Under proper conditions, water hyacinths, a floating plant, will grow at such a rate that their dry biomass increase 5% per day The total water content of these plants is high (94%) .Nevertheless, 400 kg of dry matter can be harvested daily from one hectare of plantation. Consider a plantation with one hectare area consisting of a long canal (folded upon itself). At the starting point (seeding end), The canal is 0.5 m wide It expand gradually enough to just accommodate the growing plants that yhe plants take 60 days to float the seeding end the harvesting end.
a) How wide must the canal be at harvesting end How long must the canal be?
b) How much energy is harvested per day (express this in GJ and in barrels of oil)?
c) How many kilograms of wet plants must be used daily as seed? Assume that 50% of the biomass energy is converted into methane through a digestion process. Estimate the methane yield in cubic meters per day.
d) If the methane is burned in a gas turbine or in a diesel engine with 20% efficiency ,what is the average electric power that can be generated?
e) Assuming that the average depth of the canal is 1 m, what is the amount of water that has to flow in daily provided there is no loss by evaporation and infiltration?
f) Discuss ideas to insure that the water velocity is kept reasonably constant notwithstanding the expanding canal.