School Work

An Overview of Carbon Capture Technological Processes from Fossil Fuels Utilization - A Portuguese Strategic Perspective

An Overview of Carbon Capture Technological Processes from Fossil Fuels Utilization - A Portuguese Strategic Perspective Clemente Pedro Nunes 1, Filomena Pinto 2, Carla Pinheiro 1 1 IST, Campus Alameda,
of 40
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Related Documents
An Overview of Carbon Capture Technological Processes from Fossil Fuels Utilization - A Portuguese Strategic Perspective Clemente Pedro Nunes 1, Filomena Pinto 2, Carla Pinheiro 1 1 IST, Campus Alameda, Av. Rovisco Pais, 1, Lisboa, Portugal 2 LNEG, Estrada do Paço do Lumiar, Nº 22, Lisboa, Portugal 10 th 11 th March, 2015 CCS in Process Industries - State-of- the-art and Future Opportunities 1 Table of Contents Objectives Introduction Overview of CCS technologies and R&D Needs CO 2 capture Post-combustion capture Pre-combustion/syngas approach Oxy-combustion option Co-combustion and Co-gasification CO 2 Transportation CO 2 Storage and Novel Utilisations Economic analysis of CCS Main Conclusions - The Future CCS and the Portuguese Industry 2 Objectives GNIP Group is a Portuguese Group that promotes energy efficiency in our country, in order to increase its economic competitiveness. GNIP includes Universities, Major Industries and National Laboratories and as such is responsible for the Portuguese participation in IETS. It must be stressed that Portugal has one of the highest shares in the EU in what concerns the use of renewable sources in the overall energy mix, which currently is already around 25%. For GNIP it is essential to evaluate the current status of Carbon Capture and Storage (CCS) technologies in order to better understand the economic consequences of the present and future policies to the Portuguese industry within the framework to be derived at a National and European levels. 3 Introduction Portugal has to work within the EU framework, but its economy has to compete with countries that do not obey to the Kyoto Protocol. As such we have to analyse very carefully the economics of the technologies that reduce the carbon intensivity, in which CCS is included. But we should not forget other perspectives including Carbon Capture and Utilisation (CCU), and also the fact that Europe and Portugal have consistently reduced its share of the worldwide GHG emissions. 4 Introduction - CO 2 Emissions Statistics Fuel shares in global CO 2 emissions: Change in CO 2 emissions by region ( ): Trend in CO 2 emissions from fossil fuel combustion: Source: IEA, CO 2 EMISSIONS FROM FUEL COMBUSTION Highlights, Overview of CCS Technologies CO 2 capture Pre-combustion Capture or Gasification Oxy-combustion Post-combustion Capture Co-combustion and Co-gasification CO 2 Transport CO 2 Storage CCS CCU CO 2 Novel Utilisations Microalgae (artificial photosynthesis) Conversion to Fuels (CH 3 OH, CH 4, etc.) Conversion to polymers Pharmaceuticals, building materials, etc. 6 Overview of CCS Technologies CO 2 Capture Pre-combustion Capture (Gasification) Pre-Combustion Air Air Separation Unit Gas Coal O 2 Reforming Gasification Syngas Cleaning Gas Conditioning CO 2 Capture CO 2 Production of Heat or Power N 2 Oxy-combustion Post-combustion Capture Oxy-Combustion Fuel (Coal or Gas) Combustion Air O CO Air Separation 2 CO 2 (Production of 2 Unit Purification Heat or Power) CO CO 2 N 2 2 Compression and Storrage Post-Combustion Air N Fuel 2, O 2 Combustion CO (Coal or Gas) 2 (Production of CO 2 Capture Heat or Power) Co-combustion and Co-gasification 7 Overview of CCS Technologies CO 2 Capture - Post-combustion Capture Post-Combustion Air Fuel (Coal or Gas) Combustion (Production of Heat or Power) N 2, O 2 CO 2 Capture CO 2 Absorption: Chemical (Amines) Physical (Ionic Liquids) Adsorption Chemical looping: metal oxides as CaO Cryogenic separation Membranes Biofixation by microalgae 8 Overview of CCS Technologies CO 2 Capture - Post-combustion Capture Chemical Absorption Amines Diethanolamine (DEA), Monoethanolamine (MEA) Methyldiethanolamine (MDEA) Physical Absorption Solvents Dimethylether of polyethylene glycol (Selexol process), cold methanol (Rectisol process), propylene carbonate (Fluor solvent process) and sulfolane. Hybrid solvents Purison, Sulfinol (mixture of sulfolane and alkanolamines), MDEA (activated Methyldiethanolamine) and UCARSOL Absorption Benefit Technology available to be used in new or in existing power plants Absorption Drawbacks High degradation rates, mostly due to the presence of contaminants like SO x and NO x Corrosion in the presence of O 2 Need for large scrubbers and great energy requirements for regeneration. Overview of CCS Technologies CO 2 Capture - Post-combustion Capture Adsorption CO 2 is captured by high surface area materials: activated carbons and zeolites. Different technologies: Pressure swing adsorption (PSA), Temperature swing adsorption (TSA) Electrical swing adsorption (ESA) PSA and TSA processes are available at commercial scale Adsorption Drawbacks The energy needed for regeneration in TSA is high The energy needed to achieve high pressure in PSA is high Their capacity and CO 2 selectivity is low Further R&D is needed to develop new adsorbents with higher adsorption capacities and better selectivity 10 Overview of CCS Technologies Calcium Looping Cycle Carbonation CaO(s) + CO 2 (g) Calcination CaCO 3 (s) 11 Overview of CCS Technologies CO 2 Capture - Post-combustion Capture Calcium Looping Cycle Initial high uptake of CO 2 Low energy penalty and operating costs Use of cheap and nontoxic sorbents Purge of CaO: synergies with cement industry Pre-treatment of flue gas is not needed High adsorption capacity for CO 2 at high temperature Production of a pure CO 2 stream for sequestration. Calcium Looping Cycle Drawbacks Sintering of CaO sorbent may occur during high-temperature calcination, causing the sorbent deactivation due to grain growth and pore shrinkage. Decrease of CO 2 capture capacity and stability of the sorbent with increasing number of carbonation/calcination cycles. 12 Overview of CCS Technologies CO 2 Capture - Post-combustion Capture Cryogenic Separation Flue gas is cooled below CO 2 boiling point, to condense CO 2 and separate it from other gases Particulates and other gaseous components may be also removed from flue gas Separation into pure components depends on flue gas composition, as it affects boiling points Liquid CO 2 may be easily transported without compression requirements Cryogenic Separation Drawbacks This process is highly energy dependent and should only be applied to flue gases with high CO 2 concentrations R&D needs are related with the development of more efficient refrigeration processes to allow cryogenic separation to be less energy intensive and more cost competitive 13 Overview of CCS Technologies CO 2 Capture - Post-combustion Capture Membrane Separation Either gas separation membranes or gas absorption membranes may be used In gas absorption membranes, CO 2 diffuses through the membrane and is removed from the gas stream In gas separation membranes, the separation depends on the solubility or diffusivity of the gas molecules in the membrane and on differences in partial pressure from one side of the membrane to the other Membrane Separation Drawbacks A high degree of separation can only be achieved with multiple membrane stages and/or by recycling some streams Several membranes with different characteristics are needed to obtain CO 2 with high purity, due to flue gas several components 14 Overview of CCS Technologies CO 2 Capture - Oxy-combustion Oxy-Combustion Fuel (Coal or Gas) Air Air Separation Unit O 2 Combustion (Production of Heat or Power) CO 2 Purification CO 2 N 2 CO 2 O 2 is used instead of air to avoid N 2 dilution of flue gases Flue gases (mainly CO 2 ) are recirculated to help temperature control during combustion As O 2 is used near stoichiometric conditions (95 a 99%), flue gases main compounds are CO 2 ( 90 a 95% dry basis), steam and minor amounts of SO x e NO x After steam condensation and NO x, SO x and O 2 removal, a CO 2 stream is obtained for storage 15 Overview of