Solar Upgrading of Methanol: Driven Combined Cycle Using Middle Temperature Solar Collectors

Solar Energy ◽  
2003 ◽  
Author(s):  
Hongguang Jin ◽  
Hui Hong ◽  
Jun Ji ◽  
Zhifeng Wang ◽  
Ruixian Cai
Keyword(s):  
Thermal Energy ◽  
Pressure Ratio ◽  
Thermal Power ◽  
Combined Cycle ◽  
Solar Thermal ◽  
Inlet Temperature ◽  
Solar Collectors ◽  
Solar Thermal Energy ◽  
Optimum Pressure ◽  
Middle Temperature

In this paper, we have proposed a novel solar–driven combined cycle with solar upgrading of methanol in middle temperature solar collectors, and investigated the effects of integration of solar thermal energy and methanol decomposition on the performance of the proposed cycle. The process of solar upgrading methanol is a catalytically endothermic decomposition reaction and proceeds in a range of 130–250° C. As a result, the proposed cycle has a breakthrough performance, with net solar–to–electric efficiency of 32.93% at the collector temperature of 220° C, and the turbine inlet temperature of 1062° C, superior to that of the present advanced cycle (REFOS of 20%). The exergy loss in indirect combustion of methanol proposed here is 7.5 percent points lower than that of the direct combustion. The optimum pressure ratio for thermal efficiency is approximately equal to 14. A key point emphasized here is that the proposed new cycle can utilize middle–temperature solar collector with lower cost. The promising results obtained here indicated that this novel solar–driven combined cycle could make a breakthrough in field of solar thermal power generation through integration of solar thermal energy and effective use of synthetic clean fuel.

Mechanism of Upgrading Low-Grade Solar Thermal Energy and Experimental Validation

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Hui Hong ◽  
Hongguang Jin ◽  
Jun Sui ◽  
Jun Ji
Keyword(s):  
Energy Level ◽  
Thermal Energy ◽  
Power Plants ◽  
Thermal Power ◽  
Chemical Energy ◽  
Solar Thermal ◽  
Low Grade ◽  
Thermal Power Plants ◽  
Solar Thermal Energy ◽  
Middle Temperature

Solar thermochemical processes inherently included the conversion of solar thermal energy into chemical energy. In this paper, a new mechanism of upgrading the energy level of solar thermal energy at around 200°C was revealed based on the second law thermodynamics and was then experimentally proven. An expression was derived to describe the upgrading of the energy level from low-grade solar thermal energy to high-grade chemical energy. The resulting equation explicitly reveals the interrelations of energy levels between middle-temperature solar thermal energy and methanol fuel, and identifies the interactions of mean solar flux and the reactivity of methanol decomposition. The proposed mechanism was experimentally verified by using the fabricated 5kW prototype of the receiver∕reactor. The agreement between the theoretical and the experimental results proves the validity of the mechanism for upgrading the energy level of low-grade solar thermal energy by integrating clean synthetic fuel. Moreover, the application of this new middle-temperature solar∕methanol hybrid thermochemical process into a combined cycle is expected to have a net solar-to-electric efficiency of about 27.8%, which is competitive with other solar-hybrid thermal power plants using high-temperature solar thermal energy. The results obtained here indicate the possibility of utilizing solar thermal energy at around 200°C for electricity generation with high efficiency by upgrading the energy level of solar thermal energy, and provide an enhancement to solar thermal power plants with the development of this low-grade solar thermochemical technology in the near future.

A Low Temperature Solar Thermochemical Power Plant With CO2 Recovery Using Methanol-Fueled Chemical Looping Combustion

2009 ◽  
Author(s):  
Hui Hong ◽  
Tao Han ◽  
Hongguang Jin
Keyword(s):  
Low Temperature ◽  
Thermal Energy ◽  
Combined Cycle ◽  
Energy Utilization ◽  
Solar Thermal ◽  
Chemical Looping Combustion ◽  
Inlet Temperature ◽  
Chemical Looping ◽  
Solar Thermal Energy ◽  
Oxidation Reactor

A novel solar-hybrid gas turbine combined cycle was proposed. The cycle integrates methanol-fueled chemical-looping combustion and solar thermal energy at around 200°C, and it was investigated with the aid of the Energy-Utilization Diagram (EUD). Solar thermal energy, at approximately 150°C–300°C, is utilized to drive the reduction of Fe2O3 with methanol in the reduction reactor, and is converted into chemical energy associated with the solid fuel FeO. Then it is released as high-temperature thermal energy during the oxidation of FeO in the oxidation reactor to generate electricity through the combined cycle. As a result, the exergy efficiency of the proposed solar thermal cycle may reach 58.4% at a turbine inlet temperature (TIT) of 1400°C, and the net solar-to-electric efficiency would be expected to be more than 30%. The promising results obtained here indicate that this solar-hybrid combined cycle not only offers a new approach for highly efficient use of middle-and-low temperature solar thermal energy to generate electricity, but also provides the possibility of simultaneously utilizing renewable energy and alternative fuel for CO2 capture with low energy penalty.

