scholarly journals Investigation of Applicability of Polyimide Membranes for Air Separation in Oxy-MILD Zero-Emission Power Plants

2019 ◽  
Vol 137 ◽  
pp. 01033
Author(s):  
Leszek Remiorz ◽  
Grzegorz Wiciak ◽  
Krzysztof Grzywnowicz
Keyword(s):  
Power Plants ◽  
Ambient Air ◽  
Continuous Functions ◽  
Air Separation ◽  
Low Oxygen ◽  
Recovery Coefficient ◽  
Separation Unit ◽  
Operational Conditions ◽  
Serial Connection ◽  
Zero Emission

Primary element of an oxy-combustion plants is ambient air separation unit. This paper presents the results of experimental research concerning the parameters of the separation of N2/O2 from ambient air, using capillary polymer membranes, potentially applicable in oxy-combustion technology, under variable operational conditions. Collected data were utilized to approximate continuous functions describing the variability of essential parameters of the air separation based on such membranes. The functions were introduced to develop a complete mathematical model of the separation unit, intended to be applied in oxy-Moderate or Intense Low Oxygen Dilution (oxy-MILD) zero-emission plants. Computational analyses were performed for three variants of the unit’s configuration: serial connection of membrane modules, unit with retentate recirculation and unit with permeate recirculation. The results of the research, in the form of sets of characteristic curves, depicting parameters of the separation process as a function of the variable operational conditions, show that crucial differences to the subsequent separation parameters (permeate purity, real selectivity coefficient, recovery coefficient) and with regard to the power consumed, were obtained. The highest parameters of the module were gained for serial connection, whereas the lowest – for permeate recirculation. The lowest energy consumption was acquired for the retentate recirculation variant.

An Innovative Inlet Air Cooling System for IGCC Power Augmentation: Part II—Thermodynamic Analysis

2012 ◽  
Author(s):  
Mirko Morini ◽  
Michele Pinelli ◽  
Pier Ruggero Spina
Keyword(s):  
Gas Turbine ◽  
Air Temperature ◽  
Power Plants ◽  
Cooling System ◽  
Ambient Air ◽  
Combined Cycle ◽  
Air Separation ◽  
Air Cooling ◽  
Separation Unit ◽  
Gasification Process

Integrated Gasification Combined Cycles (IGCCs) are energy systems mainly composed of a gasifier and a combined cycle power plant. Since the gasification process usually requires oxygen as the oxidant, the plant also has an Air Separation Unit (ASU). Moreover, a producer gas cleaner unit is always present between the gasifier and the gas turbine. Since these plants are based on gas-steam combined cycle power plants they suffer from a reduction in performance when ambient temperature increases. In this paper, an innovative system for power augmentation in IGCC plants is presented. The system is based on gas turbine inlet air cooling by means of liquid nitrogen spray. In fact, nitrogen is a product of the ASU, but is not always exploited. In the proposed plant, the nitrogen is first chilled and liquefied and then it can be used for inlet air cooling or stored for a postponed use. This system is not characterized by the limits of water evaporative cooling (where the lower temperature is limited by air saturation) and refrigeration cooling (where the effectiveness is limited by pressure drop in the heat exchanger). A thermodynamic model of the system is built by using a commercial code for the simulation of energy conversion systems. A sensitivity analysis on the main parameters (e.g. ambient air temperature, inlet air temperature difference, etc.) is presented. Finally the model is used to study the capabilities of the system by imposing the real temperature profiles of different sites for a whole year.

