PDF Publication Title:
Text from PDF Page: 004
makes this process an attractive option over the other two for pairing with the enhanced geothermal systems (EGS). Fig. 1 shows the schematic representation of pairing an inte- grated gasification combined cycle (IGCC) plant with binary enhanced geothermal systems. CO2 formed during the gasification and the subsequent water gas shift reaction process is separated at high pressures by pre-combustion carbon capture methods in an integrated gasification combined cycle (IGCC) plant so that it is ready for sequestration. The carbon dioxide ready to be sequestered is fed into the injection well for the absorption of geothermal heat energy. Short-circuiting flow of CO2 from the injection well to the production well may result in rapid but incomplete thermal drawdown in the reservoir [36]. So the carbon dioxide is injected in a series of wells to attain a distributed sweep of fluid. The limited permeability of these reservoirs means that multiple injection wells and production wells are required to provide sufficient throughput in the reservoir. A portion of the injected CO2 is lost in fractures in the rocks and this loss contributes to the sequestered inventory. The remainder of the CO2 circulates through the reser- voir and is the agent that removes the heat. The geothermal heat is transferred from the CO2 to a working fluid in a heat exchanger and this working fluid passes through the organic Rankine cycle (ORC) for power generation. This power generated is in addition to that obtained from IGCC through the gas turbine and steam turbine. The IGCC plant is sized such that it produces sufficient CO2 to compensate for the sequestration losses adjacent to the reservoir. This symbiotic pairing of CO2-EGS with IGCC reduces both the us- age of water in arid regions while simultaneously extracting heat from the reservoir and sequestering CO2 in the subsurface. 3. Assumptions used in this study The total amount of CO2 injected into the geothermal well is 680 kg/s at a pressure of 15 MPa and at a temperature of 60 C. In order to avoid premature depletion of the reservoir and limited by the anticipated low permeability of the stimulated reservoir [36], this flow is distributed equally among 10 injection wells so that 68 kg/s of CO2 is injected into each well. 10% of the total CO2 injected into the wells escapes through the fractures and contrib- utes to the sequestered mass. The depth of the injection well and the production well are each assumed to be 6 km. The thermal Fig. 1. Schematic representation of pairing an integrated gasification combined cycle plant (IGCC) with the Enhanced Geothermal Systems (EGS) using CO2 as a geothermal fluid in arid regions. Table 1 Ultimate Analysis of Pittsburgh no 8 coal on a dry basis [26]. Author's personal copy A. Ram Mohan et al. / Energy 57 (2013) 505e512 507 Elements Carbon Hydrogen Nitrogen Sulfur Oxygen Chlorine Ash Composition wt% 75.65 4.83 1.49 2.19 6.63 0.11 9.10 gradient in the geothermal well is assumed to be 50 C/km. The pressure drop of CO2 from the injection well through the reservoir to the production well is assumed to be 3 MPa. The remaining CO2 carries the geothermal heat and leaves the production well at a temperature of 300 C and 12 MPa. It transfers the geothermal heat energy to the working fluid in the ORC through a binary shell and tube heat exchanger. The CO2 lost to the geothermal reservoir during the sequestration process is compensated from a 315 MWe IGCC plant using Pittsburgh no 8 coal. The ultimate analysis of Pittsburgh no 8 coal on a dry basis is given in Table 1 [37]. Assuming an efficiency of 42% HHV for the IGCC plant, based on the proximate analysis, ultimate analysis and the calorific value [37], the total amount of CO2 produced from the 315 MWe IGCC plant amounts to 68 kg/s. The summary of the calculations is shown in Table 2. 4. Modeling approach for the organic Rankine cycle in EGS We modeled the binary organic Rankine cycle in ASPEN Plus V7.3 to determine the effectiveness of five different working fluids in the utilization of geothermal energy extracted when CO2 is used as a geothermal heat transfer fluid. This fluid is then used to pro- duce electricity from an enhanced geothermal system (EGS). Ammonia, neopentane, n-Butane and R134A are the four different working fluids chosen for the study. PengeRobinson Equation of state was used to calculate the properties of all the fluids. Fig. 2 shows the process flow sheet created in ASPEN Plus for the geothermal heat extraction by CO2 coupled with the organic Rankine cycle. 