TITLE:
Industrial Progress: New Energy-Efficient Absorbents for the CO2 Separation from Natural Gas, Syngas and Flue Gas
AUTHORS:
Jörn Rolker, Matthias Seiler
KEYWORDS:
Absorbent, CO2, Energy Efficiency, Sustainability, Operational Expenditure, Separation, Capture
JOURNAL NAME:
Advances in Chemical Engineering and Science,
Vol.1 No.4,
October
26,
2011
ABSTRACT: The CO2 separation from natural gas, syngas or flue gas represents an important industrial field of applications. An economic and energy-efficient CO2 separation from these gas streams is a prerequisite for sustainable industry contributions to the megatrends resource efficiency and globalization of technologies. One way of reducing operational expenditure for these separation processes is the development of better performing CO2 absorbents. Although a number of absorbents for the separation of CO2 from process gas streams exist, the need for the development of CO2 absorbents with an improved absorption performance, less corrosion and foaming, no nitrosamine formation, lower energy requirement and therefore less operational expenditure remains. Recent industrial activities have led to the development of novel high-performance CO2 scrubbing agents that can be employed in numerous industrial processes such as natural gas treatment, purification of syngas and the scrubbing of flue gas. The objective of this paper is to introduce these new high-performance scrubbing agents and to compare their performance with other state-of-the-art absorbents. It turned out, that the evaluated absorbents offer high cyclic capacities in the range of 2.4 to 2.6 mol CO2/kg absorbent and low absorption enthalpies (–30 kJ/mol) allowing for distinctive savings in the regeneration energy of the absorbent. Calculations with the modified Kremser model resulted in a reduction of the specific reboiler heat duty of 55%. Furthermore, the absorbents are less corrosive than standard amines as indicated by the measured corrosion rates of 0.21 mm/y versus 1.18 mm/y for a piperazine/methyldiethanolamine mixture. Based on new experimental results it is shown how substantial savings in operational and capital expenditure can be realized due to favorable absorbent properties. The novel high-performance CO2 system solutions meet recent industrial absorbent requirements and allow for more efficient or new CO2 separation processes.