172 results found
Bruch J-R, Bokelmann K, Grimes SM, 2021, Process development options for electronic waste fractionation to achieve maximum material value recovery., Waste Management and Research, Pages: 734242X20987895-734242X20987895, ISSN: 0734-242X
Revised legislation and bans on imports of waste electrical and electronic equipment (WEEE) into many Asian countries for treatment are driving the need for more efficient WEEE fractionation in Europe by expanding the capacity of treatment plants and improving the percentage recovery of materials of economic value. Data from a key stakeholder survey and consultation are combined with the results of a detailed literature survey to provide weighted matrix input into multi-criteria decision analysis calculations to carry out the following tasks: (a) assess the relative importance of 12 process options against the 6 industry-derived in-process economic potential criteria, that is, increase in product quality, increase in recycling rate, increase in process capacity, decrease in labour costs, decrease in energy costs and decrease in disposal costs; and (b) rank 25 key technologies that have been selected as being the most likely to benefit the efficient sorting of WEEE. The results indicate that the first stage in the development of any total system to achieve maximum economic recovery of materials from WEEE has to be the selection and application of appropriate fractionation process technologies to concentrate valuable components such as critical metals into the smallest possible fractions to achieve their recovery while minimising the disposal costs of low-value products. The stakeholder-based study has determined the priority for viable technical process developments for efficient WEEE fractionation and highlighted the economic and technical improvements that have to be made in the treatment of WEEE.
Grimes SM, Maguire D, 2020, Assessment of priorities in critical material recovery from waste electrical and electronic equipment, Resources Policy, Vol: 68, Pages: 1-10, ISSN: 0301-4207
A major problem in developing environmental management systems for assessing recovery priorities for high added-value materials such as critical metals from wastes is that the input data required are contained in a variety of databases compiled for different purposes with different levels of content and accuracy. To deal with decision-making priorities for environmental issues where uncertainties and inconsistencies are inherent in input data sources a Multi-Criteria Decision Analysis (MCDA) approach using an Analytic Hierarchy Process (AHP) to determine weights and fuzzy numbers to account for input data uncertainties is developed and is illustrated for determination of critical metal recovery priorities from Waste Electrical and Electronic Equipment (WEEE) in Europe. A spreadsheet programme with many user-friendly input and output features is developed to aid data-handling and the calculations required in the MCDA approach. Where data uncertainties exist, weighted input parameters for the critical metals are determined by an absolute judgement panel of key stakeholders and include data on: recovery potential, geographical supply concentration and stability, end use substitution, future metal demand and economic importance in key industrial sectors. Sensitivity analyses can be carried out on results of recovery priority outputs by simple numerical variation of input parameters and/or by the use of specialist input decision panels representing stakeholder groups with differing priorities, and the results suggest that recovery priorities in the European situation should concentrate on gallium, indium and germanium. The spreadsheet-MCDA program set up in developing the methodology for criticality has wide general application in environmental decision-making analysis particularly where uncertainties exist in the input data required.
Grimes SM, Ciuffa F, Cooper J, et al., 2018, Development of a vacuum-packing system for food waste from urban catering facilities, Proceedings of the Institution of Civil Engineers. Waste and Resource Management., Vol: 171, Pages: 114-120, ISSN: 1747-6526
A novel vacuum-packing system is developed for food waste storage and collection under the conditions found in high-density urban and metropolitan catering establishments that has the following beneficial outcomes: (a) a reduction of 38% in the volume of food waste to be stored for collection; (b) a reduction in the physical space required on-site for storage of multiple vacuum packs of waste; (c) containment of the food waste stored in sanitised conditions, thus maintaining the integrity of the waste and extending the useful life of the waste in terms of its ideal composition for optimum beneficial recovery by anaerobic digestion or in-vessel composting, and reducing problems due to odour and vermin; and (d) reduction in the number of vehicle movements required to transfer the wastes to treatment facilities and their environmental impacts, while also achieving savings of £13–16 per bin lift in London, along with a considerable reduction in overall cost.
