EFFECTIVENESS AND ENERGY EFFICIENCY OF SAVANNAH GRASS BRIQUETTES ALTERNATIVE TO WOOD ENERGY COMPARED TO BRIQUETTES OF RICE HUSKS, PLANING CHIPS AND SAWDUST.

PHYSICAL SCIENCE AND ENVIRONMENT

92% of Madagascar's energy supply is dominated by wood energy. Households are the major consumers of energy and are responsible for deforestation. Currently, only more than 21% of the country's surface area is covered by forest. To restore the country's image of the former "green island", the government has opted for a policy of diversifying energy sources by developing alternative energy sources such as the agrofuel sector for the production of bioethanol and biodiesel and the production of fuel briquettes from the energy recovery of rice waste, wood processing waste (planning chips, sawdust) and savannah grasses, which are invasive plants in the south of the country. These wastes are potential in three different study sites: rice husk in Morombe District, Atsimo Andrefana region, wood processing wastes (planning chips, sawdust) in Moramanga District, Alaotra Mangoro region, and finally, savanna grasses in Ihosy District, Ihorombe region. The purpose of this research work is to determine the most suitable fuel to compete with or substitute for wood energy. The methodology adopted is both qualitative and quantitative. Its long-term realization requires a priori by passing through the chronological order of the following activities: the collection of bibliographical data and webographies relating to the different types of recoverable biomass with a view to identifying potential waste that can be exploited, going down to the field to see first-hand the inventoried waste with its potential, collecting respective samples for experimental tests, making briquettes from the inventoried potential waste, to determine their physical-chemical character, to test the briquettes manufactured through the different universally recognized tests including those of water boiling, controlled cooking and energy efficiency in order to know respectively, the PCI, the boiling time per hour, the fuel consumption in kg/h, the power and the efficiency of each type of briquette manufactured. Knowledge of these parameters will make it possible to dictate which alternative fuel can compete with charcoal and firewood. The aim is therefore to find the manufactured briquette with the following criteria: suitable for firing, with an ICP comparable with coal or wood, with a better output and power than coal and, finally, with a lower fuel consumption and boiling time compared to wood energy. Previous research results have made it possible to determine the physical-chemical characteristics of fuel briquettes produced from rice husks, planning shavings, sawdust and recently savannah grasses. The variation in the binder (cassava starch) content and the granulometry of the fine particles making up the manufactured briquettes are the most studied parameters for the research work. The most convincing results from the different works carried out such as water boiling tests (fuel consumption, boiling time), energy efficiency (power, yield) and physical-chemical characteristics (PCI) for each type of fuel briquette manufactured make it possible to dictate the most efficient fuel able to compete with wood energy. In this context, the 10% savannah grass briquette in binder is the most energy-efficient fuel compared to briquettes made from rice husks, planning shavings and sawdust, as the savannah grass briquette not only has better fuel consumption, boiling time and yield than wood energy and the other briquettes studied. Moreover, the potentiality of the savannah grass resource is very significant with a dry matter content of about 10 to 15 t MS/ha/year. It is therefore the most appropriate fuel to substitute wood energy and to mitigate or even reduce deforestation in the country.

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.