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Pierluigi Leone - One of the best experts on this subject based on the ideXlab platform.

  • BioGas blending into the Gas grid of a small municipality for the decarbonization of the heating sector
    Biomass and Bioenergy, 2019
    Co-Authors: Marco Cavana, Pierluigi Leone
    Abstract:

    Abstract The practice of blending bioGas into the Gas network, especially at the distribution level, offers the opportunity to use bioGas as a substitute of Fossil Gas. The ‘greening’ of the Gas network through bioGas blending would indeed take advantage of the robustness and extensiveness of an already existing energy infrastructure. A steady state and multi-component thermal-fluid-dynamic model of the Gas network is applied to a portion of the Italian distribution network. The receiving potential capacity of the existing infrastructure is assessed with respect to bioGas injection. Fluid-dynamic aspects of this practice are considered and commented. The maximum allowable percentage of injectable bioGas (purified from sulphur compounds, O2 and siloxanes but not upgraded to bio-methane by removing CO2) is calculated on a nodal basis, referring to the actual Gas network configuration, and in agreement with the quality constraints set by the current regulation (UNI/TR 11537:2016). A major hypothesis has been assumed in this work: Gas quality requirements are enforced on the network as a whole (i.e., after blending the injected Gas into grid) rather than at the injection point, which is instead the current prescription of most of the EU countries. By exploiting the quality-tracking feature of the model, the constraint on the quality assessment at the injection point is thus relaxed and its effect on the grid Gas quality has been quantified. Results from the case study shows how bioGas blending into the Gas grid may lead to a reduction on the Fossil Natural Gas dependence of up to 4.7%.

  • Synthetic Natural Gas via integrated high-temperature electrolysis and methanation: Part II-Economic analysis
    Journal of Energy Storage, 2015
    Co-Authors: Emanuele Giglio, Andrea Lanzini, Massimo Santarelli, Pierluigi Leone
    Abstract:

    This part II work is built on the energy performance results of part I and focuses on the cost of producing synthetic Natural Gas and sensitivity scenarios around main economic variables.Capital costs for each plant section have been evaluated taking into account operational parameters such as pressure and temperature of the SOEC. The costing and financial methodology is based on a discounted cash flow analysis that was used to calculate the specific cost of synthetic Natural Gas (SNG) which ensures economic profitability of the investment.The co-electrolysis case has higher capital, operating and maintenance costs; however it shows a weaker dependence on the electricity cost due to its higher plant efficiency. The impact of key parameters such as electrolysis stack cost, cell degradation rate and carbon dioxide feedstock cost were further investigated. Both "state-of-the-art" and "target" scenarios were defined to account for the expected enhanced technological maturity of the SOEC technology that is expected to occur in the following decade.For the co-electrolysis case, break-even electricity prices (i.e., costs that yield an SNG cost comparable to that of Fossil Natural Gas) of 8 $/MWh and 67 $/MWh were calculated for "state-of-the-art" and "target" scenarios, respectively.

Stefan Heyne - One of the best experts on this subject based on the ideXlab platform.

  • impact of choice of co2 separation technology on thermo economic performance of bio sng production processes
    International Journal of Energy Research, 2014
    Co-Authors: Stefan Heyne, Simon Harvey
    Abstract:

    Three different CO2 separation technologies for production of synthetic Natural Gas (SNG) from biomass Gasification – amine-based absorption, membrane-based separation and pressure swing adsorption – are investigated for their thermo-economic performance against the background of different possible future energy market scenarios. The studied scale of the SNG plant is a thermal input of 100 MWth,LHV to the Gasifier at a moisture content of 20 wt-% with a preceding drying step reducing the biomass' Natural moisture content of 50 wt-%. Preparation of the CO2-rich stream for carbon capture and storage is investigated for the amine-based absorption and the membrane-based separation technology alternatives. The resulting cold Gas efficiency ηcg for the investigated process alternatives ranges between 0.65 and 0.695. The overall system efficiency ηsys ranges from 0.744 to 0.793, depending on both the separation technology and the background energy system. Amine-based absorption gives the highest cold Gas efficiency whereas the potential for cogeneration of electricity from the process' excess heat is higher for membrane-based separation and pressure swing adsorption. The estimated specific production costs for SNG cSNG for a process input of 90.3 MWth,LHV at 50 wt-% moisture vary between 103–127 €2010/MWhSNG. The corresponding production subsidy level csubsidy needed to achieve end-user purchase price-parity with Fossil Natural Gas is in the range of 56–78 €2010/MWhSNG depending on both the energy market scenario and the CO2 separation technology. Sensitivity analysis on the influence of changes in the total capital cost for the SNG plant on the production cost indicates a decrease of about 12% assuming a 30% reduction in total capital investment. Capture and storage of biogenic CO2 – if included in the emission trading system – only becomes an option at higher CO2 charges. This is due to increased investment costs but, in particular, due to the rather high costs for CO2 transport and storage that have been assumed in this study.