Grimes SM, Kewcharoenwong P, 2017, Dual-functionality ionic liquid mix for extraction and esterification of fatty acids as a step towards increasing the efficiency of conversion of waste cooking oils to biodiesel, Journal of Chemical Technology and Biotechnology, Vol: 92, Pages: 2098-2105, ISSN: 0268-2575
BACKGROUND: The increasing value of pure vegetable oils has made the use of waste cooking oils an attractive alternative feedstock for biodiesel production but the presence of free fatty acids in the waste significantly reduces efficiency of the conversion.RESULTS: A low-temperature mixed ionic liquid system with dual extraction and catalytic functions for the conversion of waste oils containing high levels of free fatty acids to biodiesel was successfully trialled. The solvent, a totally miscible system of HPyrBr and the Brønsted acid, SPyrHSO4, allows the key properties of each ionic liquid, as extractant or catalyst, to work uninhibited by the presence of the other. Extraction of free fatty acids from vegetable oils and their conversion to methyl esters in high yield is demonstrated for vegetable oils, containing single and mixed fatty acids, and for a model waste cooking oil. The oil separated from free fatty acids in the waste has a low acid value and can be converted efficiently to biodiesel; with the ionic liquid solvent recovered unchanged for reuse.CONCLUSIONS: A mixed ionic liquid extraction-esterification solvent process has been developed to effect efficient conversion of free fatty acids in waste vegetable oils to biodiesel and their conversion to esters.
Wang W, Ma X, Grimes S, et al., 2017, Study on the absorbability, regeneration characteristics and thermal stability of ionic liquids for VOCs removal, Chemical Engineering Journal, Vol: 328, Pages: 353-353, ISSN: 1385-8947
A novel method of removal of volatile organic compounds (VOCs) using the ionic liquid [Bmim][NTf2] as an absorbent is developed as a contribution to dealing with recent severe smog incidents in China. The effects of concentration, temperature and flow rates on the ability of [Bmim][NTf2] to absorb VOCs were studied using toluene as a model volatile organic pollutant. The potential of the use of [Bmim][NTf2] as an absorbent for VOCs is shown by the solubility of toluene in the ionic liquid; the absorptivity of the ionic liquid for toluene; and the fact that absorbed toluene can be removed easily from [Bmim][NTf2], permitting recycle of the ionic liquid in multiple reuse phases. The solubility of toluene in [Bmim][NTf2] is 61.5% at 20 °C and atmospheric pressure; the highest absorptivity of [Bmim][NTf2] for toluene is 98.3%, achieved at a toluene concentration of 300 ppm and a flow rate of 50 mL min−1 at 20 °C; and the absorptivity of the ionic liquid is >94% over a wide range of conditions. The ionic liquid can be recovered and recycled in the absorption process at least five times, reducing the reagent cost in the VOC removal process.
Wang W, Fu L, Sun J, et al., 2017, Experimental Study of Microwave-Induced Discharge and Mechanism Analysis Based on Spectrum Acquisition, IEEE Transactions on Plasma Science, Vol: 45, Pages: 2235-2242, ISSN: 0093-3813
When conductor or semiconductor materials areexposed to microwave radiation in different atmospheres (Ar, He,N2, and O2+N2) intense discharge phenomena are observed. Thedischarge phenomena, generated when strips of the metals Fe, Al,and Zn or particles of the semiconductor SiC are irradiated withmicrowaves, are characterized experimentally using spectrumacquisition and analysis. Filamentary discharge is observed inan Ar atmosphere while spark discharge is observed in He, N2,and O2+N2 atmospheres. The spectral lines of the dischargesare concentrated mainly in the visible region, but there are alsopeaks in the ultraviolet region. The nature of the discharge andthe specific details of the spectra are influenced by: 1) the targetmetal or semiconductor used; 2) the atmosphere; and 3) themicrowave field characteristics. The spectra always consist of twoparts: one corresponding to the target metal or semiconductorirradiated by the microwaves and the other due to the formationof the high-energy excitation states of atoms, molecules, andions induced in the gaseous atmosphere. The microwave-induceddischarge and the corresponding luminous and plasma effectshave potential uses as energy sources in many applicationsincluding chemical or photocatalytic enhancement of reactionsand the destruction of volatile organic compounds for whichpreliminary results are encouraging.
