Abstract

This article highlights the environmental challenge posed by water hyacinth on fresh water sources in Zimbabwe and investigates the use of the harvested weed as a source of energy in the form of briquettes. The water hyacinth (Eichhornia crassipes), known to be native to South America, has now become an environmental and social challenge throughout most water sources in Zimbabwe. It adversely affects the environment and humans in diverse ways. However, the plant leaves and stem release thermal energy when burned. The amount of thermal energy released depends on the moisture content and other factors. The water hyacinth organic matter and other leaf species were briquetted and their thermal energy content investigated in this exercise. The thermal energy content of the various samples was measured using a bomb calorimeter. Results of the experiments showed that the calorific value of briquetted hyacinth was 14.55 MJ/kg. The calorific value of briquetted samples of other eleven leaf species ranged from 14 to 20 MJ/kg. Moisture content, volatile matter and ash content results of the samples are also reported in this paper. The results show that water hyacinth briquettes can be used as thermal and lighting energy source particularly for communities staying in the vicinity of the affected water sources.

Highlights

  • Materials and methodsThe hydraulic press machine compacted the biomass producing cylindrical briquettes

  • This article highlights the environmental challenge posed by water hyacinth on fresh water sources in Zimbabwe and investigates the use of the harvested weed as a source of energy in the form of briquettes

  • The water hyacinth organic matter and other leaf species were briquetted and their thermal energy content investigated in this exercise

Read more

Summary

Materials and methods

The hydraulic press machine compacted the biomass producing cylindrical briquettes. The gross calorific value of briquette samples was determined in the laboratory using a bomb calorimeter. The heat produced from the combustion is used to heat the water and routine manual monitoring of temperature and the heat calculations is taken care of by the computerised system of the bomb calorimeter. The temperature rise of the system is a measure of the heat energy that is given out by the combustion sample inside the bomb. Knowing the heat capacity of the calorimeter, the heat released from the combustion of the samples can be determined from the relationship: DUb 1⁄4 CvDT ð1Þ where DUb is the change in internal energy of the bomb calorimeter and its contents, Cv is the heat capacity of the calorimeter, DT is the temperature change.

Results processing
Conclusion
Compliance with ethical standards
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call