James Hanley Clark

University of York · Department of Chemistry

This study focuses on the fabrication and characterisation of single-walled carbon nanotube (SWCNT) buckypapers and polyethersulfone (PES) flat-sheet membranes using Cyrene, aiming toevaluate its efficacy as a green solvent for these applications. Pristine SWCNTs were dispersed inCyrene without surfactants and compared to N-Methyl-2-pyrrolidone (NM...

Lignin valorisation into chemicals and fuels is of great importance in addressing energy challenges and advancing biorefining in a sustainable manner. In this study, on the basis of the high microwave absorption performance of carbon nanotubes (CNTs), a series of copper-oxide-loaded CNT catalysts (CuO/CNT) were developed to facilitate the oxidative...

Gold nanoparticles (Au-NPs) are used as catalysts for a diverse range of industrial applications. Currently, Au-NPs are synthesized chemically, but studies have shown that plants fed Au deposit, this element naturally as NPs within their tissues. The resulting plant material can be used to make biomass-derived catalysts. In vitro studies have shown...

Extensive use of grey hydrogen in traditional hydrodeoxygenation (HDO) severely reduces the sustainable development of lignin valorization processes. Conversely, the catalytic transfer hydrogenation (CTH) mediated by green hydrogen is an alternative strategy that promotes the sustainability of in-situ hydrogenation of lignin. In this work, a bifunc...

A combination of supercritical carbon dioxide (scCO2) extraction and microwave-assisted pyrolysis (MAP) have been investigated for the valorisation of waste rice straw. ScCO2 extraction of rice straw led to a 0.7% dry weight yield of lipophilic molecules, at elevated temperatures of 65 °C and pressures of 400 bar. Lipid compositions (fatty acids, f...

Pyrethrin are effective agents against mosquito larval but their rapid degradation rate in water reduces the deinsectization efficiency and increases the cost of deinsectization. Based on liquid marble,a biodegradable slow-release...

Preparation of high-value monomers from PET waste plastic.

The bio-based solvent dihydrolevoglucosenone (Cyrene) is a green and sustainable alternative to petroleum-based dipolar aprotic solvents. Cyrene can be prepared from cellulose in a simple two-step process and can be produced in a variety of yields. Cyrene is compatible with a large number of reactions in the chemical industry and can be applied in...

Critical metals are key to lithium-ion batteries (LIB), but metal mining has inflicted many socio-environmental harms. Recovering metals from spent LIBs can partially overcome this challenge, but existing recovery and re-cycling techniques such as pyrometallurgy and hydrometallurgy are either energy intensive or require toxic chemicals. Solvometall...

In this study, CO2- and N2-pressurized HTC processes were investigated to understand the catalytic effects of CO2 on hydrochar production and its quality (e.g., surface properties, energy recovery, and combustion behaviour). Both CO2- and N2-pressurized HTC processes could enhance the energy recovery (from 61.5% to 63.0-67.8%) in hydrochar by enhan...

Graffiti can create detrimental aesthetic and environmental damage to city infrastructure and cultural heritage and requires improved removal methods. Incumbent laser, mechanical and chemical removal techniques are often not effective, are expensive or damage the substrate. Solvents are generally hazardous and not always effective because of the in...

The synthesis of surfactants from fatty acid esters via epoxide chemistry has been known for its accompanying challenges, which usually involve the use of toxic homogeneous catalysts in the ring-opening reaction step and generation of many side reaction products. This paper presents environmentally benign routes to a library of nonionic surfactants...

Hazardous reactive dyes can cause serious environmental problems, as they are difficult to remove from water using conventional adsorbents due to their large molecular sizes and bulky structures. Sustainable mesoporous carbons derived from alginic acid demonstrated promising adsorbent capacity for several representative industrial bulky reactive dy...

Bio-based chemicals synthesis by lignin offers a promising pathway of bioenergy utilization to achieve the target of the Paris Agreement with < 2°C of climate warming temperature. Recently, numerous efforts...

Recalcitrance and the inherent heterogeneity of lignin structure are the major bottlenecks to impede the popularization of lignin-based chemicals production processes. Recent works suggested a promising pathway for lignin depolymerization and lignin-derived bio-oil upgrading via an electrochemical biorefinery (a process in which lignin valorization...

