Skip to main content

Flexible Hybrid separation system for H2 recovery from NG Grids

Periodic Reporting for period 2 - HyGrid (Flexible Hybrid separation system for H2 recovery from NG Grids)

Reporting period: 2017-11-01 to 2019-04-30

HyGrid aims at developing novel hybrid system integrating three technologies for hydrogen purification integrated in a way that enhances the strengths of each of them: Membrane separation technology is employed for removing H2 from the “low H2 content” (e.g. 2-10 %) followed by electrochemical hydrogen separation (EHP) optimal for the “very low H2 content” (e.g. <2 %) and finally temperature swing adsorption (TSA) technology to purify from humidity produced in both systems upstream. The objective is to give a robust proof of concept and validation of the new technology (TRL 5) by designing, building, operating and validating a prototype system tested at industrial relevant conditions for continuous and transient loads.
The coordination is proceeding as planned.
Face to face meeting are organized every 6 months. In between meetings, every three months a teleconference is organized as well. Exchange of info is achieved via the private website and/or via email.
This work package has been completed in the first reporting period.
Porous supports, palladium based membranes, carbon membranes and sealing have been developed for hydrogen separation with the recovery of hydrogen from low concentration streams (2% -10%) up to 99.97%, 99.9% and 98.0% H2 purity for ISO14687 grade D, E category 3 and A respectively in the whole range of pressures of the Natural Gas Network. In the last two years, different alumina porous tube geometries have been characterized at Tecnalia for their use as Pd-based membrane supports. More than 65 ceramic supported Pd membranes are now prepared to be integrated into the HyGrid prototype.
The first task of this WP is the theoretical support for the design of the EHP. Different subjects have been investigated up to now, like an application of a high-temperature membrane with the addition of various polymers to immobilize the acid in the membrane. Also, a theoretical optimization is done on membrane type and membrane thickness, based on actual measured data. In the second task, the most important part is the development and testing of the actual EHP. The main three improvements are the larger total surface area, a new cell plate design with adapted gas distribution flow field and a new gas seal design to contain high-pressure hydrogen. The development of the sub-system for the prototype in WP7 is in progress. Tests in the second task have already shown the importance of water management in an EHP cell.
In WP5 HyGear has designed and assembled the TSA pilot plant. Sizing of the pilot plant was performed using the TSA chemical model developed in Task 8.2. HyGear finished the installation on the test site successfully and finished the integration in this period. The system was connected to the gas infrastructure and the cooling system and the safety check was passed successfully. Testing the TSA pilot plant using air and hydrogen was finished. The data was used to validate the model. Tests confirmed that the model with adapted kinetic parameter predicts most trends, such as bed temperatures, cycle time, water adsorption and break through quite well.
Carbon membranes were tested in the high-pressure setup to understand the behavior in terms of permeance and selectivity especially in case of HyGrid conditions. Initially, pure gas tests and later mixtures at different temperatures and pressure were performed. Cases with atmosphere, vacuum and higher pressure in the permeate side were taken into account. Humidified and dry membrane conditions were tested to understand the effect of water adsorption to improve membrane purity. Gases were saturated in a tank full of water in case humidified conditions were applied. The purpose is to compare experimental results of carbon and Pd-Ag membranes at higher pressure to verify which could suit better the HyGrid configuration. Enough results have been obtained.
This period HyGear continued working on the design and started ordering components for the assembly of the HyGrid pilot plant. Discussions were held with partners Tecnalia, TU/e and HyET regarding the integration of the main components of the HyGrid pilot plant. One of the results was that HyGear has taken over part of the activities from partner HyET. A process flow diagram with the main streams of the HyGrid prototype was prepared after the discussions.
Different simulations were carried out for optimizing the HyGrid system. One and more membrane stages were considered to obtain high purity and hydrogen recovery factor. The possibility of integrating the vacuum pump instead of using sweep gas in the permeate side was considered as well. Total flow rate, grid pressure and permeate pressure were varied to find the best conditions for improving the separation. After the sensitivity analysis, a techno-economic evaluation was performed based on NETL method to calculate the hydrogen separation cost and understand the more convenient configuration from an economic point of view.
The aim of WP9 is to perform an environmental LCA and economic assessment of the hydrogen recovery systems developed within HyGrid. Since the LCA will accompany the research, the idea is to use the LCA work to steer the development of the systems towards more sustainable solutions. Finally, a comparison will be made between the life cycle performance of the systems developed within HyGrid and the conventional technology currently able to deliver the same service.
The activities on “exploitation and dissemination” were mainly focused on the implementation of the dissemination and communication strategy and tools, the development of the initial Plan for Use and Dissemination of Foreground (PUDF) and the stakeholder analysis. A project website has been prepared and is continuously updated; non-confidential presentations, to present the HyGrid project, have been prepared.
Currently the value of H2 in natural gas is only the caloric value of the gas as most of natural gas is used for heating. The value for chemical use is negative as most chemical plants are not equipped for using hydrogen in natural gas. The HyGrid system will convert this low caloric value into fuel for passenger car value. This will increase the value of around €3, 50 up to €6, 00 per kg. Almost doubling the value of hydrogen in the grid. Moreover, the successful results of HyGrid will indeed make it possible to distribute hydrogen also within the natural gas grid, thus reducing the costs of transportation or on-site production of hydrogen for many applications including hydrogen refuelling stations.

The new technology has also a great environmental and societal impact. In particular, the project will reduce specific CO2 emissions as well as other pollutants like NOx and SOx. Furthermore, the HyGrid separation technology itself will lead to: more efficient use of raw material resources and minimization of by-products formation (less wastes) due to the high selectivity and separation rates; fostering of green transportation and energy supply technologies due to lower H2 prices; reduction of fossil fuels dependence and as such will increase economic security.