  • Bio-SNG Production via Gasification - Process Integration Aspects for Improving Process Performance
    2013
    Co-Authors: Stefan Heyne, Henrik Thunman, Martin Seemann, Simon Harvey
    Abstract:

    This paper presents results from a comprehensive process integration study of different process alternatives for Bio-SNG production based on biomass Gasification. The influence of the different conversion steps in the process chain – drying, Gasification, Gas cleaning, methanation, and Gas upgrade – on the overall process performance is investigated. Process bottlenecks as well as heat and material integration aspects are highlighted. Using future energy market scenarios, the energetic, economic, and carbon footprint performance of different process configurations are evaluated from a system perspective. About 63 M LHV of Bio-SNG can be produced from a process converting 100 MW th,LHV (20 wt-% moisture) of forestry residues. Drying of the feedstock from a Natural moisture content of 50 wt-% using internal process heat recovery is shown to be important for increasing the process energy efficiency, while the choice of Gasification and methanation technology is shown to be of minor importance from a process integration perspective. Amine-based CO 2 separation for Gas upgrade is shown to be preferable to membrane or pressure-swing adsorption based options both from an economic and Bio-SNG yield perspective. Production cost estimates in the range of 103–112 € 2010 /MWh SNG indicate that price parity with Fossil Natural Gas would require specific and significant support policies.

  • bio sng from thermal Gasification process synthesis integration and performance
    2013
    Co-Authors: Stefan Heyne
    Abstract:

    Biomethane or synthetic Natural Gas (Bio-SNG) produced from Gasified renewable woody biomass is a promising option for replacing Fossil Natural Gas. The complete interchangeability with Natural Gas in all its conventional applications such as in the power generation, transportation and chemical industry sector is of particular interest. This work presents results from a comprehensive process integration study of different process alternatives for Bio-SNG production from Gasified biomass. The influence of the main conversion steps in the process chain – drying, Gasification, Gas cleaning, methanation, and Gas upgrade – on the overall process performance is investigated. Process bottlenecks and both heat and material integration opportunities are highlighted. Using future energy market scenarios the energetic, economic, and carbon footprint performance of the investigated processes are evaluated from a system perspective clearly showing the sensitivity of the obtained results to underlying assumptions. It is shown that drying of the biomass feedstock prior to Gasification using excess process heat – using steam drying or low-temperature air drying technology – is an important aspect for improving the process energy efficiency. The results also indicate that indirect and direct Gasification technologies perform equally well within the overall Bio-SNG production process. Existing infrastructure in the form of biomass-fired combined heat and power plants based on fluidised bed combustion technology presents interesting opportunities for integrating indirect Gasification for Bio-SNG production, with beneficial effects on the cogeneration of electricity from the Bio-SNG process excess heat. The choice of methanation technology between fixed and fluidised bed is not a critical one with respect to process integration, since both technologies allow for efficient heat recovery and consequent cogeneration. For Gas upgrade, in particular removal of CO2 from the product Gas, amine based separation is shown to achieve better energy efficiency and economic performance than membrane based or pressure swing adsorption processes. Preliminary estimations of Bio-SNG costs are significantly higher than current Natural Gas prices, thus dedicated and long term policy measures are necessary in order to stimulate Bio-SNG production. The process integration aspects presented in this thesis can contribute to reducing production costs by increasing energy efficiency and in consequence increasing economic robustness of Bio-SNG process concepts.