Comparison Between Oxygen-Blown and Air-Blown IGCC Power Plants: A Gas Turbine Perspective

2011 ◽  
Author(s):  
Prashant S. Parulekar
Keyword(s):  
Power Plants ◽  
Ambient Air ◽  
End Users ◽  
Combined Cycle ◽  
Air Separation ◽  
Integrated Gasification Combined Cycle ◽  
Gaseous Oxygen ◽  
Separation Unit ◽  
Advantages And Disadvantages ◽  
Integrated Gasification

The gasifier in an Integrated Gasification Combined Cycle (IGCC) Power Plant gasifies coal using an oxidant gas that facilitates partial combustion and effective gasification of the coal feed. When electricity generation is the prime objective of the IGCC facility this oxidant can be ambient air, or gaseous oxygen produced from an Air Separation Unit (ASU). Gasification technology providers are presently divided in their type of offering and information in the public domain does not effectively guide End Users in the advantages and disadvantages of the two gasification methods as applicable to the particular project being developed. This paper highlights key design aspects that should guide End Users in making an effective assessment and perform detailed evaluation of the gasification technologies for the particular IGCC project in consideration.

Techno-Economic Evaluation of Pressurized Oxy-Fuel Combustion Systems

2010 ◽  
Author(s):  
Jongsup Hong ◽  
Ahmed F. Ghoniem ◽  
Randall Field ◽  
Marco Gazzino
Keyword(s):  
Carbon Dioxide ◽  
Carbon Dioxide Emissions ◽  
Power Plants ◽  
Carbon Dioxide Capture ◽  
Fuel Combustion ◽  
Economic Feasibility ◽  
Operating Conditions ◽  
Air Separation ◽  
Separation Unit ◽  
Coal Price

Oxy-fuel combustion coal-fired power plants can achieve significant reduction in carbon dioxide emissions, but at the cost of lowering their efficiency. Research and development are conducted to reduce the efficiency penalty and to improve their reliability. High-pressure oxy-fuel combustion has been shown to improve the overall performance by recuperating more of the fuel enthalpy into the power cycle. In our previous papers, we demonstrated how pressurized oxy-fuel combustion indeed achieves higher net efficiency than that of conventional atmospheric oxy-fuel power cycles. The system utilizes a cryogenic air separation unit, a carbon dioxide purification/compression unit, and flue gas recirculation system, adding to its cost. In this study, we perform a techno-economic feasibility study of pressurized oxy-fuel combustion power systems. A number of reports and papers have been used to develop reliable models which can predict the costs of power plant components, its operation, and carbon dioxide capture specific systems, etc. We evaluate different metrics including capital investments, cost of electricity, and CO2 avoidance costs. Based on our cost analysis, we show that the pressurized oxy-fuel power system is an effective solution in comparison to other carbon dioxide capture technologies. The higher heat recovery displaces some of the regeneration components of the feedwater system. Moreover, pressurized operating conditions lead to reduction in the size of several other critical components. Sensitivity analysis with respect to important parameters such as coal price and plant capacity is performed. The analysis suggests a guideline to operate pressurized oxy-fuel combustion power plants in a more cost-effective way.

scholarly journals Cutting Oxygen Production-Related Greenhouse Gas Emissions by Improved Compression Heat Management in a Cryogenic Air Separation Unit

2021 ◽  
Vol 18 (19) ◽  
pp. 10370
Author(s):  
Miroslav Variny ◽  
Dominika Jediná ◽  
Miroslav Rimár ◽  
Ján Kizek ◽  
Marianna Kšiňanová
Keyword(s):  
Power Consumption ◽  
Greenhouse Gas Emissions ◽  
Greenhouse Gas ◽  
Ambient Air ◽  
Air Separation ◽  
Oxygen Production ◽  
Gas Emissions ◽  
Separation Unit ◽  
Air Separation Unit ◽  
Air Dryer