Schaeffer N, Feng X, Grimes SM, et al., 2017, Recovery of an yttrium europium oxide phosphor from waste fluorescent tubes using a Brønsted acidic ionic liquid, 1-methylimidazolium hydrogen sulfate, Journal of chemical technology and biotechnology, Vol: 92, Pages: 2731-2738, ISSN: 0142-0356
BACKGROUNDSpent fluorescent lamps, classified as hazardous waste in the EU, are segregated at source. Processes for the recovery of critical rare-earth (RE) elements from the phosphor powder waste, however, often involve use of aggressive acid or alkali digestion, multi-stage separation procedures, and production of large aqueous waste streams which require further treatment.RESULTSTo overcome these difficulties phosphor powder pre-treated with dilute HCl was leached with a 1:1 wt. [Hmim][HSO4]:H2O solution at a solid:liquid ratio of 5%, at 80 °C for 4 h with stirring at 300 rpm to recover 91.6 wt% of the Y and 97.7 wt% of the Eu present. The yttrium-europium oxide (YOX), (Y0.95Eu0.05)2O3, recovered by precipitating the dissolved RE elements from the leach solution with oxalic acid and converting the oxalate to an oxide phase by heating, was characterised by FTIR, XRD and luminescence analysis. The analyses suggest the recovered oxide has the potential to be directly reused as YOX phosphor. Regeneration and reuse of the ionic liquid is achieved with only minor leaching efficiency losses found over four leaching/recovery cycles.CONCLUSIONThe recovery of yttrium europium oxide from waste fluorescent tube phosphor by a simple efficient low cost ionic liquid process has been developed.
Grimes SM, Yasri NG, Chaudhary AJ, 2017, Recovery of critical metals from dilute leach solutions - Separation of indium from tin and lead, Inorganica Chimica Acta, Vol: 461, Pages: 161-166, ISSN: 1873-3255
The strategic metal indium is recovered from solutions containing tin and lead that are typical of those obtained from leach solutions of metal component fractions of electronic waste including the leach solutions from indium tin oxide thin film conductive layers that contain only indium and tin. Almost total recovery of the metals can be achieved from nitric, perchloric and acetic acid leach solutions using a novel cylindrical mesh electrode electrolysis cell under appropriate conditions. The optimum separation of indium from tin and lead is achieved by a novel three-stage process from nitric acid media in the presence of SCN− as a complexing agent. Lead is removed from dilute indium-tin-lead solutions in the first stage from 0.1 mol L−1 nitric acid solution by electrodeposition over an 8 h period in the absence of SCN− to give a residual solution containing a maximum of 2 mg L−1 of lead (97% recovery). Tin is removed in the second stage by electrodeposition over an 8 h period from the solution after addition of 0.02 mol L−1 SCN− to give a maximum residual electrolyte tin concentration of 3 mg L−1 (94% recovery). In the third stage indium is recovered at the anode of the cylindrical mesh electrode cell as an oxy-hydroxide phase by increasing the SCN− concentration to 0.1 mol L−1 and carrying out the electrolysis for a period of 24 h to give a residual solution containing 1 mg L−1 of indium (98% recovery).
Schaeffer N, Grimes SM, Cheeseman CR, 2016, Use of extraction chromatography in the recycling of critical metals from thin film Leach solutions, Inorganica Chimica Acta, Vol: 457, Pages: 53-58, ISSN: 1873-3255
Phosphors and optoelectronic thin film electronic device layers contain critical metals including lanthanides and indium that should be recycled. Solvent impregnated resins (SIRs) containing (i) DEHPA (ii) DODGAA and (iii) DODGAA with the ionic liquid [C4mim][Tf2N] are investigated in extraction chromatography methodologies to recover and separate critical metals from dilute solutions that model those leached from thin films. Optimum adsorption of metals occurs at pH 1.5-3.5 but is highest on DODGAA-[C4mim][Tf2N]. The recovery and separation of adsorbed metal species on the DODGAA-[C4mim][Tf2N] SIR resin from solutions containing the glass matrix ions, Ca(II) and Al(III), along with In(III) and Sn(IV) or lanthanide ions is achieved by elution with HNO3. Ca(II) and Al(III) are completely eluted with 0.1M HNO3 retaining the target critical metal species on the resin. Separation of In from Sn is achieved by elution of In(III) with 2.5M HNO3 and Sn(IV) with 5M acid. La is separated from the other lanthanides by elution of La(III) with 2.5M HNO3 and the remaining lanthanides with 5M acid. The SIR resins can be reused over a series of at least five cycles of loading,stripping, and rinsing to reduce reagent costs and achieve economic critical metal recovery byextraction chromatography.