  • Process Integration Opportunities for Synthetic Natural Gas (SNG) Production by Thermal Gasification of Biomass
    2010
    Co-Authors: Stefan Heyne
    Abstract:

    Synthetic Natural Gas (SNG) from Gasified biomass is one promising option to produce renewable transport fuels. This thesis presents a process integration study investigating thermal Gasification of biomass for the production of SNG and identifies critical conversion steps for the overall process performance. A base case process consisting of an indirect Gasification unit followed by tar reforming, aminebased CO2 separation, isothermal methanation and, finally, compression, H2-purification by membrane separation and Gas drying is presented. Based on the lower heating value (LHV) of the wet fuel feedstock, the estimated conversion efficiency from biomass to SNG is 69.4 %. The process mass and energy balances are obtained by using flow-sheeting software and are analysed by using pinch methodology. The integration studies performed highlight the significant potential for improvement of the overall process performance offered by integrated feedstock drying. In particular, steam drying and low-temperature air drying – using available process excess heat – are shown to influence the process performance favourably. The integration of SNG production with existing combined heat and power (CHP) steam power plants is proven to be a promising option to efficiently convert excess heat of the SNG process to electricity. The process integration study performed shows that an increased level of thermal integration leads to an increase in electricity production attributed to the SNG process (100 MWLHV dry fuel input) from 2 to 4.9 MW when using steam drying for feedstock drying, and from 0.5 to 5.6 MW for air drying, without any negative effects on SNG yield. Alternative integration opportunities for biomass Gasification not aiming at SNG production specifically, but at replacing Fossil fuels for power production, are also highlighted. Biomass Gasification integrated to a Fossil Natural Gas combined cycle plant results in high biomass-specific electrical efficiencies of up to 49.6 %.

L P L M Rabou - One of the best experts on this subject based on the ideXlab platform.

  • the production of synthetic Natural Gas sng a comparison of three wood Gasification systems for energy balance and overall efficiency
    Biomass & Bioenergy, 2010
    Co-Authors: C M Van Der Meijden, H J Veringa, L P L M Rabou
    Abstract:

    Abstract The production of Synthetic Natural Gas from biomass (Bio-SNG) by Gasification and upgrading of the Gas is an attractive option to reduce CO 2 emissions and replace declining Fossil Natural Gas reserves. Production of energy from biomass is approximately CO 2 neutral. Production of Bio-SNG can even be CO 2 negative, since in the final upgrading step, part of the biomass carbon is removed as CO 2 , which can be stored. The use of biomass for CO 2 reduction will increase the biomass demand and therefore will increase the price of biomass. Consequently, a high overall efficiency is a prerequisite for any biomass conversion process. Various biomass Gasification technologies are suitable to produce SNG. The present article contains an analysis of the Bio-SNG process efficiency that can be obtained using three different Gasification technologies and associated Gas cleaning and methanation equipment. These technologies are: 1) Entrained Flow, 2) Circulating Fluidized Bed and 3) Allothermal or Indirect Gasification. The aim of this work is to identify the Gasification route with the highest process efficiency from biomass to SNG and to quantify the differences in overall efficiency. Aspen Plus ® was used as modeling tool. The heat and mass balances are based on experimental data from literature and our own experience. Overall efficiency to SNG is highest for Allothermal Gasification. The net overall efficiencies on LHV basis, including electricity consumption and pre-treatment but excluding transport of biomass are 54% for Entrained Flow, 58% for CFB and 67% for Allothermal Gasification. Because of the significantly higher efficiency to SNG for the route via Allothermal Gasification, ECN is working on the further development of Allothermal Gasification. ECN has built and tested a 30 kW th lab scale Gasifier connected to a Gas cleaning test rig and methanation unit and presently is building a 0.8 MWth pilot plant, called Milena, which will be connected to the existing pilot scale Gas cleaning.

Simon Harvey - One of the best experts on this subject based on the ideXlab platform.

