Q. Consider the following statements:

Maize can be used for the production of starch.
Oil extracted from maize can be a feedstock for biodiesel.
Alcoholic beverages can be produced by using maize.

Which of the statements given above is/are correct?

1 only.
1 and 2 only
2 and 3 only
1, 2 and 3

Answer: (d) 1, 2 and 3

Notes

Maize starch is produced by the wet milling process, which involves the grinding of softened maize and separation of corn oil seeds (germs), gluten (proteins), fibers (husk), and finally pure starch.
- Corn starch is made from maize kernels, which are high in starch.
- Corn starch has a wide variety of applications. It is used as a thickening agent in soups.
- Corn starch is also used in manufacturing bio-plastics and the preparation of corn syrup.
The general way to Produce Biodiesel fuels is transesterification of fat or oil triacylglycerols with short-chain alcohol such as methanol or ethanol in the presence of alkaline or acid catalysts.
- Corn Biodiesel chemically is a mixture of long-chain fatty acid methyl esters (FAMEs).
- Oil extracted from maize that can be converted into ethanol or biodiesel.
The type of alcohol in the alcoholic drinks we drink is a chemical called ethanol. To make alcohol, you need to put grains, fruits, or vegetables through a process called fermentation. the common source of ethanol is maize and other grains.

Biofuels

Any hydrocarbon fuel that is produced from an organic matter (living or once living material) in a short period of time (days, weeks, or even months) is considered a biofuel.
Biofuels may be solid, liquid or gaseous in nature.
- Solid: Wood, dried plant material, and manure
- Liquid: Bioethanol and Biodiesel
- Gaseous: Biogas
These can be used to replace or can be used in addition to diesel, petrol or other fossil fuels for transport, stationary, portable and other applications. Also, they can be used to generate heat and electricity.
- Some of the main reasons for shifting to biofuels are the rising prices of oil, emission of greenhouse gases from fossil fuels and the interest in obtaining fuel from agricultural crops for the benefit of farmers.
Different Categories of Biofuels:
- First Generation Biofuels:
  - These are made from food sources such as sugar, starch, vegetable oil, or animal fats using conventional technology.
  - Common first-generation biofuels include Bioalcohols, Biodiesel, Vegetable oil, Bioethers, Biogas.
  - Though the process of conversion is easy but use of food sources in the production of biofuels creates an imbalance in the food economy, leading to increased food prices and hunger.
- Second Generation Biofuels:
  - These are produced from non-food crops or portions of food crops that are not edible and considered as wastes, e.g., stems, husks, wood chips, and fruit skins and peeling.
    - Examples include cellulose ethanol, biodiesel.
  - Thermochemical reactions or biochemical conversion processes are used for producing such fuels.
  - Though these fuels do not affect food economy, their production is quite complicated.
  - Also, it is reported that these biofuels emit less greenhouse gases when compared to first generation biofuels.
- Third Generation Biofuels:
  - These are produced from micro-organisms like algae.
  - Example- Butanol
  - Micro-organisms like algae can be grown using land and water unsuitable for food production, therefore reducing the strain on already depleted water sources.
  - One disadvantage is that fertilizers used in the production of such crops lead to environmental pollution.
- Fourth Generation Biofuels:
  - In the production of these fuels, crops that are genetically engineered to take in high amounts of carbon are grown and harvested as biomass.
  - The crops are then converted into fuel using second generation techniques.
  - The fuel is pre-combusted, and the carbon is captured. Then the carbon is geo-sequestered, meaning that the carbon is stored in depleted oil or gas fields or in unmineable coal seams.
  - Some of these fuels are considered carbon negative as their production pulls out carbon from the environment.
Major Types of Biofuels:
- Bioethanol
  - It is derived from corn and sugarcane using fermentation process.
  - A litre of ethanol contains approximately two thirds of the energy provided by a litre of petrol.
  - When mixed with petrol, it improves combustion performance and lowers the emissions of carbon monoxide and sulphur oxide.
- Biodiesel
  - It is derived from vegetable oils like soybean oil or palm oil, vegetable waste oils, and animal fats by a biochemical process called “Transesterification.”
  - It produces very less or no amount of harmful gases as compared to diesel.
  - It can be used as an alternative for to conventional diesel fuel.
- Biogas
  - It is produced by anaerobic decomposition of organic matter like sewage from animals and humans.
  - Major proportions of biogas are methane and carbon dioxide, though it also has small proportions of hydrogen sulfide, hydrogen, carbon monoxide and siloxanes.
  - It is commonly used for heating, electricity and for automobiles.
- Biobutanol
  - It is produced in the same way as bioethanol, i.e., through the fermentation of starch.
  - The energy content in butanol is the highest among the other gasoline alternatives. It can be added to diesel to reduce emissions.
  - It serves as a solvent in textile industry and is also used as a base in perfumes.
- Biohydrogen
  - Biohydrogen, like biogas, can be produced using a number of processes such as pyrolysis, gasification or biological fermentation.
  - It can be the perfect alternative for fossil fuel.