Team:METU HS Ankara/Demonstrate




Humans, as a species rely on energy greatly since the industrial revolution; whether it is for lighting, heating; or much more advanced systems of contemporary life. Thus, it's fair to say that security in electric energy supply is essential to us which made us rely heavily on fossil fuels (McDaniel et al., 2002).

Problem Statement

Typical energy sources of now; which are petroleum, coal and natural gas have proven to bring tremendous economic progress where they are abundant (Abu-Rub et al., 2014). Worldwide primary energy consumption has grown by 1,8% in 2012 alone (Abu-Rub et al., 2014). In the same year; coal, natural gas, and oil accounted for 87% of the global primary energy consumption (Cusick, 2013). With this data, it’s fair to conclude that we are actually growing more dependent to fossil fuels by the day.

A dependency like this is very unhealthy; since such fuels' combustion produce plenty of air pollutants, which contribute to greenhouse gas emissions, also the resources are very limited (Radovič, 2006; Frost, 2015). Furthermore, they cause a plethora of political and socio-economical problems; which can reach catastrophic levels, even in regions prospering from them (Radovič, 2006). They are like a poisonous band-aid to a larger problem.

Among fossil fuels, oil starts hurting us even before getting a chance to be used; when they are being transferred (Nikiforuk, 2016). Oil spills happen more than one would think; just in 2016, 11 oil spills happened just near the lake in Saskatchewan (Suzuki, 2016).

Cleaning an oil spill comes at a hefty price; costs can snowball up to $21.47 per liter oil (Etkin, 2000). A big spill is next to impossible to deal with; since it is impossible to mobilize the body of labor needed and the technologies to clean up soon enough (Suzuki, 2016). Available "technologies" consist of burning the oil or using chemical dispersants (Suzuki, 2016). Such techniques are crippled; they can't get rid of large spills, nor they work in icy waters, or where waves run amok (Nikiforuk, 2016).

Figure 2: Efforts to clean an oil spill. Retrieved from:

Oil spills are disastrous, they kill all the aquatic birds they come in contact with by sticking to birds' feathers, making them heavier which limit their movements, causing either their inability to catch prey or reducing their mobility in water leading to their death (Nikiforuk, 2016). They also wreck the marine organisms' habitat (Moore, 1974).

Fossil fuels and their combustions in energy conversion devices are the primary causes of the pollution of the atmosphere (Radovič, 2006). This pollution can be divided into two; primary and secondary (Radovič,2006). Primary air pollutants, which are COx, SOx, NOx, and particulates of very fine soot and ash particles, are all harmful to the environment (Radovič, 2006). Whether it's the potentially fatal CO or SO2's strong acidity causing acid rains, these pollutants are immensely harmful (Radovič, 2006).

Carbon emissions are so harmful that, in 2010, 4,5 million people died from it (Rathi, 2015). This makes air pollution related to carbon emissions more deadly than wars, murders and traffic accidents combined (Rathi, 2015).

Carbon monoxide; the most poisonous gas that is a product of incomplete combustion of any fuel (Radovič, 2006). Urban cars and vehicles are the culprit, since fossil fuel combustion vehicles are incapable of burning fuel fully when cold, which make up the majority of their use scenarios, they incompletely burn fuels the most (Radovič, 2006). It's estimated that some 100 million tons of CO are emitted every year in the U.S. (Radovič, 2006).

Primary pollutants can further damage by interacting with the environment, such as acid rains and smog, the greenhouse effect and the high ozone levels in the air we breathe (Radovič, 2006).

Figure 3: The amount of toxicity factories and such buildings, using fossil fuels cause. Retrieved from:

Acid rains introduce plentiful problems for humans, nature and artifacts (EPA). In humans, the NOx and SO2x gases cause or exacerbate respiratory diseases such asthma, bronchitis, and pneumonia all of which can be deadly (EPA, 2016). Its harm to nature is through it seeping into the soil to dissolve its nutrients, eroding it (EPA, 2016). Furthermore, it can release aluminum, which prevents trees from getting water (EPA, 2016). Such weakening conditions for trees make them vulnerable to various infections and infestations of insects, damaging forests which compensate some of the harm made by fossil fuels (EPA; EIA, 2016).

Greenhouse gas emissions accelerate global warming by releasing a gas covering the atmosphere are mostly sourced by fossil fuels' combustion in the U.S. (US EPA, 2016). All but agricultural greenhouse gases (which accounted for just 9% of it) were caused by fossil fuels (US EPA, 2016).

