Co-production Of Power Research Articles

Feasibility analysis of H2 production by calcium looping process based on coal gasification in a transport reactor

Calcium looping process (CLP) is one kind of carbonaceous material gasification process applied in the H2 rich syngas production and CO2 separation. In this research, a transport reactor with efficient heat and mass transfer and better gas and solid mixing was applied as the gasifier to produce H2 rich syngas with in situ CO2 capture. The primary objective of this research was to investigate the feasible operation conditions for gasifier and entire looping process. The gasification process was analyzed by model based on the reactor hydrodynamics and chemical kinetics. Influences of operating parameters, i.e. temperature, steam to carbon ratio and pressure, on the reactor hydrodynamics, reaction rates and conversion ratios, syngas flow and compositions, steam and power consumption were given and discussed. Feasible operation conditions for gasifier and system configuration were proposed according to the heat and power balance, H2 yield and systematic energy conversion efficiency. Simulation results indicated that feasible operation with H2 and power co-production can be achieved with the gasification temperature of 1273 K, pressure of 0.9 MPa, steam to carbon ratio of 1.8 and CaO to carbon ratio of 1.0. For this feasible operation, the H2 output exceeded 0.78 Nm3 per kg coal and energy conversion efficiency was higher than 40%.

Pressure swing adsorption for coproduction of power and ultrapure H2 in an IGCC plant with CO2 capture

The coproduction of power and ultrapure H2 within an Integrated Gasification Combined Cycle (IGCC) plant implementing CO2 capture offers advantages in terms of flexible operation while retaining good efficiency. The common design includes an absorption unit for removing CO2 from a high pressure syngas followed by a Pressure Swing Adsorption (PSA) unit for purifying a part of the resulting H2-rich gas stream. A drawback of this design consists in the necessity for compression of the PSA tail gas in order to recover the energy available in the residual H2 content. This paper presents two novel configurations for power and H2 coproduction with CO2 capture, entirely based on PSA technology. The first relies on two PSA trains in series (Two-train PSA), while the other is able to carry out CO2 separation and H2 purification within a single PSA train (One-train PSA). The two systems were defined and simulated through a composite model of the whole plant. The process simulation results showed that both the configurations proposed are able to shift between the two energy products without compromising the performance of the plant. The load of the plant could be decreased by increasing the ultrapure H2 throughput, while maintaining a constant feed of coal to the gasifier. The Two-train PSA configuration achieved higher performance in terms of energy efficiency and H2 purity. The One-train PSA configuration returned slightly lower but still good performance, while its design includes a single separation stage instead of two. Additionally, both configurations enable the avoidance of PSA tail gas compression giving an advantage against the absorption-based design. A comparative analysis with results taken from the literature seems to confirm this assertion.

‏ארי בראל‎ [Ari Barell]. ‏מלך-מהנדס: דוד בן-גוריון, מדע ובינוי אומה‎ [Engineer-King: David Ben-Gurion, Science, and Nation Building]. ‏וט‎ + 338 pp., apps., bibl., index. ‏מכון בן-גוריון לחקר ישראל והציונות‎ [Sede Boqer: Ben-Gurion Research Institute for the Study of Israel and Zionism, 2014]. ₪55, $14.21 (paper).

Previous articleNext article No Access‏ארי בראל‎ [Ari Barell]. ‏מלך-מהנדס: דוד בן-גוריון, מדע ובינוי אומה‎ [Engineer-King: David Ben-Gurion, Science, and Nation Building]. ‏וט‎ + 338 pp., apps., bibl., index. ‏מכון בן-גוריון לחקר ישראל והציונות‎ [Sede Boqer: Ben-Gurion Research Institute for the Study of Israel and Zionism, 2014]. ₪55, $14.21 (paper).Tal GolanTal Golan Search for more articles by this author PDFPDF PLUSFull Text Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Isis Volume 107, Number 1March 2016 Publication of the History of Science Society Article DOIhttps://doi.org/10.1086/686208 Views: 146Total views on this site © 2016 by The History of Science Society. All rights reserved.PDF download Crossref reports no articles citing this article.

Co-production of power and urea from coal with CO2 capture: performance assessment

Coal-based power plants are largest emitter of CO2 as a single sector. To use fossil fuels (including coal), CO2 capture and storage is a visible option. But large energy requirement for this process and risk associated with storage of CO2 demand alternative solutions including recycling of captured CO2. In this paper, a co-production of power and urea is proposed using coal with captured CO2. Detailed ASPEN Plus® model is developed for this plant. As shift reaction for producing H2 has significant effect on output parameters, analysis is done for two different values of shift reaction, i.e., 90 and 95 % conversion. Plant consumes substantial auxiliary power (~19 % for the base case). Auxiliary power becomes a minimum for about 25 % captured CO2 utilization for 95 % shift conversion. An economy factor is also defined to estimate the economic advantage of utilizing captured CO2. Results show that economic advantage is obtained for CO2 utilization beyond ~5 % for 95 % water gas shift reaction and it is beyond ~10 % for a 90 % shift reaction.

