Life cycle assessment of hydrogen production by thermal cracking of methane based on liquid-metal technology

Abstract Thermal cracking of methane into carbon and hydrogen is considered as potential hydrogen production technology without direct CO 2 -emissions. In this work, a novel methane-cracking process based on a liquid-metal technology is analyzed using life cycle assessment to evaluate the process' environmental impacts. Based on lab-scale experimental data, the novel methane-cracking process is benchmarked against the existing hydrogen production routes: steam reforming and water electrolysis. We consider the following environmental impact categories: global warming, fossil depletion, metal depletion, and particulate matter formation. According to our analysis, the methane-cracking process can reduce the global warming impact by up to 64% compared to steam reforming. However, the fossil depletion impact is higher for the methane-cracking process due to the higher methane input. The fossil depletion impact can be reduced by utilizing the energy of co-produced carbon to increase process efficiency at the expense of additional CO 2 -emissions. Methane supply to the process and electricity demand for H 2 -separation were identified as crucial parameters for the process’ environmental impacts. Thus, we perform parameter studies on alternatives for supply of methane and electricity to identify locations where lowest environmental impacts can be achieved.

[1]  André Bardow,et al.  Comparative LCA of multi-product processes with non-common products: a systematic approach applied to chlorine electrolysis technologies , 2013, The International Journal of Life Cycle Assessment.

[2]  Richard D. Doctor,et al.  Hydrogen Production by Direct Contact Pyrolysis of Natural Gas , 2003 .

[3]  Reinout Heijungs,et al.  Identifying best existing practice for characterization modeling in life cycle impact assessment , 2012, The International Journal of Life Cycle Assessment.

[4]  Gilles Flamant,et al.  Co-production of hydrogen and carbon black from solar thermal methane splitting in a tubular reactor prototype , 2011 .

[5]  Robert M. Enick,et al.  Hydrogen permeance of palladium–copper alloy membranes over a wide range of temperatures and pressures , 2004 .

[6]  C. Rubbia,et al.  Thermal cracking of methane into Hydrogen for a CO2-free utilization of natural gas , 2013 .

[7]  R. K. Rathnam,et al.  Thermal cracking of methane in a liquid metal bubble column reactor: Experiments and kinetic analysis , 2015 .

[8]  I. Dincer,et al.  Environmental impact assessment and comparison of some hydrogen production options , 2015 .

[9]  Boštjan Drobnič,et al.  Life-cycle assessment of a hydrogen-based uninterruptible power supply system using renewable energy , 2014, The International Journal of Life Cycle Assessment.

[10]  Alan W. Weimer,et al.  Solar-thermal dissociation of methane in a fluid-wall aerosol flow reactor , 2004 .

[11]  André Sternberg,et al.  Power-to-What? : Environmental assessment of energy storage systems , 2015 .

[12]  David Pennington,et al.  Recent developments in Life Cycle Assessment. , 2009, Journal of environmental management.

[13]  G. Naterer,et al.  Life cycle assessment of various hydrogen production methods , 2012 .

[14]  J. Fierro,et al.  Life cycle assessment of alternatives for hydrogen production from renewable and fossil sources , 2012 .

[15]  Denise Ott,et al.  Rules and benefits of Life Cycle Assessment in green chemical process and synthesis design: a tutorial review , 2015 .

[16]  O. Machhammer,et al.  Financial and Ecological Evaluation of Hydrogen Production Processes on Large Scale , 2016 .

[17]  P. Ekins,et al.  Hydrogen and fuel cell technologies for heating: A review , 2015 .

[18]  Jianli Hu,et al.  An overview of hydrogen production technologies , 2009 .

[19]  Eric Croiset,et al.  Review of methane catalytic cracking for hydrogen production , 2011 .

[20]  D. Agar,et al.  Decarbonisation of fossil energy via methane pyrolysis using two reactor concepts: Fluid wall flow reactor and molten metal capillary reactor , 2015 .

[21]  Nazim Muradov,et al.  Thermocatalytic decomposition of natural gas over plasma-generated carbon aerosols for sustainable production of hydrogen and carbon , 2009 .

[22]  Carlo Rubbia,et al.  Development of methane decarbonisation based on liquid metal technology for CO2-free production of hydrogen , 2016 .

[23]  R. K. Rathnam,et al.  Experimental investigation and thermo-chemical modeling of methane pyrolysis in a liquid metal bubble column reactor with a packed bed , 2015 .

[24]  Michael Müller,et al.  Carbon Dioxide-Free Hydrogen Production with Integrated Hydrogen Separation and Storage. , 2017, ChemSusChem.

[25]  Reinout Heijungs,et al.  Allocation and 'what-if' scenarios in life cycle assessment of waste management systems. , 2007, Waste management.

[26]  Carlo Rubbia,et al.  Hydrogen production via methane pyrolysis in a liquid metal bubble column reactor with a packed bed , 2016 .

[27]  W. Bujalski,et al.  Effects of thin film Pd deposition on the hydrogen permeability of Pd60Cu40 wt% alloy membranes , 2015 .

[28]  José M. Martínez-Val,et al.  Experimental analysis of direct thermal methane cracking , 2011 .

[29]  Christopher J. Koroneos,et al.  Life cycle assessment of hydrogen fuel production processes , 2004 .

[30]  Carlo Rubbia,et al.  Technological challenges for industrial development of hydrogen production based on methane cracking , 2012 .