The use of conservation biomass feedstocks as potential bioenergy resources in the United Kingdom

A Critical Review of the Decarbonisation Potential in the U.K. Cement Industry

As urbanisation and infrastructure development continue to drive rising cement demand, the imperative to significantly reduce emissions from this emissions-intensive sector has become increasingly urgent, especially in the context of global climate goals such as achieving net zero emissions by 2050. This review examines the status, challenges and prospects of low-carbon cement technologies and mitigation strategies through the lens of the U.K. cement industry. A mixed-methods approach was employed, combining structured literature searches across academic databases with analyses of industry reports, market data and technological roadmaps to ensure a comprehensive evaluation. Following an outline of cement production, resource flows and the sector's landscape in the U.K., the review delves into an array of decarbonisation pathways. This includes deploying the best available technologies (BATs), fuel switching, carbon capture utilisation and storage (CCUS), clinker substitution and low-carbon cement formulations. A critical assessment is provided on the technological readiness, costs, resource availability considerations and scalability aspects governing the widespread implementation prospects of these approaches within the U.K. cement industry. Furthermore, this study proposes a roadmap that considers priority avenues and policy needs essential for facilitating the transition towards sustainable cement production aligned with the U.K.'s net zero obligations by 2050. This evaluation contributes significantly to the ongoing decarbonisation discourse by holistically mapping technological solutions and strategic imperatives tailored to the unique challenges and opportunities presented by the U.K. cement sector.

Turning waste into treasure: Biosynthesis of value-added 2-O-α-glucosyl glycerol and d-allulose from waste cane molasses through an in vitro synthetic biology platform

The efficient and economical conversion of agricultural waste into glycosides and rare sugars is challenging. Herein, an in vitro synthetic bienzyme system consisting of sucrose phosphorylase and d-allulose 3-epimerase was constructed to produce 2-O-α-glucosyl glycerol and d-allulose from cane molasses. Lactic acid in the cane molasses significantly induced sucrose phosphorylase to hydrolyze sucrose instead of glycosylation. Notably, lactic acid significantly inhibited the catalytic performance of d-allulose 3-epimerase only in the presence of Na+ and K+, with an inhibition rate of 75%. After removing lactic acid and metal ions, 116 g/L 2-O-α-glucosyl glycerol and 51 g/L d-allulose were synthesized from 500 mM sucrose in the treated cane molasses with a sucrose consumption rate of 97%. Our findings offer an economically efficient and environmentally friendly pathway for the industrial production of glycosides and rare sugars from food industry waste.

A review on global perspectives of sustainable development in bioenergy generation

Over the last few decades, the globe has much relied on fossil fuels; however, environmental concerns forced the World to look at biofuel as an alternative for stable economic development. Biofuel also facilitates national energy security maintenance and reduces environmental complications. The present study is focused on an in-depth analysis of bioenergy policy measures undertaken by various federal agencies of different countries in order to shed light on the bottlenecks that impede biofuel's growth as a sustainable and alternative fuel. An in-depth assessment of feedstock utilization, blending targets, and policy assistance schemes have been thoroughly reviewed. In addition, the potential of commercial firms for the production of bioenergy is highlighted in order to grasp the current bioenergy market scenario better. Finally, the article is concluded with the viewpoints of the authors to address the standing issues of global bioenergy generation.

Forest Dendromass as Energy Feedstock: Diversity of Properties and Composition Depending on Systematic Genus and Organ

Exhaustion of fossil fuel resources, shrinking forest areas, with accompanying deterioration of their quality and striving (also of the society) to make forests perform their ecological function, with simultaneous development and propagation of the biomass conversion technologies—all of this necessitates research of forest biomass diversification. It is a consequence of the fact that its properties and composition depend not only on the genus but also on the plant organ, and they each time determine its usability as a raw biomaterial in a wide range of thermal, physical, or chemical conversion processes. This study reviewed and analysed selected qualitative and quantitative features of forest dendromass, taking into account the genus and a plant organ/morphological part, followed by a group of trees (coniferous and deciduous) and without the latter differentiation. The study involved an analysis of data covering 15 selected qualitative-quantitative features of forest dendromass within three main and nine additional plant organs/morphological parts and 21 genera (5 coniferous and 16 deciduous) typical of the temperate climate.

Co-Processing Lignocellulosic Biomass and Sewage Digestate by Hydrothermal Carbonisation: Influence of Blending on Product Quality

Hydrothermal carbonisation (HTC) can be integrated with anaerobic digestion (AD) for the treatment of digestate, resulting in a solid hydrochar or bio-coal and a process water, which can be recirculated back into AD to produce biogas. The properties of digestate-derived hydrochars do not lend themselves to producing high quality bio-coal and blending with lignocellulosic feedstocks can improve its properties. This study investigates the co-processing of sewage sludge (SS) digestate with three lignocellulosic biomass (grass, privet hedge, and woodchip). The calorific value of the resulting bio-coal is increased following co-processing, although feedstock interactions result in non-additive behaviour. The largest increase in calorific value was observed for co-processing with woodchip. There is evidence for non-additive partitioning of metals during co-processing resulting in only moderate improvements in ash chemistry during combustion. Co-processing also effects the composition of process waters, influencing the potential for biogas production. Experimental biomethane potential (BMP) tests indicate that grass clippings are the most suitable co-feedstock for maintaining both calorific value and biogas production. However, above 200 °C, BMP yields appear to decrease, suggesting the process water may become more inhibitory. Co-processing with wood waste and privet hedge produce the higher CV bio-coal but significantly reduced BMP.

