Effective Adsorbents for Establishing Solids Looping as a Next Generation NG PCC Technology

Lead Research Organisation: University of Nottingham
Department Name: Faculty of Engineering

Abstract

To achieve the UK's ambitious target of reducing greenhouse gas emissions by 80% by 2050, it is widely accepted that from ca. 2030 Carbon Capture and Storage (CCS) needs to be fitted to both coal and natural gas fired power plants.

The flue gas characteristics of natural fired gas power plants, mostly operating in a combined cycle of gas turbine and steam turbine (NGCC), differ significantly from those from coal-fired power plants. Comparing to the flue gas of the same size coal-fired power plant, the flue gas of a NGCC power plant contains significantly lower CO2 (3-5 vs. 13-15%) and higher O2 concentrations (12-15 vs. 2-4%) and has ca. 50% higher flow rate, which make the separation of CO2 equally, if not more, challenging.

The most mature PCC technology, CO2 amine scrubbing, suffers from well-know problems of high energy penalty, oxidative solvent degradation and corrosion, large capture plant footprint and high rate of water consumption. A new generation of PCC technologies for NGCC power plants which overcome these drawbacks need to developed and demonstrated in the next 10 ~ 20 years in order for their commercialisation from ca. 2030. Solid adsorbents looping technology (SALT) is widely recognised as having the potential to be a viable next generation PCC technology for CO2 capture compared to the state-of-art amine scrubbing, offering potentially significantly improved process efficiency at much reduced energy penalty, lower capital and operational costs and smaller plant footprints.

The aim of this project is to overcome the performance barriers for implementing the two types of candidate adsorbent systems developed at Nottingham, namely the supported/immobilised polyamines and potassium-promoted co-precipitated sorbent system, in the solid looping technology specifically for NGCC power plants, which effectively integrates both materials and process development and related fundamental issues underpinning the technology development. The objectives are:

1. To overcome the following major specific challenges:
(a) To examine and enhance the oxidative and/or hydrolytic stability of supported/immobilised polyamine adsorbents and hence to identify efficient and cost-effective management strategies for spent materials.
(b) To optimise the formulation and preparation of the potassium-promoted co-precipitated sorbents for improved working capacity, reaction kinetics and regeneration behaviour at lower temperatures.
(c.) To gain comprehensive understanding of to what degree and how different flue gas conditions, particularly oxygen and moisture, can impact the overall performance of adsorbent materials and related techno-economic performance of a solid looping process.

2. To produce kilogram quantities of the optimum adsorbent materials and then demonstrate their performances over repeated adsorption/desorption cycles and to establish the optimal process thermodynamics in fluidized bed testing.

3. To investigate a novel rejuvenation strategy for oxidised polyethyleneimines involving low temperature hydrogenation.

4. To conduct techno-economic studies to assess the cost advantages of the solids looping technology for NGCC power plants over amine scrubbing based on the improved adsorbent performance and optimised process configuration achieved in the project.

The know-how acquired in this project will be of direct benefit to academics, CCS research community, power generation and energy industries, energy policy makers/regulators, environmental organisations and government departments such as DECC.

The successful delivery of the proposed project represents a major step forward in the development and demonstration of the novel and cost-effective Solids Adsorbents Looping CO2 capture technology for NGCC power stations.

Planned Impact

In order to develop and assess the solid adsorbents looping technology for the CO2 capture of NGCC power stations for the first time across the world, the consortium brings together strong research expertise in Engineering, Chemistry, Materials and Energy Policy, and the supports of major industrial partners in power generation, engineering manufacturers/consultancies, and manufacturers of inorganic particles. This provides an ideal multidisciplinary environment for enhancing the skills set of the researchers working on the project. The employed RAs by the grant and any PhD students such as the one to be fully funded by the University of Nottingham involved with the project will gain much value-added transferable skills in materials synthesis, advanced characterisation techniques, fluidized bed testing and design, techno-economic assessment, problem posing and solving approaches and interpersonal skills through project meetings, progress reporting/presenting, working as part of the integrated research team across the whole consortium.

The project contributes directly to an effective technology to mitigate environmental and energy security concerns. The main stumbling block to the widespread implementation of Carbon Capture and Storage (CCS) in power plants is the energy cost associated with solvent regeneration in the most mature Post Combustion Capture (PCC) technology - amine absorption, which will become even greater when applied to a gas-fired power plant because of its flue gas characteristics (lower CO2 concentration, higher O2 concentration and higher flue gas flow rate compared to a similar size of coal-fired power plant). Hence, alternative PCC technologies for gas power plants need to be developed that have the potential to lower this energy penalty and also have lower capital and operating costs. With the proposed project, the consortium partners will develop and assess the solid adsorbents looping technology (SALT) as a novel, low-cost and high-performing PCC technology for carbon capture from natural gas-fired power plants to overcome the main drawbacks of amine absorption. The project will focus on not only the development and characterisation of novel, highly performing organic (amine-based) and inorganic (alkali-based) adsorbents but also the process development, optimisation and adsorption/regeneration strategies/testing of the adsorbent materials under gas-fired power plant flue gas conditions. The developed adsorbents and SALT process can be rapidly scaled up by industrial partners to speed up the technology transfer process. The development of SALT and its underline technologies will be of great interest to not only the industrial partners (see the letters of support attached from these companies) but also industrial companies outside the consortium such as RWE and Foster Wheeler which are one of the main power companies and the developers of Circulating Fluidized Bed technologies that are ideal technologies for the realisation of SALT in demonstration- and commercial-scales. Innovations in SALT can also bring about new job opportunities and UK export opportunities.

Regular project meetings with the academic partners, the industrial partners and the Advisory Board will be used to discuss future research and opportunities for timely scale-up and demonstration.

All investigators have a strong track record of publishing high-impact technical papers in international, peer reviewed journals, and presenting at international conferences and they will supervise the publications and co-author papers with the other researchers working on the project, giving plenary and keynote addresses at conferences and media interviews as appropriate.

Specific public engagement event is currently being planned for energy research at Nottingham, on the occasion of the grand opening of the Energy Technologies Research Institute building in 2012, through which this project would be showcased.

Publications

10 25 50
publication icon
Colantuono G (2017) Selective strategy for solid sorbent replacement in CCS in Chemical Engineering Research and Design

publication icon
Gadipelli S (2015) Graphene-based materials: Synthesis and gas sorption, storage and separation in Progress in Materials Science

 
Description (1) Development of new adsorbent materials
(a) The polyethyleneimine (PEI) impregnated on a large mesoporous silica support (MCF-17) has been developed and assessed. MCF-17 has much higher CO2 uptake than the baseline PEI-silica adsorbent under the simulated NGCC flue gas conditions (14.5 wt% vs 9.1 wt%, TGA tests) and therefore has greater potential for future large-scale applications. (b) The hybrid PEI-K2CO3 immobilized on mesoporous silica and other supports can enhance the CO2 capture through a combinative adsorption mechanism by both PEI and K2CO3. However, its adsorption kinetics is much slower than PEI-based adsorbents. This observation needs to be considered when considering K2CO3-based solid adsorbents for future large-scale applications. (c) An amine-loaded hierarchically porous carbon solid adsorbent has also been developed and found to have a very high level of CO2 uptake and remain stable over multi-cycles of adsorption-desorption.

(2) Performance evaluation of the baseline PEI/silica adsorbent in a bubbling fluidized bed (BFB) reactor
Production of the baseline PEI/silica adsorbent has been scaled up to 20 kg. The performance of the PEI/silica adsorbent has been assessed over repeated adsorption/desorption cycles with the purpose-built BFB reactor. The breakthrough capacity (7%) and equilibrium capacity (10%) achieved under simulated NGCC flue gas conditions represent one of the highest reported capacities. The presence of moisture during adsorption and desorption has been found to have a pronounced effect on alleviating the thermal degradation of the adsorbent and stabilizing the adsorption capacity. To obtain high purity product CO2 gas, the feasibility of using steam as the sweep gas during regeneration has been verified. Real flue gas from a domestic gas boiler has been fed into the BFB to further evaluate the performance of the PEI/silica adsorbent.

(3) Process simulation and techno-economic assessment
Process simulation has been conducted for a retrofitted closed-loop CCS system integrated with a typical 555MWe NGCC power plant. Based on a coupled CFB-BFB conceptual design, the net power plant efficiency with the SALT (solids adsorbent looping technology) of PEI/silica CCS system has been determined to be 48.1%, in comparison with 55.7% for the original power plant without CCS and 47.5% for a benchmark advanced MEA based CCS system. The techno-economic workpackage of the project demonstrated that the cost of the adsorbent replacement is crucial to making the process viable. There are a number of possible strategies that could be implemented to reduce this, for example using much cheaper materials, making the materials more resilient or greatly increasing the sorption capacity of the material.

(4) Modelling of surface adsorption and advanced characterization
To mimic more realistic silica surfaces, a new porous silica model was established by "hand-writing" its coordinates based on the structure of the precursors for mesoporous silica. The new structure consists of all three silanole groups of a typical silica surface, i.e. isolated, geminal and vicinal -OH groups on the silica surface. The model possesses 27 SiO2 units, manageable by DFT calculations. From macro- and micro-data comparison, our structure is the closest atomic level model for amorphous silica.
Exploitation Route (1) Discuss with our industrial partners;
(2) Discuss with other national stakeholders;
(3) Make wider dissemination through international conferences and open-access journal paper publications.
Sectors Chemicals,Energy,Environment

 
Description Potential exploitation of the research findings has been discussed with the project industrial partners. Further scale-up production (up to 100 kg) of the baseline PEI-silica adsorbents can now be realized at the leader partner's laboratory (University of Nottingham) in collaboration with an industrial company. Collaborations with other interested parties (mainly resulted from reading the open access publications) are yet to be realised.
First Year Of Impact 2016
Sector Chemicals,Energy,Environment
Impact Types Economic

 
Description International Collaboration R&D (Korea)
Amount ₩240,000,000 (KRW)
Organisation Korea Institute of Energy Research 
Sector Academic/University
Country Korea, Republic of
Start 06/2015 
End 05/2018
 
Description Gas CCS Project Partners 
Organisation Doosan Babcock Energy Ltd
Country United Kingdom 
Sector Private 
PI Contribution The latest research findings in the field
Collaborator Contribution Technical advice from industry point of view
Impact 10.1016/j.ijggc.2016.12.003
Start Year 2013
 
Description Gas CCS Project Partners 
Organisation PQ Corporation
Country United States 
Sector Private 
PI Contribution The latest research findings in the field
Collaborator Contribution Technical advice from industry point of view
Impact 10.1016/j.ijggc.2016.12.003
Start Year 2013
 
Description Gas CCS Project Partners 
Organisation Parsons Brinckerhoff
Country United States 
Sector Private 
PI Contribution The latest research findings in the field
Collaborator Contribution Technical advice from industry point of view
Impact 10.1016/j.ijggc.2016.12.003
Start Year 2013
 
Description Gas CCS Project Partners 
Organisation Uniper Technologies Limited
Country United Kingdom 
Sector Private 
PI Contribution The latest research findings in the field
Collaborator Contribution Technical advice from industry point of view
Impact 10.1016/j.ijggc.2016.12.003
Start Year 2013
 
Description International research visits to China (Southeast University, Shandong University, Guangzhou Institute of Energy Conversion (Chinese Academy of Sciences) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Research findings were presented to researchers/research students (Master/PhD levels) of the named three organisations in 2019 and Southeast University in 2018.
Year(s) Of Engagement Activity 2019
 
Description Project Kick-off meeting involving all industrial partners and academic partners, related researchers 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact About 20 people attended project formal kick-off meeting with all national/international industrial partners present.
There were formal presentations and discussions.
An Industrial Advisory Board was formally formed with the chair duly appointed.
Year(s) Of Engagement Activity 2015
 
Description Project-kick off meeting involving all industrial partners and employed researchers as well as related project students 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact All participants, especially the industrial partners, had discussed the proposed project workpackages/tasks and provided various technical advices.
Year(s) Of Engagement Activity 2013
 
Description Regular project consortium meetings 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Research results have been presented at the project consortium and the industrial partners have provided technical advice, potential exploitation of the research outcomes, national/international research landscape and future research directions etc.
Year(s) Of Engagement Activity 2013,2014,2015