CCS Technologies CO 2 Capture - Oxy-combustion Benefits: Production of flue gas without N 2 Avoids the costly post-combustion CO 2 capture processes Drawbacks: Requires an expensive air separation unit (ASU) for oxygen purification Lower efficiency due to the cost of ASU Requires a large portion (roughly 70%) of flue gas stream to be recycled back to the boiler to maintain normal operating temperatures Requires careful sealing to prevent any leakage of air into the flue gas 16 Overview of CCS Technologies CO 2 Capture - Pre-combustion Capture (Gasification) Pre-Combustion Gas Reforming Syngas Cleaning Air Air Separation Unit O 2 CO 2 Capture CO 2 Coal Gasification Gas Conditioning Carbon is removed from the fuel before combustion Gasification to produce syngas, whose main components are: CO, CO 2, H 2 and CH 4 Syngas cleaning to remove particulates: tar, NH 3, H 2 S and HCl Water gas-shift reaction: CO + H 2 O CO 2 + H 2 (41kJ/mol) CO 2 /H 2 separation. A CO 2 stream ready for storage H 2 rich fuel for energy production is obtained 17 Overview of CCS Technologies CO 2 Capture - Pre-combustion Capture (Gasification) Hot Syngas Cleaning Syngas Upgrading Partículates Removal S, Cl, etc. Compounds Abatement Tar and N Compounds Abatement C-based Compounds Abatement Coal Gasification Steam Steam Char H 2 Separation Water gas Shift Reaction Ar / O 2 Syngas (rich in H 2 ) CO 2 Steam 18 Overview of CCS Technologies Implementation of CCS Technologies in Power Plants Ease implementation (also in other industries) High degree of CO 2 purity (99%) Needs completely new installations Low efficiency due to the cost of the air separation unit (ASU)/oxygen purification 19 Overview of CCS Technologies Co-gasification and Co-combustion Different fuels and biomass wastes are mixed before combustion or gasification CO 2 reduction emissions are achieved by: Substituting fossil fuels by biomass/wastes Interaction between different fuels and compositions (coal, biomass and wastes) However, the use of wastes with undesirable elements, such as: halogens, sulphur and heavy metals may lead to the formation of pollutants precursors and thus may oblige to more expensive gas cleaning processes 20 Overview of CCS Technologies CO 2 Transport and Storage CO 2 Transport Before transport CO 2 is compressed to near supercritical conditions Water and other contaminants need to be removed. Transport by pipeline or by ships (large distances) CO 2 Storage Depleted oil and gas reservoirs Use of CO 2 in enhanced oil recovery Deep unused saline water-saturated reservoir rocks Deep unmineable coal seams Use of CO 2 in enhanced coal bed methane recovery Other options (basalts, oil shales, cavities) 21 Economic analysis of CCS To date, most large-scale CCS projects are in OECD countries! This is where key project enablers such as public support programs, marketable opportunities for CO 2, storage assessments and regulatory frameworks are most advanced. Progress must be accelerated in non-oecd countries! 22 Economic analysis of CCS Overall Cost of CCS includes: Cost of capture Cost of compression Cost of transport Cost of storage The cost of capture means the cost of the technological processes by which CO 2 is separated from the other gas components present in the flue gas from the burning of fossil fuels. There have been a limited number of studies of CO 2 capture costs for industrial processes other than power plants and cement plants... 23 Economic analysis of CCS Cost of CO 2 capture is the largest component of the CCS value chain More relevant than the capture cost is the CO 2 avoidance cost: the cost after installation of the capture equipment including the energy penalty with the initial costs. The CO 2 capture step (which includes CO 2 compression) accounts for 80% to 90% of this cost increase. Given the limited experience with capture from power plants at a large scale, there will probably be a period of learning, during which costs will likely decline. 