Sustainable, low-cost composites for net-zero infrastructure: Green hydrogen pressure vessels for self-sufficient rural and off gas grid detached homes.

Academic Institution: University of Edinburgh

Academic Supervisor: Dr. Colin Robert

Industry Partner: Hexcel

Phd Student: Hanisa Hasrin

Start date: October 2022

Abstract

The actual context of global warming must lead to innovative ways to reduce carbon emission overall. When it comes to infrastructure solutions, rural and off gas grid individual homes are a good place to start. Whilst renewable systems can help producing the power needed to achieve self-sufficiency, the charge limitations, lack of flexibility and price/cumbersomeness of electric battery systems are a real issue. The idea of adopting green hybrid hydrogen solutions from local renewable sources (solar, wind, hydro, etc) will allow complete energy self-sufficiency to new homeowners has recently got some traction.

However, hydrogen gas requires significant space for storage at low pressure, which can be cumbersome. This issue can be sorted by pressurising hydrogen significantly, over 300 Bars. This kind of pressure requires special pressure vessels (type 3 to 5) and involves structural composite materials.

These composite tanks are usually manufactured with a Filament Winding system or more recently via Automated Fibre Placement. Both manufacturing systems need a very specific composite material called towpreg, which is a small width (quarter or half inch) unidirectional carbon fibre tow embedded in polymer, whereas thermoplastic or thermoset.

The composite group has previous experience in building a fully automated towpregging tapeline for thermoset in scope of manufacturing type 3 pressure vessels. Mainly, the use of powdered polymer allowed for a range of cost-effective innovations. However, the industrial landscape is facing more and more issues due to the inability to recycle thermoset, and more scrutiny is put on thermoplastic tapes.

In this project, a low-cost, fully automated thermoplastic powder tapeline will be designed and assembled. Hexcel will facilitate & recommend suppliers to obtain the best thermoplastic powders suitable for hydrogen storage applications (i.e. very low porosity). Thermoplastic tape will be produced, characterised and optimised.

The tape will be used with Filament Winding or Automated Fibre Placement to manufacture pressure vessels in collaboration with the Lightweight Manufacturing Centre (University of Strathclyde).

Type 4 and 5 pressure vessels will be manufactured for green hydrogen pressure vessels applications, for self-sufficient rural and off gas grid detached homes. A field study will be organised by the end of the PhD to assess the feasibility of the pressure vessels manufactured