Renewable Energy Multiple Choice Questions on “Hydrogen Energy – 1”.
1. Which of the following supplies maximum amount of hydrogen gas?
a) Natural gas
b) Anaerobic Digestion
c) Wastewater treatment
Clarification: All the four options produce hydrogen gas. However, fossil fuels, specifically natural gas is the major producer of hydrogen gas. Biomass and biogas are the also commonly used to produce hydrogen gas.
2. In terms of green house gas emissions, how good or bad is hydrogen fuel?
a) Major contributor of greenhouse gas emissions
b) Zero-emission fuel
c) Lowest contributor of greenhouse gas emissions
d) Hydrogen cannot be used as fuel
Clarification: Hydrogen fuel is a clean source of energy. It is a zero-emission fuel burned with oxygen and is used in different applications to generate electricity. Among all sources of energy, burning fossil fuels produces maximum amount of greenhouse gases.
3. Which of the following use hydrogen as fuel?
a) Fossil fuels
b) Anerobic digestion
c) Fuel cells
Clarification: Fuel cells and internal combustion engines used hydrogen as fuel cells. Anaerobic digestion requires biomass in the form of waste water to generate electricity. Though fossil fuels contain hydrogen atoms, they do not require external supply of hydrogen as fuels. Cooking does not require hydrogen as fuel.
4. Which of the following is the most popular application of hydrogen fuel cell?
a) Fuel cell vehicles
b) Fuel cell energy power plants
c) Fuel cells stand-alone power supplies
d) Fuel cells spacecraft
Clarification: Spacecraft propulsion uses hydrogen as fuel with the help of fuel cells. It is one of the most established techniques to deploy spacecrafts into outer-space. Though fuel cell vehicles are becoming popular, they are not well established yet.
5. How is hydrogen gas produced from fossil fuels?
a) Partial oxidation of methane
d) Biomass gasification
Clarification: Hydrogen gas is produced from fossil fuels by different techniques like partial oxidation of methane, steam reforming and coal gasification. Biomass gasification and electrolysis produce hydrogen gas in small quantities.
6. What is the major drawback of steam-methane reforming technique to produce hydrogen?
a) Capital intensive
b) Releases greenhouse gases into atmosphere
c) A niche technology
d) Poor efficiency
Clarification: The steam-methane reforming technique is the current leading technology to produce hydrogen. However, the main drawback of steam-methane reforming technique is that it releases greenhouse gases, carbon dioxide and carbon monoxide into the atmosphere.
7. How does electrolysis produce hydrogen?
a) By running electricity to combine hydrogen and water
b) By separating water into hydrogen and oxygen and generating electricity
c) By passing electricity into water to separate it into hydrogen and oxygen
d) By passing electricity into water to evaporate it into hydrogen
Clarification: Electrolysis is one of the cleanest techniques to produce hydrogen. Electricity is passed through water to separate it into oxygen and hydrogen. In electrolysis, electricity is not generated and instead is used to perform a chemical reaction
8. Why is hydrogen hazardous as fuel?
a) Because of high ignition and low combustion energy
b) Because of high ignition and high combustion energy
c) Because low ignition and low combustion energy
d) Because of low ignition and high combustion energy
Clarification: Hydrogen is extremely dangerous as fuel. This is because hydrogen has a low ignition temperature and releases large amounts of energy during burning – high combustion energy. Also, it is hard to store as it tends leak easily from storage tanks.
9. Traditionally, why is steam methane reforming preferred over electrolysis?
a) Because electrolysis requires electricity
b) Because electrolysis has lower production efficiency
c) Because steam methane reforming produces greenhouse gases
d) Because electrolysis produces greenhouse gases
Clarification: Traditionally, steam methane reforming preferred over electrolysis. This is simply because electrolysis requires electricity. Currently, producing electricity is expensive. As the cost of producing a unit of electricity becomes cheaper, electrolysis will be favoured over steam methane reforming because it does not release greenhouse gases.
10. What is the main problem in using hydrogen as fuel for vehicles?
a) Capital intensive
c) Fuel cell technology is not well established
d) Cars will become heavy
Clarification: The main problem in using hydrogen as fuel for vehicles is storage of hydrogen. Hydrogen is difficult to store because it leaks easily. Moreover, it is extremely hazardous as fuel due to its low ignition temperature and high combustion energy.
11. What is a fuel cell?
a) Converts heat energy to chemical energy
b) Converts heat energy to electrical energy
c) Converts chemical energy to electrical energy
d) Converts kinetic energy to heat energy
Clarification: A fuel cell works just like a battery. It converts chemical energy to electrical energy. The chemical energy from a redox reaction occurring within the cell is converted to electrical energy due to the flow of electrons.
12. How does hydrogen fuel cell work?
a) Membrane → hydrogen ions → electric current and recombination with oxygen
b) Electric current and recombination with oxygen → hydrogen ions → membrane
c) Hydrogen ions → membrane → electric current and recombination with oxygen
d) Recombination with oxygen → electric current → membrane → hydrogen ions
Clarification: The hydrogen ions in one chamber of the cell flow into the other chamber through a membrane to recombine with oxygen. Since this is a redox reaction, electric current is generated due to flow of electrons.
13. What does hydrogen fuel cell emit?
c) Greenhouse gas
Clarification: Hydrogen fuel cell produces water – its only emission. It does not release any greenhouse gases or carbon compounds like methane because the reaction occurs with two substances, hydrogen and oxygen.
14. Fuel cell vehicle is sourced by a battery.
Clarification: A fuel cell vehicle (FEV) or a fuel cell electric vehicle (FCEV) is sourced by a fuel cell. It may work in combination with a battery to supply sufficient power to run the systems. But the source of the energy is a fuel cell.
15. High pressure containers are used to store hydrogen.
Clarification: Hydrogen is stored in a variety of ways to prevent hazards. One of them is by using high pressure containers. Another commonly used technique is cryogenics – low temperatures.