Thermal Analysis Technologies for Biomass Feedstocks: A State-of-the-Art Review

An effective analytical technique for biomass characterisation is inevitable for biomass utilisation in energy production. To improve biomass processing, various thermal conversion methods such as torrefaction, pyrolysis, combustion, hydrothermal liquefaction, and gasification have been widely used to improve biomass processing. Thermogravimetric analysers (TG) and gas chromatography (GC) are among the most fundamental analytical techniques utilised in biomass thermal analysis. Thus, GC and TG, in combination with MS, FTIR, or two-dimensional analysis, were used to examine the key parameters of biomass feedstock and increase the productivity of energy crops. We can also determine the optimal ratio for combining two separate biomass or coals during co-pyrolysis and co-gasification to achieve the best synergetic relationship. This review discusses thermochemical conversion processes such as torrefaction, combustion, hydrothermal liquefaction, pyrolysis, and gasification. Then, the thermochemical conversion of biomass using TG and GC is discussed in detail. The usual emphasis on the various applications of biomass or bacteria is also discussed in the comparison of the TG and GC. Finally, this study investigates the application of technologies for analysing the composition and developed gas from the thermochemical processing of biomass feedstocks.

GHG Emissions and Efficiency of Energy Generation through Anaerobic Fermentation of Wetland Biomass

We conducted the Life Cycle Analysis (LCA) of energy production from biogas for maize and three types of wetland biomass: reed Phragmites australis, sedges Carex elata, and Carex gracilis, and “grassy vegetation” of wet meadows (WM). Biogas energy produced from maize reached over 90 GJ ha−1, which was more than four times higher than that gained from wetland biomass. However, an estimation of energy efficiency (EE) calculated as a ratio of energy input to the energy produced in a biogas plant showed that the wet fermentation (WF) of maize was similar to the values obtained for dry fermentation (DF) of sedge biomass (~0.30 GJ GJ−1). The greenhouse gases (GHG) emissions released during preparation of the feedstock and operation of the biogas plant were 150 g CO2 eq. kWhel.−1 for DF of sedges and 262 g CO2 eq. kWhel.−1 for WF of Phragmites. Compared to the prevailing coal-based power generation in Central Europe, anaerobic digestion (AD) of wetland biomass could contribute to a reduction in GHG emissions by 74% to 85%. However, calculations covering the GHG emissions during the entire process “from field to field” seem to disqualify AD of conservation biomass as valid low-GHG energy supply technology. Estimated emissions ranged between 795 g CO2 eq. kWhel.−1 for DF of Phragmites and 2738 g CO2 eq. kWhel.−1 for the WM and, in most cases, exceeded those related to fossil fuel technologies.

Multi-Criteria and Life Cycle Assessment of Wood-Based Bioenergy Alternatives for Residential Heating: A Sustainability Analysis

Moving towards a global bioeconomy can mitigate climate change and the depletion of fossil fuels. Within this context, this work applies a set of multi-criteria decision analysis (MCDA) tools to prioritise the selection of five alternative bioenergy systems for residential heating based on the combination of three commercial technologies (pellet, wood stove and traditional fireplace) and two different feedstocks (eucalypt and maritime pine species). Several combinations of MCDA methods and weighting approaches were compared to assess how much results can differ. Eight indicators were used for a sustainability assessment of the alternatives while four MCDA methods were applied for the prioritisation: Weighted Sum Method (WSM), Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), Elimination and Choice Expressing Reality (ELECTRE), and Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE). Regarding the sustainability performance indicators, the highest environmental impacts were calculated for the fireplace alternatives, and there was not a best environmental option. Also, no clear trend was found for the economic and social dimensions. The application of MCDA tools shows that wood stove alternatives have the best sustainability performance, in particular wood stove with combustion of maritime pine logs (highest scores in the ranking). Regarding the worst alternative, fireplaces with combustion of eucalypt logs ranked last in all MCDA rankings. Finally, a sensitivity analysis for the weighting of the performance indicators confirmed wood stoves with combustion of maritime pine logs as the leading alternative and the key role of the analysts within this type of MCDA studies.

Promotion of hydrogen-rich gas and phenolic-rich bio-oil production from green macroalgae Cladophora glomerata via pyrolysis over its bio-char

Conversion of Cladophora glomerata (C. glomerata) as a Caspian Sea's green macroalgae into gaseous, liquid and solid products was carried out via pyrolysis at different temperatures to determine its potential for bio-oil and hydrogen-rich gas production for further industrial utilization. Non-catalytic tests were performed to determine the optimum condition for bio-oil production. The highest portion of bio-oil was retrieved at 500°C. The catalytic test was performed using the bio-char derived at 500°C as a catalyst. Effect of the addition of the algal bio-char on the composition of the bio-oil and also gaseous products was investigated. Pyrolysis derived bio-char was characterized by BET, FESEM and ICP method to show its surface area, porosity, and presence of inorganic metals on its surface, respectively. Phenols were increased from 8.5 to 20.76area% by the addition of bio-char. Moreover, the hydrogen concentration and hydrogen selectivity were also enhanced by the factors of 1.37, 1.59 respectively.