  • impact of choice of co2 separation technology on thermo economic performance of bio sng production processes
    International Journal of Energy Research, 2014
    Co-Authors: Stefan Heyne, Simon Harvey
    Abstract:

    Three different CO2 separation technologies for production of synthetic Natural Gas (SNG) from biomass Gasification – amine-based absorption, membrane-based separation and pressure swing adsorption – are investigated for their thermo-economic performance against the background of different possible future energy market scenarios. The studied scale of the SNG plant is a thermal input of 100 MWth,LHV to the Gasifier at a moisture content of 20 wt-% with a preceding drying step reducing the biomass' Natural moisture content of 50 wt-%. Preparation of the CO2-rich stream for carbon capture and storage is investigated for the amine-based absorption and the membrane-based separation technology alternatives. The resulting cold Gas efficiency ηcg for the investigated process alternatives ranges between 0.65 and 0.695. The overall system efficiency ηsys ranges from 0.744 to 0.793, depending on both the separation technology and the background energy system. Amine-based absorption gives the highest cold Gas efficiency whereas the potential for cogeneration of electricity from the process' excess heat is higher for membrane-based separation and pressure swing adsorption. The estimated specific production costs for SNG cSNG for a process input of 90.3 MWth,LHV at 50 wt-% moisture vary between 103–127 €2010/MWhSNG. The corresponding production subsidy level csubsidy needed to achieve end-user purchase price-parity with Fossil Natural Gas is in the range of 56–78 €2010/MWhSNG depending on both the energy market scenario and the CO2 separation technology. Sensitivity analysis on the influence of changes in the total capital cost for the SNG plant on the production cost indicates a decrease of about 12% assuming a 30% reduction in total capital investment. Capture and storage of biogenic CO2 – if included in the emission trading system – only becomes an option at higher CO2 charges. This is due to increased investment costs but, in particular, due to the rather high costs for CO2 transport and storage that have been assumed in this study.

  • Bio-SNG Production via Gasification - Process Integration Aspects for Improving Process Performance
    2013
    Co-Authors: Stefan Heyne, Henrik Thunman, Martin Seemann, Simon Harvey
    Abstract:

    This paper presents results from a comprehensive process integration study of different process alternatives for Bio-SNG production based on biomass Gasification. The influence of the different conversion steps in the process chain – drying, Gasification, Gas cleaning, methanation, and Gas upgrade – on the overall process performance is investigated. Process bottlenecks as well as heat and material integration aspects are highlighted. Using future energy market scenarios, the energetic, economic, and carbon footprint performance of different process configurations are evaluated from a system perspective. About 63 M LHV of Bio-SNG can be produced from a process converting 100 MW th,LHV (20 wt-% moisture) of forestry residues. Drying of the feedstock from a Natural moisture content of 50 wt-% using internal process heat recovery is shown to be important for increasing the process energy efficiency, while the choice of Gasification and methanation technology is shown to be of minor importance from a process integration perspective. Amine-based CO 2 separation for Gas upgrade is shown to be preferable to membrane or pressure-swing adsorption based options both from an economic and Bio-SNG yield perspective. Production cost estimates in the range of 103–112 € 2010 /MWh SNG indicate that price parity with Fossil Natural Gas would require specific and significant support policies.

Jeongwoo Han - One of the best experts on this subject based on the ideXlab platform.

  • Life-cycle energy use and greenhouse Gas emissions of production of bioethanol from sorghum in the United States
    Biotechnology for Biofuels, 2013
    Co-Authors: Hao Cai, Jennifer B. Dunn, Jeongwoo Han, Zhichao Wang, Michael Q Wang
    Abstract:

    Background The availability of feedstock options is a key to meeting the volumetric requirement of 136.3 billion liters of renewable fuels per year beginning in 2022, as required in the US 2007 Energy Independence and Security Act. Life-cycle greenhouse Gas (GHG) emissions of sorghum-based ethanol need to be assessed for sorghum to play a role in meeting that requirement. Results Multiple sorghum-based ethanol production pathways show diverse well-to-wheels (WTW) energy use and GHG emissions due to differences in energy use and fertilizer use intensity associated with sorghum growth and differences in the ethanol conversion processes. All sorghum-based ethanol pathways can achieve significant Fossil energy savings. Relative to GHG emissions from conventional Gasoline, grain sorghum-based ethanol can reduce WTW GHG emissions by 35% or 23%, respectively, when wet or dried distillers grains with solubles (DGS) is the co-product and Fossil Natural Gas (FNG) is consumed as the process fuel. The reduction increased to 56% or 55%, respectively, for wet or dried DGS co-production when renewable Natural Gas (RNG) from anaerobic digestion of animal waste is used as the process fuel. These results do not include land-use change (LUC) GHG emissions, which we take as negligible. If LUC GHG emissions for grain sorghum ethanol as estimated by the US Environmental Protection Agency (EPA) are included (26 g CO_2e/MJ), these reductions when wet DGS is co-produced decrease to 7% or 29% when FNG or RNG is used as the process fuel. Sweet sorghum-based ethanol can reduce GHG emissions by 71% or 72% without or with use of co-produced vinasse as farm fertilizer, respectively, in ethanol plants using only sugar juice to produce ethanol. If both sugar and cellulosic baGasse were used in the future for ethanol production, an ethanol plant with a combined heat and power (CHP) system that supplies all process energy can achieve a GHG emission reduction of 70% or 72%, respectively, without or with vinasse fertigation. Forage sorghum-based ethanol can achieve a 49% WTW GHG emission reduction when ethanol plants meet process energy demands with CHP. In the case of forage sorghum and an integrated sweet sorghum pathway, the use of a portion of feedstock to fuel CHP systems significantly reduces Fossil fuel consumption and GHG emissions. Conclusions This study provides new insight into life-cycle energy use and GHG emissions of multiple sorghum-based ethanol production pathways in the US. Our results show that adding sorghum feedstocks to the existing options for ethanol production could help in meeting the requirements for volumes of renewable, advanced and cellulosic bioethanol production in the US required by the EPA’s Renewable Fuel Standard program.

  • Well-to-wheels analysis of fast pyrolysis pathways with the GREET model.
    2011
    Co-Authors: Jeongwoo Han, Amgad Elgowainy, Jennifer B. Dunn, Ignasi Palou-rivera, Michael Q Wang
    Abstract:

    The pyrolysis of biomass can help produce liquid transportation fuels with properties similar to those of petroleum Gasoline and diesel fuel. Argonne National Laboratory conducted a life-cycle (i.e., well-to-wheels [WTW]) analysis of various pyrolysis pathways by expanding and employing the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) model. The WTW energy use and greenhouse Gas (GHG) emissions from the pyrolysis pathways were compared with those from the baseline petroleum Gasoline and diesel pathways. Various pyrolysis pathway scenarios with a wide variety of possible hydrogen sources, liquid fuel yields, and co-product application and treatment methods were considered. At one extreme, when hydrogen is produced from Natural Gas and when bio-char is used for process energy needs, the pyrolysis-based liquid fuel yield is high (32% of the dry mass of biomass input). The reductions in WTW Fossil energy use and GHG emissions relative to those that occur when baseline petroleum fuels are used, however, is modest, at 50% and 51%, respectively, on a per unit of fuel energy basis. At the other extreme, when hydrogen is produced internally via reforming of pyrolysis oil and when bio-char is sequestered in soil applications, the pyrolysis-based liquid fuel yield is low (15%more » of the dry mass of biomass input), but the reductions in WTW Fossil energy use and GHG emissions are large, at 79% and 96%, respectively, relative to those that occur when baseline petroleum fuels are used. The petroleum energy use in all scenarios was restricted to biomass collection and transportation activities, which resulted in a reduction in WTW petroleum energy use of 92-95% relative to that found when baseline petroleum fuels are used. Internal hydrogen production (i.e., via reforming of pyrolysis oil) significantly reduces Fossil fuel use and GHG emissions because the hydrogen from fuel Gas or pyrolysis oil (renewable sources) displaces that from Fossil fuel Natural Gas and the amount of Fossil Natural Gas used for hydrogen production is reduced; however, internal hydrogen production also reduces the potential petroleum energy savings (per unit of biomass input basis) because the fuel yield declines dramatically. Typically, a process that has a greater liquid fuel yield results in larger petroleum savings per unit of biomass input but a smaller reduction in life-cycle GHG emissions. Sequestration of the large amount of bio-char co-product (e.g., in soil applications) provides a significant carbon dioxide credit, while electricity generation from bio-char combustion provides a large energy credit. The WTW energy and GHG emissions benefits observed when a pyrolysis oil refinery was integrated with a pyrolysis reactor were small when compared with those that occur when pyrolysis oil is distributed to a distant refinery, since the activities associated with transporting the oil between the pyrolysis reactors and refineries have a smaller energy and emissions footprint than do other activities in the pyrolysis pathway.« less