24 Economic analysis of CCS Levelized cost of electricity (LCOE) for new-build power plants with or without CCS Power Plant Type (new-build) Average LCOE without CCS ($/MWh) Average LCOE with CCS ($/MWh) IGCC PCoal NGCC Power plants: IGCC - Integrated Gas Combined Cycle PCoal - Pulverized Coal NGCC - Natural Gas Combined Cycle 25 Economic analysis of CCS Current power plant efficiencies and Capture System Energy Penalty Post-combustion capture on PCoal plants is the most energy-intensive! Power plant type, and capture system type Net plant efficiency (%) without CCS Net plant efficiency (%) with CCS Energy penalty: Added fuel input (%) per net kwh output Existing subcritical PCoal, post-combustion capture New supercritical PCoal, post-combustion capture New supercritical PCoal, oxy-combustion capture New IGCC, pre-combustion capture New natural gas combined cycle, post-combustion capture Source: Carbon Capture: A Technology Assessment, Peter Folger, Notes: All efficiency values are based on the higher heating value (HHV) of fuel. For each plant type, 26 there is a range of efficiencies around the representative values shown here. Economic analysis of CCS List of penalties for existing coal combustion plants: Lower plant efficiency More fuel needed to generate electricity relative to a similar plant without CO 2 capture More solid waste produced More chemicals, such as ammonia and limestone, needed (per unit of electrical output) to control NO x and SO 2 emissions Additional cooling water needed (for current amine capture systems) 27 Economic analysis of CCS Energy penalty for CO 2 capture at supercritical PCoal and IGCC power plants Energy Type and Function Thermal energy for amine solvent regeneration (post-combustion) or loss in water-gas shift reaction (pre-combustion); or, electricity for purified oxygen production (oxy-combustion) Electricity for CO 2 compression Electricity for pumps, fans, etc. Approximate % of Total Energy Penalty ~60 ~30 ~10 Source: E. Rubin et al, Prospects for Improved Carbon Capture Technology, Report, Thermal energy requirements (or losses) for solvent regeneration (in PCoal plants) or for the water-gas shift reaction unit (in IGCC plants) are clearly the largest source of net power losses and the priority area for research to reduce those losses. For oxy-combustion systems, the electrical energy required for the production of purified oxygen is the biggest contributor to the energy penalty. 28 Economic analysis of CCS Estimated cost of CO 2 capture and transportation for various industrial CO 2 Sources Industrial CO 2 Source Cost of CO 2 Capture and Transport ($/Metric ton CO 2 ) Coal and biomass-toliquids Natural gas processing Hydrogen plants to Refineries (Hydrogen) to Ammonia plants Ethanol plants Cement plants Source: U.S. Energy Information Administration Annual Energy Outlook (AEO), Economic analysis of CCS CO 2 capture in the cement industry Up to 2013, no large-scale CO 2 capture projects have been implemented from cement plants. Up to now, a limited number of studies have explicitly estimated the cost of CO 2 avoidance for cement plants. At the moment, the studies we have reviewed suggest that Oxyfuel is estimated to have a lower cost than post-combustion capture, however this does not take into account the costs of oxygen purification. Such views need to be tempered by the technical and economic improvements associated with postcombustion emerging technologies: Calcium looping post-combustion capture technology is an emerging technology for the cement industry. 30 Economic analysis of CCS Main CO 2 capture performance indicators (modelling study) of a reference cement plant with and without CO 2 capture Technology Base case: No Capture Post-combustion Amine scrubbing Postcombustion Ca Looping Oxy-combustion Capture efficiency (%) CO 2 capture energy penalty (kj/kg CO2) * CO 2 in flue Gas (%) * This value does not include the energy consumption costs for oxygen purification. Source: K. Vatopoulos, E. Tzimas, Journal of Cleaner Production, 32 (2012) Advantage of the Calcium Looping (Ca Looping) process over Amine scrubbing, in terms of energy penalty for CO 2 capture. Less capture efficiency for Oxy-combustion technology, less energy penalty (if not taking into account the energy consumption costs for oxygen purification) and higher concentration of CO 2 in the flue gases. 