The markets: Pressure vessels (2020)
Display of a the carbon fiber pressure vessel for the hydrogen-powered Toyota Marai at the 2019 North American International Auto Show (NAIAS) in Detroit, Mich., U.S. Source | CW
High-pressure gas storage vessels represent one of the biggest and fastest-growing markets for advanced composites, particularly for filament wound carbon fiber composites. Although they are used in self-contained breathing apparatuses and provide oxygen and gas storage on aerospace vehicles, the primary end-markets for composite-reinforced pressure vessels are bulk transportation of compressed natural gas (CNG) products, and fuel storage in passenger cars, buses and trucks with powertrains dependent on CNG and hydrogen alternatives to gasoline and diesel.
Pressure vessels are organized into one of five types:
- Type I: All-metal construction, generally steel.
- Type II: Mostly metal with some fiber overwrap in the hoop direction, mostly steel or aluminum with a glass fiber composite; the metal vessel and composite materials share about equal structural loading.
- Type III: Metal liner with full composite overwrap, generally aluminum, with a carbon fiber composite; the composite materials carry the structural loads.
- Type IV: An all-composite construction, polymer (typically high-density polyethylene or HDPE) liner with carbon fiber or hybrid carbon/glass fiber composite; the composite materials carry all the structural loads.
- Type V: Linerless, all-composite construction.
Of these four vessel types, Type 1 has, by far, the largest market share at >90%. Type II vessels have about 4% market share, followed by Type III and Type IV, with Type V — a new designation — a distant fifth. However, in terms of material use, composites are the fastest growing material type, with 5.9% CAGR, according to Grand View Research.
Demand for alternative fuels is growing, in large part, because the extraction of natural gas from shale reserves has contributed to lower prices in North America and parts of Europe. In the North American market, for example, the cost of natural gas fuels currently runs about 36% less than diesel, per diesel gallon equivalent. In addition, increasingly stringent emissions regulations, including the EU Euro 6 Standard, which became effective earlier in 2016, are making diesel-powered buses and commercial vehicles more expensive for operators. Impending regulations are improving the marketability not only of CNG but also of hydrogen — after a period of relative dormancy — for fuel-cell powered vehicles.
Average retail fuel prices in the United States, gasoline gallon equivalent (GGE). Source | U.S. Dept. of Energy, Alternative Fuels Data Center
By 2023, the NGV population could be more than 65 million trucks, buses, and fork-lift vehicles. Based on strong demand in Argentina, Brazil, China, India, Iran, Italy and Pakistan, NGV deliveries could reach nearly 11 million per year by 2023. The vast majority (94%) of these NGVs are expected to be equipped with high-pressure (200+ bar) fuel storage systems.
At CW’s Carbon Fiber 2017 conference, Chris Red of Composites Forecasts and Consulting LLC (Mesa, A, US) predicted that the demand for carbon fiber in composite pressure vessels will grow from 5.4 metric tonnes (MT) per year in 2016 to 26 MT/yr in 2021 and 45 MT/yr by 2025. At this 2025 volume, composite CNG and hydrogen cylinders for fuel cell vehicles (FCVs) will consume almost as much carbon fiber as projected for wind turbine blades, 50% more than forecast for automotive, rail and other ground transportation chassis and body components, and twice what is estimated for aerospace. Red cited forecasts for 2.1 million hydrogen FCVs to be produced from 2016 to 2025, corresponding to 3 million pressure vessels.
Type IV composite pressure vessels used to store hydrogen are made by filament winding carbon fiber and epoxy over a plastic liner. Highly automated turnkey tank production lines are designed and produced by composites equipment suppliers including Engineering Technology Corp. (Salt Lake City, Utah, U.S.), McClean Anderson (Schofield, Wis., U.S.), MIKROSAM (Prilep, Macedonia) and Roth Composite Machinery (Steffenberg, Germany), with the latter claiming it has accelerated hydrogen tank production 5-10 times with its new Rothawin technology. Cevotec (Munich, Germany) claims it can save 20% material and cycle time by using its fiber patch placement (FPP) system in dome areas. Cevotec’s CEO explains that working pressure of up to 700 bar in the tanks translates into ≈10 kilograms of carbon fiber for 1 kilogram of hydrogen storage — a very high ratio. FPP, however, applies carbon fiber in precise patches, designed to exactly cover the areas causing problems in filament winding. One FPP system is said to reinforce vessels for several winding machines.
