JNTU
JNTU B.Tech IV GREEN FUEL TECHNOLOGIES Previous Question Paper (July/August - 2022 - R18)
Answer any five questions
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Main
Define biomass. List the various sources and uses of biomass in energy sector.
Answer
Biomass is organic material derived from plants and animals, which functions as a renewable energy source by storing sunlight as chemical energy. Primary sources include agricultural residues, forestry waste, animal manure, municipal solid waste, and energy crops like sugarcane or maize. In the energy sector, biomass is used for electricity generation through combustion, heat production, and the manufacturing of liquid biofuels for transportation.
Explain the raw materials required and process steps for the production of bioethanol and biodiesel. Mention the uses of biofuels in transport sector.
Answer
Bioethanol is produced primarily from sugar-rich crops (sugarcane), starch-rich crops (corn, wheat), or lignocellulosic biomass. The process involves:
- Pretreatment to break down complex structures.
- Hydrolysis to convert starch or cellulose into fermentable sugars.
- Fermentation using yeast to convert sugars into ethanol.
- Distillation and dehydration to achieve fuel-grade purity.
Discuss the technical steps for biomass liquefaction and biomass pyrolysis process. Mention the products obtained from these processes.
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Explain the advantages and disadvantages of biofuels.
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Describe the composition of different types of molasses.
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Define amylases. Explain the types of amylase family enzymes based on type of cleavage caused on starch.
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Discuss the various microbial sources of starch saccharifying enzymes.
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With a schematic diagram, explain the starch hydrolysis and ethanol fermentation process using acid hydrolysis method and enzymatic hydrolysis method.
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Discuss the chemical reactions and process steps for biodiesel production by alkaline catalyzed trans-esterification reaction.
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Explain the methods followed to improve the storage stability of the biodiesel.
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Describe the process details for the production of biodiesel from Jatropha oil. Mention the chemical composition of this biodiesel.
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Explain the kinetics of the trans-esterification reaction of Pongamia pinnata oil with methanol and ethanol.
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With a schematic diagram, explain the process detail for microbial production of methane. Mention the domestic and industrial uses of methane.
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What are Bio-digesters? List the uses and types of Bio-digesters.
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Explain the principle of hydrogen production using microbial electrolysis cells.
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Describe the two main fermentative pathways for hydrogen production by dark fermentation process.
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