31 Economic analysis of CCS Cement plant performance assumptions and normalised costs of CO 2 avoidance (US$/tCO 2 ) Study Plant Location IEA GHG (2008) Mott MacDonald North East Scotland, UK IEA GHG (2008) Mott MacDonald North East Scotland, UK Australian Industrial CO 2 capture Ho et al. (2011) Australia Guangdong Cement Plant CCS study Liang and Li (2012) Guangdong, China Capture Technology PC-MEA Oxyfuel PC-MEA PC-MEA (retrofit) CO 2 Avoided (kt/y) CO 2 Captured (kt/y) Cost of CO 2 emissions avoided (US$/tCO 2 ) adjusted* Insufficient information * Adjusted to common location (Europe), fuel cost ( 2.5/GJ for coal) and discount rate (10%). Source: Li et al., Energy Policy, 61 (2013) PC-MEA Post-combustion Mono Ethanol Amine For cement plants, Oxyfuel is estimated to have a lower CO 2 avoided cost compared to post-combustion capture, but it has a lower capture efficiency 32 and requires high energy consumption costs in oxygen purification!! 83.8 The Future 33 Main Conclusions - The Future Main actions for the period from now to 2020 include: Introduction of financial support mechanisms for research, development and demonstration, and facilitation of multi-lateral financing, Complete the legal and regulatory frameworks at the international, national and provincial levels, Increase efforts towards public and stakeholders awareness, Support the introduction of CCS in non-oecd countries through technology exchange and financial support, CO 2 -EOR implementation outside of North America, Generalise the capture-ready concept for new plants, Continue the knowledge capture from existing projects, Increase the investments in technologies to decrease the capture cost. (International Energy Agency (IEA), Technology Roadmap: CO2 Capture and Storage, OECD/IEA, Paris, 2013) Main Conclusions - The Future In the subsequent decade (from 2020 to 2030) key actions are the following: Manage the transition from demonstration to large-scale deployment, Support the development of the required infrastructure, e.g. main CO 2 transport pipelines, Standardise practices for storage, including monitoring and verification, Continue the development and deployment of capture technologies and minimise the electricity output penalty, Expand CCS use in the industry (steel, cement, refineries, pulp and paper), Increased participation of non-oecd countries in the large-scale deployment of CCS. (International Energy Agency (IEA), Technology Roadmap: CO2 Capture and Storage, OECD/IEA, Paris, 2013) 35 CCS and the Portuguese Industry As it was shown in slide 29 the cost of capture and transportation of CO 2 is estimated between 36 and 81 US$/Metric ton CO 2, and this does not yet include the storage costs that can also be considerable. Of course, in the case of Portugal we can give as an alternative, a great contribution to CCU, by optimizing the use of our forests that cover more than 36% of our territory, to absorb in a sustainable way CO 2 from the atmosphere. As such, we consider that any political attempt to increase the value of the carbon taxes in order to force an uneconomical introduction of CCS technologies in industry, shall have to be made on a worldwide scale. 36 CCS and the Portuguese Industry For the portuguese industry, taking into account the tremendous economic and financial challenges that our country has been recently facing, we think that it is unconceivable to have to accommodate any extra charge that will hinder even more its competitiveness towards other countries, that would not have to apply any carbon tax. So: Either there is a technological breakthrough that makes CCS economical or There will have to be a worldwide level playing field in terms of carbon tax. But we certainly look forward to receiving new technological insights during this fascinating Internationa
Similar documents
View more...
Related Search
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks