Production of Synthetic Natural Gas From Carbon Dioxide and Renewably Generated Hydrogen: A Techno-Economic Analysis of a Power-to-Gas Strategy

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
William L. Becker ◽  
Michael Penev ◽  
Robert J. Braun
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Production ◽  
Natural Gas ◽  
Economic Analysis ◽  
Production Costs ◽  
Plant Design ◽  
Low Carbon ◽  
Synthetic Natural Gas ◽  
Methanation Reaction ◽  
Power To Gas

Power-to-gas to energy systems are of increasing interest for low carbon fuels production and as a low-cost grid-balancing solution for renewables penetration. However, such gas generation systems are typically focused on hydrogen production, which has compatibility issues with the existing natural gas pipeline infrastructures. This study presents a power-to-synthetic natural gas (SNG) plant design and a techno-economic analysis of its performance for producing SNG by reacting renewably generated hydrogen from low-temperature electrolysis with captured carbon dioxide. The study presents a “bulk” methanation process that is unique due to the high concentration of carbon oxides and hydrogen. Carbon dioxide, as the only carbon feedstock, has much different reaction characteristics than carbon monoxide. Thermodynamic and kinetic considerations of the methanation reaction are explored to design a system of multistaged reactors for the conversion of hydrogen and carbon dioxide to SNG. Heat recuperation from the methanation reaction is accomplished using organic Rankine cycle (ORC) units to generate electricity. The product SNG has a Wobbe index of 47.5 MJ/m3 and the overall plant efficiency (H2/CO2 to SNG) is shown to be 78.1% LHV (83.2% HHV). The nominal production cost for SNG is estimated at 132 $/MWh (38.8 $/MMBTU) with 3 $/kg hydrogen and a 65% capacity factor. At U.S. DOE target hydrogen production costs (2.2 $/kg), SNG cost is estimated to be as low as 97.6 $/MWh (28.6 $/MMBtu or 1.46 $/kgSNG).

Evaluation of Synthetic Natural Gas Production From Renewably Generated Hydrogen and Carbon Dioxide

2014 ◽  
Author(s):  
W. L. Becker ◽  
R. J. Braun ◽  
M. Penev
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Natural Gas ◽  
The United States ◽  
Methane Content ◽  
Plant Design ◽  
Carbon Oxides ◽  
Synthetic Natural Gas ◽  
Methanation Reaction ◽  
Wobbe Index

The natural gas distribution infrastructure is well developed in many countries, enabling the fuel to be transported long distances via pipelines and easily delivered throughout cities. Using the existing pipeline to transport renewably generated synthetic natural gas (SNG) can leverage the value of the product. While the price of natural gas is near record lows in the United States, many other countries are working to develop SNG as an alternative fuel for transportation markets, especially in Europe and for island nations. This study presents an SNG plant design and evaluates its performance for producing SNG by reacting renewably generated hydrogen with carbon dioxide. The carbon dioxide feedstock is assumed to be captured and scrubbed from an existing coal fired power plant at the city-gate, where the SNG plant is co-located. Historically, methanation has been a common practice for eliminating carbon monoxide and carbon dioxide in various chemical processes such as ammonia production and natural gas purification; for these processes, only small amounts (1–3% molar basis) of carbon oxides need to be converted to methane. A “bulk” methanation process is unique due to the high concentration of carbon oxides and hydrogen. In addition, the carbon dioxide is the only carbon source, and the reaction characteristics of carbon dioxide are much different than carbon monoxide. Thermodynamic and kinetic considerations of the methanation reaction are explored to model and simulate a system of reactors for the conversion of hydrogen and carbon dioxide to SNG. Multiple reactor stages are used to increase temperature control of the reactor and drain water to promote the forward direction of the methanation reaction. Heat recuperation and recovery using organic Rankine cycle units for electricity generation utilizes the heat produced from the methanation reaction. Bulk recycle is used to increase the overall reactant conversion while allowing a satisfactorily high methane content SNG product. A hydrogen membrane separates hydrogen for recycle to increase the Wobbe index of the product SNG by increasing the methane content to nearly 93% by volume. The product SNG has a Wobbe index of 47.5 MJ/m3 which is acceptable for natural gas pipeline transport and end-use appliances in the existing infrastructure. The overall plant efficiency is shown to be 78.1% HHV and 83.2% LHV. The 2nd Law efficiency for the SNG production plant is 84.1%.

scholarly journals Comparative analysis of carbon dioxide methanation technologies for low carbon society development

2020 ◽  
Author(s):  
Gheorghe Lazaroiu ◽  
Dana-Alexandra Ciupageanu ◽  
Lucian Mihaescu ◽  
Rodica-Manuela Grigoriu
Keyword(s):  
Carbon Dioxide ◽  
Conversion Rate ◽  
Renewable Energy Sources ◽  
Clean Energy ◽  
Detailed Comparison ◽  
Co2 Conversion ◽  
Low Carbon ◽  
Co2 Methanation ◽  
Synthetic Natural Gas ◽  
Methanation Reaction

Conversion technologies able to transform renewable energy sources (RES) based electricity in gaseous fuels, which can be stored over long timeframes, represent a key focus point considering the low carbon society development. Thus, Power-to-Gas technologies emerge as a viable solution to mitigate the variability of RES power generation, enabling spatial and temporal balancing of production vs. demand mismatches. An additional benefit in this context is brought by the decarbonization facilities, employing polluting carbon dioxide (CO2) emissions and RES-based electricity to produce synthetic natural gas with high methane (CH4) concentration. The fuel obtained can be stored or injected in the gas distribution infrastructure, becoming a clean energy vector. This paper investigates the functional parameters of such technologies, aiming to comparatively analyze their suitability for further integration in hybrid and ecofriendly energy systems. Given the stability of CO2 molecule, a catalyst must be used to overcome the methanation reaction kinetics limitations. Therefore, the required conditions (in terms of pressure and temperature) for CO2 methanation reaction unfolding are analyzed first. Further, CO2 conversion rate and CH4 selectivity are investigated in order to provide a detailed comparison of available technologies in the field, addressing moreover the particularities of catalyst preparation processes. It is found that Nickel (Ni) based catalysts are performing well, achieving good performances even at atmospheric pressure and low temperatures. It is remarkable that, within a [300,500]℃ temperature range, Ni-based catalysts enable a CO2 conversion rate over 78% with a CH4 selectivity of up to 100%. Last, integration perspectives and benefits are discussed, highlighting the crucial importance of the results presented in this paper.

Optimal Design of Renewable Hydrogen Production for Gas Turbine Test Facilities

2021 ◽  
Author(s):  
M. A. Ancona ◽  
M. Bianchi ◽  
L. Branchini ◽  
A. De Pascale ◽  
F. Ferrari ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Natural Gas ◽  
Gas Turbine ◽  
Calculation Model ◽  
Test Facility ◽  
Design Calculation ◽  
Renewable Source ◽  
Electricity Grid ◽  
Synthetic Natural Gas ◽  
Power To Gas

Abstract The growing attention to environmental issues has led to an increase in renewable source exploitation. These resources, in addition to their characteristic of zero emissions, can be employed where there is no connection to the electricity grid or to produce synthetic fuels (e.g. hydrogen or synthetic natural gas) via power-to-gas technologies. In the context of the ERA-Net Project ZEHTC (Zero Emission Hydrogen Turbine Center), the aim of this paper is the development of a design calculation model for the ZEHTC pilot plant, consisting in the first gas turbine test facility making use of the power produced during tests — along with renewables — for hydrogen production, integrated with batteries. The hydrogen is locally used — mixed with natural gas — to run the gas turbine, reducing its environmental impact. The developed code aims at maximizing the conversion of the renewable source into hydrogen and guaranteeing its availability for the planned tests. It includes physical-mathematical models for each component and has been used to perform a parametric analysis varying the main components size, thus estimating the total produced hydrogen. The main innovation of the ZEHTC micro-grid project consists in the use of a gas turbine — instead of a fuel cell — as system to reconvert the stored hydrogen.