Green chemistry places an emphasis on safer chemicals, waste reduction, and efficiency. Processes should be optimized with green chemistry at the forefront of decision making, embedded into research at the earliest stage. To assist in this endeavor, we present a spreadsheet that can be used to interpret reaction kinetics via Variable Time Normaliza...

Lignin is a natural and renewable aromatic raw material of aromatic chemicals and its depolymerization and downstream products conversion has drawn considerable attention. Herein, a series of Ni loaded metal phosphates (Ni/MP, M = Ti, Zr, Nb, La, or Ce) catalysts were fabricated for the hydrodeoxygenation (HDO) of lignin-derived vanillin (VAN) to p...

The potential of mitigation actions to limit global warming within 2 °C (ref. ¹) might rely on the abundant supply of biomass for large-scale bioenergy with carbon capture and storage (BECCS) that is assumed to scale up markedly in the future2–5. However, the detrimental effects of climate change on crop yields may reduce the capacity of BECCS and...

The application of biocontrol agent is important for the sustainable development of agriculture. Unsuccessful or limited colonisation by plant growth-promoting rhizobacteria (PGPR) has become an important constraint factor for their commercial application. Here, we report that Ulva prolifera polysaccharide (UPP) promotes root colonisation by Bacill...

This study innovated the concept in designing an efficient and reusable microwave (MW) absorbent through concurrent exploitation of carbon graphitization, oxygen functionalization, and carbothermal iron reduction underpinned by an endothermic co-pyrolysis of wood waste and low-dosage iron. A powerful MW assimilation was accomplished from nanoscale...

Biomass valorization to chemicals is an important application of this renewable resource. This study reports the production of two versatile value-added organic acids, i.e., gluconic acid (GOA) and glucuronic acid (GUA), from biomass-derived glucose via microwave-assisted catalytic oxidation. A series of novel low-cost biochar-supported Cu-based ca...

Oleaginous yeast, cultured on second-generation lignocellulosic resources, has the potential to be a key part of the future energy sector. However, the multiple unit operations necessary to produce concentrated hydrolysates, with a minimum of fermentation inhibitors, limit the applicability to date. In this study, a simple microwave-assisted hydrot...

The aza-Michael addition is a versatile reaction for the modification of α,β-unsaturated carbonyl compounds with amines. The reactivity of dimethyl itaconate as a bio-based Michael acceptor is explored in this work. Through its reactions with piperidine and dibutylamine, it was found that the order of reaction can be changed by the choice of cataly...

Hierarchically porous activated Starbons® derived from starch are found to make excellent adsorbents for methylene blue, even in the presence of other dyes and inorganic salts, highlighting their potential to be used in water purification. The optimal material (S950C90) has a methylene blue adsorption capacity (891 mg g⁻¹) almost nine times higher...

The current process to purify CBD from C. sativa extract is long and intensive, requiring several steps such as winterification for 48 hours at -45 °C and high-temperature, high vacuum distillation. These processes are capital intensive and generate large amounts of toxic solvent waste. In contrast, the solid phase extraction (SPE) methodology prop...

Cottonseed protein (CP) was compounded with polycaprolactone (PCL) in different concentrations by melt blending, and then hot-pressed to prepare CP/PCL blend films. A co-continuous phase is formed when the CP/PCL content is 50/50, and the tensile strength, modulus and toughness are 9, 10, and 63 times greater than that of neat CP film. This remarka...

With mounting concerns over critical element sustainability in future bio-refineries, the conversion of phyto-extracted nickel (from contaminated lands) into an inexpensive and clean catalyst could help to reduce demand for virgin precious metals. Utilizing this green approach, noble metal catalysts, which require substantial downstream processing,...

A considerable amount of food waste generated globally could be upcycled to synthesise platform chemicals to enhance environmental sustainability and help realise a circular economy. This study investigates the catalytic production of the vital platform molecule levulinic acid (LA) from bread waste, a typical stream of starch-rich food waste genera...

Due to the global shortage of phosphate ore, sewage sludge is an important resource for P recovery. This study aims to investigate how P was migrated and transformed during the microwave hydrothermal (MHT) process of sewage sludge. The effects of MHT and hydrothermal (HT) conversion were compared. The results reveals that there were no significant...

