| 1. |
- Andersson, Viktor, 1983, et al.
(author)
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Integration of algae-based biofuel production with an oil refinery: Energy and carbon footprint assessment
- 2020
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In: International Journal of Energy Research. - : Hindawi Limited. - 1099-114X .- 0363-907X. ; 44:13, s. 10860-10877
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Journal article (peer-reviewed)abstract
- Biofuel production from algae feedstock has become a topic of interest in the recent decades since algae biomass cultivation is feasible in aquaculture and does therefore not compete with use of arable land. In the present work, hydrothermal liquefaction of both microalgae and macroalgae is evaluated for biofuel production and compared with transesterifying lipids extracted from microalgae as a benchmark process. The focus of the evaluation is on both the energy and carbon footprint performance of the processes. In addition, integration of the processes with an oil refinery has been assessed with regard to heat and material integration. It is shown that there are several potential benefits of co-locating an algae-based biorefinery at an oil refinery site and that the use of macroalgae as feedstock is more beneficial than the use of microalgae from a system energy performance perspective. Macroalgae-based hydrothermal liquefaction achieves the highest system energy efficiency of 38.6%, but has the lowest yield of liquid fuel (22.5 MJ per 100 MJalgae) with a substantial amount of solid biochar produced (28.0 MJ per 100 MJalgae). Microalgae-based hydrothermal liquefaction achieves the highest liquid biofuel yield (54.1 MJ per 100 MJalgae), achieving a system efficiency of 30.6%. Macro-algae-based hydrothermal liquefaction achieves the highest CO2 reduction potential, leading to savings of 24.5 resp 92 kt CO2eq/year for the two future energy market scenarios considered, assuming a constant feedstock supply rate of 100 MW algae, generating 184.5, 177.1 and 229.6 GWhbiochar/year, respectively. Heat integration with the oil refinery is only possible to a limited extent for the hydrothermal liquefaction process routes, whereas the lipid extraction process can benefit to a larger extent from heat integration due to the lower temperature level of the process heat demand.
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| 2. |
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| 3. |
- Arvidsson, Maria, 1984, et al.
(author)
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Integration opportunities for substitute natural gas (SNG) production in an industrial process plant
- 2012
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In: CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference PRES.
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Conference paper (peer-reviewed)abstract
- The integration opportunities for SNG production based on thermal gasification of lignocellulosic biomass in one of the production plants currently importing natural gas for further processing to speciality chemicals was studied. To solve material and energy balances, the SNG process was modeled in Aspen Plus. Three opportunities for SNG process heat recovery was studied, i.e., the steam production potential from the SNG process excess heat, the electricity production potential by maximizing the heat recovery in the SNG process without additional fuel firing, and the electricity production potential with increased steam cycle efficiency and additional fuel firing. About 217 MwLHV of woody biomass were required to substitute the site's natural gas demand with SNG. There is a potential to recover heat from the SNG process to completely cover the site's net steam demand or to produce enough electricity to cover the demand of the SNG process. There is also a possibility to fully exploit the heat pockets in the SNG process Grand Composite Curve resulting in an increase of the steam cycle electricity output. This is an abstract of a paper presented at the CHISA 2012 - 20th International Congress of Chemical and Process Engineering and PRES 2012 - 15th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction
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| 4. |
- Arvidsson, Maria, 1984, et al.
(author)
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Integration opportunities for Substitute Natural Gas (SNG) production in an industrial process plant
- 2012
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In: Chemical Engineering Transactions. - 2283-9216 .- 2283-9216. ; 29, s. 331-336
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Journal article (peer-reviewed)abstract
- This paper investigates opportunities for integration of a Substitute Natural Gas (SNG) process based on thermal gasification of lignocellulosic biomass in an industrial process plant currently importing natural gas (NG) for further processing to speciality chemicals. The assumed SNG process configuration is similar to that selected for the ongoing Gothenburg Biomass Gasification demonstration project (GoBiGas) and is modelled in Aspen Plus. The heat and power integration potentials are investigated using Pinch Analysis tools. Three cases have been investigated: the steam production potential from the SNG process excess heat, the electricity production potential by maximizing the heat recovery in the SNG process without additional fuel firing, and the electricity production potential with increased steam cycle efficiency and additional fuel firing. The results show that 217 MWLHV of woody biomass are required to substitute the site's natural gas demand with SNG (162 MWLHV). The results indicate that excess heat from the SNG process has the potential to completely cover the site's net steam demand (19 MW) or to produce enough electricity to cover the demand of the SNG process (21 MW el). The study also shows that it is possible to fully exploit the heat pockets in the SNG process Grand Composite Curve (GCC) resulting in an increase of the steam cycle electricity output. In this case, there is a potential to cover the site's net steam demand and to produce 30 MWel with an efficiency of 1 MWel/MWadded heat. However, this configuration requires combustion of 36 MWLHV of additional fuel, resulting in a marginal generation efficiency of 0.80 MW el/MWfuel (i.e. comparing the obtained electricity production potentials with and without additional fuel firing).
