scholarly journals Absorption Chillers to Improve the Performance of Small-Scale Biomethane Liquefaction Plants

Energies ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 92
Author(s):  
Alessio Ciambellotti ◽  
Gianluca Pasini ◽  
Andrea Baccioli ◽  
Lorenzo Ferrari ◽  
Stefano Barsali
Keyword(s):  
Natural Gas ◽  
Waste Heat ◽  
Economic Assessment ◽  
Specific Consumption ◽  
Small Scale ◽  
Agricultural Activities ◽  
Electricity Cost ◽  
Absorption Chillers ◽  
Levelized Cost ◽  
Biogas Plants

Biomethane liquefaction may help decarbonization in heavy transportation and other hard-to-abate sectors. Small-scale liquefaction plants (<10 ton/day) are suitable for small biogas plants located near farms and other agricultural activities. “Internal refrigerant” refrigeration cycles (e.g., Kapitza cycle) are often proposed for small-scale natural gas liquefaction due to their simplicity. An optimized Kapitza-based cycle is modeled and simulated, and then several modifications were studied to evaluate their influence on the energetic and economic performances. Results showed a specific consumption ranging between 0.65 kWh/kg and 0.54 kWh/kg of bio-LNG with no significant improvements by increasing cycle complexity. Instead, a reduction of 17% was achieved with the implementation of absorption chillers, that effectively turn waste heat into useful cooling energy. An economic assessment was finally carried showing that the Levelized Cost of Liquefation is more affected by electricity cost than additional CapEx.

scholarly journals Economic assessment of heat and power generation from small-scale liquefied natural gas in Russia

2020 ◽  
Vol 6 ◽  
pp. 391-402 ◽  
Author(s):  
Pavel Tcvetkov ◽  
Alexey Cherepovitsyn ◽  
Alexey Makhovikov
Keyword(s):  
Power Generation ◽  
Natural Gas ◽  
Economic Assessment ◽  
Liquefied Natural Gas ◽  
Small Scale

Efficiency Improvement of Natural Gas Combined Cycle Power Plant With CO2 Capturing and Sequestration

2012 ◽  
Author(s):  
Abdullah Al-Abdulkarem ◽  
Yunho Hwang ◽  
Reinhard Radermacher
Keyword(s):  
Natural Gas ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Simulation Software ◽  
Combined Cycle ◽  
Co2 Removal ◽  
Efficiency Improvement ◽  
Absorption Chillers ◽  
Natural Gas Combined Cycle

Although natural gas is considered as a clean fuel compared to coal, natural gas combined cycles (NGCC) emit high amounts of CO2 at the plant site. To mitigate global warming caused by the increase in atmospheric CO2, CO2 capture and sequestration (CCS) using amine absorption is proposed. However, implementing this CCS system increases the energy consumption by about 15–20%. Innovative processes integration and waste heat utilization can be used to improve the energy efficiency. Four waste heat sources and five potential uses were uncovered and compared using a parameter defined as the ratio of power gain to waste heat. A new integrated CCS configuration is proposed, which integrates the NGCC with the CO2 removal and CO2 compression cycles. HYSYS simulation software was used to simulate the CO2 removal cycle using monoethanolamine (MEA) solution, NGCC, CO2 compression cycle, CO2 liquefaction cycles and Organic Rankine Cycle (ORC). The developed models were validated against experimental data from the literature with good agreements. Two NGCC with steam extraction configurations were optimized using Matlab GA tool coupled with HYSYS simulation software. Efficiency improvement in one of the proposed CCS configurations that uses the available waste heat in absorption chillers to cool the inlet-air to the gas turbine and to run an ORC, and uses the developed CO2 liquefaction and pumping instead of multistage compression is 6.04 percent point, which represents 25.91 MW more power than the conventional CCS configuration.