Oxygen production in cryogenic air separation units is related to a significant carbon footprint and its supply in the medicinal sphere became critical during the recent COVID-19 crisis. An improved unit design was proposed, utilizing a part of waste heat produced during air pre-cooling and intercooling via absorption coolers, to reduce power consumption. Variable ambient air humidity impact on compressed air dryers’ regeneration was also considered. A steady-state process simulation of a model 500 t h−1 inlet cryogenic air separation unit was performed in Aspen Plus® V11. Comparison of a model without and with absorption coolers yielded an achievable reduction in power consumption for air compression and air dryer regeneration by 6 to 9% (23 to 33 GWh year−1) and a favorable simple payback period of 4 to 10 years, both depending on air pressure loss in additional heat exchangers to be installed. The resulting specific oxygen production decrease amounted to EUR 2–4.2 t−1. Emissions of major gaseous pollutants from power production were both calculated by an in-house developed thermal power plant model and adopted from literature. A power consumption cut was translated into the following annual greenhouse gas emission reduction: CO2 16 to 30 kilotons, CO 0.3 to 2.3 tons, SOx 4.7 to 187 tons and NOx 11 to 56 tons, depending on applied fossil fuel-based emission factors. Considering a more renewable energy sources-containing energy mix, annual greenhouse gas emissions decreased by 50 to over 80%, varying for individual pollutants.

Analytical Formulation of the Performance of the Allam Power Cycle

2020 ◽  
Author(s):  
Yousef Haseli
Keyword(s):  
Power Plants ◽  
Fossil Fuels ◽  
Air Separation ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Separation Unit ◽  
Power Cycle ◽  
Functional Relationships ◽  
Oxyfuel Combustion ◽  
Co2 Flow

Abstract Thermal power plants operating on fossil fuels emit a considerable amount of polluting gases including carbon dioxide and nitrogen oxides. Several technologies have been developed or under development to avoid the emissions of, mainly, CO2 that are formed as a result of air-fuel combustion. While post-combustion capture methods are viable solutions for reduction of CO2 in the existing power plants, implementation of the concept of oxyfuel combustion in future power cycles appears to be a promising technique for clean power generation from fossil fuels. A novel power cycle that employs oxyfuel combustion method has been developed by NET Power. Known as the Allam cycle, it includes a turbine, an air separation unit (ASU), a combustor, a recuperator, a water separator, CO2 compression with intercooling and CO2 pump. (Over 90% of the supercritical CO2 flow is recycled back to the cycle as the working fluid, and the rest is extracted for further processing and storage. The present paper introduces a simplified thermodynamic analysis of the Allam power cycle. Analytical expressions are derived for the net power output, optimum turbine inlet temperature (TIT), and the molar flowrate of the recycled CO2 flow. The study aims to provide a theoretical framework to help understand the functional relationships between the various operating parameters of the cycle. The optimum TIT predicted by the presented expression is 1473 K which is fairly close to that reported by the cycle developers.

scholarly journals Evaluation of biomass-based production of below zero emission reducing gas for the iron and steel industry

2020 ◽  
Author(s):  
Martin Hammerschmid ◽  
Stefan Müller ◽  
Josef Fuchs ◽  
Hermann Hofbauer
Keyword(s):  
Natural Gas ◽  
Direct Reduction ◽  
Economic Assessment ◽  
Air Separation ◽  
Production Costs ◽  
Test Plant ◽  
Separation Unit ◽  
Iron And Steel ◽  
Reducing Gas ◽  
Zero Emission

Abstract The present paper focuses on the production of a below zero emission reducing gas for use in raw iron production. The biomass-based concept of sorption-enhanced reforming combined with oxyfuel combustion constitutes an additional opportunity for selective separation of CO2. First experimental results from the test plant at TU Wien (100 kW) have been implemented. Based on these results, it could be demonstrated that the biomass-based product gas fulfills all requirements for the use in direct reduction plants and a concept for the commercial-scale use was developed. Additionally, the profitability of the below zero emission reducing gas concept within a techno-economic assessment is investigated. The results of the techno-economic assessment show that the production of biomass-based reducing gas can compete with the conventional natural gas route, if the required oxygen is delivered by an existing air separation unit and the utilization of the separated CO2 is possible. The production costs of the biomass-based reducing gas are in the range of natural gas-based reducing gas and twice as high as the production of fossil coke in a coke oven plant. The CO2 footprint of a direct reduction plant fed with biomass-based reducing gas is more than 80% lower compared with the conventional blast furnace route and could be even more if carbon capture and utilization is applied. Therefore, the biomass-based production of reducing gas could definitely make a reasonable contribution to a reduction of fossil CO2 emissions within the iron and steel sector in Austria.

Introducing ASME PTC 48

2014 ◽  
Author(s):  
Olivier Le Galudec ◽  
James Oszewski ◽  
John Preston ◽  
David Thimsen
Keyword(s):  
Co2 Capture ◽  
Carbon Capture ◽  
Power Plants ◽  
Performance Test ◽  
Heat Rate ◽  
Air Separation ◽  
Plant Performance ◽  
Small Scale ◽  
Separation Unit ◽  
Combined Cycles

In the field of Power Generation, Operators — Plant Owners, Utilities, IPPs … — have had to face severe constraints linked not only with price of electricity and cost of fuel, but also with more and more demanding environmental constraints. It appears that the next atmospheric emission coming under scrutiny is CO2. Some small scale laboratory size experiments and pilot scale tests demonstrating the ability to capture CO2 before it reaches the atmosphere have already been conducted, and some industrial scale demonstrators are already at the permitting stage and will soon reach construction. In order to anticipate the needs of Performance Tests within this coming market, ASME decided to form a new committee in order to prepare and deliver ASME Performance Test Code – PTC 48 “Overall Plant Performance with Carbon Capture” test code. This new code may be seen as an evolution of ASME PTC 46 “Performance Test Code on Overall Plant Performance” 1996 (currently under revision), which goes beyond the sole verification of components to provide guidelines for testing a full Plant. Capturing CO2 from fuel–fired power plants will have a significant impact on net capacity and net heat rate of the plant. Such plants will, in addition to the Power Block and Steam Generator, also include systems not commonly included in non-CO2 capture power plants. The addition of an ASU (Air Separation Unit, for oxy-combustion with CO2 capture) and/or CPU (CO2 Purification Unit, for oxy-combustion or post-combustion CO2 capture) has made necessary the preparation of a dedicated test code based upon same guiding principle than PTC 46, i.e. treating the plant globally as a “Black Box”. This approach allows correction of output and efficiency at the plant interfaces, but at the exclusion of internal parameters. It is anticipated that the code can inform development of regulations that define the rules and obligations of Operators. Currently, the proposed PTC 48 aims at fossil fuel fired Steam-electric power plants using either post-combustion CO2 capture or oxy-combustion with CO2 capture technologies. Combined cycles and Integrated Gasification Combined Cycles — IGCCs — are not addressed.

Challenges Facing Performance Evaluations of IGCC Power Plants

2007 ◽  
Author(s):  
Justin Zachary ◽  
Alex Khochafian
Keyword(s):  
Measurement Uncertainty ◽  
Heat Input ◽  
Power Plants ◽  
Performance Test ◽  
Performance Testing ◽  
Air Separation ◽  
Plant Performance ◽  
Plant Design ◽  
Separation Unit