Grimes SM, Thompson F, 2016, Recovery of lubricant base oils using ionic liquid processes, Proceedings of Institution of Civil Engineers: Waste and Resource Management, Vol: 169, Pages: 73-82, ISSN: 1747-6526
Two novel low-temperature ionic liquid processes are developed for the recovery of base oils from waste lubricant oils. One uses 3-(triethoxysilyl)-propylammonium-3-(triethoxysilyl)-propyl carbamate (TESAC), in which the waste lubricant base oil is insoluble, and the other uses trihexyl(tetradecyl)phosphonium chloride (P6,6,6,14Cl) in which the base oil is soluble. In the 3-aminopropyl-triethoxysilane (TESA)/TESAC process, waste oil components, including the base oil, are dissolved in the solvent TESA which is converted, in situ, with carbon dioxide to TESAC, recovering the base oil as an insoluble layer. In the P6,6,6,14Cl process, the base oil is separated from most additives as a solution in the ionic liquid from which it can be extracted with methanol. The recovered oils from both processes have properties consistent with lubricant oils in commercial use and the ionic liquids can be recovered for recycle minimising reagent use and providing a route to closed-loop base oil recovery and recycle.
Schaeffer N, Grimes S, Cheeseman C, 2015, Interactions between trivalent rare earth oxides and mixed [Hbet][Tf2N]:H2O systems in the development of a one-step process for the separation of light from heavy rare earth elements, Inorganica Chimica Acta, Vol: 439, Pages: 55-60, ISSN: 1873-3255
The factors, including ionic liquid:water ratios, temperature, solvent:solute contact times, and the effect of dissolved rare earth metal ions on the [Hbet][Tf2N]:H2O thermometric phase change are determined to develop a process for separating the light from the heavy rare earth metal oxides in [Hbet][Tf2N]:H2O mixtures. The relative solubility data for three light (La2O3, Nd2O3, and Eu2O3), two heavy (Y2O3 and Yb2O3) rare earth metal oxides (REOs), and Gd2O3 at different temperatures and different solute:solvent contact times are reported for 1:1 [Hbet][Tf2N]:H2O. The light REOs dissolve easily at 57 °C with the La and Eu reaching maximum solubility within minutes while the heavy REOs have very low solubilities at this temperature with negligible amounts being dissolved for contact times less than 80 min. Gd2O3 dissolves more slowly than the La, Eu, and Nd oxides at 57 °C reaching maximum solubility only after 160 min. Changing the [Hbet][Tf2N]:H2O ratio from 1:1 to 16:1 increases the time required to dissolve the REOs. The times taken to reach maximum solubility decrease for all of the REOs up to 95 °C, resulting in the separations between the light and heavy rare earth elements, and Gd becoming less distinct. The presence of rare earth metal ions in [Hbet][Tf2N]:H2O results in a reduction in the upper critical solution temperature (UCST) of the solvent from 55.6 °C to as low as 31.8 °C with Gd3+. The best separation of light from heavy REOs is achieved at 57 °C but better separation of Gd from the light REOs is achieved at 40 °C, below the solvent UCST. The best conditions for a one-step separation of light from heavy REOs in [Hbet][Tf2N]:H2O mixtures is achieved with 1:1 [Hbet][Tf2N]:H2O at 57 °C using short contact oxide:solvent times (maximum 5 min). Separations of light from heavy REOs, in waste phosphor samples, containing La2O3, CeO2, Eu2O3, Gd2O3, Tb3O4 and Y2O3, are also achieved even in the presence of high concentrations
Bourtsalas A, Vandeperre L, Grimes S, et al., 2015, Properties of ceramics prepared using dry discharged waste to energy bottom ash dust, Waste Management & Research, Vol: 33, Pages: 794-804, ISSN: 1096-3669
Bourtsalas A, Vandeperre LJM, Grimes SM, et al., 2015, Production of pyroxene ceramics from the fine fraction of incinerator bottom ash, Waste Management, Vol: 45, Pages: 217-225, ISSN: 0956-053X
