environmental impact and further increases costs yet again. Thus it becomes obvious as to why shale oil is not widely used.

However the original untreated kerogen shale oil could be used to burn as boiler fuel. Thus some countries actually use shale oil for electrical generation such as Estonia, where in 2005 95% of electricity is generated using shale oil (Estonian Energy in Figures, 2007). Other countries that also use shale oil include China, Brazil, Germany and Russia. Figure 1 below shows production of oil shale of several countries that utilize it and hence we assume that they do use it for something if money is being invested for its extraction.

Figure 1.

Source: USGS, 2005. Production of oil shale in millions of metric tons, 1880-2010.

Another advantage of oil shale is some of the byproducts it produces such as uranium, vanadium, zinc, alumina, phosphate, sodium carbonate minerals, ammonium sulfate and sulfur (USGS, 2005). The spent shale could also be used for making cement and this is undertaken by countries such as Germany and China.

Despite all the costs and environmental implications, shale oil has the potential to become a realistic substitute for crude oil we use now especially if the costs of its production are lowered. According to the US Department of Energy, it has been nearly two decade since any meaningful research has been done concerning shale oil (USDepartment of Energy, 2014) and the world has seen a lot of new technologies since so perhaps it is time to undertake some new research into the field and re consider it as one of the methods to obtain energy for our civilization.