Methane up-carbonizing: A way towards clean hydrogen energy?

A global transition to a hydrogen economy requires widespread adoption of clean hydrogen energy. Methane cracking is one of the most viable technologies for producing clean hydrogen, nearing the ultimate zero-carbon-emissions targets. While major progress has been made in the lab-scale development of high-performance reactors and catalysts for methane pyrolysis, research focusing on industry-relevant scale and process conditions is in its infancy. Herein, recent advances in fundamental and applied research in methane pyrolysis are critically examined, focusing on physico-chemical mechanisms to achieve energy-efficient, low-carbon-emission, scalable processes. The highlighted recent efforts to bridge the gap between laboratory research and industrial applications reveal rapid advances in practical applications based on synergistic chemical engineering, catalysis, and materials science research. Perspectives, challenges, and opportunities for translational research towards commercial applications of methane cracking are discussed aiming at clean hydrogen production

The Resource Basis of Magnetic Refrigeration

Emerging economies such as China and India are currently experiencing a “refrigeration revolution.” Energy spent for domestic cooling is expected to outreach that for heating worldwide over the course of the twenty-first century. Magnetic refrigeration is an alternative cooling technology that works without gas-based refrigerants and has the potential to be significantly more energy efficient. We evaluate to what extent the raw materials needed to produce this kind of technology on a mass-market scale are critical in terms of demand and supply, thus identifying potential supply bottlenecks that might hinder the breakthrough of this promising technology. We assess the criticality of three promising magnetocaloric materials, that is, Gd5(SiGe)4, La(FeSi)13, and (MnFe)2P), as well as of Nd2Fe14B, as the candidate permanent magnet material to drive the cooling cycle. The Gd-based alloys are disqualified as a mass-market refrigerant in terms of resource criticality, whereas La- and Mn-based alloys are much less problematic. Given the current state of technology and projected resource supply, Nd in Nd2Fe14B magnets would experience a significant bottleneck only at a later innovation stage, that is, when magnetic cooling technology would largely dominate the domestic refrigerator and air-conditioning market

Oxidation of trivalent arsenic to pentavalent arsenic by means of a BDD electrode and subsequent precipitation as scorodite

In order to deposit arsenic residues from copper production in a stable way, the trivalent arsenic must first be xidized to arsenic(V). A well-known but quite expensive method for this is oxidation with hydrogen peroxide. In order to enable the oxidation of arsenic on a large scale in the future, a potentially cheaper method has to be found, which offers the possibility of oxidizing extremely high arsenic concentrations. As a novel alternative, electrochemical oxidation using a boron-doped diamond electrode is investigated. Based on previous work, this paper concentrates on the presence of interfering ions during oxidation. Furthermore, it is shown that the electrochemically xidized arsenic(V) can be precipitated as scorodite. Finally, an economic analysis shows the potential financial benefit of oxidation via BDD electrodes compared to hydrogen peroxide

Plasma pyrolysis for a sustainable hydrogen economy

Producing low-carbon hydrogen to use as a clean energy carrier is an important step towards a decarbonized economy. Plasma pyrolysis is an emerging technology that has great potential for the large-scale production of low-carbon and affordable hydrogen