M1L6: Biofuels

Hello and welcome back. In the previous lecture, we uncovered the missing linkages in India’ ambitious e-vehicle program and saw if fuel cell can be an answer to it.

In today’ lecture, we will try to look at one more option which is biofuels

Lemme start with the basics

What do you mean by the word Bio? We often use the word bio in many places. Biology, Biosphere, Biotechnology, Bioaccumulation, Bioremediation, Biomagnification etc.

What does it mean? It means life. So, now may I ask what are BIOFUELS?

Obviously, it means fuel that is made from living things. This may animal fat (e.g. chicken tallow), or it can be from plants that can easily undergo fermentation.

Now the second question. What do you mean by carbon fixation? And is this different from CCUS, that we studied earlier? The answer is yes. Carbon capture use and storage refer to an artificial mechanism to store carbon. This can be done by pumping CO2 into the ground and make it limestone. In the case of carbon capture, we hijack this in living and organic compounds.

So, what are biofuels? They are the fuels, whose energy is obtained by biological carbon fixation. In this process, we convert CO2 into glucose using the process of fermentation.

6CO₂ + 6H₂O → C₆H₁₂O_{6 (}Bio-ethanol)

While this appears to be simple, it is not the case. In the actual scenario, a gasification process is used biomass is converted into syn-gas (a synthesis of the gaseous mixture of hydrogen & carbon monoxide) in the presence of high temperature and low oxygen concentration. This Syn gas is then converted to ethanol or other BIOFUELS

Bioethanol is used as a blending agent in petrol. Its percentage in fossil petrol is denoted by a capital E as follows.

E85 = 85% ethanol + 15% petrol

Biodiesel is blended with fossil diesel. Its percentage is denoted with capital B as follows

B20 = 20% Biodiesel + 80% fossil diesel

The major sources of biofuels are

Fuel	Crop	Fuel Yield (Gallons)
Ethanol	Sugar beet (France)	714
	Sugarcane (Brazil)	662*
	Cassava (Nigeria)	410
	Sweet Sorghum (India)	374
	Corn (U.S.)	354
	Wheat (France)	277
Biodiesel	Oil palm	508
	Coconut	230
	Rapeseed	102
	Peanut	90
	Sunflower	82
	Soybean	56*

When we look at these crops, you must have noticed one thing. The crops that are used to make bioethanol contain more starch and the crops that are used to make biodiesel contain more fats and lipids.

The reason being is, bioethanol is made through a process known as fermentation while biodiesel is made through a process known as transesterification.

What are the advantages that India will get if it switches to biofuels as a source of energy for its automobiles?

(1) One obvious advantage would be that this will help to reduce overdependence on fossil fuels that we import from other nations especially West Asia. Overdependence has already shown that this may become a threat to economic security based on the events we saw during the year 1973 Yom Kippur war that and the year 1991 Gulf war.  

(2) Most of these biofuels are made from farm products. This means that they will increase demand for agricultural products thereby improving farmers financial security and helping the government realize the goal of doubling the income of farmers by 2022. This will be helpful, particularly in case of the sugar industry that is already suffering from a glut due to an oversupply of sugarcane than existing market demand for sugar.

(3) It has been found that bioethanol reduces carbon monoxide emissions. BUT it produces more smoke and therefore contributes more to SMOG. The converse is true for Biodiesel. Biodiesel produces less smoke than fossil diesel and therefore contributes less to smog. Thus, it helps to reduce certain emissions and helps to make the air clean.

However, we also find some technical problems with biofuels.

(a) The energy content of bioethanol is half of gasoline. This means that it reduces the overall pickup of your vehicle when mixed in significant amounts. On the other side, the overall energy content (calorific value) of biodiesel is only little bit less than fossil diesel. But it should not be neglected that biodiesel is also corrosive to engine parts as well as contributes to knocking (engine vibrations).

(b) Since both the biofuels are made from organic compounds, they are perishable. This means, if the vehicle is kept unused for a long span of time, the overall quality of your fuel may reduce as the blended biofuels start decaying/undergo decomposition. To avoid this, stabilizers and antioxidants are mixed into it.