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| 5. |
- Bokinge, Pontus, et al.
(author)
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Renewable OME from biomass and electricity—Evaluating carbon footprint and energy performance
- 2020
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In: Energy Science and Engineering. - : Wiley. - 2050-0505. ; 8:7, s. 2587-2598
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Journal article (peer-reviewed)abstract
- Energy Science & Engineering published by the Society of Chemical Industry and John Wiley & Sons Ltd. Renewable drop-in fuels provide a short- to medium-term solution to decreasing carbon dioxide emissions from the transport sector. Polyoxymethylene ethers (OME) are among interesting candidates with production pathways both from biomass (bio-OME) as well as electricity and CO2 (e-OME) proposed. In the present study, both bio- and e-OME production via methanol are assessed for energy performance and carbon footprint. Process integration methods are applied to evaluate synergies from colocating methanol production with further conversion to OME. Even a hybrid process, combing bio- and e-OME production is evaluated. The energy efficiency of bio-OME is considerably higher than for the e-OME pathway, and colocation synergies are more evident for bio-OME. Carbon footprint is evaluated according to EUs recast Renewable Energy Directive (RED II). If renewable electricity and natural gas are used for power and heat supply, respectively, results indicate that all pathways may be counted toward the renewable fuel targets under RED II. The largest emissions reduction is 92.8% for colocated hybrid-OME production. Carbon footprints of e- and hybrid-OME are highly sensitive to the carbon intensity of electricity, and the carbon intensity of the heat supply has a major impact on results for all pathways except colocated bio- and hybrid-OME.
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| 6. |
- Heyne, Stefan, 1979, et al.
(author)
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Assessment of the energy and economic performance of second generation biofuel production processes using energy market scenarios
- 2013
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In: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 101, s. 203-212
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Journal article (peer-reviewed)abstract
- In this paper performance assessment of second generation biofuel production using energy market scenarios and system-level performance indicators is proposed. During biofuel production a number of products and services can be co-generated while import of energy services (e.g. electricity and heat) in addition to the fuel supply may also be needed. This needs to be reflected by a well-defined performance indicator enabling a comparison between different process alternatives. A marginal production perspective is proposed in this study for the definition of a general energy performance indicator, recalculating all services to primary energy on a system level. The Energy Price and Carbon Balance Scenarios (ENPAC) tool developed at Chalmers is used for the definition of the energy system background. Thereby, a scenariospecific comparison of the processes’ thermodynamic, economic and carbon footprint performance ispossible. The usefulness of the approach is illustrated for production of synthetic natural gas (SNG) from biomass. The shortcomings of common performance indicators are also discussed.
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| 7. |
- Heyne, Stefan, 1979
(author)
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Bio-SNG from Thermal Gasification - Process Synthesis, Integration and Performance
- 2013
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Doctoral thesis (other academic/artistic)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.
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| 8. |
- Heyne, Stefan, 1979, et al.
(author)
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Bio-SNG Production via Gasification - Process Integration Aspects for Improving Process Performance
- 2013
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In: Proceedings of the 21st European Biomass Conference and Exhbition. - 2282-5819. - 9788889407530 ; , s. 1291 - 1304
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Conference paper (peer-reviewed)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 MLHV of Bio-SNG can be produced from a process converting 100 MWth,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 CO2 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/MWhSNG indicate that price parity with fossil natural gas would require specific and significant support policies.
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| 9. |
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| 10. |
- Heyne, Stefan, 1979, et al.
(author)
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Coal and biomass gasification for sng production
- 2016
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In: Synthetic Natural Gas from Coal and Dry Biomass, and Power?to?Gas Applications. - Hoboken, NJ, USA : John Wiley & Sons, Inc.. - 9781119191339 ; , s. 5-40
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Book chapter (other academic/artistic)abstract
- Within the production of synthetic natural gas - basically methane-from solid feed stock such as coal or biomass the major conversion step is gasification, generating a product gas containing a mixture of permanent and condensable gases, as well as solid residues. The gasification step can be conducted in different atmospheres and using different reaction agents. This chapter discusses the role of gasification for the overall substitute natural gas (SNG) process, and the basic thermodynamic aspects within gasification. The gasification process is a series of different conversions involving both homogeneous and heterogeneous reactions. The basic steps from solid fuel to product gas are drying, pyrolysis, and gasification. From a technological viewpoint, there basically exist three different gasification reactor types that are used at large scale: fixed bed reactors, entrained flow reactors, and fluidized bed reactors. Coal is mainly used in entrained flow gasification or fixed bed units, whereas biomass gasification is mostly done in fluidized bed reactors. © 2016 by John Wiley & Sons, Inc. All rights reserved.
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