  • Energy and Greenhouse Gas Emissions of Renewable Natural Gas as Vehicle Fuel
    Transportation Research Record, 2011
    Co-Authors: Marianne Mintz, Jeongwoo Han
    Abstract:

    Today more than 300 million standard cubic feet per day of Natural Gas and 1,680 MW of electricity are produced from the decomposition of organic waste at 541 U.S. landfills. Since landfill Gas (LFG) is a renewable resource, this energy is considered renewable. When used as a vehicle fuel, LFG-based compressed Natural Gas (CNG) consumes up to 1,100 Btu of Fossil fuel and generates up to 120 g of carbon dioxide equivalent (gCO2e) greenhouse Gas emissions per mile on a well-to-wheel basis. This amount compares with about 7,500 Btu and 500 gCO2e per mile for CNG from Fossil Natural Gas and 8,000 Btu and 650 gCO2e per mile for petroleum Gasoline. Liquefying the LFG consumes another 400+ Btu of Fossil fuel and 30+ gCO2e per mile if grid electricity is used for the process. However, if some of the LFG is used to generate electricity for Gas cleanup and liquefaction (or compression), liquefied Natural Gas (or CNG) produced from LFG can have no Fossil fuel input and only minimal CO2e emissions on a well-to-wheel ...

  • Well-to-Wheels analysis of landfill Gas-based pathways and their addition to the GREET model.
    2010
    Co-Authors: Marianne Mintz, Jeongwoo Han, M. Wang, C. Saricks
    Abstract:

    Today, approximately 300 million standard cubic ft/day (mmscfd) of Natural Gas and 1600 MW of electricity are produced from the decomposition of organic waste at 519 U.S. landfills (EPA 2010a). Since landfill Gas (LFG) is a renewable resource, this energy is considered renewable. When used as a vehicle fuel, compressed Natural Gas (CNG) produced from LFG consumes up to 185,000 Btu of Fossil fuel and generates from 1.5 to 18.4 kg of carbon dioxide-equivalent (CO{sub 2}e) emissions per million Btu of fuel on a 'well-to-wheel' (WTW) basis. This compares with approximately 1.1 million Btu and 78.2 kg of CO{sub 2}e per million Btu for CNG from Fossil Natural Gas and 1.2 million Btu and 97.5 kg of CO{sub 2}e per million Btu for petroleum Gasoline. Because of the additional energy required for liquefaction, LFG-based liquefied Natural Gas (LNG) requires more Fossil fuel (222,000-227,000 Btu/million Btu WTW) and generates more GHG emissions (approximately 22 kg CO{sub 2}e /MM Btu WTW) if grid electricity is used for the liquefaction process. However, if some of the LFG is used to generate electricity for Gas cleanup and liquefaction (or compression, in the case of CNG), vehicle fuel produced from LFG can have no Fossilmore » fuel input and only minimal GHG emissions (1.5-7.7 kg CO{sub 2}e /MM Btu) on a WTW basis. Thus, LFG-based Natural Gas can be one of the lowest GHG-emitting fuels for light- or heavy-duty vehicles. This report discusses the size and scope of biomethane resources from landfills and the pathways by which those resources can be turned into and utilized as vehicle fuel. It includes characterizations of the LFG stream and the processes used to convert low-Btu LFG into high-Btu renewable Natural Gas (RNG); documents the conversion efficiencies and losses of those processes, the choice of processes modeled in GREET, and other assumptions used to construct GREET pathways; and presents GREET results by pathway stage. GREET estimates of well-to-pump (WTP), pump-to-wheel (PTW), and WTW energy, Fossil fuel, and GHG emissions for each LFG-based pathway are then summarized and compared with similar estimates for Fossil Natural Gas and petroleum pathways.« less