Cyclohexanol is an essential intermediate in the chemical industry for the synthesis of nylon and other materials, but the direct hydrogenation of phenol to produce cyclohexanol is problematic due to excessive energy consumption associated with the harsh reaction conditions. In this regard, the novel composite catalysts (Ru/Nb2O5-nC18PA) coated wit...

Methylation of acetoin with dimethyl carbonate was performed in a sustainable one-step process, with improved process mass intensity (PMI) and atom economy compared to previously published methods. The resulting product, 3-methoxybutan-2-one (MO) was successfully evaluated as a bio-based solvent, while both Kamlet–Taft solvatochromic parameters and...

There is ever increasing demand to develop surfactants based on sophorolipids because they are produced by non-pathogenic organisms, biodegradable and less toxic to humans and the environment. Herein, commercially available lactonic sophorolipid was modified via epoxidation of the fatty acid units C[double bond, length as m-dash]C and subsequent ri...

The lignin-first biorefinery strategy could produce bio-based phenols from the extraction and depolymerization of native lignin in lignocellulosic biomass. Herein, we report an effective Lewis acid-promoted delignification and production of monophenolic compounds in birch sawdust assisted by microwave heating without external hydrogen for the first...

2,2,5,5-tetramethyloxolane (TMO) has recently been identified and demonstrated as a safer solvent to replace toluene, THF, and hydrocarbons in a handful of applications. Herein, several bio-based routes to TMO are presented and assessed for greenness, assisted by the CHEM21 Metrics Toolkit and BioLogicTool plots. Using glucose as a common starting...

This study explores a binary solvent system composed of biobased Cyrene and its derivative Cygnet 0.0 for application in membrane technology and in biocatalytic synthesis of polyesters. Cygnet‐Cyrene blends could represent viable replacements for toxic polar aprotic solvents. The use of a 50 wt % Cygnet‐Cyrene mixture makes a practical difference i...

This study explores a binary solvent system of bio-based Cyrene and its derivative, Cygnet 0.0, with novel properties for applications in membranes technology and bio-catalysed synthesis of polyesters. Cygnet-Cyrene blends have not been reported prior to this work and could represent viable replacements for toxic polar aprotic solvents. The use of...

The coating of the beech sawdust using a catalytic amount of graphite (as low as 0.25 wt%) allowed a step improvement in the microwave-assisted thermolysis. Results demonstrated that the pyrolysis performance was linked to an electrical conductivity threshold of the coated samples rather than a gradual increase. With as low as 0.13 mS m−1 of electr...

The methylation of alcohols is of great importance since a broad number of bioactive and pharmaceutical alcohols contain methyl groups. Here, a highly efficient β-methylation of primary and secondary alcohols with methanol has been achieved by using bis-N-heterocyclic carbene iridium (bis-NHC-Ir) complexes. Broad substrate scope and up to quantitat...

Furfural is a promising platform chemical that can be catalyzed from lignocellulose biomass. In this study, a novel micro-mesoporous carbon supported tin oxide catalyst (MC-SnOx) was developed to convert xylose into furfural in a low sodium chloride (NaCl) concentration and acid-free biphasic system. The catalysts synthesized by annealing from 400...

A multifunctional Ru/SBA-15 catalyst is prepared via impregnation, and used in the depolymerization of crude waste corn stover enzymatic lignin (CSEL) to produce monophenols and unexpectedly, the industrially important organic siloxanes. In the depolymerization of CSEL over Ru/SBA-15, a high phenolic monomer yield of 13.91 wt. % with a high selecti...

As China ramped-up coal power capacities rapidly while CO 2 emissions need to decline, these capacities would turn into stranded assets. To deal with this risk, a promising option is to retrofit these capacities to co-fire with biomass and eventually upgrade to CCS operation (BECCS), but the feasibility is debated with respect to negative impacts o...

An oligosaccharide-based masking agent suitable for chrome-free metal tanning was produced from cellulose via a stepwise degradation and oxidation process. Firstly, an AlCl3-NaCl-H2O/γ-valerolactone (GVL) biphasic solvent system was established for cellulose conversion (87.6%), which allowed in situ separation of the oligosaccharides and valuable s...

Biomass-derived N-doped carbon (BNC) is an important environmental material and widely used in the fields of water purification and soil remediation. However, the toxicant in the commonly used synthesis process of BNC materials have been largely ignored. Herein, we firstly report the presence of a highly toxic by-product (KCN) in the activation pro...