Incinerator bottom ash (IBA) is normally processed to extract metals and the coarse mineral fraction is used as secondary aggregate. This leaves significant quantities of fine material, typically less than 4mm, that is problematic as reuse options are limited. This work demonstrates that fine IBA can be mixed with glass and transformed by milling, calcining, pressing and sintering into high density ceramics. The addition of glass aids liquid phase sintering, milling increases sintering reactivity and calcining reduces volatile loss during firing. Calcining also changes the crystalline phases present from quartz (SiO2), calcite (CaCO3), gehlenite (Ca2Al2SiO7) and hematite (Fe2O3) to diopside (CaMgSi2O6), clinoenstatite (MgSiO3) and andradite (Ca3Fe2Si3O12). Calcined powders fired at 1080°C have high green density, low shrinkage (<7%) and produce dense (2.78g/cm3) ceramics that have negligible water absorption. The transformation of the problematic fraction of IBA into a raw material suitable for the manufacture of ceramic tiles for use in urban paving and other applications is demonstrated.
Grimes SM, Tanpoonkiat W, 2013, Thailand: Steps towards integrated solid waste management, Proceedings of Institution of Civil Engineers: Waste and Resource Management, Vol: 166, Pages: 167-176, ISSN: 1747-6526
The current waste management practices in Thailand have been analysed to identify changes that would be beneficial in achieving the criteria set by authorities for improvements in recycling and diversion from landfill to 2030. The numbers and combinations of selected treatment plants that would have to be introduced into Thailand to meet targets for diversion of biological waste from landfill and the production of energy over the planning period have been calculated for a number of scenarios. Sensitivity analyses are performed on the results obtained to account for changes in future assumptions on the amount of waste generated and the organic content of the residual waste. The methodology adopted in this work, to aid planning decisions on technology requirements into the future, was previously used to predict the treatment options for handling the organic fraction of waste generated in London. As a generic methodology, applied in this work to illustrate the types of results obtained from the analyses using specific sets of assumptions relevant to Thailand, it offers the capability and flexibility to take account of the effects on the outcome of any relevant scenarios that planners might wish to consider and any assumptions that they might wish to make.
Hussain Z, Grimes S, Shahid M, et al., 2013, Leaching of Copper Secondary Wastes: Possible Soil Contaminants, ASIAN JOURNAL OF CHEMISTRY, Vol: 25, Pages: 4051-4054, ISSN: 0970-7077
Grimes SM, Lateef H, 2013, RECOVERY OF CHONDROITIN SULPHATE AND HYALURONIC ACID FROM SIMULATED SCALLOP GUT WASTE USING IONIC LIQUID METHODOLOGY, 13th International Conference on Environmental Science and Technology (CEST), Publisher: GLOBAL NEST, SECRETARIAT, ISSN: 1106-5516
Lateef H, Gooding A, Grimes SM, 2012, Use of 1-hexyl-3-methylimidazolium bromideionic liquid in the recovery of lactic acidfrom wine, Journal of Chemical Technology and Biotechnology
BACKGROUND: Lactic acid has many different applications in a variety of industries including the food, cosmetics, packaging,leather and chemical industries. Current methodologies for lactic acid production are lengthy and complicated and moreefficient methods are being sought. Some organic wastes contain lactic acid and our work investigates the use of ionic liquids(ILs) in the efficient and selective extraction of lactic acid from organic waste using wine as a model system. The ionic liquidwaschosen based on its ability to selectively solvate and separate lactic acid from the remaining bulk waste material.RESULTS: Several ILs including 1-hexyl-3-methylimidazolium chloride (hmimCl), 1-hexyl-3-methylimidazolium bromide(hmimBr), 1-hexyl-3-methylimidazolium iodide (hmimI) and N-hexylpyridinium iodide (hpyrI) have been synthesized in highyield (68-95%) using microwave technology. Lactic acid is soluble in each of the ILs synthesized with optimum results achievedwith hmimBr where lactic acid is miscible in all proportions. HmimBr has been used to successfully separate and extract lacticacid from wine as confirmed by FTIR spectroscopy. Furthermore, it has been possible to recover the IL for recycle in subsequentextraction cycles where the efficiency for the extraction process increases with each recycle.CONCLUSION: HmimBr has been used for the first time in a novel process for the separation and recovery of lactic acid fromwine, as confirmed by FTIR spectroscopy. This work demonstrates a novel processwhich can be applied to the recovery of lacticacid from organic waste.
