Amine Solvent Properties

Physical and CO&sub2;/H&sub2;S loading properties for MEA, DEA, MDEA, and piperazine blends used in gas treating units.

Overview

Amine Solvent Properties Reference — Acid Gas Removal (H2S / CO2) · Reference data for solvent selection and sizing. Data sourced from GPSA, Kohl & Nielsen, Polasek & Bullin.

Solvent	Type	Typical Conc. wt%	Lean Loading (mol/mol)	Rich Loading (mol/mol)	Heat of Absorption ΔH (Btu/lb)	Regen Temp °F	Primary Duty	Comment
MEA	Primary amine	15-25	0.10-0.15	0.40-0.50	825 (CO2); 610 (H2S)	230-260	CO2 bulk / H2S	Non-selective; prone to corrosion and degradation; reclaimer needed
DEA	Secondary amine	25-35	0.05-0.10	0.35-0.45	680 (CO2); 555 (H2S)	240-260	H2S bulk / CO2	Common in refinery; mild selective H2S over CO2 in high kinetics
MDEA	Tertiary amine	30-50	0.005-0.010	0.30-0.40	600 (CO2); 522 (H2S)	220-240	H2S selective	Slow CO2 kinetics → strong H2S slip selectivity; low corrosion
MDEA + PZ	Blend (tertiary + activator)	40-50	0.02-0.05	0.40-0.50	650	240-260	Bulk CO2	Piperazine kinetic promoter; higher capacity; widely used in PCC
DGA	Primary amine	50-65	0.05-0.10	0.35-0.45	735	250-280	CO2 bulk; COS	Low vapor pressure; degrades to BHEP; Fluor Econamine
DIPA	Secondary amine	30-40	0.10-0.20	0.40-0.50	600	240-260	H2S selective; COS	Sulfinol-M blend; low foaming; carbon steel friendly
Sulfinol-D	Sulfolane + DIPA + water	-	-	-	-	260-280	H2S + COS + mercaptans	Physical+chemical hybrid; strong selectivity, higher CAPEX
Selexol	Physical (DMPEG)	-	-	-	-	Ambient flash	H2S + CO2 + COS	Physical solvent; high partial-pressure duty; integrated in IGCC

Circulation Sizing

Amine Circulation Rate Sizing — Heuristics · Per GPSA 13th Ed. Section 21 and Kohl & Nielsen Ch 2 (2020 reprint)

Service	Loading delta (mol/mol)	Typical gal/mol acid gas	Reboiler duty Btu/gal	Comment
Refinery DEA (H2S/CO2)	0.30	113 gal/mol	1,050	Lean <0.05 mol/mol H2S for treated gas <4 ppm
NG Treating MDEA	0.30	110 gal/mol	900	Selective H2S; CO2 slip accepted
CO2 Capture MEA 30 wt%	0.30	135 gal/mol	1,550	Higher duty; thermal degradation risk
Blended MDEA/PZ 40/5	0.35	95 gal/mol	1,200	PZ boost reduces circulation ~15%
Formulated MDEA (Shell)	0.35	90 gal/mol	1,100	Proprietary blends (ADIP-X)

Degradation

Amine Degradation Products — ID and Mitigation

Solvent	Primary Degradation Products	Conditions	Mitigation
MEA	HEIA, HEEU, oxazolidone, bicine	Heat-stable salts above 290 F reboiler	Reclaimer, inhibitor, filter carbon, keep bulk below 250 F
DEA	BHEP, tris-(HEE), THEED	High CO2 partial pressure	Vacuum reclaim, monitor pH, purge
MDEA	DEA, bicine (slow)	Oxidative degradation with O2	N2 blanket, deoxygenation, antifoam
Piperazine	EDA, PIPH2OH	Thermal >300 F	Keep reboiler <270 F
DGA	BHEP (same as DEA family)	Same as MEA	Vacuum reclaim; replace when HSS>2 wt%

References

Source: Amine_Solvent_Properties_Reference_v1.xlsx

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