As the world pledges to significantly cut carbon emissions, the demand for sustainable and clean energy has now become more important than ever. This includes both production and storage of energy carriers, a majority of which involve catalytic reactions. This article reviews recent developments of homogeneous catalysts in emerging applications of sustainable energy. The most important focus has been on hydrogen storage as several efficient homogeneous catalysts have been reported recently for (de)hydrogenative transformations promising to the hydrogen economy. Another direction that has been extensively covered in this review is that of the methanol economy. Homogeneous catalysts investigated for the production of methanol from CO2, CO, and HCOOH have been discussed in detail. Moreover, catalytic processes for the production of conventional fuels (higher alkanes such as diesel, wax) from biomass or lower alkanes have also been discussed. A section has also been dedicated to the production of ethylene glycol from CO and H2 using homogeneous catalysts. Well-defined transition metal complexes, in particular, pincer complexes, have been discussed in more detail due to their high activity and well-studied mechanisms.

Homogeneous Catalysis for Sustainable Energy: Hydrogen and Methanol Economies, Fuels from Biomass, and Related Topics.

Recycling lithium ion batteries

Hydrothermal liquefaction and gasification of biomass and model compounds: a review

Adopting a new paradigm for social development implies a transition to a circular economy. The above requires the reduction of greenhouse gas emissions, the utilization of wastes, and the use of renewable energy sources. The most promising way is the use of methanol for industrial and transport applications. China is experiencing a boom in methanol production and its use in almost every sector of the economy. The purpose of this study was to reveal economic benefits, carbon dioxide emissions and the potential production of green methanol. Fuel price history, energy costs and fuel economy were used for economic assessment. Life cycle analysis to evaluate carbon dioxide emissions was applied. It was revealed that only the use of green methanol as a fuel results in decreases in well-to-wheel CO2 emissions compared to fossil fuels. The potential methanol production by using recycled waste and wind power was determined. Its annual production can range from 6.83 to 32.43 million tones. On this basis, a gradual transition to a circular and methanol economy is possible. Policymakers are recommended to support green methanol production in China. It can result in boosting the application of vehicles fueled by methanol and can control CO2 emissions.

https://www.mdpi.com/1996-1073/13/12/3113/pdf

Assessment of Green Methanol Production Potential and Related Economic and Environmental Benefits: The Case of China

In light of advancing climate change, environmentally-friendly methods for generating renewable energy are being employed to an increasing extent. This use, however, leads to rising spatial and temporal disbalances between electricity generation and consumption. To address the associated challenges, Power-to-X technologies are considered to harness surplus electricity from renewable sources and convert it into an alternative energy source that can be utilized, transported and stored. The aim of this paper is to compare four different Power-to-X technologies, whereby surplus electricity “Power” is converted to chemical entities “X”. It is shown that the implementation of PtX technologies and a shift of energy distribution to other transport methods could significantly relieve the electricity grid. Moreover, by converting the electricity from renewable sources, like wind farms, into chemical energy sources, the PtX concept offers the opportunity of making larger quantities of energy storable over longer periods of time. By considering a model case where electricity generation and consumption are several hundred kilometres apart, the generation of fuels emerges as a technology with the highest potential to mitigate climate change. Also with regard to transport, fuels emerge as the most favourable option for transporting chemically bound energy. Common to all options is the yield of a significant stream of oxygen as by-product. Utilizing this oxygen may be one of the key factors towards improving the economic viability of Power-to-X technologies.

Promising pathways: The geographic and energetic potential of power-to-x technologies based on regeneratively obtained hydrogen

https://onlinelibrary.wiley.com/doi/pdf/10.1002/cben.201900012

Renewable Methanol Synthesis

Methyl formate is a key component for both defossilized industry and mobility. The current industrial production via carbonylation of methanol has various disadvantages such as high requirements on reactant purity and low methanol conversion rates. In addition, there is a great interest in replacing the conventional homogeneous catalyst with a heterogeneous one, among other things to improve the downstream processing. This is why new approaches for methyl formate are sought. This review summarizes promising approaches for methyl formate production using methanol as a reactant.

Conversion of Green Methanol to Methyl Formate

The design of new composite materials using extreme biomimetics is of crucial importance for bioinspired materials science. Further progress in research and application of these new materials is impossible without understanding the mechanisms of formation, as well as structural features at the molecular and nano-level. It presents a challenge to obtain a holistic understanding of the mechanisms underlying the interaction of organic and inorganic phases under conditions of harsh chemical reactions for biopolymers. Yet, an understanding of these mechanisms can lead to the development of unusual-but functional-hybrid materials. In this work, a key way of designing centimeter-scale macroporous 3D composites, using renewable marine biopolymer spongin and a model industrial solution that simulates the highly toxic copper-containing waste generated in the production of printed circuit boards worldwide, is proposed. A new spongin-atacamite composite material is developed and its structure is confirmed using neutron diffraction, X-ray diffraction, high-resolution transmission electron microscopy/selected-area electron diffraction, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy, and electron paramagnetic resonance spectroscopy. The formation mechanism for this material is also proposed. This study provides experimental evidence suggesting multifunctional applicability of the designed composite in the development of 3D constructed sensors, catalysts, and antibacterial filter systems.

Extreme Biomimetics: Designing of the First Nanostructured 3D Spongin-Atacamite Composite and its Application.

The global market of lithium-ion batteries (LIB) has been growing in recent years, mainly owed to electromobility The global LIB market is forecasted to amount to $1293 billion in 2027 Considering the global reserves needed to produce these batteries and their limited lifetime, efficient recycling processes for secondary sources are mandatory A selective process for Li recycling from LIB black mass is described Depending on the process parameters Li was recovered almost quantitatively by the COOL-Process making use of the selective leaching properties of supercritical CO2/water Optimization of this direct carbonization process was carried out by a design of experiments (DOE) using a 33 Box-Behnken design Optimal reaction conditions were 230 °C, 4 h, and a water:black mass ratio of 90 mL/g, yielding 986 ± 019 wt% Li Almost quantitative yield (9905 ± 064 wt%), yet at the expense of higher energy consumption, was obtained with 230 °C, 4 h, and a water:black mass ratio of 120 mL/g Mainly Li and Al were mobilized, which allows for selectively precipitating Li2CO3 in battery grade-quality (>998 wt%) without the need for further refining Valuable metals, such as Co, Cu, Fe, Ni, and Mn, remained in the solid residue (977 wt%), from where they are recovered by established processes Housing materials were separated mechanically, thus recycling LIB without residues This holistic zero waste-approach allows for recovering the critical raw material Li from both primary and secondary sources

https://www.mdpi.com/2075-4701/11/2/259/pdf

The COOL-Process—A Selective Approach for Recycling Lithium Batteries

Recovery of Al, Co, Cu, Fe, Mn, and Ni from Spent LIBs after Li Selective Separation by the COOL-Process. Part 1: Leaching of Solid Residue from COOL-Process

Doreen Kaiser

Papers

Renewable Methanol Synthesis

Conversion of Green Methanol to Methyl Formate

Extreme Biomimetics: Designing of the First Nanostructured 3D Spongin-Atacamite Composite and its Application.

The COOL-Process—A Selective Approach for Recycling Lithium Batteries

Recovery of Al, Co, Cu, Fe, Mn, and Ni from Spent LIBs after Li Selective Separation by the COOL-Process. Part 1: Leaching of Solid Residue from COOL-Process