No abstract

Cashew nut shells are one type of the most abundant biomass tropical wastes, which can be used for energy generation. However, there is lack of data for the thermal conversion process of cashew nut shells such as pyrolysis individual gas products, yields, and reaction kinetics. In this research work, the pyrolysis processes of cashew nut shells at low heating rates (10, 30, and 100 K/min) were studied. Thermogravimetric analyzer coupled with a Fourier transform infrared spectrometer (TG-FTIR) was used. The pyrolysis product yields obtained were compared with the available data in the literature for wood and Miscanthus Giganteus. It was found that cashew nut shells have tars and volatiles at levels equivalent to those of wood pellets, both above the tar and volatile content of M. Giganteus. Further, kinetic parameters were obtained from the TG-FTIR results using an approach based on parallel independent first-order reactions with a Gaussian distribution of activation energies and following the T max method. The data obtained through this approach included the identification, kinetics, and yield of each gas product precursor. These results are then used as input files for a distributed activation energy model (DAEM) for biomass pyrolysis, based on a functional group analysis, which still does not include the devolatilization, cross-linking competitive reactions. The predicted evaluation data from this model were found to generally agree with that from TG-FTIR analysis. However, the model still demands improvement to accommodate secondary and cross-linking competitive reactions.

Mozambique relies on wood biomass for meeting its household energy demand. This has been for long referred to as one of the main causes of the ongoing deforestation, mainly around the large cities and village. On the other hand, the country produces large quantities of agricultural crops residue which are still not being appropriately and integrally used as additional source of energy, especially for communities in the countryside where these residues are generated. Cashew nut shells (CNS) are among those residues. This kind of feedstock is said to be of high energy content. However, its utilization as energy source within the country is still poor. In Mozambique, 90% of the households depend on biomass for cooking. Biomass has already emerged in the renewable energy area as one of the promising candidates for the future energy source. Historically, biomass has been a major source of fuel from the existence of making rapid urbanization, but widespread use of fossil fuels in the industrialization has relegated it to a minor source of energy. The CNS Gasifier Stove developed has a thermal efficiency of 35.5% and an energy output of 2.19 kW. The corresponding values for LPG stove and Kerosene stove are 53.53% (0.69 kW) and 39.3% (0.6 kW), respectively. Though the use of CNS gasifier as a fuel is less efficient than the aforementioned one, with the rising oil prices and the search for alternatives to contemporary cooking fuels, it is still a viable alternative in this comparison.

Hydropower energy is one of most promising clean energy technologies, however this energy technology has many challenges. Compared with other renewable energies for example biomass, solar and wind energies, it has high capital investment cost. In Mozambique, access to conversional energy in form of electricity has been limited to most of the rural population. The objectives of the investigation research are to analyze Chua micro-hydropower plant exploration in Manica district in Mozambique and to examine the possibility of increasing energy production. The current total installed power generation capacity in Mozambique is about 939 MW. Hydropower contributes 561 MW, making a contribution of 61%. Oil contributes 27%, and natural gas contributes 12% of the total electric grid generation in Mozambique.