Nowadays, fossil fuels are used in a clearly unsustainable way that can bring potentially catastrophic consequences. Electricity is currently delivered to end users by generation and energy transmission companies. Previous research shows that the development of modern circular economy sets a need for the re-orientation of socio and economic development of decentralized systems, including energy basis. In addition to being ecological, the use of renewable energy sources also has economic significance by contributing to energy independence. Citizens, industries, local and national authorities become interconnected within emerging novel renewable energy sourcing communities, through which they establish trade of energy and, most importantly, models of investing and reshaping the distribution of renewable energy. The modern portfolio management of renewable energy networking is aiming toward decentralized systems of trade, where the consumer becomes a producer (prosumer) within the network, itself managed by users. Excess energy produced in the micro-grid nets within the over-arching national and transnational energy grid should be accounted for and managed with blockchain technology for financial and structural security. The decentralization of the energy market requires the establishment of strict norms that will regulate the market and taxation of profits arising. The extensive literature review on blockchain in the energy sector reflects a very pragmatic and narrow approach to the topic, although it is evident that the distribution of energy within the blockchain would enable economic development through reducing cost and ensuring more secure energy trade. Blockchain technology embeds the related digital codes, in which information will be visible to all, but also secured from hacking and duplicating. However, there are challenges to this paradigm, not least the energy consumption of the extensive nodal mesh required to perform the necessary protocols. This paper aims to provide an overview of the application of blockchain technology and the need for the development of the regulatory system and of potential solutions to the challenges posed. By undertaking an energy consumption analysis of blockchain implementation from first electronic principles, which has not been constructed before in the literature, this paper’s conclusion stresses the future demand for reducing energy consumption and considers the latest findings in the quantum coupling of light signals as a potential for solving the enormous ledger duplication structure problem.

The bioeconomy aims at decreasing reliance on fossil fuels, preventing or reducing climate change, eliminating insecurity, and efficiently using resources; however, fierce controversy exists on conceivable pathways to accomplish these objectives. The transport sector alone, which encompasses all other industrial sectors, has grown with regard to its energy demand by 50% over the past 30 years. The aim of this paper is to promote a dialogue as to whether an economy based on biomass can be more sustainable than today’s existing economies, considering that the economy needs to expand and be boosted, while creating a cascading and recycling system. This semi-systematic review paper discusses four research questions based on findings from the last 20 years: (i) What are the crucial issues in the ongoing debate on the development of a sustainable bioeconomy concept? (ii) Where are the major conflicting points and focuses? (iii) How does the bioeconomy follow current urbanization and land-abandonment trends? (iv) How will the crisis linked to the COVID-19 pandemic change these previous scenarios? As it is not easy to currently predict which pathway will be the most effective, whether it be the one taken as of now or a specific novel pathway, this article recommends following a strategy that is diverse regarding its approaches to shaping the bioeconomy and further funding of renewable energy sources, along with the involvement of urban planning. In addition, conclusions are validated through a questionnaire completed by 51 experts in the field.

Nano-lignocellulose (NLC) and lignin-free nanocellulose (nano-holocellulose, NHC) were used in paper coating to investigate their effect on coating layer quality and offset printing. The NLC was produced by microfluidisation of unbleached secondary fibres while the reference NHC was obtained from the same fibre source after lignin removal (OHE_PH bleaching), following the same mechanical process. TEMPO-mediated oxidation of the fibres prior to microfluidisation was applied to increase the electrostatic charge and hydrophilicity of the nanofibrils. The coatings, displaying given surface morphology and energy, were applied on Kraft, printing-grade papers at three grammage levels. The structure of the coated and uncoated (reference) papers were accessed (SEM and AFM) and IGT printing was carried out to determine the print density, print gloss, rub-off resistance, surface energy, roughness, ink transfer, dry pick resistance, water interference and set-off. The results highlight the important effect of residual lignin or type of nanocellulose on the coating layer and the development of offset printing properties. It was observed that roughness was a key factor leading to a deterioration of the print properties, predominantly affecting the NLC coating. Considering the lower hydrophilicity of NLC, an alternative dispersion with water-alcohol mixtures is proposed. By using this dispersing medium, tailorable surface coverage, surface smoothness, ink acceptance and improved printability was achieved. We show that under these conditions and compared to NHC, NLC is equally effective as a coating layer.

Cellulose nanofibrils (CNFs) have emerged as sustainable options for a wide range of applications. However, the high aspect ratio and biopersistence of CNFs raise concerns about potential health effects. Here, we evaluated the in vivo pulmonary and systemic toxicity of unmodified (U-CNF), carboxymethylated (C-CNF), and TEMPO (2,2,6,6-tetramethyl-piperidin-1-oxyl)-oxidized (T-CNF) CNFs, fibrillated in the same way and administered to mice by repeated (3×) pharyngeal aspiration (14, 28, and 56 μg/mouse/aspiration). Toxic effects were assessed up to 90 days after the last administration. Some mice were treated with T-CNF samples spiked with lipopolysaccharide (LPS; 0.02-50 ng/mouse/aspiration) to assess the role of endotoxin contamination. The CNFs induced an acute inflammatory reaction that subsided within 90 days, except for T-CNF. At 90 days post-administration, an increased DNA damage was observed in bronchoalveolar lavage and hepatic cells after exposure to T-CNF and C-CNF, respectively. Besides, LPS contamination dose-dependently increased the hepatic genotoxic effects of T-CNF.

It has been a persistent challenge to develop eco-friendly packaging cellulose film providing the required multiple barrier properties whilst simultaneously contributing to a circular economy. Typically, a cellulosic film made from nanocellulose materials presents severe limitations, such as poor water/moisture resistance and lacking water vapour barrier properties, related primarily to the hydrophilic and hygroscopic nature of cellulose. In this work, alkyl ketene dimer (AKD) and starch, both eco-friendly, non-toxic, cost-effective materials, were used to achieve barrier properties of novel cellulose–calcium carbonate composite films regenerated from paper components, including paper waste, using ionic liquid as solvent. AKD and starch were applied first into the ionic cellulose solution dope mix, and secondly, AKD alone was coated from hot aqueous suspension onto the film surface using a substrate surface precooling technique. The interactions between the AKD and cellulose film were characterised by Fourier-Transform Infrared Spectroscopy (FTIR) and X-ray Diffraction (XRD) showing the formation of a ketone ester structure between AKD and the hydroxyl groups of cellulose. The presence of calcium carbonate particles in the composite was seen to enhance the cellulose crystallinity. The initial high-water vapour and oxygen transmission rates of the untreated base films could be decreased significantly from 2.00 to 0.14 g m⁻² d⁻¹, and 3.85 × 10² to 0.45 × 10² cm³ m⁻² d⁻¹, respectively. In addition, by applying subsequent heat treatment to the AKD coating, the water contact angle was markedly increased to reach levels of superhydrophobicity (>150°, and roll-off angle < 5°). The resistance to water absorption, grease-permeation, and tensile strength properties were ultimately improved by 41.52%, 95.33%, and 127.33%, respectively, compared with those of an untreated pure cellulose film. The resulting regenerated cellulose–calcium carbonate composite-based film and coating formulation can be considered to provide a future bio-based circular economy barrier film, for example, for the packaging, construction and agriculture industries, to complement or replace oil-based plastics.