A Low Temperature Solar Thermochemical Power Plant With CO2 Recovery Using Methanol-Fueled Chemical Looping Combustion

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Hui Hong ◽  
Tao Han ◽  
Hongguang Jin
Keyword(s):  
Low Temperature ◽  
Thermal Energy ◽  
Combined Cycle ◽  
Energy Utilization ◽  
Solar Thermal ◽  
Chemical Looping Combustion ◽  
Inlet Temperature ◽  
Chemical Looping ◽  
Solar Thermal Energy ◽  
Oxidation Reactor

A novel solar-hybrid gas turbine combined cycle was proposed. The cycle integrates methanol-fueled chemical-looping combustion and solar thermal energy at around 200°C, and it was investigated with the aid of the energy-utilization diagram (EUD). Solar thermal energy, at approximately 150°C–300°C, is utilized to drive the reduction in Fe2O3 with methanol in the reduction reactor, and is converted into chemical energy associated with the solid fuel FeO. Then it is released as high-temperature thermal energy during the oxidation of FeO in the oxidation reactor to generate electricity through the combined cycle. As a result, the exergy efficiency of the proposed solar thermal cycle may reach 58.4% at a turbine inlet temperature of 1400°C, and the net solar-to-electric efficiency would be expected to be 22.3%. The promising results obtained here indicate that this solar-hybrid combined cycle not only offers a new approach for highly efficient use of middle-and-low temperature solar thermal energy to generate electricity, but also provides the possibility of simultaneously utilizing renewable energy and alternative fuel for CO2 capture with low energy penalty.

A Novel Solar-Hybrid Gas Turbine Combined Cycle With Inherent CO2 Separation Using Chemical-Looping Combustion by Solar Heat Source

2006 ◽  
Vol 128 (3) ◽  
pp. 275-284 ◽  
Author(s):  
Hui Hong ◽  
Hongguang Jin ◽  
Baiqian Liu
Keyword(s):  
Metal Oxide ◽  
Thermal Energy ◽  
Combined Cycle ◽  
Solar Thermal ◽  
Chemical Looping Combustion ◽  
Co2 Separation ◽  
Inlet Temperature ◽  
Low Grade ◽  
Chemical Looping ◽  
Solar Thermal Energy

In this paper we propose a novel CO2-recovering hybrid solar-fossil combined cycle with the integration of methane-fueled chemical-looping combustion, and investigate the system with the aid of the Energy-Utilization Diagram (EUD). Chemical-looping combustion (CLC) consists of two successive reactions: first, methane fuel is oxidized by metal oxide(NiO)as an oxygen carrier (reduction of metal oxide); and second, the reduced metal (Ni) is successively oxidized by combustion air (the oxidation of metal). The oxidation of methane with NiO requires a relative low-grade thermal energy at 300°C-500°C. Then concentrated solar thermal energy at approximately 450°C-550°C can be utilized to provide the process heat for this reaction. By coupling solar thermal energy with methane-fueled chemical-looping combustion, the energy level of solar thermal energy at around 450°C-550°C can be upgraded to the chemical energy of solid fuel Ni for better utilization of solar energy to generate electricity. The synergistic integration of solar thermal energy and chemical-looping combustion could make the exergy efficiency and the net solar-to-electric efficiency of the solar hybrid system more than 60% and 30%, respectively, at a turbine inlet temperature (TIT) of 1200°C. At the same time, this new system has an extremely important advantage of directly suppressing the environmental impact due to lack of energy penalty for CO2 recovery. Approximately 9–15 percentage points higher efficiency can be achieved compared to the conventional natural gas-fired combined cycle with CO2 separation. The results obtained here are promising and indicate that this novel solar hybrid combined cycle offers the new possibility of CO2 mitigation using both green energy and fossil fuels. These results also provide a new approach for highly efficient use of solar thermal energy to generate electricity.