Lakes and streams get their share of damage from fossil fuels too (EPA, 2016). Conventionally at a pH of near 6.5, such bodies of water house a colorful variety of aquatic wildlife including phytoplankton, mayflies, rainbow trout, frogs, crayfish and many more (EPA, 2016).

Buildings and objects also get harmed by acidic rains too (EPA, 2016). Acidity in rain water corrode the paint and stone on them; wearing them out, vanishing their value and beauty (EPA, 2016).

Figure 4: Comparison between a tree that has been damaged by acid rains and a healthy tree. Retrieved from:

Since fossil fuels bring tremendous economic growth where they are abundant, many countries are in search of it. Oil, in particular, is a nightmare dressed like a daydream, a demanding mistress; because despite the enormous sums of money oil attracts wherever it's abundant, it also brings political instability, armed conflicts or a "mini-world war" in some cases (Rabie, 1992). As soon as it's discovered, many countries and co-operations seek to control the oil present, and this often ends in international conflict as can be seen in the infamous instance in the Persian Gulf, where its oil caused or triggered 35 years of international and economical crises responsible for far-reaching consequences like perhaps the best known one; 1973-74 oil embargo (Rabie, 1992). Such disputes occur frequently, wrecking world peace, ruining lives of millions, raising eyebrows, making one question its ethics.

With all of these reasons concerned, it's a no-brainer to say that fossil fuels are vile; and we desperately need to cut their use. They harm in almost every single way possible; from an environmental standpoint to a political one. Abandoning fossil fuels is not just essential; but also possible, and viable.

Figure 5: Current solutions to fossil fuels. Retrieved from:

Current Solutions

Despite the world relying mostly on fossil fuels, the high cost and progressively limited sources of them, along with the ever so growing pressure of having to reduce greenhouse gasses' emission made renewable energy resources more attractive (Abu-Rub et al., 2014).

The potential renewable energy has is virtually limitless; since renewable energy can replenish itself in a relatively short period of time, it is sustainable (Abu-Rub et al., 2014; U.S. Energy Information Administration [eia], 2017a). Renewable sources such as biomass, wind, solar, hydropower and geothermal are first to come to mind (EPA).

Wind energy, for instance, has a considerable potential for being a clean energy source, thanks to it not producing pollution and wide availability (Herzog et al., 2001). Having been used since antiquity in windmills, this source of replenishable energy started being used for electricity generation since 20th century in the West (Herzog et al., 2001). Despite its potential, the costs exceed the supply by a fair margin; initial costs are astronomical and maintaining them are troublesome. Also, the harm it induces on the environment is undeniable; because wide bodies of land are required for them to work, they inevitably intersect wild life, and its acoustics make it impossible to incorporate it to urban settings; which ruin the acoustics, endangering species of birds.

Hydro-Energy uses the kinetic energy of water and has the largest capacity among renewable energy sources. (Herzog et al., 2001) However, despite it does not involve fossil fuels, its effects on the environment aren’t that much better; defeating the purpose. (Herzog et al., 200) The need to make space for mechanisms involves flooding the water mass, which wrecks the aquatic life, devastated water quality, reduce dam efficiency because of sedimentation and waterborne diseases along with the need to displace native residents. (Herzog et al., 2001) Not to mention; the initial costs are colossal. (Herzog et al., 2001)

Energy derived from natural heat within the earth, better known as geothermal energy, is another conventional renewable energy. (Herzog et al., 2001) It is inexhaustible; only 1% of the heat in the uppermost 10 km's of earth's crust is 500 times all the oil and gas we have. (Herzog et al., 2001) Yet, this energy is distributed unevenly, rarely concentrated and often too deep to be viable, making it less than optimal. Also, it's associated with the release of toxic substances like hydrogen sulfide, ammonia, mercury, radon, and boron, although it's a minor concern. (Herzog et al., 2001)

Solar energy, energy from the sun with the use of solar panels, are seemingly viable since the sunlight falls on earth in one hour is alleged to meet world’s energy demands for a year. (Aster, 2012) However, its disadvantages make it less than optimal; it not being available everywhere year-round, it's incredibly astronomical prices, it requiring an AC inverter to be usable in daily life, not meeting demand in terms of heat, taking up large spaces with low efficiency are to name a few. (Aster, 2012) All of which are major deal breakers; not many will be convinced to pay outrageous prices for solar panels that will be obsolete in a year only to produce little DC energy on sunny days. (Aster, 2012) So it is not a viable renewable energy source.

