Additive-manufactured (3D-printed) electrochemical sensors: A critical review.

Sustainable biorefinery depends on the development of efficient processes to convert locally abundant, energy-rich renewable biomass into fuels, chemicals, and materials. Hydrothermal processing has emerged as an attractive approach for wet biomass conversion with less environmental burden. Although considerable efforts have been made in sustainable biorefinery by unitizing innovative technologies at a laboratory scale, its scaling-up is still impeded by the biomass heterogeneity. This article critically reviews the recent advances in hydrothermal carbonization and liquefaction technologies for the sustainable production of hydrochar and aromatics from different biomass wastes. Three main aspects, including lignocellulose-/lignin-rich feedstock, operating conditions, and design of liquid/solid catalysts, are critically reviewed and discussed to understand the reaction mechanisms and system designs for increasing the yields of aromatics and improving the properties of hydrochar. The latest knowledge and technological advances demonstrate the importance of identifying the physical and chemical properties of feedstock. The science-informed design of hydrothermal technology and optimization of operational parameters with reference to the biomass properties are crucial for the selective production of value-added chemicals and multifunctional hydrochar. This review identifies current limitations and offers original perspectives for advancing hydrothermal processing of biomass towards carbon-efficient resource utilization and circular economy in future applications.

Hydrothermal carbonization and liquefaction for sustainable production of hydrochar and aromatics

Background The technology of food packaging is responding to significant market dynamics such as the rapid growth in e-commerce and preservation of fresh food, a sector that accounts for over 40% of plastic waste. Further, mandates for sustainability and recent changes in national governmental policies and regulations that include banning single-use plastic products as observed in sweeping reforms in Europe, Asia, and several US States are forcing industries and consumers to find alternative solutions. Scope and approach This review highlights an ongoing shift of barrier coatings from traditional synthetic polymers to sustainable breakthrough materials for paper-based packaging and films. Advantages, challenges and adapting feasibility of these materials are described, highlighting the implications of selecting different materials and processing options. A brief description on progress in methods of coating technologies is also included. Finally, the end fate of the barrier materials is classified depending on the packaging type, coating materials used and sorting facility availability. Key findings and conclusions Different types of coatings, such as water-based biopolymers, due to their greater environmental compatibility, are making inroads into more traditional petroleum-based wax and plastic laminate paperboard products for fresh food bakery, frozen food, and take-out containers applications. In addition, nano-biocomposites have been studied at an accelerating pace for developing active and smart packaging. Based on the momentum of recent developments, a strong pace of continuing developments in the field can be expected.

Advances in barrier coatings and film technologies for achieving sustainable packaging of food products – A review

Lignocellulosic waste materials are the most promising feedstock for generation of a renewable, carbon-neutral substitute for existing liquid fuels The development of value-added products from lignin will greatly improve the economics of producing liquid fuels from biomass This review gives an outline of lignin chemistry, describes the current processes of lignocellulosic biomass fractionation and the lignin products obtained through these processes, then outlines current and potential value-added applications of these products, in particular as components of polymer composites

Research highlights

The use of lignocellulosic biomass to produce platform chemicals and industrial products enhances the sustainability of natural resources and improves environmental quality by reducing greenhouse and toxic emissions In addition, the development of lignin based products improves the economics producing liquid transportation fuel from lignocellulosic feedstock Value adding can be achieved by converting lignin to functionally equivalent products that rely in its intrinsic properties This review outlines lignin chemistry and some potential high value products that can be made from lignin

Keywords: Lignocellulose materials; Lignin chemistry; Application

Value-adding to cellulosic ethanol: Lignin polymers

Electronic tongue and cyclic voltammetric sensors based on carbon nanotube/polylactic composites fabricated by fused deposition modelling 3D printing.

Supercritical CO2 (sCO2) removes both water and extractives from wood chips and flakes at 60 °C. The water appears to be mostly displaced by sCO2 because its nominal concentration in sCO2 exceeds its solubility limit. SEM imaging and contact angle measurements show no major differences in surface properties between sCO2-treated and thermally dried flakes, which suggests that their interaction with resin should be similar. An economic analysis for the removal of water and extractives from pine flakes for the manufacture of oriented strand board shows that sCO2 treatment is potentially much more cost-effective than thermal drying from both capital and operational perspectives. The main reasons are that the water is removed by displacement rather than through evaporation, environmental control costs are drastically reduced, and the extractives removed represent a value stream instead of pollutants whose emissions need to be controlled. Because the sCO2 is largely recirculated, the process is greener than con...

Removal of Water and Extractives from Softwood with Supercritical Carbon Dioxide

There are a large variety of different materials currently used for producing 3D printing filaments. In this paper we are investigating the utilization of diatomaceous earth as a potential component for polylactic acid based 3D printing composite materials. The results clearly show that with only minor deterioration of the basic mechanical properties of the 3D printed material at least 10 wt% of the polylactic acid usage can be reduced and replaced by diatomaceous earth. Our thermal analysis also shows nucleation and chain mobility phenomena in the presence of diatomaceous earth particles. The results also show that we are able to engineer 3D printing surfaces with diatomaceous earth protruding from the composite structure and thus allowing us to create high surface area on the 3D printed objects surface. With this research we have shown for the first time an opportunity for cost reduction compared to using pure polylactic acid filaments and a pathway to immobilizing chemical sensing, antibacterial and antiviral agents on 3D printed objects for many applications such as biomedical.

Novel 3D printing filament composite using diatomaceous earth and polylactic acid for materials properties and cost improvement

This effort is focused on work completed publicly and privately within academic research and industrial sectors on the utilization of lignin to produce thermosets, thermoplastics, foams, hydrogels, and rubbers. The size of the plastics market and the current and projected influence of lignin on it were evaluated. Further, an analysis of patent activity was employed to show the direction of and interest for lignin in these markets. The market trends documented in the literature, when coupled with detailed patent research, offer a new approach to evaluate potential markets and future directions. The analysis of the commercial market sizes of bioplastics and segmentation showed low penetration of actual lignin-based bioplastics. This exposed the contradiction between the abundance of technologies for lignin-based materials and their little practical use. In addition, this finding highlighted a severe gap between lignin research and development and the actual market.

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A Perspective of Lignin Processing and Utilization Technologies for Composites and Plastics with Emphasis on Technical and Market Trends

The morphological and physical properties of hydrochar from the hydrothermal carbonization of nanofibrillated cellulose (NFC) are herein described; it was found that the initial starting structure ...

Shelly Johnson

Papers

Removal of Water and Extractives from Softwood with Supercritical Carbon Dioxide

Novel 3D printing filament composite using diatomaceous earth and polylactic acid for materials properties and cost improvement

A Perspective of Lignin Processing and Utilization Technologies for Composites and Plastics with Emphasis on Technical and Market Trends

Hydrothermal Carbonization of Nanofibrillated Cellulose: A Pioneering Model Study Demonstrating the Effect of Size on Final Material Qualities