(c) Since biofuels are made from farm products, what if the farmers grow their crops only to be sold to the refineries that mix biofuels with fossil fuels? This will lead to diversion of crops from human consumption to commercial purposes. This will cause a cascading effect on nutrition and food security of Indians, akin to what we are already witnessing due to the agricultural revolution.

During the agricultural revolution, we saw that the government provided MSPs to certain food crops, most of them being cereals. The farmers shifted their cultivation to cereals in lure of gaining financial security since MSPs act as a buffer against fluctuations in farm prices. This led to drop-in cultivation of pulses leading to shortages in its supply. Inflation in prices of pulses has now made them unaffordable for a low-income family leading to protein deficiency.

(d) It is argued that this will aggravate the existing problems like the deterioration of land due to overuse of fertilizers and depletion of aquifers due to over-extraction of groundwater.  Reason being is, certain crops used to make biofuels esp. sugarcane come under the category of thirsty crops or water-guzzling crops. If the farmers gain more income by selling sugarcane to refineries that use biofuels.

(e) Last but not the least, the farmers who shift to biofuel crops will never care about their former indigenous and endemic varieties of crops and seeds, that they were using till that time. This may lead to a loss in biodiversity and make us more vulnerable to disruptions caused by external calamities.

So, to what extent should we shift towards biofuels?

One answer would be, that since it has benefits and contributes to improvement in earnings in the farm sector, the government should push its requirements to increase the proportion of blending in fossil fuels like petrol and diesel, to the extent that this doesn’t lead to the problem of food and nutrition security.

In order to do that, it is equally important to search for other alternatives to this generation of biofuels that is sourced from farm products.

On this basis, we divided the biofuels into four generations

The first generation of biofuels uses food crops. Diversion of these crops for bioethanol or biodiesel may lead to the problem of food and nutrition security.  In order to resolve this problem, scientists have tried to source biofuels from non-food crops like jatropha, pongamia pinnata, weeds and grass, farm and crop waste/stubble, bamboo etc.

This generation of biofuel crops, that uses non-food crops is called the Second generation of biofuels. Here they convert cellulose into biofuels, unlike the first case where starch or fats were converted to bioethanol or biodiesel.

However, in the case of the second generation of biofuels, one problem is that the amount of bioethanol obtained is very less as compared to the amount that we get from the first generation of biofuels. This can be attributed to the fact that cellulose content in these crops is less compared to the starch content in food crops. To resolve this problem, scientists then tried finding a source that contains more cellulose so that it can produce more amount of biofuel than the second generation. That source is algae.

Thus, in the second generation, our motive was to use non-food crops. In the third generation, we intend to use sources that contain more amount of cellulose and lignocellulose. In the light of this fact, algae-based biofuels come in third generation.

Algae carry a distinct feature to grow fast. You must have encountered these words viz. algae bloom, eutrophication and iron fertilization. In all the cases, we find one common thing. Enrich the water body with minerals like urea and the algae starts multiplying exponentially. So, while algae can replace the second generation of biofuels with cellulose-rich source, this can also prove harmful to the water body in the long run and contribute to water pollution. (At an individual level, algae contain less cellulose. However, collectively, they can contribute more amount of cellulose because they grow fast.)

So, what is the solution to this problem? Scientists are now resorting to genetic engineering to engineer crops and algae that carry more biomass and can also be grown of wastelands and deserted soils. They want to engineer crops and algae that require less water and thereby reduce the intensity of the requirements of large amounts of water. Such Genetically engineered crops and algae come under the fourth generation of Biofuels. They are under the research phase and development may take around a decade or so.

So, in this chapter, we have studied biofuels and how can they help to reduce the problem of air pollution. Along with it, we saw the pros and cons of it. Now in the next lecture, we shall jump to the other option, which can prove equally effective to combat air pollution which is CNG and H-CNG. What is CNG and how it is different from LPG? What are the scopes of LNG in India? These things will be covered in the next lecture. But before turning the page, think about it. Many of these species of biofuels do not belong to India and they may act as invasive species over a period of time. It is argued that over obsession with these crops may prove detrimental to endemic species in the long run. How should we balance this?