Tag Archives: Membrane Reactor

Low-Pressure Electrolytic Ammonia Synthesis Via High-Temperature Polymer-Based Proton Exchange Membrane

Ted Aulich, Energy & Environmental Research Center (EERC), University of North Dakota, USA

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

The University of North Dakota Energy and Environmental Research Center (EERC) and North Dakota State University (NDSU) have developed a low-pressure electrolytic ammonia (LPEA) production process. The LPEA process uses an electrochemical cell based on an innovative polymer–inorganic composite (PIC) high-temperature (300°C) gas-impermeable proton-exchange membrane conceptualized and partially developed by EERC and NDSU. Because of its operability at ambient pressure and quick start-up capability (versus traditional high-pressure Haber Bosch-based plants), the LPEA process offers compatibility with smaller-scale plants and intermittent operation, and a cost-effective means of monetizing (and storing) renewable energy as ammonia. EERC, NDSU, and Proton OnSite are embarking on a project to optimize the PIC membrane, optimize and assess the technical and commercial viability of the LPEA process, and develop an LPEA process commercialization plan. To be presented will be information and data regarding 1) the configuration and working principles of the PIC membrane and LPEA process, 2) how the PIC membrane and LPEA process will be optimized, and 3) plans for LPEA process demonstration and commercialization. Continue reading

A Low Pressure Membrane Based Renewable Ammonia Synthesis

Sarbjit Giddey, CSIRO, Australia

15th Annual NH3 Fuel Conference, Pittsburgh, PA, October 31, 2018
NH3 Energy+ Topical Conference at the AIChE Annual Meeting

ABSTRACT

Ammonia is currently mostly produced by the highly energy and carbon-intensive Haber–Bosch process, which requires temperatures of 450–500 °C and pressures of up to 200 bar. The feedstock for this process is hydrogen from natural gas (NG), coal or oil, and nitrogen produced from air by cryogenic route or pressure swing adsorption (PSA). The share of NG, coal and fuel oil feedstock for the global production of ammonia is 72%, 22% and 4% respectively, contributing to approximately 420 million tons of CO2 emissions per annum, representing over 1% of global energy related emissions. The energy consumed for ammonia synthesis by Haber-Bosch process is in the 10 to 15 MWh/tonne range, depending on the type of fossil fuel feedstock used.

In an alternative route renewable hydrogen produced by an electrolyser can be fed to the Haber-Bosch reactor along with nitrogen for ammonia synthesis, and this route has been suggested to consume energy around 12 MWh/tonne of ammonia.

CSIRO has developed a metal membrane based ammonia synthesis process that uses hydrogen and nitrogen as feedstock. The materials and catalyst developed for the process allow the synthesis process at much lower pressures (~ 10 bar) at 450 °C. The synthesis rates achieved are two orders of magnitude higher than with any electrochemical route. The catalyst and the metal / catalyst interfacial structure have been specifically tailored for low pressure ammonia synthesis. The low pressure membrane reactor allows direct coupling to an electrolyser and air separation unit (ASU) operated by a renewable source, thus promising over 25% reduction in the energy input, substantial capital savings on reactors compared to conventional Haber-Bosch process, and allows distributed or centralised ammonia production. Continue reading