A critical review of the production and advanced utilization of biochar via selective pyrolysis of lignocellulosic biomass.

Lignin nanomaterials have emerged as a promising alternative to fossil-based chemicals and products for some potential added-value applications, which benefits from their structural diversity and biodegradability. This review elucidates a perspective in recent research on nanolignins and their nanocomposites. It summarizes the different nanolignin preparation methods, emphasizing anti-solvent precipitation, self-assembly and interfacial crosslinking. Also described are the preparation of various nanocomposites by the chemical modification of nanolignin and compounds with inorganic materials or polymers. Additionally, advances in numerous potential high-value applications, such as use in food packaging, biomedical, chemical engineering and biorefineries, are described.

https://www.mdpi.com/2079-4991/11/5/1336/pdf

Lignin Nanoparticles and Their Nanocomposites.

Nanobiochar has received much attention recently among engineered biochar types owing to its useful chemical and physical properties. Research efforts have attempted to discover novel methods for nanobiochar preparation and applications. In this review, we summarize the literature on various aspects of nanobiochar preparation, production and use. Often, the bulk parent biochar is obtained from biomass pyrolysis, and mechanically ground using different milling processes to fabricate nanobiochar. Apart from mechanical means, direct fabrication of nanobiochar through flash heating resulting in graphitic nanosheets has been reported. Process conditions applied to the parent biochar directly influence the properties of the resulting nanobiochar. For instance, over 70% of 33 nanobiochar samples derived from biomass pyrolyzed above 450 °C demonstrated 32 times greater BET specific surface areas than nanobiochar produced at <450 °C. Nanobiochar has diverse applications, such as in wastewater treatment, health care applications, use as an electrode material, and in supercapacitors and sensors, owing to its wide range of physical and chemical properties. However, the toxicity of nanobiochar to human and ecosystem health has not received sufficient research attention. More research should be performed to elucidate the drawbacks, such as the high agglomeration potential and low yield, of nanobiochar for practical uses. Furthermore, reported data are insufficient to obtain a clear idea of the nature and behavior of nanobiochar, despite the growing interest in the research topic. Hence, future research should be driven towards exploring techniques to improve the yield of nanobiochar, reduce agglomeration, upscale it for electrode supercapacitor production and understand toxicological aspects.

Nanobiochar: production, properties, and multifunctional applications

In the context of climate change, there is an urgent need for rapid and efficient methods to capture and sequester carbon from the atmosphere. For instance, production, use and storage of biochar are highly carbon negative, resulting in an estimated sequestration of 0.3–2 Gt CO2 year−1 by 2050. Yet, biochar production requires more knowledge on feedstocks, thermochemical conversion and end applications. Herein, we review the design and development of biochar systems, and we investigate the carbon removal industry. Carbon removal efforts are currently promoted via the voluntary market. The major commercialized technologies for offering atmospheric carbon removal are forestation, direct air carbon capture utilization and storage, soil carbon sequestration, wooden building elements and biochar, with corresponding fees ranging from 10 to 895 GBP (British pounds) per ton CO2. Biochar fees range from 52 to 131 GBP per ton CO2, which indicates that biochar production is a realistic strategy that can be deployed at large scale. Carbon removal services via biochar are currently offered through robust marketplaces that require extensive certification, verification and monitoring, which adds an element of credibility and authenticity. Biochar eligibility is highly dependent on the type of feedstock utilized and processing conditions employed. Process optimization is imperative to produce an end product that meets application-specific requirements, environmental regulations and achieve ultimate stability for carbon sequestration purposes.

