Abstract: In order to promote the innovative development of coal based acrylic acid, a large integrated refining and chemical enterprise plans to build a coal to acrylic acid industry chain. In order to further enhance product competitiveness, the low recovery and utilization rate of effective components in the methanol unit release gas and the low-grade steam produced by the thermal energy system in the coal to acrylic acid industry chain are addressed. By comparing the advantages and disadvantages of traditional hydrogen recovery processes from release gas such as membrane separation and pressure swing adsorption, a hydrogen recovery coupled synthetic ammonia production process scheme is proposed, achieving an effective gas recovery rate of 91.2% and a hydrogen recovery rate of 98.82%. Based on the characteristics of the thermal energy system process, the process thermal energy coupling utilization among units is carried out to increase the total steam production by 45.54 t/h, and the proportion of driving steam is increased to 79.5%. The driving steam is completely self-used and partially supplied externally, achieving the conversion of low-grade thermal energy to high-grade and obtaining high economic benefits.

Key words: purge gas, hydrogen recovery, thermal energy coupling, optimization, energy saving