What to do with the byproduct of biodiesel? You know, that low-grade sludge that's produced, molecule for molecule, alongside biodiesel. Well, scientists at the University of Leeds have turned the unwanted crude glycerol (sludge) into a high-value hydrogen rich gas. The novel process developed by Valerie Dupont and her co-investigators mixes glycerol with steam at controlled temperatures and pressures, separating the waste product into hydrogen, water and carbon dioxide, with no residues. A special absorbent material filters out the CO2, leaving a purer product.
Currently hydrogen production is expensive and unsustainable, using either increasingly scarce fossil fuels or other less efficient methods such as water electrolysis. The new process is near carbon neutral, since the CO2 generated is not derived from the use of fossil fuels.
Let's hope the new processes emerging from a worldwide explosion of research prove green, sustainable, and economically feasible.
Julia Whitty is Mother Jones' environmental correspondent. You can read from her new book, The Fragile Edge, and other writings, here.