/pdf/industrial-biochar-systems-for-atmospheric-carbon-removal-a-1o26t8inm1.pdf

Industrial biochar systems for atmospheric carbon removal: a review

In general, composite materials are difficult to recycle. Tires belong to this class of materials. On top, one of their main constitutents, vulcanized rubber, is as elastomer, which cannot be remolten and hence is particularly challenging to put to a new use. Today, the main end-of-life routes of tires and other rubber products are landfilling, incineration in e.g., cement plants, and grinding to a fine powder, generating huge quantities and indicating a lack of sustainable recycling of this valuable material. True feedstock recycling is not feasible for complex mixtures such as tires, but devulcanization can be done to reactivate the cross-linked polymer for material recycling in novel rubber products. Devulcanization, i.e., the breaking up of sulfur bonds by chemical, thermophysical, or biological means, is a promising route that has been investigated for more than 50 years. This review article presents an update on the state-of-the art in rubber devulcanization. The article addresses established devulcanization technologies and novel processes described in the scientific and patent literatures. On the one hand, tires have become high-tech products, where the simultaneous improvement of wet traction, rolling resistance, and abrasion resistance (the so-called “magic triangle”) is hard to achieve. On the other hand, recycling and sustainable end-of-life uses are becoming more and more important. It is expected that the public discussion of environmental impacts of thermoplastics will soon spill over to thermosets and elastomers. Therefore, the industry needs to develop and market solutions proactively. Every year, approximately 40 million tons of tires are discarded. Through the devulcanization of end-of-life tires (ELT), it is possible to produce new raw materials with good mechanical properties and a superior environmental footprint over virgin products. The devulcanization process has become an interesting technology that is able to support the circular economy concept.

Devulcanization Technologies for Recycling of Tire-Derived Rubber: A Review.

Converting waste lignin into nano-biochar as a renewable substitute of carbon black for reinforcing styrene-butadiene rubber

A sustainable reduction route of graphene oxide by industrial waste lignin for versatile applications in energy and environment

The invention, which relates to the technical field of preparation of a sensing material, provides a preparation method of a multilayer capacitive flexible smart wearable sensor device. The method comprises: step one, preparing an elastic film and oxidizing the film; step two, immersing the film in a polycationic solution; step three, preparing an anionic dispersion solution of a conductive substance having a mass concentration of 0.5 to 2%; step four, coating the anionic dispersion solution on the elastic film prepared in the step two, carrying out drying, immersing the film in the polycationic solution, and repeating the step; step five, immersing the film processed in the step four into a pre-vulcanized latex and carrying out ultraviolet irradiation of the surface layer; step six, repeating the steps three, four, and five to obtain a multilayer capacitive device; and step seven, packaging the multilayer capacitive device. On the basis of the layer-by-layer self-assembling technology, the conductive filler is loaded on the surface of the elastic film to form an elastic conductive film with stable electrical conductivity; and then the multilayer capacitive sensor device is laminated by layer-by-layer lamination, so that the device has the high GF and high response speed.

Preparation method of multilayer capacitive flexible smart wearable sensor device

The invention belongs to the technical field of new functional materials science and particularly relates to a method for preparing an ultra-thin high elasticity transparent strain sensor device. Themethod comprises steps that (1), an elastomer is made into an original film and then pre-stretched, the original film is stretched to 120-1000% of the original size, and the original film is oxidizedto obtain an elastic film; (2), the elastic film is made to contact with polycationic surfactant; (3), the surface of the elastic film treated in the step (2) is coated with the anion solution of a conductive material to obtain the elastic film with a conductive layer; (4), the (2) and (3) are repeated to obtain a super elastomer conductive film; and (5), packaging is performed to obtain a strainsensor device. The strain sensor device is advantaged in that under the very small size and ultra-thin thickness, multiple conductive layers are constructed, low resistivity and high transparency arerealized, and the device is made to be more sensitive and responsive through the relatively large radius of undulating pleats formed in the structure and the relatively small individual wavy dimension.

Bo Jinyu

Papers

Converting waste lignin into nano-biochar as a renewable substitute of carbon black for reinforcing styrene-butadiene rubber

A sustainable reduction route of graphene oxide by industrial waste lignin for versatile applications in energy and environment

Preparation method of multilayer capacitive flexible smart wearable sensor device

Method for preparing ultra-thin high elasticity transparent strain sensor device