Fiber patch placement system. Source | Cevotec
Hexagon Composites is a leading manufacturer pressure vessels, producing composite hydrogen storage tanks for cars and light vehicles in Raufoss, Norway, and Kassel, Germany, and tanks for its mobile pipeline system as well as for medium- and heavy-duty trucks and buses in Lincoln, N, US. It has vertically integrated through a merger with Agility Fuel Solutions (Costa Mesa, C, US), sending tanks from Lincoln to Salisbury, NC, US, where they are integrated into complete alternative fuel systems and installed on trucks and buses. Hexagon composite hydrogen storage tanks are also used on boats, ships and rail vehicles, as well as in stationary power systems, and are now being investigated for aircraft.
In 2019, Agility Fuel Solutions announced
e model, Solaris (Owińska, Poland), says it has reduced the mass of its bus fuel system by approximately 20% compared to the previous model.
Hexagon claims to be the second largest user of carbon fiber in the world, but it will begin to face increased competition as Plastic Omnium (Paris, France), a world leader in plastic exteriors and front end modules for cars, has begun developing hydrogen storage tank and fuel cell capability. In 2017, it bought Optimum CPV, a Belgian company that makes composite hydrogen storage vessels, and Swiss Hydrogen, which works in fluid and thermal management. Further competition will come from Symbio, a 50/50 joint venture between French autocomposites manufacturer Faurecia (Nanterre) and tire producer Michelin (Clermont-Ferrand), announced in March 2019 with the aim to create a world leader in hydrogen fuel cell systems. Faurecia has invested $28 million in its global center of expertise for hydrogen storage systems at its R&D campus in Bavans, France. It also announced it would work with Airbus composite fuselage supplier Stelia Aerospace (Toulouse, France) to develop high-pressure carbon fiber composite hydrogen tanks for fuel cells.
The Toyota Mirai at the 2019 North American International Auto Show in Detroit, Mich., U.S. This FCV offers 67 mpge fuel efficiency and a range of 312 miles. Source | CW
Currently, 13 automotive OEMs have fielded FCV demonstrators and test fleets. Further, at the 2019 North American International Auto Show (Detroit, Mich., U.S.), Toyota exhibited its new Mirai fuel cell electric vehicle (FCEV), which is currently on the market and for sale. It offers 67 mpge fuel efficiency, a range of 312 miles and has a manufacturers suggested retail price (MSRP) of $58,500.
Linerless, all-composite pressure vessels, which fit the more recent and radical Type V classification and are best able to reduce mass in weight-sensitive applications, are the goal for a number of pressure vessel manufacturers. Infinite Composites Technologies (ICT), Tulsa, OK, US) offers one of a growing number of Type V vessels coming to market. The company’s patented infinite composite pressure vessel or infiniteCPV (iCPV), an all-composite design, enables users to take advantage of the maximum fuel storage capacity by reducing vessel weight. The iCPV provides 10% more usable volume and reduces vessel weight by 90% compared to conventional vessels. While the company has a focus on developing next-generation fuel storage and delivery systems for natural gas vehicles and storage applications, it also hopes to introduce its Type V tank technologies to the commercial space industry.
A growing and likely huge, sustainable market for pressure vessels is the construction of seawater reverse osmosis (SWRO) desalination plants. SWRO depends on membrane systems that serially cleanse water piped onshore from the ocean (See “Utility Infrastructure”). These membranes must be encased in membrane housings. Filament-wound fiberglass pressure vessels are used almost exclusively for this purpose today, in quantities of as many as 6,000 per desalination plant. The Freedonia Group (Cleveland, Ohio) predicts demand for SWRO housings and related equipment will increase 6.9% per year. In the US alone, the market was worth about US$495 million in 2017.
Powerhouse manufacturer’s high-pressure compression molding process forms prepregged CFRP components with forged-metal properties.
Automated process cuts cycle time and cost for CFRP parts with potential for 65% fiber volume via Dynamic Fluid Compression Molding variant.
The structural properties of composite materials are derived primarily from the fiber reinforcement. Fiber types, their manufacture, their uses and the end-market applications in which they find most use are described.