Municipal solid waste management instruments that influence the use of the refuse as fuel in developing countries: A critical review

Landfills are the destination of most of the refuse generated whereas composting, material recycling, and Waste-to-Energy (WtE) technologies are not commonly employed in developing countries. However, the destination for energy purposes could be supplied with this refuse, improving the viability of energy use. Thus, this article raises some questions to identify aspects that could encourage its use as refuse-derived fuel (RDF) in these countries. Among them, does environmental education affect the municipal solid waste (MSW) source separation with emphasis on a destination? Can selective collection and extended producer responsibility (EPR) affect the MSW for energy recovery? Is there competition between the recycling market and the energy market for RDF? A systematic review of the literature was conducted to gather data and provide answers to such questions. This enabled to observe that EPR, selective collect expansion and source separation influence the quantity and quality of waste sent for energy use. Both internal and external factors impact on source separation. Additionally, there is evidence to support that despite several studies showing their technical, economic, environmental and social viability, the methods of energy usage of the refuse still need to improve their deployment in developing countries. In addition to identifying the main research gaps to be filled in future studies, the article also identified the instruments of MSW management that are to be applied in developing countries to divert recyclable and organic waste from landfill.

Evaluation of the Zinc Sulfate Catalytic Effect in Empty Fruit Bunches Pyrolysis

The effect of zinc sulfate as a catalyst on the pyrolysis of empty fruit bunches (EFB) from oil palm was assessed. Thus, a thermo-gravimetric analyzer coupled with a Fourier transform infrared spectroscopy (TG-FTIR) was used, while the percentage of catalyst varied between 0 wt% and 3 wt% at different heating rates (10, 30, and 50 K/min). The kinetic parameters (activation energy, pre-exponential factor, and reaction order) and activation energy distribution were calculated using three kinetic models. The thermogravimetric curves for the EFB pyrolysis showed three prominent peaks in which the maximum mass loss rate was mainly due to cellulose and lignin pyrolysis. On the other hand, FTIR analysis indicated that the main gaseous products were CO2, CO, H2O, CH4, NH3, acids, and aldehydes (CH3COOH). The samples with 2 wt% of catalyst presented higher activation energies in pseudo reactions 1 and 2, ranging between 181,500 kJ/mol–184,000 kJ/mol and 165,200 kJ/mol–165,600 kJ/mol, respectively. It was highlighted that the first pseudo reaction with an activation energy range between 179,500 kJ/mol and 184,000 kJ/mol mainly contributes to the cellulose pyrolysis, and the second pseudo reaction (165,200 kJ/mol–165,600 kJ/mol) could be ascribed to the hemicellulose pyrolysis.