Estimation of landfill gas production and potential utilization in a South Africa landfill

ABSTRACT

Landfill gas composition comprises mainly of methane and carbon dioxide emissions and other Nonmethane Organic Carbons (NMOCs). Methane gas has a global warming potential that is estimated to be 25–36 over 100 years. Interestingly, methane generated from landfills is a renewable source of energy that has been used over the years as a source of electricity generation especially in developed and in some developing countries. However, methane from landfills has been underutilized in South Africa. Due to the recent unreliable electricity disruptions (load shedding) in South Africa, which is caused by a variety of factors. Prioritizing methane produced from landfills for use as a fuel for electricity generation is critical. This will assist to minimize the over-reliance on coal and, reduce the ongoing landfill gas generation. Therefore, the purpose of this study is to estimate the amount of methane emitted from Weltervenden landfill site using the LandGEM version 3.02 and Afvalzorg models and to evaluate the potential utilization of the gases emitted. The study was also aimed at determining the cost and benefits related to the implementation of a landfill gas utilization technology. The findings of this study show that methane emissions from the landfill will peak in the year 2023 with values of 4613 Mg/year and 3128 Mg/year for LandGem and Afvalzorg models, respectively. Also, the total methane emissions from the year 1999 to 2050, are 111,799.25 Mg/year and 27,898.93 Mg/year for both LandGEM and Afvalzorg models, respectively. The LFGcost web model simulations showed that the implementation of a LFG utilization project using Microturbine and CHP microturbine engines are economically feasible. This is considering the sales of electricity to the people. However, considering the sales of electricity generated and Certified Emission Reductions (CER) (carbon credits) to the global market all engines used in this study will be economically feasible.

Implications: The methane emitted from the Polokwane landfill estimated from LandGEM and Afvalzorg models will peak in year 2023 at 4613 Mg/year and 3128 Mg/year, respectively. Also, the total methane emissions from the year 1999 to 2050, are 111,799.25 Mg/year and 27,898.93 Mg/year for both LandGEM and Afvalzorg models, respectively. The LFGcost web model simulations showed that the implementation of a LFG utilization project using Microturbine and CHP microturbine engines are economically feasible. This is considering the sales of electricity to the people. Therefore, implementation of LFG utilization is economically feasible from sales of electricity generated and Certified Emission Reductions

Acknowledgment

The authors appreciatively acknowledge the financial support from Eskom Power Plant Engineering Institute (EPPEI) (E349) and University of Venda.

Data availability Statement

The data that support the findings of this study are available from the corresponding author, (P.O Njoku), upon reasonable request.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Eskom Power Plant Engineering Institute (EPPEI) [E349].

Notes on contributors

Prince Obinna Njoku

Prince Obinna Njoku is currently a Ph.D. student in the Department of Ecology and Resource Management, University of Venda. His research focus is on the remediation of environmental pollution, especially its effects on human health. He is currently focused on the possible reduction of gaseous emissions from landfills and the potential impact of these emissions have on human health.

Joshua Nosa Edokpayi

Joshua Nosa Edokpayi has a doctoral degree from the University of Venda, South Africa and a postdoctoral training from the University of Virginia, USA. He is currently a senior lecturer in the School of Environmental Sciences in the University of Venda. He is recognized and rated as a researcher by the National Research Foundation (NRF) of South Africa. He is basically into teaching and postgraduate training of students. His research interest include pollution assessment, impact and mitigation strategies of the environmental media including soil, air and water.