Electricity Generation from Municipal Solid Waste in Nigeria: A Prospective LCA Study

Abstract

Diverse opportunities and environmental impacts could occur from a potential move towards waste-to-energy (WtE) systems for electricity generation from municipal solid waste (MSW) in Lagos and Abuja, Nigeria. Given this, the purpose of this study is to use life cycle assessment (LCA) as a primary analytical approach in order to undertake a comparative analysis from an environmental impact perspective of different WtE scenarios, along with diesel backup generators (DBGs) and grid electricity. A functional unit of 1 kilowatt-hour of electricity produced was used in assessing the following environmental impact categories: abiotic depletion (fossil fuels) potential (ADP), global warming potential (GWP 100a), human toxicity potential (HTP), photochemical oxidation potential (POCP), acidification potential (AP), and eutrophication potential (EP). The overall result indicated that anaerobic digestion (AD) had the highest energy generated per one tonne of MSW processed for both Lagos (683 kWh/t) and Abuja (667 kWh/t), while landfill gas to energy (LFGTE) had the lowest for both (Lagos 171 kWh/t, Abuja 135 kWh/t). AD also had the lowest environmental impacts amongst the four WtE systems for both cities based on all the impact categories except for POCP. In contrast, LFGTE had the highest impact in all the categories except ADP and HTP. Extending the analysis to include diesel-based generators (DBG) and grid electricity saw the DBGs having the highest impact overall in ADP (14.1 MJ), HTP (0.0732 Kg, 1.4 DB eq), AP (0.0129 Kg SO2 eq), and EP (0.00313 Kg PO4 eq) and grid electricity having the lowest impact in GWP (0.497 Kg CO2 eq), AP (0.000296 Kg SO2 eq), and EP (0.000061 Kg PO4 eq). It was concluded that additional electricity supply from AD to the grid, with its potential to reduce the reliance on DBGs (worst scenario overall), would be a positive action in environmental impact terms.

Life Cycle Sustainability Assessment of Electricity Generation from Municipal Solid Waste in Nigeria: A Prospective Study

“…Equation (1) above proposes that the sustainability assessment of a product or a system should be performed by the application of the three life cycle techniques [38] followed by comparison and aggregation of their respective results using weighting [39]. The LCSA in this study involves an integration of the three sustainability dimensions (environmental, economic, and social) as reported independently for the WtE systems in [40][41][42]. The sustainability results for WtE in Lagos and Abuja are presented and compared with other studies, and the limitations that exist in integrating the three assessment tools are discussed, along with the implications for policy regarding the implementation of WtE in Nigeria.…”

“…For the LCA, LCC, and sLCA, the detailed methodologies have been described by the authors in previous studies [40][41][42]. Therefore, to prevent repetition, only brief summaries of the methods and findings are provided here, with full detail available in [40][41][42].…”

“…For the LCA, LCC, and sLCA, the detailed methodologies have been described by the authors in previous studies [40][41][42]. Therefore, to prevent repetition, only brief summaries of the methods and findings are provided here, with full detail available in [40][41][42]. Primary data were acquired from field observation, questionnaire-based surveys, and Despite their geographical and historical differences, both cities share the same challenges associated with rapid increases in population, increases in the amount of MSW generated, and issues associated with an inadequate electricity supply.…”

“…For the LCA, LCC, and sLCA, the detailed methodologies have been described by the authors in previous studies [40][41][42]. Therefore, to prevent repetition, only brief summaries of the methods and findings are provided here, with full detail available in [40][41][42]. Primary data were acquired from field observation, questionnaire-based surveys, and interviews, while secondary data were obtained from sources such as technical reports and relevant pieces of literature.…”

“…); these led to 46 social indicators (some of which included Number of Jobs created and Level of expected Accidents/Injuries/Fatalities etc. ), which were quantified using a 5-scale Likert system (see [40][41][42]).…”