IR monitoring of absorbent composition and degradation during pilot plant operation
- Authors: Puxty, Graeme , Bennett, Robert , Conway, Will , Webster-Gardiner, Mike , Yang, Qi , Pearson, Pauline , Cottrell, Aaron , Huang, Sanger , Feron, Paul , Reynolds, Alicia , Verheyen, Vincent
- Date: 2020
- Type: Text , Journal article
- Relation: Industrial and Engineering Chemistry Research Vol. 59, no. 15 (2020), p. 7080-7086
- Full Text: false
- Reviewed:
- Description: The monitoring of the absorbent during the operation of CO2 separation processes is a necessary and challenging task. The most common absorbent used is an aqueous amine solution. Traditional approaches to analysis such as titration and chromatography are time-consuming and only provide limited information. This hinders the ability of process operators to rapidly respond to changes in operating conditions. In this work, a combination of infrared (IR) spectroscopy and principle component regression (PCR) analyses have been demonstrated as a rapid and reliable technique to determine the composition of an absorbent during a pilot plant campaign at a brown coal power station. The concentration of amine, a degradation product, CO2, and water was monitored throughout the campaign by a method that provided results in minutes. The results were verified by independent sample analysis using acid-base titration, high-performance liquid chromatography (HPLC), and 13C NMR spectroscopy. It was necessary to use spectral windowing when building the IR-PCR model, but this resulted in a robust and reliable method that has been demonstrated to work in a real-world process environment. © 2019 American Chemical Society.
- Description: The authors wish to acknowledge the financial assistance provided by the Brown Coal Innovation Australia, Ltd., a private member-based company with funding contracts through the Australian National Low Emissions Coal Research and Development, Ltd. (ANLEC R&D) and the Victorian State Government. The work described here was made possible through the PICA project, a collaboration between AGL Loy Yang, IHI, and CSIRO that aims to advance post-combustion CO 2 -capture technology in Australia.
A technology review for regeneration of sulfur rich amine systems
- Authors: Garg, Bharti , Verheyen, Vincent , Pearson, Pauline , Feron, Paul , Cousins, Ashleigh
- Date: 2018
- Type: Text , Journal article , Review
- Relation: International Journal of Greenhouse Gas Control Vol. 75, no. (2018), p. 243-253
- Full Text: false
- Reviewed:
- Description: Reducing the capital cost of post combustion CO2 capture by eliminating flue gas desulfurisation (FGD) pre-treatment, requires management of the amines preferential SO2 absorption. Novel technologies such as CS-Cap restrict the impact of SO2 to only a small fraction of the amine inventory resulting in high sulfate burden amines. Traditional thermal reclamation of these spent absorbents has advantages regarding simplicity, but ranks poorly for industrial ecology around PCC. These amines require low energy regeneration technologies compatible with their physico-chemical properties that also maximise the potential for valorising by-products. This review summarises the sulfur chemistry and outlines several amine reclamation processes. It assesses the status of established and novel regeneration technologies for their applicability to high sulfur loaded amines. Should deep sulfur removal be required, a hybrid approach with initial bulk removal (as product) followed by a polishing step to further reduce sulfur is prospective. A preliminary estimation of the relative cost of using standard reclamation methods for treating Sulfur loaded CS-Cap absorbent revealed the cost would increase due to its higher sulfate burden despite comparable treatment volumes. Research gaps are identified which would enable better comparison between the costs of traditional FGD versus higher reclamation costs for combined capture technologies.
Regeneration of sulfate-rich postcombustion capture amines through reactive crystallisation
- Authors: Garg, Bharti , Pearson, Pauline , Cousins, Ashleigh , McKnight, Stafford , Verheyen, Vincent
- Date: 2020
- Type: Text , Journal article
- Relation: Asia-Pacific Journal of Chemical Engineering Vol. 15, no. 6 (2020), p.
- Full Text: false
- Reviewed:
- Description: Flue gas desulfurisation is a prerequisite for successful CO2 capture in coal-fired power stations utilising aqueous amine absorbents. For nations like Australia, where there is nonexistence of mandatory flue gas desulfurisation, this increases the cost for power plants retrofitting CO2 capture. The CSIRO's CS-Cap process, a potentially low cost method for combined CO2 and SO2 capture, provides an alternate sulfur management solution to such plants. The CS-Cap process, however, results in high sulfur-loaded amines that require continuous regeneration to retain cost benefits. Reactive crystallisation by KOH addition is shown to be successful in removing the bulk of the sulfate from aqueous amines without any additional heating or cooling requirements. Increasing initial sulfate loading by amine recycling initially improves sulfate removal efficiency, up to the postsaturation level where the systems ionic strength determines further sulfate solubility. Oxidative amine degradation had no significant effect on the precipitation efficiency or purity of K2SO4 crystals apart from their slight discoloration. The behaviour of the residual potassium in these regenerated aqueous amines needs further investigation as it could lead to unwanted precipitation inside the absorber column and other parts of the process. © 2020 Curtin University and John Wiley & Sons, Ltd.