H2REF – Advanced new compression and buffering solution for hydrogen refueling stations

Recently, the results of the H2REF project , including the main findings, have been presented.

The project aimed to develop an advanced new compression and buffering solution for hydrogen refueling stations (HRS) of 70 MPa passenger FC-vehicles. This solution is based on the use of hydro-pneumatic accumulators, which provides a more reliable and economical solution while improving performance. The project was developed by a consortium of six partners from European countries (France, Germany, Norway and the United Kingdom) bringing together the key experience, knowledge base and resources for reaching the objectives of the project.

According to the various project partners, the system would reduce investment costs by 40% compared to a “conventional” hydrogen refueling station. Which solves the delicate economic equation related to the deployment of stations.

Results

First of a kind high-pressure bladder accumulators in composite material, for operation at up to 90 MPa with demonstrated lifetime.

The H2Ref consortium is composed of six partners from four European countries (France, Germany, Norway, and United Kingdom) bringing together the key experience, knowledge base and resources necessary for reaching the objectives of the project with the work-plan proposed.

The focus from the two main industrial partners Haskel and Hexagon are in the continued development of this compression technology, with the view of eventually jointly developing a highly competitive Compression and Buffering Module (CBM) product offer. This aim certainly has the potential of a major commercial breakthrough if the project results are achieved. H2Nova , as developer and owner of intellectual property and CCSwith expertise in RCS development and compliance, are also interested in such a development. Cetim and LBST will support the consortium with their wealth of knowledge of experience in this particular field of development.

The basic concept

Bladder accumulator-based compression is applicable to any refueling applications, thanks to the combined high scalability of hydraulics technology and carbon composite pressure vessels. Indeed, high-pressure hydraulic pumps are already available and successfully delivering very large capacities for many oil and gas applications. Similarly, high-pressure accumulators in carbon composite material are also currently available and can be built to very large sizes.

Main advantage of the concept compared to conventional technologies

A fundamental advantage of bladder accumulator-based compression for compression and transfer of hydrogen over conventional mechanical compression, is that it uses serially produced components from a mature and standardized industry (hydraulics and composite pressure vessels) with a world-wide supplier base, minimizing cost while providing excellent robustness and reliability.

Other advantages of the concept compared to conventional technologies

Furthermore, bladder accumulator-based compression provides the following additional benefits:

high scalability, thanks to the combined high scalability of hydraulics and carbon composite pressure vessels;

high flexibility, thanks to the wide operating pressure ranges of the components;

high flow-rate and small foot-print: as compression effort is applied by means of a working fluid driven by a hydraulic pump;

maximized compression capacity, thanks to uniquely taking advantage of varying pressure upstream, while operating at constant power (even though the discharge pressure to suction pressure ratio changes);

reduced energy consumption, thanks to the exploitation of upstream pressure: the average energy consumption is halved as the pressure of the stored hydrogen is fully taken advantage of; the on-going adoption of higher storage pressure in the hydrogen supply chain further increases the benefit of taking full advantage of the source storage pressure;

improved reliability and reduced maintenance requirements, intrinsic to hydraulic power technology;

exploitation of the full compression power capacity at all times, maximizing effective throughput.