Abbe OE, Grimes SM, Fowler GD, 2011, Decision support for the management of oil well drill cuttings, Proceedings of Institution of Civil Engineers: Waste and Resource Management, Vol: 164, Pages: 213-220, ISSN: 1747-6526
Depending on the hole size and mud type used in the drilling process, oil well drill cuttings can be a relatively high-volume solid waste stream from drilling operations in the oil and gas exploration and production industry. Current management practices tend to involve thermal treatment followed by landfill disposal. The waste-to-resource conversion approach, however, provides opportunities that are not reflected in the current management system. The drill cuttings waste management decision support tool described in this work allows for the consideration of alternative reuse applications such as in construction materials, oil well reinjection, wetlands restoration, and the manufacture of stable leach-resistant material such as glass ceramics, in a move to divert treated drill cuttings from landfill towards zero waste disposal.
Cahill R, Grimes SM, Wilson DC, 2011, Extended producer responsibility for packaging wastes and WEEE - a comparison of implementation and the role of local authorities across Europe, WASTE MANAGEMENT & RESEARCH, Vol: 29, Pages: 455-479, ISSN: 0734-242X
Grimes SM, Abbe OE, Fowler GD, 2011, Decision support for themanagement of oil well drillcuttings, Proceedings of the Institution of Civil Engineers. Waste and Resource Management., Vol: 164, Pages: 213-220
Depending on the hole size and mud type used in the drilling process, oil well drill cuttings can be a relativelyhigh-volume solid waste stream from drilling operations in the oil and gas exploration and production industry.Current management practices tend to involve thermal treatment followed by landfill disposal. The waste-to-resourceconversion approach, however, provides opportunities that are not reflected in the current management system. Thedrill cuttings waste management decision support tool described in this work allows for the consideration ofalternative reuse applications such as in construction materials, oil well reinjection, wetlands restoration, and themanufacture of stable leach-resistant material such as glass ceramics, in a move to divert treated drill cuttings fromlandfill towards zero waste disposal
Zglobisz N, Castillo-Castillo A, Grimes S, et al., 2010, Influence of UK energy policy on the deployment of anaerobic digestion, ENERGY POLICY, Vol: 38, Pages: 5988-5999, ISSN: 0301-4215
Zglobisz N, Castillo-Castillo A, Grimes S, et al., 2010, Influence of UK energy policy on the deployment of anaerobic digestion, Energy Policy, Vol: 38, Pages: 5988-5999
Lateef H, Grimes S, Kewcharoenwong P, et al., 2009, Separation and recovery of cellulose and lignin using ionic liquids: a process for recovery from paper-based waste, JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY, Vol: 84, Pages: 1818-1827, ISSN: 0268-2575
Bark M, Bland M, Grimes S, 2009, Report: Potential environmental impact of exempt site materials - a case study of bituminous road planings and waste soils, WASTE MANAGEMENT & RESEARCH, Vol: 27, Pages: 611-616, ISSN: 0734-242X
Abbe OE, Grimes SM, Fowler GD, et al., 2009, Novel sintered glass-ceramics from vitrified oil well drill cuttings, JOURNAL OF MATERIALS SCIENCE, Vol: 44, Pages: 4296-4302, ISSN: 0022-2461
Chaudhary AJ, Hassan M-U, Grimes SM, 2009, Simultaneous recovery of metals and degradation of organic species: Copper and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), JOURNAL OF HAZARDOUS MATERIALS, Vol: 165, Pages: 825-831, ISSN: 0304-3894