612 kg/s of CO2 is recirculated back after transferring the geothermal heat energy to the working fluid in a shell and tube heat exchanger. 68 kg/s of CO2 from a 315 MWe IGCC plant is compressed to 15 MPa for sequestration. The total amount of CO2 injected as geothermal fluid into the geothermal well is 680 kg/s at 15 MPa. A flow splitter is used to represent the mass rate seques- tered in the geothermal reservoir where 10% of the total injected mass of CO2 (68 kg/s) is assumed sequestered and is lost to the closed circuit. The remaining 90% of the CO2 (612 kg/s at 15 MPa) is fed across the geothermal reservoir. The geothermal reservoir is modeled as a heater where the temperature of CO2 is raised to 300 C. The pressure drop from the injection well to the production well is assumed to be 3 MPa and represents the flow impedance of Table 2 Calculation showing the amount of CO2 emitted from an IGCC plant. Electrical output of the IGCC power plant Efficiency of an IGCC power plant Thermal output of the IGCC power plant Calorific value of Pittsburgh no 8 coal (HHV) Amount of Pittsburgh no 8 coal consumed by the IGCC plant Amount of CO2 emitted from a 315 MWe IGCC plant Leakage of CO2 through the geothermal well Total amount of CO2 injected into the injection wells Number of injection/production wells Amount of CO2 injected through each well 315 MWe 42% 750 MWth 31,000 kJ/kg 24.3 kg/s 68 kg/s 10% 680 kg/s 10 68 kg/sPDF Image | Energy Technology ORC
PDF Search Title:
Energy Technology ORCOriginal File Name Searched:
2013_j_energy_sco2_egs_arun.pdfDIY PDF Search: Google It | Yahoo | Bing
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
IT XR Project Redstone NFT Available for Sale: NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Be part of the future with this NFT. Can be bought and sold but only one design NFT exists. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Turbine IT XR Project Redstone Design: NFT for sale... NFT for high tech turbine design with one part 3D printed counter-rotating energy turbine. Includes all rights to this turbine design, including license for Fluid Handling Block I and II for the turbine assembly and housing. The NFT includes the blueprints (cad/cam), revenue streams, and all future development of the IT XR Project Redstone... More Info
Infinity Turbine ROT Radial Outflow Turbine 24 Design and Worldwide Rights: NFT for sale... NFT for the ROT 24 energy turbine. Be part of the future with this NFT. This design can be bought and sold but only one design NFT exists. You may manufacture the unit, or get the revenues from its sale from Infinity Turbine. Royalties go to the developer (Infinity) to keep enhancing design and applications... More Info
Infinity Supercritical CO2 10 Liter Extractor Design and Worldwide Rights: The Infinity Supercritical 10L CO2 extractor is for botanical oil extraction, which is rich in terpenes and can produce shelf ready full spectrum oil. With over 5 years of development, this industry leader mature extractor machine has been sold since 2015 and is part of many profitable businesses. The process can also be used for electrowinning, e-waste recycling, and lithium battery recycling, gold mining electronic wastes, precious metals. CO2 can also be used in a reverse fuel cell with nafion to make a gas-to-liquids fuel, such as methanol, ethanol and butanol or ethylene. Supercritical CO2 has also been used for treating nafion to make it more effective catalyst. This NFT is for the purchase of worldwide rights which includes the design. More Info
NFT (Non Fungible Token): Buy our tech, design, development or system NFT and become part of our tech NFT network... More Info
Infinity Turbine Products: Special for this month, any plans are $10,000 for complete Cad/Cam blueprints. License is for one build. Try before you buy a production license. May pay by Bitcoin or other Crypto. Products Page... More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)