Zero Energy Penalty Hydrogen Injection into Natural Gas Pipelines via Asynchronous Electrolysis and Venturi Valve Integration
The purpose of this SBIR topic (27A) is to “reduce the energy penalty of traditional compression methods when applied to hydrogen” to improve the cost-effectiveness of utilizing the gas-grid to deliver hydrogen. BST Systems’ novel Spontaneous Electrolyzer lowers the cost of hydrogen by lowering the capital expense (CapEx) of electrolysis (inexpensive design with no precious metal catalyst, no membrane, and no complicated ‘bi-polar’ assembly) and by eliminating compression and storage CapEx and energy costs. Under the Phase I program, BST built and tested a series-string of 10 “full-sized” Spontaneous Electrolyzer cells and met or exceeded all of its milestone objectives. The series-string is delivering approximately 170 grams of hydrogen per discharge (1.7X the original goal) and is demonstrating a stable H2 delivery with cycling to-date. Further, it was demonstrated that this low-pressure gas can be “boosted” via Venturi expansion to distribution line pressures without incurring a compression energy penalty, which is the objective of this SBIR topic (27A). Performance testing is on-going. BST’s Spontaneous Electrolyzer not only reduces the energy penalty of compression and CapEx of compression, but eliminates it completely. Thus, 100% of the SBIR topic objective is achievable with Spontaneous Electrolyzer technology. During discharge, H2 is generated “spontaneously”, i.e., no input energy is required (no generation energy penalty is incurred), thus the H2 can be burned at time-of-generation. For gas grid applications, H2 delivery without incurring a compression energy penalty is achieved by integration with Venturi expansion. High pressure upstream natural gas (NG) requires throttling down at distribution facilities. Thereby, the natural gas feed to the facility can be directed to the input, motive flow port of a Venturi expansion valve, which in turn increases the low pressure H2 at the suction line port of the valve, delivering the desired H2/NG mix proportion at the output distribution pressure. Therefore, the low pressure H2 spontaneously delivered by a Spontaneous Electrolyzer during discharge requires no external compressor and no compression energy penalty to reach distribution pressure and delivery through a dedicated grid with H2 compatible appliances in-line. It should be noted that for “onsite” applications, integration with Venturi expansion is not required, as the hydrogen is delivered to customers by direct injection of spontaneous, low-pressure H2 into boilers for heat, or combined heat & power (CHP) engines. It is important to emphasize that conventional electrolyzers, such as Polymer Electrolyte Membrane (PEM) electrolyzers, cannot be integrated along the distribution network without separate compression and storage subsystems because PEM electrolyzers do not spontaneously generate hydrogen. Therefore, separate compression and storage capital would be required to store surplus, renewable electrical energy as hydrogen to be delivered as a fuel at a later time for heat or power. In the long term, BST plans to integrate its Spontaneous Electrolyzer at or near natural gas distribution facility for injection of green H2 into the distribution network. In the short term, BST plans to commercialize into the Combined Heat and Power (CHP) market. The hydrogen community is addressing market barriers by the development of “fuel flexible” devices that can operate on available fossil fuels now and can seamlessly transition to hydrogen when it’s available without requiring new equipment. BST has concluded that Spontaneous Electrolyzer technology is feasible and applied for Phase II SBIR funding in April 2022. Under Phase II, if the program is awarded, BST will build and test a prototype product, i.e., a Spontaneous Electrolyzer 12-cell “portable module”. Four (4) of these modules will be series-connected to yield a “1 kg H2” capacity unit, from which larger systems can be constructed. The modules will be charged with off-peak grid power at night, which in the state of CT is mostly baseload, carbon-free nuclear, and then discharged during on-peak hours, delivering hydrogen to a H2 compatible boiler. The project will demonstrate that green hydrogen sourced from Spontaneous Electrolyzer technology can feasibly and affordably be delivered to customers either directly (integrated onsite with a “H2 ready” appliance) or via the distribution gas-grid.
- Research Organization:
- BST Systems
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- SC0021834
- OSTI ID:
- 1875255
- Type / Phase:
- SBIR (Phase I)
- Report Number(s):
- DOE-BST-0021834
- Country of Publication:
- United States
- Language:
- English
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