Investigation of provincial capacity to produce biogas from waste disposal sites in Turkey

The main aim of this study is to determine the theoretical capacities of waste disposal sites to produce biogas and electricity in Turkey in 81 provinces by using the First Order Decay (FOD) methodology. The population data of each province starting from 1950 to 2020 was used as time series to estimate the best fit model. The same model was also used for the future population estimations until the year 2080. The provinces have different characteristics. The big provinces in Turkey are best fitted with polynomial models. For 38 provinces the best fit models are “third order polynomials”, and for 10 provinces the “second order polynomials” are best fitted. The exponential and linear models are good for 15 and 13 provinces, respectively. Many statistical and “model performance studies” are done for increasing the accuracy level of this study. The results of this study have shown that the best fitted model is acceptable at province level although there are small differences between observed and fitted values. The CH₄ emission potential of disposal sites are calculated as 273 thousand tonnes in 1950. This has increased and reached 1.2 million tonnes in 2020. It is projected that it will reach 3.1 million tonnes in 2080. The methane production capacity in Marmara and Central Anatolia regions is calculated as 46% of total capacity. In 2020 these two regions have 1.7 and 0.9 million kW-hr/year electricity production capacity, respectively. The highest provincial capacity of electricity production is observed in İstanbul, Ankara, İzmir, Bursa and Antalya with respective values of 1.02, 0.37, 0.29, 0.20 and 0.16 million kW-hr/year. These top five provinces constitute 37% of Turkey's total capacity. The results of this study have shown that approximately 4.8–7.4% of GHG emissions can be stopped by using CH₄ produced in waste disposal sites in energy production. Further usage of methane instead of solid fuels or other non-renewable fuels will decrease the total GHG emissions an extra 2–3.5%. In 2020, 35 million tonnes of CO₂ eq. emissions can be reduced in Turkey due to biogas production in waste disposal sites. This is very important from the Climate Change point of view.