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Hydrogen production from natural gas, combined with advanced CO2 capture technologies, such as iron-based chemical looping (CL), is considered in the present work. The processes are compared to the conventional base case, i.e. hydrogen production via natural gas steam reforming (SR) without CO2 capture. The processes are simulated using commercial software (ChemCAD) and evaluated from a technical point of view considering important key performance indicators such as hydrogen thermal output, net electric power, carbon capture rate and specific CO2 emissions. The environmental evaluation is performed using Life Cycle Analysis (LCA) with the following system boundaries considered: i) hydrogen production from natural gas coupled to CO2 capture technologies based on CL, ii) upstream processes such as: extraction and processing of natural gas, ilmenite and catalyst production and iii) downstream processes such as: H2 and CO2 compression, transport and storage. The LCA assessment was carried out using the GaBi6 software. Different environmental impact categories, following here the CML 2001 impact assessment method, were calculated and used to determine the most suitable technology. Sensitivity analyses of the CO2 compression, transport and storage stages were performed in order to examine their effect on the environmental impact categories. 12th International Conference on Greenhouse Gas Control Technologies, GHGT-12 Energy Procedia, 63 ISSN:1876-6102

Hydrogen is expected to play a significant role in the future energy systems, given the global increase in energy demand, which is driven by the accelerated growth of the world's population, the on-going industrial development and urbanization as well as the higher standards of living and education. In this paper, the life cycle assessment (LCA) methodology is used to evaluate the environmental impact of two different gasification based hydrogen production technologies: hydrogen production by biomass steam gasification in a dual fluidized bed reactor system (DFB) and hydrogen production by gasification of coal and biomass using entrained flow technology (EF). For both hydrogen production pathways the gasification plant, raw materials production, pre-processing, and transportation are included in the life cycle assessment and also hydrogen delivery to consumers. The DFB cases have lower global warming potential than the EF cases. Also the abiotic depletion fossil potential and the human toxicity potential are lower. The acidification and eutrophication potentials are lower for the EF cases.

Decarbonizing the cement manufacturing sector presents an interesting and pressing challenge as it is one of the largest energy consumers in industry (i.e., 7%), emitting considerable amounts of anthropogenic carbon dioxide (i.e., 7%). This paper performs a technical and environmental assessment of decarbonisation of cement production through process modelling and simulation, thermal integration analysis, and Life Cycle Assessment (LCA). Integration of three post-combustion capture methods for a conventional cement plant with an annual productivity of one million tons and a carbon capture rate of 90% is evaluated in comparison to the reference case without carbon capture and storage (CCS). Mass and energy balances derived from simulations are used for the assessment of three innovative capture systems: reactive gas-liquid absorption using Methyl-Di-Ethanol-Amine, reactive gas-solid adsorption using calcium looping (CaL) technology and membrane separation. For the LCA study, a "cradle-to-gate" approach is carried out using GaBi software, according to the ReCiPe impact assessment method. The general conclusion is that integrating the CCS methods into the cement production process leads to a decrease in global warming potential (GWP) in the range of 69.91%-76.74%. Of the CCS technologies analysed, CaL technically outperforms the others as it requires 34% less coal and provides 1.6 times higher gross energy efficiency. From an environmental perspective, CaL integration ranks first, with the lowest scores in six of the nine impact categories and a GWP reduction of 76.74% compared to the baseline scenario without CCS.

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.