Energy and Environment - Environmental Management and Sustainable Development - Environmental Science & Engineering Previous Year Questions

In a region, total annual consumption of gasoline is 30.6 million tons. The land required for growing sugarcane to produce enough bioethanol to replace the gasoline completely is ______ km² (an integer value).
Ethanol energy equivalent is 67% of gasoline, gasoline density is 850 kg/m³, yield of bioethanol produced from sugarcane per hectare of land is 3750 L, and 1 km² = 100 hectares.

The net profit expected from a manufacturing unit is ₹ 6000 per year. The operational life of the unit is 15 years. Assuming a fixed discount rate of 8 % per annum, the net present worth of the profit earned over the operational life is ₹ ______________ (answer in integer).

Ms. Anita uses a BS-IV two wheeler petrol scooter, with a mileage of 50 km/L, to travel 30 km every day. She exchanges this two wheeler with an electric scooter, which consumes electricity at 0.1 kWh/10 km. Assuming the cost of petrol and electricity are fixed at Rs. 90 per L and Rs. 3.5 per kWh, respectively, and maintenance cost of both BS-IV two wheeler and electric scooter is negligible, the operational cost saved in a year by Ms. Anita is __________ (in Rs., in integer).

An agricultural land can support energy crops yield to produce 7000 L of bioethanol per hectare and energy content of bioethanol is 21 MJ/L. This bioethanol displaces fossil-based petrol.
The CO₂ offset potential of land used for growing energy crops as a bioethanol feedstock is _____ × 10⁶ g of CO₂/hectare (rounded off to one decimal place).
Consider CO₂ footprints of 10 g and 80 g of CO₂ per MJ for bioethanol and petrol, respectively.