Power and Compression Analysis of Power-To-Gas Implementations in Natural Gas Pipelines With Up to 100% Hydrogen Concentration

2021 ◽  
Author(s):  
Timothy C. Allison ◽  
John Klaerner ◽  
Stefan Cich ◽  
Rainer Kurz ◽  
Marybeth McBain
Keyword(s):  
Natural Gas ◽  
Co2 Emissions ◽  
Production Costs ◽  
Pipeline Transport ◽  
Transport Capacity ◽  
Gas Pipelines ◽  
Electrical Transmission ◽  
High Hydrogen ◽  
Synthetic Natural Gas ◽  
Power To Gas

Abstract The introduction of hydrogen or synthetic natural gas produced from renewable electricity into gas pipelines is being considered to enable decarbonization and energy storage. Prior published studies show that hydrogen concentrations over 20–30% are likely to require significant infrastructure modifications and that significant concentrations of hydrogen will decrease energy transport capacity and/or reduce transport efficiency due to higher compression work. A comparative analysis of four power-to-gas implementations utilizing alkaline electrolysis, steam methane reforming, and catalytic methanation at hydrogen concentrations from 0–100% is performed in order to quantify production and transport power requirements utilizing pipeline or electrical transport. The pipeline transport analysis evaluates the pipeline transport capacity, efficiency, and emissions at various hydrogen concentrations and their sensitivity to pipeline diameter and compressor station spacing. The results show that production costs for hydrogen and synthetic natural gas dominate the overall energy requirement, requiring more power to create product than will be delivered for end use. Pipeline transport power requirements also increase by a maximum factor of 6–8 depending on surface roughness at high hydrogen percentages, but pipeline transport losses are less than electrical transmission losses in all cases. The increased pipeline compression power increases CO2 emissions along the pipeline up to a peak value of 240% relative to pure methane at a mole fraction of 65% hydrogen, above which CO2 emissions reduce. An analysis of pipeline compression conditions shows that flow requirements for all cases exceed the capabilities of reciprocating compressors but are mostly within the capabilities of centrifugal compressors, although multiple bodies may be required at hydrogen concentrations exceeding approximately 40–85%.

Direct conversion of carbon dioxide to liquid fuels and synthetic natural gas using renewable power: Techno-economic analysis

2019 ◽  
Vol 34 ◽  
pp. 293-302 ◽  
Author(s):  
Chundong Zhang ◽  
Ruxing Gao ◽  
Ki-Won Jun ◽  
Seok Ki Kim ◽  
Sun-Mi Hwang ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Natural Gas ◽  
Economic Analysis ◽  
Direct Conversion ◽  
Liquid Fuels ◽  
Synthetic Natural Gas ◽  
Renewable Power

scholarly journals Cost Analysis of Nuclear Hydrogen Production Using IAEA-HEEP 4 Software

2021 ◽  
Vol 2048 (1) ◽  
pp. 012005
Author(s):  
E Dewita ◽  
R Prassanti ◽  
K S Widana ◽  
Y S B Susilo
Keyword(s):  
Carbon Dioxide ◽  
High Temperature ◽  
Hydrogen Production ◽  
Natural Gas ◽  
Production Cost ◽  
Large Scale ◽  
Production Costs ◽  
Outlet Temperature ◽  
Nuclear Heat ◽  
The Cost

Abstract Hydrogen is a commercially important element. Basically, there are several methods of hydrogen production that have been commercially used, such as Steam Methane Reforming (SMR), High Temperature Steam Electrolysis (HTSE), and thermochemical cycles, like Sulphur-Iodine (SI). Among these methods, SMR is the most widely used for large-scale hydrogen production, with conversion efficiency between 74–85% and it has commercially used in some fertilizer industries in Indonesia. Steam reforming is a method to convert alkane (natural gas) compounds to hydrogen and carbon dioxide (synthetic gas) by adding moisture at high pressure and temperature (35-40 bar; 800-900°C). These hydrogen production technologies can be coupled with different nuclear reactors based on the heat required in the process. The High Temperature Gas-cooled Reactor (HTGR) using helium as a coolant, has a high outlet temperature (900°C), so it can potentially be used to supply for process heat for hydrogen production, coal liquefaction/gasification or for other industrial processes requiring high temperature heat. Hydrogen production cost from SMR method is influenced by a range of technical and economic factors. The fuel component of natural gas needed in the SMR method can be replaced by nuclear heat from a nuclear power plant (NPP) operating in cogeneration mode (i.e. simultaneous producing electric power and heat), hence contributing to the reduction of carbon dioxide in the process. In the SMR method, fuel costs are the largest cost component, accounting for between 45% and 75% of production costs. Therefore, there is opportune to assess the economics of hydrogen production by using nuclear heat. The economic evaluation is done by using IAEA HEEP-4 Software. The results comprise cost break up for 2 cases, coupling SMR process for hydrogen production with: (1) 2 HTGRs of 170 MWth/unit; and (2) 1 HTGR of 600 MWth/unit. The cost of hydrogen production is highly depend on the scale of the NPP as energy source and results indicated that hydrogen production cost of the 1 HTGR Unit600 MWth (Case 2) has a lower value (1.72 US$/kgH2), than the cost obtained when 2 HTGR units of 170 MWth each (case 1) are considered (2.72 US$/kgH2). For comparison, the hydrogen production cost by using SMR with carbon capture and storage (CCS) with natural gas as fuel is 2.27 US$/kgH2.