The valorization of carbon dioxide (CO2) to fine chemicals is one of the most promising approaches for CO2 capture and utilization. Herein we demonstrated a series of porous organometallic polymers could be employed as highly efficient and recyclable catalysts for this purpose. Synergetic effects of specific surface area, iridium content, and CO2 a...

ABSTRACT: This work addresses the management of Brewers’ Spent Grain (BSG) using a state-of-the-art, microwave-assisted, hydrothermal carbonization (MA-HTC) process, for the production of hydrochar, i.e., a renewable solid biomaterial with many industrial applications. For the first time, a detailed relationship has been established between the pro...

Hesperidin and rutin are two sought-after natural flavonoids, traditionally extracted from abundant natural citrus fruits and tea leaves using large amounts of ethanol or methanol solvents. Recent trends in extractions have focused on minimizing the use of solvents and creating simpler cost-effective processes. This study aims to apply the concept...

An approach of largely improving the properties of protein-based biopolymers is reported. Cottonseed protein concentrate (CPC) purified from cottonseed protein powder waste, with a protein content of >70% and a plasticizing efficiency of 4.2, was used to produce bioplastic polymer. A prepreg consisting of relatively oriented sisal fiber (SF) was tr...

Porous organometallic polymers (POMPs) with controllable porosity and enhanced CO2 adsorption capability were fabricated via the direct knitting strategy. Excellent selectivity and activity with a record turnover number (TON=1.58×10⁶) in the N‐formylation reaction with CO2 and H2 to N,N‐dimethylformamide (DMF) were achieved under mild reaction cond...

Microwaves (MWs) are promising technologies for energy-efficient biorefineries which reduce our dependence on petroleum. Here we present evidence for the first time of important interactions between MW and starch, a major biomass from massive global food wastes, which can be observed under both hydrolytic and pyrolytic conditions. Starch is transfo...

The cultivation of oleaginous yeast on second-generation feedstocks is an attractive alternative for edible lipid production. Despite many studies in this area addressing single aspects of this bioprocess, one of the major bottlenecks is the integration and optimization of the multiple unit operations while demonstrating this on a larger scale. In...

Floridoside (2-α-O-D-galactopyranosyl glycerol) is a glycerol glycoside that is biosynthesised by most species of red algae and has been implicated as an intracellular regulator of various homeostatic functions. Here, we report the identification of two unforeseen crystal forms of the ubiquitous natural osmolyte floridoside including a seemingly un...

The efficient valorization of lignin could dictate the success of the 2nd generation biorefinery. Lignin, accounting for on average a third of the lignocellulosic biomass, is the most promising candidate for sustainable production of value‐added phenolics. However, the structural alteration induced during lignin isolation is often depleting its pot...

This study investigated migration and transformation mechanism of P in waste activated sludge (WAS) during anaerobic fermentation (AF) process and the subsequent hydrothermal conversion (HTC) process. Control of pH during the AF processes was found to be significant, whereby the use of acidic (pH = 5.5) or alkaline conditions (pH = 9.5) facilitated...

In this study, a facile and eco-friendly method for synthesis of granular fuel and granular activated carbon was developed. The approach needs not to add a harmful binder due to inherent characteristics of sawdust hydrochar and has not been previously reported. Granular fuel was prepared from densification of sawdust hydrochar acquired from hydroth...

Catalytic hydrogenolysis of lignin to obtain value-added phenolic chemicals is a sustainable and cost-effective strategy for the efficient valorization of biomass derived wastes. Herein, an innovative approach by using a single-step microwave assisted depolymerization of lignin from birch sawdust without external hydrogen in the mixture of water-al...

Green Tycoon is a free-of-charge game-based mobile application that embraces a systems thinking approach to introducing students to a biorefining process model within green chemistry. Players adopt the role of a manager in a chemical factory, synthesizing the fictional compound, Yorkanone. Through upgrading the system and engaging with the integrat...

Driven by the worldwide demand for sustainable resources and renewable energy, the synthesis of bio-based platform chemicals has attracted broad interest. The isomerisation of glucose to fructose acts as a critical intermediate step among many chemical synthesis routes. In this study, biochar (BC), graphitic oxide (GIO), and graphene oxide (GO) wer...