Environmental Analysis of Waste-to-Energy—A Portuguese Case Study

Abstract

Environmental evaluation of the waste treatment processes for the area of Greater Porto (Portugal) is presented for the year 2015. The raw data for the energy recovery plant (ERP) provided by the waste management entity were modelled into nine environmental impact categories, resorting to a life cycle assessment dedicated software (GaBi) for the treatment of 1 tonne of residues. Also, a sensitivity analysis was conducted for five scenarios in order to verify the assessment quality. Results were compared to two European average situations (typical incineration plant and sanitary landfill with no waste pre-treatment), which showed that these facilities perform better or at the same level as the average European situation, mostly due to the high efficiency observed at the ERP and to the electricity production in the incineration process. A detailed analysis concluded that these helped to mitigate the environmental impacts caused by some of the processes involved in the waste-to-energy technology (landfill showing the harder impacts), by saving material resources as well as avoiding emissions to fresh water and air. The overall performance of the energy recovery plant was relevant, 1 tonne of waste saving up to 1.3 million kg of resources and materials. Regarding the environmental indicators, enhanced results were achieved especially for the global warming potential (−171 kg CO 2-eq.), eutrophication potential (−39 × 10 −3 kg PO 4-eq.) and terrestrial ecotoxicity potential (−59 × 10 −3 kg DCB-eq.) categories. This work was the first to characterize this Portuguese incineration plant according to the used methodology, supporting the necessary follow-up required by legal frameworks proposed by European Union (EU), once this facility serves a wide populational zone and therefore is representative of the current waste management tendency in the country. LCA (life cycle assessment) was confirmed as a suitable and reliable approach to evaluate the environmental impacts of the waste management scenarios, acting as a functional tool that helps decision-makers to proceed accordingly.

Evaluation of the Environmental Impact and Efficiency of N-Doping Strategies in the Synthesis of Carbon Dots

“…The sustainability of each N-doping route was determined by performing a life cycle assessment (LCA) study of each synthesis. LCA is the most appropriate tool to address this issue, as it aims to quantify the environmental impacts of a given system during its life cycle [40,41]. Moreover, LCA has already been used in the environmental evaluation of different nanomaterials, such as silver NPs [36], copper NPs [37], carbon nanotubes [38], and magnetic NPs [39].…”

Municipal Solid Waste as a Source of Electric Power Generation in Colombia: A Techno-Economic Evaluation under Different Scenarios

“…Some analyses show that landfills have a greater environmental impact than most WTE technologies [42,[62][63][64]. However, for a holistic evaluation, an environmental impact assessment must be conducted in accordance with the International Organization for Standardization (ISO) standards 14040 and 14044, using Life Cycle Assessment (LCA) [42].…”

BioEnergy and BioChemicals Production from Biomass and Residual Resources

“…The twenty-one published papers cover a variety of biomass or waste residuals that have been converted into different types of energy, biofuels or biochemicals including heat [1,11,16], methane [2,4,[7][8][9]17,[19][20][21], electricity [2,11,16], short chain fatty acids [2,19], ethanol [3,12,19], syngas [5,19], nutrient pellets [6], hydroxymethylfurfura [15], and hydrogen [2,10,14,18,19]. The key information including biomass or residuals, products, and technology for the production and type of research are summarized in Table 1.…”

“…Ramos et al [16] provided a case study for the environmental analysis and life cycle assessment of the waste-to-energy process in Portugal. Nine environmental impact categories were grouped from the raw data for the energy recovery plant.…”