Riikonen A.,Gasum OY |
International Gas Research Conference Proceedings | Year: 2011
This paper analyses LNG properties of the world LNG market and compares them with European pipeline gases. The target is to analyse which LNG qualities can be regasificated and fed directly to the natural gas pipeline network without any processing. The target is also to find LNG qualities that can be used as ferry and ship fuel.
Suomalainen M.S.,VTT Technical Research Center of Finland |
Arasto A.,VTT Technical Research Center of Finland |
Teir S.,VTT Technical Research Center of Finland |
Siitonen S.,Gasum OY
Energy Procedia | Year: 2013
This paper describes modifications to improve the feasibility of a pre-combustion CCS concept for a gas turbine combined cycle. A natural gas-fired greenfield combined heat and power (CHP) plant equipped with pre-combustion capture was used as a base case, for which various improvement options were identified, assessed and selected. The base case was modified using the selected improvement options, after which the investment costs were re-evaluated. The results showed that the investment cost can be reduced with 8 % by excluding the pre-reformer and the low temperature water-gas-shift reactor from the reforming process. The exclusion of the pre-reformer did not affect the performance of the plant, but the exclusion of the low temperature water-gas-shift reactor led to higher CO2 emissions.
Siitonen S.,Gasum OY |
Pirhonen L.,AF Consult Oy
International Gas Union World Gas Conference Papers | Year: 2012
Climate change is one of the biggest challenges of our time, and carbon capture and storage (CCS) is expected to play a significant role in reducing carbon dioxide emissions worldwide and abating climate change. This study analyses how the integration of pre-combustion carbon capture technology in the gas-fired combined heat and power (CHP) plant affects the efficiency, power-to-heat ratio, CO2 emissions and costs of the power plant. The study shows that carbon capture reduces the efficiency of the combined cycle gas turbine power plant by 11 %-points. Same time, the power-to-heat ratio increases due to the fact that carbon capture reduces heat production of the plant more than electricity production. The investment in greenfield gas turbine combined cycle CHP power plant with pre-combustion carbon capture technology would not be a reasonable investment with the current prices of electricity, heat, and emission allowances.
Kohla T.,Aalto University |
Laukkanena T.,Aalto University |
Tuomaalaa M.,Aalto University |
Niskanenb T.,Gasum OY |
And 3 more authors.
Proceedings of the 26th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2013 | Year: 2013
Fossil fuels applied in energy generation-, transport- and refinery processes can be replaced by biofuels. This offers plenty processing options for biomass resources such as thermo-chemical. For process evaluation different criteria is applied, usually including costs, energy efficiency and CO2 emission. However, comparative evaluation of the energy efficiency is difficult since no general standard method exists. The objective of this paper is to compare different methods of energy efficiency and CO2 emission assessment in order to systematically analyse their differences qualitatively and quantitatively. The methods include a general engineering approach, CO2 assessment according to the EU's Renewable Energy Sources Directive, primary energy efficiency analysis (incl. CO2 assessment) and exergy analysis. In this paper the methods are compared, based on a case study of Bio-SNG generation from woody biomass (simulated with Aspen+). The work shows the differences of the methods when applied to the same process allowing critical discussions of the methods applicability and providing a starting point for the future work on developing novel energy efficiency and CO2 emission assessment methods.
Kohl T.,Aalto University |
Laukkanen T.,Aalto University |
Tuomaala M.,Aalto University |
Niskanen T.,Gasum OY |
And 3 more authors.
Energy | Year: 2014
The goal of biofuel production is to partially replace fossil fuels in energy generation and transport. For the evaluation of biofuel production processes different criteria are applied and usually they include costs, efficiency aspects and emissions. However, evaluation of the energy efficiency of biofuels production is difficult since no general standard method exists for that. This paper compares three different assessment methods of energy efficiency both qualitatively and quantitatively. The methods are: thermal efficiency, exergy analysis and primary energy analysis. The feasibility of the methods is tested on a Bio-SNG (synthetic natural gas) production process which was modelled in AspenPlus and MS Excel. The results show that the exergy analysis seems to be advantageous when it comes to detailed (sub-) process analysis whereas the primary energy analysis offers the advantage of showing how the system is influencing the global primary energy resources. The results obtained by the thermal efficiency analysis do not add any new information to the results obtained by exergy and primary energy analyses. Exergy and primary energy analyses should be the preferred means for process assessment. Especially a combination of the two methods could offer the chance to develop a more holistic energy efficiency indicator. © 2014 Elsevier Ltd.