As Common As It Gets – But Hard to Get

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Since Michael Faraday first split water into hydrogen and oxygen in 1820, scientists have puzzled over how to do this economically in large quantities.   The Blog continues to run stories about “artificial leaves,” low-energy approaches to dividing the hydrogen in water from the oxygen, and doing so economically.  The current most widely-used approach to capturing hydrogen is pulling it from natural gas via several processes.  The Office of Energy Efficiency and Renewable Energy explains the process on its web site. Steam-methane Reforming In steam-methane reforming, “high-temperature steam (700°C–1,000°C) is used to produce hydrogen from a methane source, such as natural gas. In steam-methane reforming, methane reacts with steam under 3–25 bar pressure (1 bar = 14.5 psi) in the presence of a catalyst to produce hydrogen, carbon monoxide, and a relatively small amount of carbon dioxide. Steam reforming is endothermic—that is, heat must be supplied to the process for the reaction to proceed.” In a “’water-gas shift reaction,’ the carbon …

Corncobs as a Source of Supercapacitors?

Dean Sigler Electric Powerplants, Sustainable Aviation Leave a Comment

Researchers at the Illinois Sustainable Technology Center at the University of Illinois report, “that wood-biochar supercapacitors can produce as much power as today’s activated-carbon supercapacitors at a fraction of the cost – and with environmentally friendly byproducts.” Junhua Jiang, senior research engineer at the Center, has been reducing wood and cellulose products such as corncobs to biochar by heating the fibers in a reduced oxygen environment.  This pyrolysis process creates a  porous, black substance that can be used as electrodes in supercapacitors.  While other researchers use carbon black or more advanced forms of carbon such as nanotubes, this more humble approach yields equal or better performance at a fraction of the cost of the more labor-intensive methods.  Many of the alternatives obtain their carbon from fossil-fuels, making biochar the environmental option. Jiang notes, “Supercapacitors are ideal for applications needing instant power and can even provide constant power – like batteries, but at lower cost,” adding that they are useful in transportation, electronics …

Commercially Viable (and Nearly Buyable) Australian Algae-Based Biofuel

Dean Sigler Diesel Powerplants, Sustainable Aviation Leave a Comment

Both Aviation Week and Flight Global reported on Algaetec’s announcement at the ILA (Berlin Air Show) that it had signed a memorandum of understanding with Lufthansa to provide algae-based jet fuel to the German carrier. Algae.Tec is an Australian maker of clear algae oil that pulls CO2 from industrial processes, combines it with sunlight, and produces large batches of odorless oil. The product achieves the “holy grail” of sustainability, according to Executive Chairman Roger Stroud, because it is made from non-food sources, unlike corn- or agave-based ethanol, for instance. It also uses CO2 that would otherwise be subject to expensive sequestration processes. The technology is proprietary and barely hinted at in the company’s videos, but is housed in 40-foot long shipping containers connected to solar arrays. CO2 and sunlight combine to produce a fuel stream in a compact production space. Aviation Week reports that, “The company’s process grows algae in a controlled environment in 40-ft shipping containers, feeding the algae …