Based on the present revival of coal as the fossil fuel of choice for power generation, there is a high probability that several IGCC projects will materialize in the near future. One of the challenges facing the Owners, EPC Contractors and OEM’s will be to define the performance commercial guarantees and the practical means to determine them. In addition following the current huge upturn in conventional supercritical coal fired power plants, a large number of facilities will conduct thermal performance tests. The proper conductance of the test, data collection and correction to reference conditions, have many technical implications and could affect drastically the commercial outcome of a project both for the Contractor and the Owner. For IGCC plants, in anticipation of this probability, ASME Performance Test Committee had developed a Performance Test Code for such type of plant — PTC 47, which was published in January 2007. In the first part, the paper will provide details about the specific challenges facing the implementation of the Code, in particular the proposed use of the input/output method (mass and energy balance). The presentation will cover other highlights of the code recommendations. The methodology is fully applicable to conventional power plants, since they use same type of fuel. The determination of the heat input based on actual continuous measurement of the mass flow and composition of the coal will be discussed in details. The practicality and the measurement uncertainty associated with fuel composition will also be analyzed. A comparison with the indirect method for determination of the heat input will also be presented. The article will evaluate how the code requirements are reflected in the definition of the power plant design, configuration and instrumentation. The implications of test tolerance as a commercial issue and measurement uncertainty as a technical issue will also be presented and evaluated Other unique aspects of the entire IGCC plant performance testing will be discussed: (1) stability criteria related to the gasification and integration processes, (2) corrections from test to guarantees conditions due to complex chemical, mechanical processes. Finally, the article will indicate the progress on the development of performance evaluation methodologies for other main IGCC components: gasifier, air separation unit, gas cleaning systems and Power Island.

Optimization of Thermodynamically Efficient Nominal 40 MW Zero Emission Pilot and Demonstration Power Plant in Norway

2005 ◽  
Author(s):  
Carl-W. Hustad ◽  
Inge Trondstad ◽  
Roger E. Anderson ◽  
Keith L. Pronske ◽  
Fermin Viteri
Keyword(s):  
Power Plant ◽  
Gas Turbine ◽  
Phase 1 ◽  
Clean Energy ◽  
Air Separation ◽  
Working Fluid ◽  
Maintenance Cost ◽  
Thermodynamic Efficiency ◽  
Separation Unit ◽  
Zero Emission

In Aug 2004 the Zero Emission Norwegian Gas (ZENG) project team completed Phase-1: Concept and Feasibility Study for a 40 MW Pilot & Demonstration (P&D) Plant, that is proposed will be located at the Energy Park, Risavika, near Stavanger in South Norway during 2008. The power plant cycle is based upon implementation of the natural gas (NG) and oxygen fueled Gas Generator (GG) (1500°F/1500 psi) successfully demonstrated by Clean Energy Systems (CES) Inc. The GG operations was originally tested in Feb 2003 and is currently (Feb 2005) undergoing extensive commissioning at the CES 5MW Kimberlina Test Plant, near Bakersfield, California. The ZENG P&D Plant will be an important next step in an accelerating path towards demonstrating large-scale (+200 MW) commercial implementation of zero-emission power plants before the end of this decade. However, development work also entails having a detailed commercial understanding of the techno-economic potential for such power plant cycles: specifically in an environment where the future penalty for carbon dioxide (CO2) emissions remains uncertain. Work done in dialogue with suppliers during ZENG Project Phase-1 has cost-estimated all major plant components to a level commensurate with engineering pre-screening. The study has also identified several features of the proposed power plant that has enabled improvements in thermodynamic efficiency from 37% up to present level of 44–46% without compromising the criteria of implementation using “near-term” available technology. The work has investigated: i. Integration between the cryogenic air separation unit (ASU) and the power plant. ii. Use of gas turbine technology for the intermediate pressure (IP) steam turbine. iii. Optimal use of turbo-expanders and heat-exchangers to mitigate the power consumption incurred for oxygen production. iv. Improved condenser design for more efficient CO2 separation and removal. v. Sensitivity of process design criteria to “small” variations in modeling of the physical properties for CO2/steam working fluid near saturation. vi. Use of a second “conventional” pure steam Rankine bottoming cycle. In future analysis, not all these improvements need necessarily be seen to be cost-effective when taking into account total P&D program objectives; thermodynamic efficiency, power plant investment, operations and maintenance cost. However, they do represent important considerations towards “total” optimization when designing the P&D Plant. We observe that Project Phase-2: Pre-Engineering & Qualification should focus on optimization of plant size with respect to total capital investment (CAPEX); and identification of further opportunities for extended technology migration from gas turbine environment that could also permit raised turbine inlet temperatures (TIT).

Sign in / Sign up

Export Citation Format

Share Document