Process Intensification for Post-combustion Carbon Capture using Rotating Packed Bed through Systems Engineering Techniques

Lead Research Organisation: University of Sheffield
Department Name: Chemical & Biological Engineering

Abstract

The emission of carbon dioxide into the atmosphere has caused huge concerns around the world, in particular because it is widely believed that the increase in its concentration in the atmosphere is a key driver of climate change. If the current trend in the release of carbon dioxide continues, global temperatures are predicted to increase by more than 4 degrees centigrade, which would be disastrous for the world.

With the increase in world population, the energy demand is also increasing. Coal-fired and gas-fired power plants still play a central role in meeting this energy demand for the foreseeable future, even though the share of renewable energy is increasing. These power plants are the largest stationary sources of carbon dioxide. Carbon capture is a technique to capture the carbon dioxide that is emitted in the flue gas from these power plants. This proposal seeks to make a significant improvement in the methods used for carbon capture in order to reduce the total costs.

Post-combustion CO2 capture by chemical absorption using solvents (for example, monoethanolamine - MEA) is one of the most mature technologies. The conventional technology uses large packed columns. The cost to build and run the capture plants for power plants is currently very high because: (1) the packed columns are very large in size; (2) the amount of steam consumed to regenerate solvents for recirculation is significant. If we can manage to reduce the size of packed columns and the steam consumption, then the cost of carbon capture will be reduced correspondingly.

From our previous studies, we found that mass transfer in the conventional packed columns used for carbon capture is very poor. This proposed research is expected to make very significant improvements in mass transfer. The key idea is to rotate the packed column so that it spins at hundreds of times per minute - a so-called rotating packed bed (RPB). A better mass transfer will be generated inside the RPB due to higher contact area. With an intensified capture process, a higher concentration of solvent can be used (for example 70 wt% MEA) and the quantity of recirculating solvent between intensified absorber and stripper will be reduced to around 40%. Our initial analysis has been published in an international leading journal and it indicates that the packing volume in an RPB will be less than 10% of an equivalent conventional packed column.

This proposal will investigate how to design and operate the RPB in order to separate carbon dioxide most efficiently from flue gas. The work will include design of new experimental rigs, experimental study, process modelling and simulation, system integration, scale-up of intensified absorber and stripper, process optimisation, comparison between intensified capture process and conventional capture process from technical, economical and environmental points of view.

The research will include an investigation into the optimum flow directions for the solvent and flue gas stream (parallel flow or counter-current) for intensified absorber and the optimum design of packing inside the RPB.

The proposal will also compare the whole system performance using process intensification vs using conventional packed column for a CCGT power plant. Based on this, an economic analysis will be carried out to quantify the savings provided by this new process intensification technology.

Planned Impact

The proposed research project will benefit a broad range of stakeholders:

(1) The Energy sector worldwide and in the UK: Inter-governmental Panel on Climate Change (IPCC) recommended in its 2007 report that global CO2 emissions be cut by 50% by 2050 compared with 1990 levels. Power generation is the single largest contributor of CO2 emissions. There are almost 5,000 power plants worldwide with total emission of 10.5 gigatonnes CO2 per year. In 2008, the UK Government agreed to the binding target of an 80% reduction in CO2 emissions by 2050 from the 1990 baseline. Electricity generation from coal- or gas-fired power plants was 77% in 2009 in the UK. To meet the target in CO2 emissions, it is inevitable to implement carbon capture for the coal- or gas-fired power plants. The UK energy sector will benefit from less capital cost and reduced thermal efficiency penalty when capturing CO2 - the two challenges that this proposed project is to deal with.

(2) Global and the UK CCS research community: In the limited literature, most work deals only with some aspects of intensified absorbers, while intensified strippers are rarely studied (except for one study from Taiwan). New design of intensified absorber proposed in this research is unique. Development of new models from this project (i.e. process models for the intensified capture process and CFD codes) will be published and even commercially exploited. Process analysis of the intensified capture process based on the models newly developed will derive new insights on how and why mass transfer and reaction rate in the new capture process have been improved significantly. Fundamental understanding of the flow regime and flow pattern inside intensified absorber will be obtained. Through publishing in international leading journals, global CCS community will benefit.

(3) UK Policymakers and Regulators: New results (i.e. experimental data, the results on size reduction of intensified absorber and stripper, the results on savings in capital cost and operating cost with the proposed capture process applied to CCGT power plant) potentially obtained from this proposed project will provide reliable evidence base. These are very important for UK policymakers and regulators for strategic decision making.

(4) Power Utilities: Power utilities companies run different power plants. They have to make long term business decisions such as when to implement carbon capture and which technology to choose. They will directly benefit from the proposed project since they can see another choice along the route of post-combustion carbon capture with solvents. E.ON (a typical utility company) owns power plants and sits in the project advisory board of the proposed project.

(5) Original Equipment Manufacturers (OEM) and other technical providers: The OEM companies and other technical providers face different choices in carbon capture. The proposed project will inspire their product development in CCS. ALSTOM (a typical OEM) and software provider PSE Ltd and process technology provider COSTAIN are also in the project advisory board.

(6) Professional training and higher education: The research deliverables and milestones will be fed directly into the teaching programmes in the four universities generally at MSc and MEng levels. The modules relevant with this project are Energy Technologies, and Process Simulation and Design. Companies involved in this project will benefit from staff with improved knowledge and skills and even organisation of short courses for CPD.

(7) The wide public: The wider public will better appreciate the value and role of science and engineering dealing with the challenge of climate change. Technical results will be disseminated with a web site. At Hull City Guild Hall, there will be a Science week each year. University of Hull is a major participator. This proposed project will be disseminated through this event to the wide public.

Related Projects

Project Reference Relationship Related To Start End Award Value
EP/M001458/1 01/10/2014 30/09/2016 £1,274,437
EP/M001458/2 Transfer EP/M001458/1 01/10/2016 30/06/2019 £727,910
 
Description (A) There is a potential for excessive rise in the liquid phase temperature in RPBs due to the higher solvent concentration and smaller volume of the packing. Expected temperature rise is investigated in this study for different MEA concentrations (40, 50, 60 & 70 wt%) using a hypothetical scenario. Our findings show that RPBs with up to 70 wt% MEA solution as solvent commonly presented in literature should inevitably be operated with intercooling as temperature rise could reach 80oC in some cases.

(B) Under the same process conditions, RPB based intensified stripper/regenerator has volume reduction of 9.691 times compared to conventional PB based stripper/regenerator.

(C) Dynamic model was developed for RPB Absorber using MEA solvent based on Surface Renewal Theory. The model can predict distributed mass transfer coefficients, which enables the model to depict the real physics inside RPBs and can more accurately predict system performance of RPBs. Process analysis was performed through steady state and dynamic simulations. This new distributed dynamic model and the insights obtained through process simulation will promote RPB technology towards its industrial deployment in large scale carbon capture processes.
Exploitation Route Finding (A) was oral presented in International Conference of Applied Energy (ICAE2018) held in Cardiff, UK in Aug. 2018.

Finding (B) was published in Applied Energy in 2017 and this has attracted some citations.

Finding (C) has been submitted to international leading academic journal AIChE J. Now it is under review.
Sectors Chemicals,Education,Energy,Environment,Government, Democracy and Justice

 
Description From this project, (1) Experimental data on testing RPB Absorber with MEA from project team member Newcastle University has confirmed the effectiveness of the proposed technology. This gave the confidence to Carbon Clean Solutions (CCS) Ltd to use the technology for testing their own patented solvents. (2) The newly developed RPB stripper will be used for pilot scale tests - in the newly funded project from BEIS, UK in 2018 & 2019. (3) Research funded by this project has led to more active research funding from USA (USA DoE NETL) & China & India.
First Year Of Impact 2015
Sector Chemicals,Education,Energy,Environment
Impact Types Economic,Policy & public services

 
Description Advancing RPB Technology for Reduced CO2 Emissions (ARTEMIS)
Amount £891,363 (GBP)
Funding ID N/A 
Organisation Department for Business, Energy & Industrial Strategy 
Sector Public
Country United Kingdom
Start 01/2018 
End 03/2020
 
Title Dynamic Model for RPB-based Carbon Capture Process using MEA & Model Validation - XiaoBo Luo 
Description Worldwide there is no report of developing dynamic model for RPB-based Carbon Capture Process. Traditionally researchers worldwide developed steady state models for RPB Absorbers and Strippers based on two-Film Theory. In our group, a dynamic model was developed based on the surface renewal theory for RPB-based carbon capture process using MEA. The dynamic model was also validated at steady state & dynamically. 
Type Of Material Computer model/algorithm 
Year Produced 2018 
Provided To Others? No  
Impact The dynamic model development & model validation is a necessary step for studying flexible operation of RPB-based carbon capture. The manuscript is under review. Once published, it will lead the world in RPB-based carbon capture process development. 
 
Description Carbon Clean Solutions (CCS) Ltd - New solvents for Intensified Carbon Capture 
Organisation Carbon Clean Solutions (CCS) Ltd
Country India 
Sector Private 
PI Contribution Carbon Clean Solution Ltd have developed a range of solvents to remove carbon dioxide from flue gases from fossil fuel fired power stations and industrial processes. These new solvents require less energy and have improved environmental performance than the industry benchmark. Post-combustion capture using solvents takes place in large absorber vessels. For a commercial size power station, these Absorbers can be 30 meters in height. The absorbers need to be large because the mass transfer of carbon dioxide from the gas into the solvent is low. Process Intensification technology allows the size of the absorber to be reduced by improving the mass transfer from gas to liquid. It is estimated that the size of the absorber could be reduced by 90%. In addition process intensification will allow the water content of the solvent to be reduced. This will save operating costs. This project aims to compare different solvents (MEA vs the new solvent from Carbon Capture Solutions Ltd) inside an intensified absorber. Experimental study, modelling and process analysis will be used to compare performance. This is to quantify the potential in reduction of capital cost and operating cost for capturing CO2. The project is led by CCS Ltd and in collaboration with Newcastle University and University of Hull. Hull University - process modelling, simulation and analysis of intensified carbon capture process with the solvents developed by CCS Ltd. From Jan. 2018, new project funded by BEIS (UK Government Department) has started. This is large scale test of the RPB technology for solvent-based Carbon Capture.
Collaborator Contribution CCS Ltd to provide knowledge on their own solvents & sample solvent for experimental study. Newcastle University carries out experimental study using RPB Absorber. .
Impact Yes, it is multi-disciplinary ...
Start Year 2015
 
Description Collaboration with Prof J. Chen at department of Chemical Engineering, Tsinghua University, China 
Organisation Tsinghua University China
Country China 
Sector Academic/University 
PI Contribution Prof Chen has many lab equipment for measuring VLE of MEA with water and CO2, and also reaction kinetics. Started from 2015, we found that there is not enough information on different physical properties for high concentration MEA (e.g. from 45 wt% to 85 wt%) such as density, viscosity, VLE and research kinetics. We have started different tests. Now we are processing different measurement results. A journal publication is under preparation.
Collaborator Contribution University of Sheffield can raise requirements from a system point of view. Tsinghua University has enough lab equipment & technical expertise to do this job.
Impact Now we are processing different measurement results. A journal publication is under preparation.
Start Year 2015
 
Description Collarboration with Dr Dag Eimer at Tel-Tek in Norway 
Organisation Tel Tek Norway
Country Norway 
Sector Private 
PI Contribution Introduced by Prof Colin Ramshaw, we started with tele-conf to exchange ideas and latest development on intensified solvent-based carbon capture. Dr Dag Eimer also visited the project team members. In 2015, we co-authored the review paper and published in Applied Energy.
Collaborator Contribution Current status of applying Process Intensification technology to solvent-based Carbon Capture. Future perspective of Process Intensification technology in solvent-based Carbon Capture. Information on Norway Research Council funded project on Carbon Capture.
Impact In 2015, we co-authored the review paper and published in Applied Energy.
Start Year 2015
 
Description A talk or presentation - Research Seminar at Changzhou University, China - Prof Wang 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact I was invited by the President of ChangZhou University - Prof Q. Chen to have an academic visit to ChangZhou University. I was invited to give a Research Seminar on what Process/Energy Systems Engineering can do for Power Plants, Carbon Capture and Utilisation, Bio-Energy & Energy Storage. Lots of questions raised by the audiences (academics & MSc Research students).
Year(s) Of Engagement Activity 2017
URL http://uni.cczu.edu.cn/2017/1215/c8420a173493/page.htm
 
Description Keynote talk given by Prof Meihong Wang at 2nd International Conference on Functional Materials and Chemical Engineering (ICFMCE) in Nov. 2018, Abu Dhabi, UAE 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact In Nov. 2018, Prof Wang was invited to give a keynote talk on "Process/Energy Systems Engineering: CCUS and Beyond...".
This is part of the 2nd International Conference on Function Materials and Chemical Engineering (ICFMCE) held in Abu Dhabi, UAE.
Around 70 to 80 audiences from over 15 countries joined the session.
Year(s) Of Engagement Activity 2018
 
Description Research Seminar given by Prof Meihong Wang at SouthEast University in April 2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Postgraduate students
Results and Impact In April 2018, Prof Wang was invited to give a research Seminar on "Process & Energy Systems Engineering: Carbon Capture, Utilisation and Storage (CCUS) and Beyond ...".
There were around 150 audiences (mainly MSc and PhD students, also including academics and industrial practitioners) from the city of Nanjing area.

Lots of interesting questions from these early career researchers.
Year(s) Of Engagement Activity 2018