In this study, global warming, environmental and sustainability aspects of a geothermal energy based biodigester integrated SOFC system are parametrically analyzed. In this regard, a system is designed, consisting of three main subsystems such as Solid Oxide Fuel Cell, Anaerobic Digester, and a Heat Recovery Steam Generator. In order to investigate the global warming, environmental and sustainability aspects of the system, the energy and exergy analyses are performed, and the following indicators are taken into consideration, which are i) unit CO emission, ii) environmental effect factor, iii) waste exergy ratio, iv) exergy destruction ratio, v) exergy recovery ratio, vi) exergetic sustainability index. Accordingly, the maximum exergetic sustainability index and exergy efficiency of the integrated system are calculated to be 0.486 and 0.367, respectively, in case the SOFC inlet temperature is equal to 633.3 °C while electric current density is 5500 A/m. On the other hand, the minimum exergy destruction ratio and the minimum environmental effect factor are obtained to be 0.74 and 2.33 while SOFC inlet temperature is 633.3 °C and SOFC current density is 8000 A/m. The minimum unit CO emission of the whole system is determined to be 368.4 kg/MWh at 5500 A/m of SOFC current density and 727 °C of SOFC inlet temperature while determined as 258.3 kg/MWh at 8000 A/m of SOFC current density and 680 °C of SOFC inlet temperature. Thus, it can be said that such a system may be applied for reducing the CO based global warming effects and improving the environmental sustainability.

中文翻译：

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基于地热能的生物消化器集成 SOFC 系统的全球变暖、环境和可持续性问题


在这项研究中，对基于地热能的生物消化器集成 SOFC 系统的全球变暖、环境和可持续性方面进行了参数分析。为此，设计了一个系统，由三个主要子系统组成，例如固体氧化物燃料电池、厌氧消化器和热回收蒸汽发生器。为了研究系统的全球变暖、环境和可持续性方面，进行了能源和火用分析，并考虑了以下指标，即i）单位二氧化碳排放量，ii）环境影响因子，iii）废物火用比率，iv) 火用破坏率，v) 火用回收率，vi) 火用可持续性指数。因此，当 SOFC 入口温度等于 633.3 °C、电流密度为 5500 A/m 时，集成系统的最大火用可持续性指数和火用效率分别为 0.486 和 0.367。另一方面，当SOFC入口温度为633.3°C、SOFC电流密度为8000 A/m时，最小火用破坏率和最小环境影响因子分别为0.74和2.33。在 SOFC 电流密度 5500 A/m、SOFC 入口温度 727 °C 时，确定整个系统的最小单位 CO 排放量为 368.4 kg/MWh；在 SOFC 电流密度 8000 A/m 时，确定为 258.3 kg/MWh SOFC 入口温度为 680°C。因此，可以说这样的系统可用于减少基于CO的全球变暖效应并提高环境可持续性。