Biomass direct chemical looping for hydrogen and power co-production: Process configuration, simulation, thermal integration and techno-economic assessment

Large scale biomass utilisation in energy-related applications is of paramount importance to reduce the fossil CO2 emissions. At European level, about a third of energy consumption is expected to be covered by renewables in the next 15years. In addition, the CO2 emissions need to be reduced by 40% compared to the 1990 level. Within this context, innovative energy-efficient low carbon technologies have to be developed. Chemical looping is a promising conversion option to deliver reduced energy and cost penalties for CO2 capture.This paper assesses biomass direct chemical looping (BDCL) concept for hydrogen and power co-production. The concept is illustrated using an ilmenite-based system to produce 400–500MW net power with flexible hydrogen output (up to 200MWth). The performances are assessed through computational methods, with the mass and energy balances being used for in-depth techno-economic analysis. The biomass direct chemical looping delivers both high energy efficiencies (~42% net efficiency) with almost total carbon capture rate (>99%) compared to other CO2 capture options (e.g. gas–liquid absorption). The economic parameters show also a reduced CO2 capture cost penalty for biomass direct chemical looping technology compared to gas–liquid absorption (e.g. 7% reduction of specific capital investment).

Energy and exergy analyses of a solar driven Mg–Cl hybrid thermochemical cycle for co-production of power and hydrogen

Analysis and performance assessment of a solar driven hydrogen production plant running on an Mg–Cl cycle, are conducted through energy and exergy methods. The proposed system consists of (a) a concentrating solar power cycle with thermal energy storage, (b) a steam power plant with reheating and regeneration, and (c) a hybrid thermochemical Mg–Cl hydrogen production cycle. The results show that higher steam to magnesium molar ratios are required for full yield of reactants at the hydrolysis step. This ratio even increases at low temperatures, although lowering the highest temperatures appears to be more favorable for linking such a cycle to lower temperature energy sources. Reducing the maximum cycle temperature decreases the plant energy and exergy efficiencies and may cause some undesirable reactions and effects. The overall system energy and exergy efficiencies are found to be 18.8% and 19.9%, respectively, by considering a solar heat input. These efficiencies are improved to 26.9% and 40.7% when the heat absorbed by the molten salt is considered and used as a main energy input to the system. The highest exergy destruction rate occurs in the solar field which accounts for 79% of total exergy destruction of the integrated system.

A polygeneration system for methanol and power production based on coke oven gas and coal gas with CO2 recovery

Polygeneration system for chemical and power co-production has been regarded as one of the promising technologies for fossil fuel sustainable utilization. In this paper, a new polygeneration system with carbon capture is integrated, based on coal gas and coke oven gas inputs for methanol and power co-production. New system can achieve more than 5% of primary energy saving ratio, and more than 50% of exergy efficiency. Exergy balance and Energy Utilization Diagrams (EUDs) are applied to show the performance improvement. In the system, pressure swing adsorption process is used to remove hydrogen from coke oven gas to enhance methane concentration, which reduces energy consumption and exergy destruction of reforming process. And for the methane reforming process, thermal energy for reforming is sensible thermal energy of syngas out of gasifier instead of fuel gas combustion. Furthermore, fresh syngas for methanol synthesis is the mixed gas of reformed coke oven gas and coal gas, which means that syngas components are adjusted without energy consumption. Lastly, CO2 is recovered during chemical energy discharge and at the highest concentration resulting in less energy penalty. All of these energy integrating characteristics result in good thermal performance, which supplies a new direction for clean energy technology.

A review of hybrid desalination systems for co-production of power and water: analyses, methods, and considerations

The production of freshwater from seawater is a growing necessity throughout the world. In arid areas with high temperature and salinity seawater, thermal desalination and power plants (dual-purpose/cogeneration plants) are often employed for the production of power and water. In other areas, reverse osmosis is commonly employed. However, both technologies are inherently challenged with economic and performance issues. As a response to these issues, hybrid desalination, that is, employing both thermal and mechanical desalination methods, has been increasingly utilized over thermal desalination plants alone. In this article, an overview of thermal desalination, seawater reverse osmosis (SWRO), and co-generation of power and water is presented, specifically with regards to the motivation for utilizing hybrid plants, for example, process limitations and areas of potential improvement. In addition, a review of the considerations for design and economics of hybrid desalination plants is presented, for example, existing system configurations, thermoeconomic analyses, and improvements of seawater pretreatment are discussed. Finally, studies for the optimization of hybrid desalination systems are reviewed. Specifically, the use of objective functions, continuous optimization methods, and optimal hardware configurations are discussed with respect to the key considerations of hybrid desalination plants.