To bring further insult to the wound, developing novel technologies that are fundamentally different from what has been used before is wicked by principle; by the virtue of them lacking a track record makes them uncertain which intimidates investors and authorities that would use it making it hard to convince them to fund them. Also, they have an experience curve; when those new technologies aren't optimal yet, requires a lot of research and time. (Herzog et al., 2001)

Our solution and how it's distinctive

Since our project is based on bioethanol production from biomass, in which fermentation in large volumes is involved, our endeavour is best communicated with a prototype of a bioreactor, where our project kicks in.

We have considered all sorts of renewable energy sources; both biomass and otherwise and we decided on biomass energy since it can be implemented to real life in the best way possible.

A biorefinery is a facility where biomass is processed to be used in various industries. In this case, we are dealing with lignocellulosic material; which primarily comes from plants with rigid structures such as tree barks, brewer’s spent grain, corn stalk, rice husks and so on.

Our prototype was designed and its detailed blueprint was drawn long before it will be implemented. Our zero-waste approach sets an example to the industry.

Inspired from Çumra Integrated Sugar Facility, we held a meeting with engineers from BTech Innovations in METU Silicon, where we worked together on the blueprint of our facility, to be 3D printed.

Zero Waste Biorefinery Approach

Product Developing

During our visit to one of the biggest biorefineries in Europe, Çumra Integrated Sugar Facility, we have established two way dialogues with the engineers and most importantly with the director. These dialogues were established to align what we have designed on paper to a more doable design. With the engineers, we have diligently discussed our drawings; noting down the points we remained weak and making the calculations to achieve our approach of having no waste output from the refinery. After our visit, we have done further research to construct a prototype, compatible with real-life situations.

The important thing for us was to design a product which has a zero-waste approach; meaning that it would leave nothing behind. No greenhouse gas emissions or waste residues was to be released to the environment, causing pollutions. Thus, we’ve considered to make use of the carbon dioxide with a dry ice unit and a greenhouse. In addition, water that comes out as a byproduct is regained with our water purification unit.

Figure 6: The first sketch we have drawn for our prototype.
Figures 7 and 8: The inside and outside structures of our product design.
Figure 9: The final drawing before 3D printing Figure 10: Our product design, 3D printed.

Dryer: In order to kickstart the processes, the material needs to be dried first. A type of lignocellulosic material, brewer’s spent grain (BSG) is dried to a moisture content of 10% in an atmospheric drier.

Mill: After dehydration, the material needs to be shrinked in size; to maximize surface to volume ratio, facilitating the acid pretreatment that will later unroll. The matter will be reduced to 0,3-1 mm particles. A jaw mill is most commonly used, and this process along with drying prepares the material to acid hydrolysis.

Acid Pretreatment: Then, the acid pretreatment will take place. Na2SO4 is administered for hydrolysis to separate the complex lignocellulose into simpler lignin, cellulose and hemicellulose.

Enzymatic Hydrolysis: Enzymatic pretreatment will further break down cellulose to yield glucose by hydrolysis. The glucose produced will be forwarded to the fermentation plant, where E. coli will yield ethanol from it.

Fermentation: From the glucose produced in the previous step, our bacteria E.coli KO11 will produce ethanol.

Distillation: Ethanol yielded is then distilled to reduce its water content; and the water here too is canalised to the water purification plant, to be reused.

Dry Ice Unit: Carbon dioxide formed as a result in fermentation tank can also be taken advantage of by using it in a dry ice production unit.

Molecular Biology and Genetics Lab: Our bacteria creates its difference here; by the virtue of it being resistant to furfural. To learn more on the lab process; you can visit here.

Greenhouse: CO2 E. coli releases is forwarded to the greenhouse included in the facility, where it aids the growth of crops there.

Water Purification Unit: Water excreted from processes like dehydration and distillation end up here to be purified, which can be used in the greenhouse to water plants.


In conclusion, our vision of the problems stated above is expected to have the least possible amount of waste since the byproducts like CO2 will be used in other fields and the bioethanol that we yield from agricultural waste will decrease greenhouse gas emissions while increasing engine longevity, thus leading to a much greener world.