Potential Deployment and Integration of Liquid Organic Hydrogen Carrier Technology within Different Industries

The deployment of hydrogen as an infrastructure fuel and an energy vector across a range of industries is expected to aid with meeting decarbonisation goals and achieving net zero emissions. For the transition towards a low carbon hydrogen economy, not only the production of hydrogen needs to be addressed, but also its transportation and storage. Liquid organic hydrogen carriers (LOHCs) are an attractive solution for the storage and transportation of hydrogen to allow a reliable and on-demand hydrogen supply, enabling industrial decarbonisation. This work describes the potential deployment and integration of LOHCs within different industries. These include: the transportation sector; steel and cement industries; the use of stored hydrogen to produce fuels and chemicals from flue gases, and a system integration of fuel cells and LOHCs for energy storage.

CO2-capture research and Clean Energy Technologies Research Institute (CETRI) of University of Regina, Canada: history, current status and future development

Summary Clean Energy Technologies Research Institute (CETRI) was formerly known as the International Test Centre for CO2 Capture in the early 2000s. The original focus of the centre was to help lower the carbon intensity of the current energy sources to low-carbon ones in Canada. Currently, CETRI’s mandates have expanded and now include most of the low-carbon and near-carbon-free clean-energy research activities. Areas of research focus include carbon (CO2) capture, utilization and storage (CCUS), near-zero-emission hydrogen (H2) technologies, and waste-to-renewable fuels and chemicals. CETRI also brings together one of the most dynamic teams of researchers, industry leaders, innovators and educators in the clean and low-carbon energy fields.

Methanol Dehydrogenases as a Key Biocatalysts for Synthetic Methylotrophy

One-carbon (C1) chemicals are potential building blocks for cheap and sustainable re-sources such as methane, methanol, formaldehyde, formate, carbon monoxide, and more. These resources have the potential to be made into raw materials for various products used in our daily life or precursors for pharmaceuticals through biological and chemical processes. Among the soluble C1 substrates, methanol is regarded as a biorenewable platform feedstock because nearly all bioresources can be converted into methanol through syngas. Synthetic methylotrophy can be exploited to produce fuels and chemicals using methanol as a feedstock that integrates natural or artificial methanol assimilation pathways in platform microorganisms. In the methanol utilization in methylotrophy, methanol dehydrogenase (Mdh) is a primary enzyme that converts methanol to formaldehyde. The discovery of new Mdhs and engineering of present Mdhs have been attempted to develop synthetic methylotrophic bacteria. In this review, we describe Mdhs, including in terms of their enzyme properties and engineering for desired activity. In addition, we specifically focus on the application of various Mdhs for synthetic methylotrophy.

Protein acetylation regulates xylose metabolism during adaptation of Saccharomyces cerevisiae

Background As the second most abundant polysaccharide in nature, hemicellulose can be degraded to xylose as the feedstock for bioconversion to fuels and chemicals. To enhance xylose conversion, the engineered Saccharomyces cerevisiae with xylose metabolic pathway is usually adapted with xylose as the carbon source in the laboratory. However, the mechanism under the adaptation phenomena of the engineered strain is still unclear. Results In this study, xylose-utilizing S. cerevisiae was constructed and used for the adaptation study. It was found that xylose consumption rate increased 1.24-fold in the second incubation of the yYST12 strain in synthetic complete-xylose medium compared with the first incubation. The study figured out that it was observed at the single-cell level that the stagnation time for xylose utilization was reduced after adaptation with xylose medium in the microfluidic device. Such transient memory of xylose metabolism after adaptation with xylose medium, named “xylose consumption memory”, was observed in the strains with both xylose isomerase pathway and xylose reductase and xylitol dehydrogenase pathways. In further, the proteomic acetylation of the strains before and after adaptation was investigated, and it was revealed that H4K5 was one of the most differential acetylation sites related to xylose consumption memory of engineered S. cerevisiae. We tested 8 genes encoding acetylase or deacetylase, and it was found that the knockout of the GCN5 and HPA2 encoding acetylases enhanced the xylose consumption memory. Conclusions The behavior of xylose consumption memory in engineered S. cerevisiae can be successfully induced with xylose in the adaptation. H4K5Ac and two genes of GCN5 and HPA2 are related to xylose consumption memory of engineered S. cerevisiae during adaptation. This study provides valuable insights into the xylose adaptation of engineered S. cerevisiae.

Catalytic Conversion of Glycerol into Hydrogen and Value-Added Chemicals: Recent Research Advances

In recent decades, the use of biomass as alternative resources to produce renewable and sustainable biofuels such as biodiesel has gained attention given the situation of the progressive exhaustion of easily accessible fossil fuels, increasing environmental concerns, and a dramatically growing global population. The conventional transesterification of edible, nonedible, or waste cooking oils to produce biodiesel is always accompanied by the formation of glycerol as the by-product. Undeniably, it is essential to economically use this by-product to produce a range of valuable fuels and chemicals to ensure the sustainability of the transesterification process. Therefore, recently, glycerol has been used as a feedstock for the production of value-added H2 and chemicals. In this review, the recent advances in the catalytic conversion of glycerol to H2 and high-value chemicals are thoroughly discussed. Specifically, the activity, stability, and recyclability of the catalysts used in the steam reforming of glycerol for H2 production are covered. In addition, the behavior and performance of heterogeneous catalysts in terms of the roles of active metal and support toward the formation of acrolein, lactic acid, 1,3-propanediol, and 1,2-propanediol from glycerol are reviewed. Recommendations for future research and main conclusions are provided. Overall, this review offers guidance and directions for the sufficient and economical utilization of glycerol to generate fuels and high value chemicals, which will ultimately benefit industry, environment, and economy.

Co@CoO: a Unique Catalyst for Hydrogenolysis of Biomass-derived 5-Hydroxymethylfurfural to 2,5-Dimethylfuran

The development of precious-metal-free catalysts to promote the sustainable production of fuels and chemicals from biomass remains an important and challenging target. Here, we report the efficient hydrogenolysis of biomass-derived 5-hydroxymethylfurfural to 2,5-dimethylfuran over a unique core-shell structured catalyst Co@CoO that affords the highest productivity among all catalysts reported to date. Surprisingly, we found that the catalytically active sites reside on the shell of CoO with oxygen vacancies rather than the metallic Co. The combination of various spectroscopic experiments and computational modelling reveals that the CoO shell incorporating oxygen vacancies drives the heterolytic and homolytic cleavage of dihydrogen to yield active Hδ- species, resulting in the exceptional catalytic activity. Co@CoO also exhibits excellent activity toward the direct hydrodeoxygenation of lignin model compounds. This study unlocks, for the first time, the potential of metal-oxide catalysts for the production of renewable biomass-derived fuels.

Homogeneous Catalyzed Valorization of Furanics: A Sustainable Bridge to Fuels and Chemicals

The development of efficient biomass valorization is imperative for the future sustainable production of chemicals and fuels. Particularly, the last decade has witnessed the development of a plethora of effective and selective transformations of bio-based furanics using homogeneous organometallic catalysis under mild conditions. In this review, we describe some of the advances regarding the conversion of target furanics into value chemicals, monomers for high-performance polymers and materials, and pharmaceutical key intermediates using homogeneous catalysis. Finally, the incorporation of furanic skeletons into complex chemical architectures by multifunctionalization routes is also described.