Comparison of the Cost of Co-Production of Power and Desalinated Water from Different Power Cycles

The worldwide demand for portable water is steadily growing due to population, industrial and agricultural growth, the result is water shortages that are already reaching serious proportions in many parts of the world. This is particularly true in Ghana where there is an increasing reliance on bottled water due to shortage of safe, fresh drinking water. Nuclear and conventional co-production of electricity and portable water has been identified as key solution to the perennial water shortages in coastal towns in Ghana. A reliable desalination cost date catering for site-specific condition in Ghana is required for policy makers, planners, consultants, process engineers, plant suppliers and researchers. This present paper is aims comparing the cost of co-production of power and portable water using reverse osmosis (RO) plant coupled with both nuclear and fossil power plant operating under different cycles using the desalination economic evaluation programme (DEEP4.0) developed by the international atomic energy agency (IAEA). The study concentrates on conditions of seawater in Accra, Ghana. Results show that co-production nuclear power plant operating on steam cycle can be the most economic among a number of power-water production options.

Energy conversion analysis of hydrogen and electricity co-production coupled with in situ CO2 capture

CO2 adsorption enhanced gasification process is a prospective technology to be used in hydrogen and power production with nearly zero CO2 emission. In this paper, a gasification kinetics steady state model is developed based on the chemical kinetics mechanism with the condition of fluidization. It is used to predict the parameters of gas phase and solid phase for a continuous flow reactor with steady state. The variation of distribution of components with gasification temperature and pressure are determined. Conceptual configurations of H2 and power co-production system are designed with the integration of CO2 adsorption enhanced gasification process, H2 separation unit, power generation unit and other auxiliary units. Mass and heat transfer between different parts are studied systematically by flow-sheet simulation and sensitivity analysis of parameters. According to the generalized exergy efficiency of the system, the influence of gasification temperature and pressure on the system performance is investigated and the optimum gasification temperature and pressure for system operation can be determined.

Evaluation of syngas-based chemical looping applications for hydrogen and power co-generation with CCS

This paper evaluates hydrogen and power co-generation based on coal-gasification fitted with an iron-based chemical looping system for carbon capture and storage (CCS). The paper assess in details the whole hydrogen and power co-production chain based on coal gasification. Investigated plant concepts of syngas-based chemical looping generate about 350–450 MW net electricity with a flexible output of 0–200 MWth hydrogen (based on lower heating value) with an almost total decarbonisation rate of the coal used.The paper presents in details the plant concepts and the methodology used to evaluate the performances using critical design factors like: gasifier selection criteria for chemical looping applications, influence of gasifier feeding system (dry fed vs. slurry fed), heat and power integration analysis as potential ways to increase the overall energy efficiency, hydrogen and carbon dioxide quality specifications considering the use of hydrogen in transport (fuel cells) and carbon dioxide storage in geological formation or used for EOR. The results show that syngas-based chemical looping systems ensure lower carbon capture energy penalties and higher overall plant energy efficiencies than more technologically mature capture methods (e.g. pre- and post-combustion capture based on gas–liquid absorption).

Synthesis, Modeling and Exergy Analysis of Atmospheric Air Blown Biomass Gasification for Fischer-Tropsch Process

The main objective of the present work is to investigate the combination of an atmospheric and a pressurised air blown biomass gasifier towards Fischer-Tropsch (FT) synthesis of second generation biofuels and co-production of power. The complete process was simulated in AspenPlusTM software including sub-models for the gasification, gas cleaning and conditioning as well as for the FT reactor. A sensitivity analysis on exergetic performance was performed mainly examining the recycling of FT-tail gas. For the base case of 80% FT CO conversion without any recirculation, the exergetic efficiency was found to be 34.3% with atmospheric gasification and 30.64% for pressurised gasification. Recirculation of the non-reacted CO, H2 as well as light gas products of the FT-reactor back to the atmospheric gasifier can increase the overall efficiency up to 48.1 %. This paper is an updated version of a paper published in the ECOS'08 proceedings.

Economic analysis of coal-based polygeneration system for methanol and power production

Polygeneration system for chemical and power co-production has been regarded as one of promising technologies to use fossil fuel more efficiently and cleanly. In this paper the thermodynamic and economic performances of three types of coal-based polygeneration system were investigated and the influence of energy saving of oxygenation systems on system economic performance was revealed. The primary cost saving ratio (PCS) is presented as a criterion, which represents the cost saving of polygeneration system compared with the single-product systems with the same products outputs, to evaluate economic advantages of polygeneration system. As a result, the system, adopting un-reacted syngas partly recycled to the methanol synthesis reactor and without the shift process, can get the optimal PCS of 11.8%, which results from the trade-off between the installed capital cost saving and the energy saving effects on the cost saving, and represents the optimal coupling relationship among chemical conversion, energy utilization and economic performance. And both of fuel price and the level of equipment capital cost affect on PCS faintly. This paper provides an evaluation method for polygeneration systems based on both technical and economic viewpoints.

