Estimation of the Potential Global Nitrogen Flow in a Nitrogen Recycling System with Industrial Countermeasures

This study proposes a nitrogen recycling system that collects and recycles nitrogen compounds from waste gases in the industrial sector, such as those from stationary sources, from industrially processed wastewater containing livestock effluent, and from household wastewater. Multiple scenarios are set, and the potential global flows of anthropogenic nitrogen in 2050 are estimated and compared to assess the effects on the largest planetary boundary problem. In contrast to the business-as-usual (BAU) scenario, in which environmental conditions are worsened through a 47% increase in nitrogen emissions by 2050 above the 2010 levels, the agricultural countermeasures scenario produced a reduction in emissions which was less than the 2010 levels. The industrial countermeasures scenario proposed in this study achieved comfortable reductions in nitrogen production by constructing a nitrogen recycling system that installs the nitrogen compounds to ammonia (NTA) technologies. Combining the agricultural and industrial countermeasures achieves a 66% reduction in nitrogen emissions compared with the BAU scenario in 2050. The combination of both countermeasures with a high installation rate of NTA technologies can achieve the reduction of nitrogen emissions beneath the planetary boundary.