Economic Feasibility Study of a Small Scale Organic Rankine Cycle System in Waste Heat Recovery Application

2010 ◽  
Author(s):  
Bertrand F. Tchanche ◽  
Sylvain Quoilin ◽  
Sebastien Declaye ◽  
Georges Papadakis ◽  
Vincent Lemort
Keyword(s):  
Thermodynamic Model ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Payback Period ◽  
Working Fluid ◽  
Small Scale ◽  
Electricity Cost

The Organic Rankine Cycle (ORC) appears progressively as a promising solution to recover waste heat energy from thermal processes for electricity generation. A prototype of small-scale ORC has been built and successfully tested at the University of Lie`ge. It uses R-245fa and R-123 as working fluid, and an oil-free scroll compressor adapted to run in expander mode. Thermodynamic model of the system was derived and validated for performance prediction. The validated thermodynamic model is used to optimize the operation of the small ORC in waste heat recovery application (ORC-WHR). For exhaust gases at 180 °C and a mass flow rate of 0.21 kg/s, a maximum net power output of 2 kWe is obtained for an evaporator pressure of 11.84 bar. The cycle thermal efficiency is 8.23 and the recuperation efficiency, 66.32%. Based on the aforementioned conditions, the economic assessment of small scale ORC-WHR was carried out using economic criteria such as levelized electricity cost (LEC), Net present value (NPV) and depreciated payback period (DPP). For a 2kWe ORC-WHR, the specific installed cost is 5775 €/kW with a LEC of 13.27 c€/kWh while for a 50 kWe, the specific installed cost is about 3034 €/kW and the LEC, 7c€/kWh. For an electricity unit price of 20 c€/kWh, the payback period of a 2 kWe system is 6 years while it is 2.5 years for a 50 kWe system. It is concluded from the study that recovering the waste heat by way of ORCs is technically and economically feasible. As recycled energy, waste heat has the same advantages as renewable energy and should benefit from the same legislative conditions (Feed-in-Laws).

Co-Utilization of Biomass and Natural Gas in an Existing Powerplant Through Primary Steam Reforming of Natural Gas

2006 ◽  
Author(s):  
Frank Delattin ◽  
Svend Bram ◽  
Jacques De Ruyck
Keyword(s):  
Power Plant ◽  
Natural Gas ◽  
Gas Turbines ◽  
Waste Heat ◽  
Internal Combustion ◽  
Combined Cycle ◽  
Biomass Energy ◽  
Small Scale ◽  
Combined Cycles ◽  
External Combustion

Power production from biomass can occur through external combustion (e.g. steam cycles, Organic Rankine Cycles, Stirling engines), or internal combustion after gasification or pyrolysis (e.g. gas engines, IGCC). External combustion has the disadvantage of delivering limited conversion efficiencies (max 35%). Internal combustion has the potential of high efficiencies, but it always needs a severe and mostly problematic gas cleaning. The present article proposes an alternative route where advantages of external firing are combined with potential high efficiency of combined cycles through co-utilization of natural gas and biomass. Biomass is burned to provide heat for partial reforming of the natural gas feed. In this way, biomass energy is converted into chemical energy contained in the produced syngas. Waste heat from the reformer and from the biomass combustor is recovered through a waste heat recovery system. It has been shown in previous papers that in this way biomass can replace up to 5% of the natural gas in steam injected gas turbines and combined cycles, whilst maintaining high efficiencies [1,2]. The present paper proposes the application of this technique as retrofit of an existing combined cycle power plant (Drogenbos, Belgium) where 1% of the natural gas input would be replaced by wood pellets. This represents an installed biomass capacity of 5 MWth from biomass which could serve as a small scale demonstration. The existing plant cycle is first simulated and validated. The simulated cycle is next adapted to partially run on biomass and a retrofit power plant cycle layout is proposed.