scholarly journals SNG Generation via Power to Gas Technology: Plant Design and Annual Performance Assessment

2020 ◽  
Vol 10 (23) ◽  
pp. 8443
Author(s):  
Alessandra Perna ◽  
Linda Moretti ◽  
Giorgio Ficco ◽  
Giuseppe Spazzafumo ◽  
Laura Canale ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Energy Storage ◽  
Natural Gas ◽  
Electric Energy ◽  
Operation Time ◽  
Plant Performance ◽  
Load Factor ◽  
Plant Design ◽  
Synthetic Natural Gas ◽  
Power To Gas

Power to gas (PtG) is an emerging technology that allows to overcome the issues due to the increasingly widespread use of intermittent renewable energy sources (IRES). Via water electrolysis, power surplus on the electric grid is converted into hydrogen or into synthetic natural gas (SNG) that can be directly injected in the natural gas network for long-term energy storage. The core units of the Power to synthetic natural gas (PtSNG) plant are the electrolyzer and the methanation reactors where the renewable electrolytic hydrogen is converted to synthetic natural gas by adding carbon dioxide. A technical issue of the PtSNG plant is the different dynamics of the electrolysis unit and the methanation unit. The use of a hydrogen storage system can help to decouple these two subsystems and to manage the methanation unit for assuring long operation time and reducing the number of shutdowns. The purpose of this paper is to evaluate the energy storage potential and the technical feasibility of the PtSNG concept to store intermittent renewable sources. Therefore, different plant sizes (1, 3, and 6 MW) have been defined and investigated by varying the ratio between the renewable electric energy sent to the plant and the total electric energy generated by the renewable energy source (RES) facility based on a 12 MW wind farm. The analysis has been carried out by developing a thermochemical and electrochemical model and a dynamic model. The first allows to predict the plant performance in steady state. The second allows to forecast the annual performance and the operation time of the plant by implementing the control strategy of the storage unit. The annual overall efficiencies are in the range of 42–44% low heating value (LHV basis). The plant load factor, i.e., the ratio between the annual chemical energy of the produced SNG and the plant capacity, results equal to 60.0%, 46.5%, and 35.4% for 1, 3, and 6 MW PtSNG sizes, respectively.

scholarly journals CO2 Utilization Technologies: A Techno-Economic Analysis for Synthetic Natural Gas Production

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1258
Author(s):  
Szabolcs Szima ◽  
Calin-Cristian Cormos
Keyword(s):  
Hydrogen Production ◽  
Natural Gas ◽  
Economic Analysis ◽  
Performance Indicators ◽  
Biomass Gasification ◽  
Gas Production ◽  
Synthetic Natural Gas ◽  
Levelized Cost ◽  
Production Capacities ◽  
Renewable Hydrogen

Production of synthetic natural gas (SNG) offers an alternative way to valorize captured CO2 from energy intensive industrial processes or from a dedicated CO2 grid. This paper presents an energy-efficient way for synthetic natural gas production using captured CO2 and renewable hydrogen. Considering several renewable hydrogen production sources, a techno-economic analysis was performed to find a promising path toward its practical application. In the paper, the five possible renewable hydrogen sources (photo fermentation, dark fermentation, biomass gasification, bio photolysis, and PV electrolysis) were compared to the two reference cases (steam methane reforming and water electrolysis) from an economic stand point using key performance indicators. Possible hydrogen production capacities were also considered for the evaluation. From a technical point of view, the SNG process is an efficient process from both energy efficiency (about 57%) and CO2 conversion rate (99%). From the evaluated options, the photo-fermentation proved to be the most attractive with a levelized cost of synthetic natural gas of 18.62 €/GJ. Considering the production capacities, this option loses its advantageousness and biomass gasification becomes more attractive with a little higher levelized cost at 20.96 €/GJ. Both results present the option when no CO2 credit is considered. As presented, the CO2 credits significantly improve the key performance indicators, however, the SNG levelized cost is still higher than natural gas prices.

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