Lateef H, Grimes SM, Chaudhary AJ, et al., 2009, Opportunity to recycle chromium(VI) by in situ electro-oxidation, JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY, Vol: 84, Pages: 584-588, ISSN: 0268-2575
Lateef H, Grimes SM, Kewcharoenwong P, et al., 2009, Ionic liquids in the selective recovery of fatfrom composite foodstuffs, Journal of Chemical Technology and Biotechnology, Vol: 84, Pages: 1681-1687
BACKGROUND: Ionic liquids (ILs) are able to dissolve a wide range of organic and inorganic molecules and have potentialapplication in the separation and recovery of valuable components from wastes. The potential for ILs to separate sugar and fatfrom food waste is demonstrated using chocolate as amodel system.RESULTS: The ILs 1-(2-cyanoethyl)-3-methylimidazolium bromide (cyanoMIMBr), 1-propyl-3-methylimidazolium bromide(propylMIMBr), 1-hexylpyridinium bromide (hexylPyrBr) and 1-butyl-3-methylimidazolium chloride (butylMIMCl) weresynthesised by microwave technology and fully characterised by mass spectrometry, thermogravimetric differential scanningcalorimetery, thin layer chromatography, nuclear magnetic resonance and Fourier transform infrared spectroscopy. Thesolubilities of the fat and carbohydrate components in the ILs are reported for the two main ingredients in chocolate.CyanoMIMBr and propylMIMBr selectively solubilise sugar leaving the fat insoluble. Both cyanoMIMBr and propylMIMBr havebeen used to successfully separate sugars and cocoa butter fat from white, milk and dark chocolate and the Fourier transforminfrared spectra and thermogravimetric differential scanning calorimeter profiles of the extracted fat samples are in goodagreement with reference material data.CONCLUSIONS: The ILs cyanoMIMBr and propylMIMBr are successful in the separation and recovery of fat from white,milk and dark chocolate, as confirmed by FTIR and TG-DSC data.
Lateef H, Grimes S, Kewcharoenwong P, et al., 2009, Separation and recovery of cellulose and ligninusing ionic liquids: a process for recoveryfrom paper-based waste, Journal of Chemical Technology and Biotechnology, Vol: 84, Pages: 1818-1827
BACKGROUND: The production of paper makes use of cellulose and lignin as a rawmaterial, and almost all cellulose and ligninproduction comes from raw wood materials, contributing to deforestation and resulting in potential environmental harm. It istherefore beneficial to develop technologies for cellulose and lignin recovery for re-use and sustainability of resources.RESULTS: Three imidazolium based ionic liquids (ILs), 1-(2-cyanoethyl)-3-methylimidazolium bromide (cyanoMIMBr), 1-propyl-3-methylimidazolium bromide (propylMIMBr) and 1-butyl-3-methylimidazolium chloride (butylMIMCl), were synthesised bymicrowave technology and fully characterised bymass spectrometry, thermogravimetric differential scanning calorimetry, thinlayer chromatography, nuclear magnetic resonance and Fourier transform infrared spectroscopies. Cellulose and lignin weresoluble in all three ILs with solubility being greatest in cyanoMIMBr. Regeneration of cellulose and lignin was achieved fromsaturated solutions of cellulose in IL and lignin in IL for all three ILs. The ILs propylMIMBr and butylMIMBr have been used forthe first time in the separation and recovery of cellulose and lignin and regeneration of the IL from a mixture of cellulose andlignin in IL. FTIR analysis confirms successful recovery.CONCLUSIONS: This work demonstrates the ability of ILs to separate and recover cellulose and lignin from a mixed system.
Chaudhary AJ, Grimes SM, 2008, A combined photolytic-electrolytic system for the simultaneous recovery of copper and degradation of phenol or 4-chlorophenol in mixed solutions, CHEMOSPHERE, Vol: 72, Pages: 1636-1642, ISSN: 0045-6535
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