Solar thermochemical production of hydrogen: Steady-state and dynamic modeling of a Hybrid- Sulfur Process coupled to a solar tower

Transcription

1 Solar thermochemical production of hydrogen: Steady-state and dynamic modeling of a Hybrid- Sulfur Process coupled to a solar tower Nicolas Bayer-Botero, Alejandro Guerra Niehoff, Dennis Thomey, Martin Roeb*, Christian Sattler, Robert Pitz-Paal DLR, Institute of Solar Research WHEC 2014, Gwangju, 18 June 2014

2 Chart 2 Outline Introduction Process Model and Simulation Thermal management and balancing Summary Outlook: Demonstration Project SOL2HY2 2 2

3 Chart 3 Chemical Reactions for Solar Fuel Production and Storage O 2 MO x O 2 H 2 SO 4 H 2 O Storage Material MO x-1 CO 2 H 2 O CO/H 2 Storage Material SO 2 H 2 3

4 Chart 4 Hybrid Sulfur Cycle (HyS) Oxygen Water Hydrogen Heat C Electricity High temperature step Electrolysis 4

5 Chart 5 Receiver-Reactor realised Hythec HycycleS 5

6 Chart 6 Solar reactor: H 2 SO 4 evaporation and SO 3 decomposition H 2 SO 4 SO 3 + H 2 O Catalyst materials Coated on SiSiC honeycomb 400 C Construction materials Solar absorbers SiSiC foam SiSiC honeycomb Piping High-alloyed steel 850 C SO 3 SO 2 + ½ O 2 6

7 Chart 7 Operation in solar furnace 7

8 Chart 8 Scale-up study of solar HyS process 8

9 Chart 9 Process Simulation 9

10 Chart 10 Scheme of Process coupled to a Solar Tower Low temperature energy supply High temperature energy supply 10

11 Chart 11 Process flow diagram of HyS process 11

12 Chart 12 Thermal management Heat Sources / kj/mol Sum Cracking Concentration Gas separation Auxiliary steps Heat sinks / kj/mol 1500 Sum Cracking Concentration Gas separation Auxiliary steps decomposer temperature / K decomposer temperature / K Temperature dependency of heat sources and sinks (62 %-wt.) 12

13 Chart 13 Heat demand of the process Gross heat demand / kj/mol %-wt 62.5 %-wt 75 %-wt decomposer temperature / K Net heat demand / kj/mol %-wt 62.5 %-wt 75 %-wt decomposer temperature / K Gross heat demand of dynamic section (no heat recovery) Net heat demand of dynamic section (with idealised 100 % heat recovery) 13

14 Chart 14 Energy balance / estimate of annual overall efficiency Scenario A (conservative approach): Heat recovery is excluded due to technical challenges. Recovered heat is not exchanged between the stationary and dynamic process section ηη pppppppppppppp = 0.35 HH ii,hh22 qq ssssssss + qq dddddd + pp eeee ηη tttt eeee Scenario B (simplified progressive approach): Heat recovery can be fully recovered until reaching the pinch point temperature. Heat can be exchanged between the stationary and dynamic process section without constraints Process efficiency / B A 50 %-wt 62.5 %-wt 75 %-wt decomposer temperature / K 14

15 Chart 15 Summary Process model for HyS process (transient for sulfuric acid decomposition/concentration- steady state for all the other sections) Separated supply of low and high temperature heat High heat recovery rates for the dynamic section needed to achieve desired overall annual efficiencies If heat recovery rate is high H2SO4 concentration has minor infuence to the process efficiency 15 15

16 Chart 16 OUTLOOK: Project SOL2HY2 Funded by European Fuel Cell and Hydrogen Joint Undertaking (FCH JU) Duration of 36 month (June 2013 May 2016) Objectives Development/Demonstration of the relevant-scale key components of the process Demonstration of sulfuric acid decomposition in 500 kw range at the solar tower of Julich Continuation and intensification of modelling/simulation to support the design and to prepare suitable control and operational strategies 16

17 Chart 17 SOL2HY2 Consortium - Coordinator: EnginSoft, Italy - Scientific IT company - Aalto University, Finland - Expertise on electrolysers - DLR, Germany - ENEA, Italy - Solar thermal energy - Thermochemical cycles - Outotec, Finland - Sulphuric acid producer - Erbicol, Switzerland - Manufacturer of ceramic structures - Woikoski, Finland - Gas producer and distributor 17

18 Chart 18 Three concecutive European Projects: HyThec, HyCycleS, Sol2Hy2 Prototype tested on clairette loop Bowls inside the channels

19 Chart 19 Solar Tower Jülich

20 Chart 20 Acknowledgements We acknowldge the co-funding of our work through the EU funded project HycycleS (Contract No ), the JTI-FCH funded project Sol2Hy2 (Contract No ) and through the US DOE Grant DE-EE (cooperation with General Atomics). 20

21 Chart 21 Thank you for your kind attention! 21