Exploring pathways to deep de-carbonization and the associated environmental impact in China’s ammonia industry

Abstract

China is the largest producer of synthetic ammonia, accounting for one-third of the world’s total production. Ammonia is mainly used to produce fertilizer and is also considered as a potential fuel and new energy carrier for the future. Concomitantly, the ammonia industry is the largest energy consumer and CO2 emitter in China’s chemical industry. In this study, we developed the MESSAGEix-ammonia model with detailed process descriptions to evaluate the energy-saving and emission reduction potential that can be generated by energy efficiency improvement, as well as the transition path and emission characteristics in the context of deep emission reduction. Results show that the cost-effective energy efficiency measures implemented under the energy efficiency scenario (EE) could reduce fresh water, fuel coal, and electricity consumptions by 7%, 25%, and 16%, as well as reduce CO2, PM2.5, SO2, and NOx emissions by 33%, 24%, 24%, and 24%, respectively, by 2060. Regarding the exploration of the deep de-carbonization path, carbon capture and storage technology (CCS) increases the CO2 reduction potential to 62%, but it requires additional electricity. Meanwhile, electrolysis technology not only saves additional fresh water and fuel coal, but also reduces CO2, PM2.5, SO2, and NOx by 80%, 84%, 86%, and 84%, respectively. Furthermore, the integration of electrolysis technology and CCS can bring 98% carbon emission reduction, which is close to net-zero emission status. With the development of renewable electricity, sufficient, clean, and affordable electricity can be provided for electrolysis devices.Our recommendation to policy makers is that electrolysis of water to produce ammonia using renewable electricity is a feasible deep de-carbonization pathway.

The Carbon Emission Characteristics and Reduction Potential in Developing Areas: Case Study from Anhui Province, China

“…The study differs from the other research reports and their achievements devoted to low carbon emissions in the development characteristics and regional reduction potential of carbon emissions and carbon sinks in the developed areas in China [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 94 , 95 , 96 ]. For instance, the total carbon emissions increased sharply, from 76.11 to 140.19 TgC yr −1 at the provincial level, with an average annual growth rate of 10.52%, while the vegetation carbon sinks declined slightly, from 54.52 to 53.20 TgC yr −1 in Guangdong Province [ 17 ].…”

“…On September 21, 2021, Chinese President Xi Jinping advised at the 76th United Nations General Assembly to achieve the carbon peaking by 2030 and its carbon neutrality by 2060 [ 13 , 14 , 15 ]. Under the overall requirements of Chinese goals of dual carbon and carbon neutrality, understanding the overall carbon emission level and carbon sink potential is the national basis and core element of promoting low-carbon development in the China [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ]. Similarly, under the regional “14th Five-Year Plan”, the provincial government is devoted to reduce its carbon emission to 65% of that in 2005 by 2030 in Anhui Province.…”

“…For example, we might plan to speed up the adjustment of agricultural structure to promote the progress of agricultural technology [ 26 ]. Simultaneously, we might try to explore curtain pathways to promote the agricultural carbon-peaking by means of technology and finance [ 22 , 40 ], or to promote the clean agricultural production and expand the opening of agriculture to the outside world [ 41 , 42 ].…”

Towards carbon-neutral sustainable development of China

“…As demonstrated for the Guangdong-Hong Kong-Macao Greater Bay Area, the sectors with great emission reduction space should be given more priority, such as transportation and power sectors; and more efforts should be made to reduce energy intensity and accelerate economic structural transformation persistently [21]. In addition, as synthetic ammonia is the largest energy consumer among China's chemical industries, energy-efficient synthetic technologies would reduce air pollutant emissions effectively, with additional benefits of CO 2 emission reduction by 33% by 2060 [22].…”

Some Perspectives for the Gasification Process in the Energy Transition World Scenario

“…China is manufacturing syngas from small coal-fired power stations, which will be processed into ammonia and used to make fertilizer. China's synthetic ammonia industry has the world's greatest capacity and volume of production, with a total production of 57.58 Mt in 2019 [37]. Table 2 summarizes desirable syngas characteristics for various end-use options.…”