Parameterization of High Solar Share Gas Turbine Systems

2012 ◽  
Author(s):  
Stephan Heide ◽  
Christian Felsmann ◽  
Uwe Gampe ◽  
Sven Boje ◽  
Bernd Gericke ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Planning Process ◽  
Pressure Ratio ◽  
Thermal Power ◽  
Combined Cycle ◽  
Process Models ◽  
Solar Thermal ◽  
Thermal Power Plants ◽  
Solar Thermal Power

Existing solar thermal power plants are based on steam turbine cycles. While their process temperature is limited, solar gas turbine (GT) systems provide the opportunity to utilize solar heat at a much higher temperature. Therefore there is potential to improve the efficiency of future solar thermal power plants. Solar based heat input to substitute fuel requires specific GT features. Currently the portfolio of available GTs with these features is restricted. Only small capacity research plants are in service or in planning. Process layout and technology studies for high solar share GT systems have been carried out and have already been reported by the authors. While these investigations are based on a commercial 10MW class GT, this paper addresses the parameterization of high solar share GT systems and is not restricted to any type of commercial GT. Three configurations of solar hybrid GT cycles are analyzed. Besides recuperated and simple GT with bottoming Organic Rankine Cycle (ORC), a conventional combined cycle is considered. The study addresses the GT parameterization. Therefore parametric process models are used for simulation. Maximum electrical efficiency and associated optimum compressor pressure ratio πC are derived at design conditions. The pressure losses of the additional solar components of solar hybrid GTs have a different adversely effect on the investigated systems. Further aspects like high ambient temperature, availability of water and influence of compressor pressure level on component design are discussed as well. The present study is part of the R&D project Hybrid High Solar Share Gas Turbine Systems (HYGATE) which is funded by the German Ministry for the Environment, Nature and Nuclear Safety and the Ministry of Economics and Technology.

scholarly journals Performance Analysis With Different Means of Cooling in a Combined Cycle

1995 ◽  
Author(s):  
Onkar Singh ◽  
R. Yadav
Keyword(s):  
Gas Turbine ◽  
Power Plants ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Inlet Temperature ◽  
Optimum Pressure ◽  
Cooling Medium ◽  
Cooling Technology ◽  
Improved Performance ◽  
Topping Cycle

Combined cycle based power plants and their development and application for energy efficient base load power generation necessitates enforced cooling to maintain the topping cycle gas turbine blade temperature at permissible levels, attributed to the increased turbine inlet temperature and compressor pressure ratio, for the improved performance and reliability of combined cycle. The mathematical model based on expansion path inside gas turbine considering dilution of mainstream and aerodynamic mixing losses for a range of cooling medium has been developed based on internal, film, transpiration cooling technologies and a combination of these. It is found that the appreciation of a cycle configuration as well as the optimum pressure ratio and peak temperature vary significantly with types of cooling technology adopted. Steam cooling for rotor appears to be a very potential cooling medium, when employed with an appropriate cooling technology. This paper deals with the thermodynamic analysis of turbine cooling using, different means of cooling i.e. air, water and steam.

Drying of Oil Palm Fronds Using Concentrated Solar Thermal Power

2014 ◽  
Vol 699 ◽  
pp. 449-454 ◽  
Author(s):  
Shaharin Anwar Sulaiman ◽  
Farid Fawzy Fathy Taha
Keyword(s):  
Thermal Energy ◽  
Oil Palm ◽  
Thermal Power ◽  
Solar Thermal ◽  
Drying Rate ◽  
Drying Methods ◽  
Solar Thermal Energy ◽  
Oil Palm Fronds ◽  
Electric Oven ◽  
Palm Fronds

Malaysia has great potential for biomass stock. The fact that oil palm fronds contain high moisture content makes it unsuitable to be used directly as a biomass fuel neither for direct combustion nor gasification. Conventional and costly drying methods make the fronds a non-attractive fuel especially in humid tropical countries, where sources of biomass is abundant. A new solar dryer design is proposed that utilizes concentrated solar thermal energy for drying oil palm fronds. A prototype for the dryer has been fabricated and tested. The system’s target is to maximize the thermal energy received by the system and to minimize energy loss out of the system. Experiments were performed on samples of oil palm fronds at a drying temperature not exceeding 110°C; in order not to affect the organic material of the biomass. Results were compared with another experiment performed at the same temperature. An electric oven was used for drying. The samples were completely dried using the proposed system for 6.5 hours, compared to 10.5 hours by using the electric oven. The proposed system achieved an average drying rate of 4.75 g/hr compared to an average drying rate of 2.83 g/hr using the electric oven. The efficiency of the dryer was calculated to be 55.4%, implying good potential of the proposed system.

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