The objective of this work package is the development of a reformer module for diesel and biodiesel with integrated burner and subsequent water gas shift stage. The system will be operated at elevated pressures of 12 bars in order to keep system size small and reduce hydrogen production costs.
The necessary heat for the steam reforming reaction will be supplied by a dual fuel burner, able to burn liquid fuels as well as the off-gas being recycled from the PSA. A draft design of the currently used burner chamber will be given by HyGear. IST will build a prototype dual fuel burner that will be characterized in detail with in-flame measurements for single fuel and/or mixed fuel operation. This work will be supported by CFD simulation of the burner chamber. The impact of different operating conditions of the burner on reformer performance will be analysed by simulation. The results will be used to improve the basic design. The improved burner will be designed and functionally tested by IST before shipment to HYG for integration and testing. DLR will carry out basic testing with a single reformer tube in order to find optimum operating conditions with regard to fuel conversion, catalyst activity and hydrogen output. Special emphasis will be put on optimizing heat distribution and heat flux. Additionally, the possibility of cracking long hydrocarbon chains in a first cold zone by addition of small amounts of air in order to prevent carbon formation in the main reforming zone will be evaluated.
For testing of the reformer module the burner, burner chamber, reformer and catalyst inserts for reforming and water gas shift need to be integrated. The integrated reformer module will first undergo basic functional testing in real scale at HyGear’s facilities. Based on these initial tests the operational window of the module will be mapped and the acquired data will be compared with system simulation from WP2. Within these tests start-ups and shut-downs will be performed and load modulation tests will be carried out. A set of thermocouples will be installed to measure the heat distribution. In order to determine the efficiency of the reformer module the reformate gas will be analysed.
Description of work
The work in WP5 is broken down into 4 tasks:
5.1 Reformer (HYG, m04 – m21)
- Consideration of requirements generated from system simulation in WP2
- Definition of module requirements
- Definition of reformer operation strategies
- Test of functional components for operation with liquid fuel in terms of:
- Heat distribution
- Steam production
- Mixing of fuel and steam
- Integration of water gas shift stage
- Pressure drop etc.
- Design and manufacturing of reformer
- Calculation and design of reformer and water gas shift stage
- Calculation and design of integrated and external heat exchangers as well as balance of plant components
- Manufacturing of reformer and BoP components
5.2 Dual fuel burner (IST, HYG, m04 – m21)
- Burner development (HYG, IST)
- Draft design of burner chamber with definition of boundaries, thermal input, flame length
- Construction and testing of preliminary dual fuel burner, liquid atomiser and combustion chamber
- Isothermal characterisation of spray
- Combustion performance, namely flame stability data, in-flame temperatures, in-flame major gas species concentrations, incident wall radiation fluxes and pollutant emissions
- Design of burner for integration into the reformer (IST)
- Implementation of a CFD based model of the burner and combustion chamber and validation with data from the combustion characterisation
- Evaluation of burner performance, assessing the impact of heat transfer in tubes for reforming
- Update of design of burner chamber
- Specification of final burner design and integration into the burner chamber
- Manufacturing of the final burner and preliminary performance check (IST)
- Shipment of burner to HYG (IST)
5.3 Single-tube testing (DLR, HYG m04 – m21)
- A single tube of the reactor will be integrated by DLR into their liquid fuel test rig (LIFT). The use of the existing test-rig at DLR offers the advantage to investigate the influence of various operating conditions, without generation additional cost for setup of a suitable testing environment.
- The operational window of a single reformer tube will be investigated by the variation of load profile, temperature variations within the high temperature and low temperature zones and by variation of the steam to carbon ratio. Therefore the risks in testing the operational window of the overall prototype unit is lowered significantly and boundaries for allowable operating conditions can be evaluated. Upon damage of the tube, the cost of replacement is lower then that of a complete reforming reactor.
5.4 Integration and testing of reformer and burner (HYG, m22 – m27)
- Assembly of reformer, burner, and catalysts for reforming and WGS
- Execution of start-up and shut-down tests as well as load variation tests
- Measurement of temperatures to determine heat distribution and identify hot-spots and cold-spots
- Determination of the efficiency of the module in terms of hydrogen yield and energy consumption followed by optimization