Assessment of policy alternatives and key technologies for energy conservation and water pollution reduction in China’s synthetic ammonia industry

Synthetic ammonia production is an energy intensive industry in China that creates considerable water pollution. The complex structure of the sector and its dynamic development make effective environmental policy for the synthetic ammonia industry a challenge. In this paper, we established a bottom-up technology model for China’s synthetic ammonia industry. Production of synthetic ammonia was divided into 12 combinations according to different feedstock types, production processes and plant sizes. 9 key energy conservation technologies and 8 key pollution prevention technologies were incorporated into the model. 4 policy scenarios were designed to project future water pollution emission and energy consumption trends: (1) production capacity replacement, (2) promoting cleaner technologies, (3) upgrading end-of-pipe treatment and (4) a combination of the above three measures. Furthermore, a Monte Carlo stochastic simulation method was introduced to explore the correlations between environmental performances and different structural factors and technologies. Plant size was found to be the most relevant factor for reducing water pollution. However, raw material types and corresponding production processes are more relevant for energy conservation. Finally, the relative importance of all pollution prevention and energy conservation technologies was also assessed through stochastic simulations.