Validation, Operation and Smart Full-scale Design of an Efficient Reclaiming System for Carbon Capture Solvents Based on Amino Acid Salt

Abstract

This paper describes the development of an efficient reclaiming system for post combustion carbon capture technology. Impurities are emerging from the combustion of common fossil fuels (oil, coal or natural gas) such as SOx and NOx. They react with the CO 2 capture solvent by forming complexes, which will accumulate in the aqueous solvent solution and reduce its performance. Consequently they must be removed through a reclaiming system. In contrast to conventional thermal based reclaiming systems the reclaiming system described in this paper features a selective process based on crystallization to maximize solvent recycling and minimize residue disposal, hence minimizing operating costs. On the one hand it converts part of the component formed by SOx-absorption into a commercially reusable product (whilst simultaneously unblocking and recovering the solvent) and on the other hand it removes the formed heat stable salts and other impurities from the liquid solvent with a high efficiency. Experience has been gathered from pilot operation and the process has been validated and optimized. With this, a continuous full-scale design has been developed.

Sorbents for the Capture of CO2 and Other Acid Gases: A Review

“…Amino acid sorbents, are similar to their amine cousins but are generally less susceptible to oxidative degradation and their ionic nature reduces volatility. ,, Typically, amino acids exhibit favorable properties, similar to amines but at a higher sorbent cost and with challenges from solid precipitation. − Unfortunately, implementation has been largely unsuccessful, highlighting slower than expected kinetics and thermal degradation as major issues. − As with aqueous ammonia, phase change chemistry has been reconsidered as an opportunity rather than a challenge for CO 2 capture with amino acids. , The precipitation of solids may enable new designs with advantages including increased working capacity and a reduced regeneration energy requirement. − A reclaiming system has been developed to recover ionic liquids from modest SO x and NO x contamination, while others purposely precipitate salts for simultaneous acid gas capture . Amino acids have a long history of use in reducing environments where different blends of the sodium- and potassium-based amino acids were used to selectively capture CO 2 and/or H 2 S in the alkazid process …”

“…224,225 The precipitation of solids may enable new designs with advantages including increased working capacity and a reduced regeneration energy requirement. 226−228 A reclaiming system has been developed to recover ionic liquids from modest SO x and NO x contamination, 229 while others purposely precipitate salts for simultaneous acid gas capture. 230 Amino acids have a long history of use in reducing environments where different blends of the sodium-and potassium-based amino acids were used to selectively capture CO 2 and/or H 2 S in the alkazid process.…”

“…Replacement of the sorbent and disposal of the waste is an expensive option, even when the sorbent is relatively cheap. Through necessity, a number of strategies have been developed to recover sorbents, such as ionic liquids, 191 amino acids, 229 and amines, 265 from contamination with other acid gases. Once-through sorbents are often able to produce a product that is more valuable than the sorbent (accounting for the value associated with reducing emissions).…”

Carbon Capture and Storage for Enhanced Oil Recovery: Integration and Optimization of a Post-Combustion CO2-Capture Facility at a Power Plant in Abu Dhabi

“…Reclaimer concepts for amine-based solvents are not suitable for amino acid salts (AASs) because they rely on evaporating the active component. Thus, we have developed a proprietary process for reclaiming AAS solvents (Melcher et al 2014) that is based on a two-step crystallization process (Fig. 8).…”