Coproduction of ethanol and power from switchgrass

AbstractThree process designs for producing ethanol and electricity from switchgrass are evaluated: a base‐case technology scenario involving dilute acid pre‐treatment and simultaneous saccharification and fermentation, and two mature technology scenarios incorporating ammonia fiber expansion pre‐treatment and consolidated bioprocessing – one with conventional Rankine power coproduction, and one coproducing power via a gas turbine combined cycle. Material and energy balances – resulting from detailed Aspen Plus models – are reported and used to estimate processing costs and perform discounted cash flow analysis to assess plant profitability. The mature technology —designs significantly improve both process efficiency and cost relative to base‐case cellulosic ethanol technology, with the resulting fossil fuel displacement being decidedly positive and production costs competitive with gasoline, even at relatively low prices. © 2009 Society of Chemical Industry and John Wiley & Sons, Ltd

Protonic membrane for fuel cell for co-generation of power and ethylene

Yttrium-doped barium cerate, BaCe 0.85Y 0.15O 3− α (BCY15), membranes are proton-conducting electrolytes for intermediate-temperature protonic ceramic fuel cells (IT-PCFC), useful for, among other processes, co-production of power and ethylene by dehydrogenation of ethane. BCY15 membranes showed good conductivity at intermediate temperatures, 15 and 20 mS cm −1 at 700 and 750 °C, respectively. Maximum power density was 174 mW cm −2 at 700 °C, with a corresponding current density of 320 mA cm −2, using a C 2H 6,Pt/BCY15/Pt,O 2 fuel cell, with a ca. 0.5 mm thick membrane, producing 34% ethane conversion with 96% ethylene selectivity Comparison of performances using vertical and horizontal set-ups showed that horizontal set-ups are subject to torsional strain, causing reduced cell performance resulting from even minor leakage at the glass seal.

System Design and Analysis of a Direct Hydrogen from Coal System with CO2 Capture

Hydrogen is regarded as one of the main energy carriers of the future. On the basis of the previous work, a direct hydrogen production from coal based on a CO2 sorbent enhanced gasification process was constructed in this paper using the ASPEN PLUS simulator. The system is mainly composed of two paralleled fluidized bed reactors, namely a gasifier and regenerator. Then, on the basis of the proposed system, more than 95% hydrogen and less than 5% methane, CO, and CO2 (mole percent, dry basis) of gas product is computationally obtained in a wide range of operating conditions. The cold gas efficiency of the system can reach as high as 92.6%. When a hydrogen and power coproduction system is considered, in which hydrogen is used as the fuel of the solid oxide fuel cell combined cycle (SOFC-CC) hybrid system, the system equivalent power efficiency can reach 61.9% considering the CO2 capture and disposal. Finally, the influences of several key parameters on the system performance, such as operating condition of the gasifier, steam/carbon ratio, Ca/C ratio, and carbon conversion ratio, are investigated.

Chemical and process integration: Synergies in co-production of power and chemicals from natural gas with CO 2 capture

CO 2 legislation in power production decreases the overall efficiency of the plant by 9–13% points. The decrease in efficiency results in increased fuel consumption and the need for CO 2 capture increases the size of the process trains. In this paper, process and chemical integration is proposed as one option to increase the overall efficiency as co-production of power and chemicals is utilised. Chemical and process integration give economy of scale savings, better utilisation of raw materials, improved energy efficiency and savings in investment costs. Natural gas has been assumed as feedstock to the process, whereas other materials like plastic waste open up for similar benefits.

The pioneer plant concept: co-production of electricity and added-value products from coal

Although technologies have been developed for the clean, efficient use of coal for power generation, there exist some barriers to their adoption and implementation. These technologies are essentially based upon coal gasification, which also provides a route for the synthesis of chemicals and fuels from coal. An overview is given of commercial experience of power generation by integrated gasification combined-cycle, and chemicals production. Against this background, a “Pioneer Plant” concept is described that can facilitate the introduction of advanced technologies through the co-production of power and added-value products in a single plant. The term “Pioneer” in this context reflects the nature of a first-of-a-kind plant that integrates existing technologies from the utility and petrochemical industries. The potential technical, economic, and greenhouse gas reduction advantages that can be realized through the development of an integrated, multiplex operation are discussed.

95/06382 Coproduction of power, steam, and oxygen in coal or low quality fuel combustion systems

95/06382 Coproduction of power, steam, and oxygen in coal or low quality fuel combustion systems