Solar Desalination Based on Micro Gas Turbines Driven by Parabolic Dish Collectors

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
David Sánchez ◽  
Miguel Rollán ◽  
Lourdes García-Rodríguez ◽  
Gonzalo S. Martínez
Keyword(s):  
Reverse Osmosis ◽  
Gas Turbines ◽  
Waste Heat ◽  
Economic Assessment ◽  
Integrated System ◽  
Energy Utilization ◽  
Design Parameters ◽  
Small Scale ◽  
Parabolic Dish ◽  
The Cost

Abstract This paper presents the preliminary design and techno-economic assessment of an innovative solar system for the simultaneous production of water and electricity at small scale, based on the combination of a solar micro gas turbine (mGT) and a bottoming desalination unit. To assess this system, a design model is developed to select the main design parameters for two different desalination technologies, reverse osmosis (RO), and multi-effect distillation (MED), aiming to exploit the available electricity and waste heat from the turbine, respectively. The results show that, from a thermodynamic standpoint, it is possible to exceed 65% solar energy utilization if both electricity and waste heat are used to produce fresh water. Nevertheless, the better thermodynamic performance of the fully integrated system does not translate into a more economical production of water. Indeed, the cost of water turns out lower when coupling the solar microturbine and reverse osmosis units only (between 3 and 3.5 €/m3), while making further use of the available waste heat in a multi-effect distillation system rises the cost of water by 15%.

Comparative Performance Analysis of IADR Operating in Natural Gas-Fired and Waste-Heat CHP Modes

2006 ◽  
Author(s):  
Andrei Y. Petrov ◽  
James R. Sand ◽  
Abdolreza Zaltash ◽  
John Fischer ◽  
Rick Mitchell
Keyword(s):  
Natural Gas ◽  
Thermal Energy ◽  
Waste Heat ◽  
Cooling System ◽  
Cost Effective ◽  
Direct Expansion ◽  
Comparative Performance ◽  
Desiccant Wheel ◽  
Absorption Chillers ◽  
Expansion Cooling

Fuel utilization can be dramatically improved through effective recycle of "waste" heat produced as a by-product of on-site or near-site power generation technologies. Development of modular compact cooling, heating, and power (CHP) systems for end-use applications in commercial and institutional buildings is a key part of the Department of Energy's (DOE) energy policy. To effectively use the thermal energy from a wide variety of sources which is normally discarded to the ambient, many components such as heat exchangers, boilers, absorption chillers, and desiccant dehumidification systems must be further developed. Recently a compact, cost-effective, and energy-efficient integrated active-desiccant vapor-compression hybrid rooftop (IADR) unit has been introduced in the market. It combines the advantages of an advanced direct-expansion cooling system with the dehumidification capability of an active desiccant wheel. The aim of this study is to compare the efficiency of the IADR operation in baseline mode, when desiccant wheel regeneration is driven by a natural gas burner, and in CHP mode, when the waste heat recovered from microturbine exhaust gas is used for desiccant regeneration. Comparative analysis shows an excellent potential for more efficient use of the desiccant dehumidification as part of a CHP system and the importance of proper sizing of the CHP components. The most crucial factor in exploiting the efficiency of this application is the maximum use of thermal energy recovered for heating of regeneration air.

scholarly journals 2D Nanomaterials for Effective Energy Scavenging

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Md Al Mahadi Hasan ◽  
Yuanhao Wang ◽  
Chris R. Bowen ◽  
Ya Yang
Keyword(s):  
Large Scale ◽  
Waste Heat ◽  
Material Selection ◽  
Power Supplies ◽  
Small Scale ◽  
Energy Scavenging ◽  
Power Sources ◽  
Practical Applications ◽  
2D Nanomaterials ◽  
Self Powered

AbstractThe development of a nation is deeply related to its energy consumption. 2D nanomaterials have become a spotlight for energy harvesting applications from the small-scale of low-power electronics to a large-scale for industry-level applications, such as self-powered sensor devices, environmental monitoring, and large-scale power generation. Scientists from around the world are working to utilize their engrossing properties to overcome the challenges in material selection and fabrication technologies for compact energy scavenging devices to replace batteries and traditional power sources. In this review, the variety of techniques for scavenging energies from sustainable sources such as solar, air, waste heat, and surrounding mechanical forces are discussed that exploit the fascinating properties of 2D nanomaterials. In addition, practical applications of these fabricated power generating devices and their performance as an alternative to conventional power supplies are discussed with the future pertinence to solve the energy problems in various fields and applications.

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