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Life cycle of an ideal green solvent from cradle to grave for sustainability studies of green solvents.

Successful human space exploration requires more products than can be taken as payload. There is a need, therefore, for in-space circular manufacturing. Requirements for this include limited resource inflow, from either Earth or other planets and the generation of minimal waste. The provision of nutritious food is a clear need for human survival on the Moon or Mars and is one of the most complex to solve. Demand in large quantities, constant and reliable provision of food requires the development of specialist agricultural technologies. Here, we first review the history of space farming over the past five decades. This survey assesses the technologies which have been tested under the harsh conditions of space, identifying which modern horticultural components are applicable for in-space plant growth. We then outline which plants have been grown and under what conditions, and speculate upon the types of plants that could be selected to best nourish astronauts. Current systems are focussed on experimentation and exploration, but do not yet provide turn-key solutions for efficient food production within a long-term space exploration scenario. With that take, this review aims to provide a perspective on how an engineered closed circular environmental life-support system (ECCLES) might be constructed. To exemplify the latter, nutrient auto accumulation by biofortification is proposed through the integration of space farming and space mining, which is uncharted on Earth.

This paper presents the process of synthesis of copper powders obtained by the pyrometallurgical method without the participation of the liquid phase. This method is based on the simultaneous decomposition and reduction of copper (II) carbonate. Hydrogen was used as a reducing agent. Due to the strongly exothermic thermal effect of the reduction reaction, a mixture of inert gas and hydrogen was used to better control the parameters. Studies have shown that the carbonate method enables the synthesis of copper powders with a narrow distribution and controlled size. The size is controlled by the grinding time of the copper (II) carbonate. An life cycle assessment and circularity study evaluate the sustainability of the new process, and focus is given to the energy efficiency. This work was supported by project from Intelligent Development Operational Program 2014–2020, co-financed by the European Regional Development Fund, project No. POIR.01.01.01-00-1246/20-00.

Purpose: Novel process windows allow the development of faster, flexible, and greener processes. Therefore, novel process windows were applied to develop a greener process for the synthesis of vitamin D3. In this study the environmental impacts of several batch pathways to obtain vitamin D3 are benchmarked against the continuous microflow process, where novel process windows such as high temperature and pressure were applied. To evaluate the environmental impact of these processes, life cycle assessments were conducted. Methods: A new process concept was developed to optimize and simplify the synthesis of crystalline vitamin D3. This process was conducted in microflow by combining UV photoirradiation and high-p,T (photo-high-p,T) processing. Microreactors allow a high photon flux and enable the harsh conditions, respectively. The process was coupled with an integrated continuous crystallization, and its feasibility has been proven and reported before. The potential environmental impacts were assessed from a cradle-to-gate perspective. Both processes, continuous and batch, were modeled in Aspen Plus using foreground data from the experimental continuous setup, and background data from different patents. The assessment was performed in the software Umberto NXL LCA using the ReCiPe Midpoint 2008 method. Results and discussion: The continuous process has a significantly lower environmental impact than the batch processes. This lower impact is largely due to the fact that fewer amounts of material, particularly solvents, are used. Moreover, the continuous process is faster and has fewer steps, i.e., process-simplified. Among the industrial processes, the synthesis conducted in isopropanol has the lowest environmental impact, although, even in this case, the impact is between 20 and 30 times higher—depending on the conditions—compared with the continuous process. When the batch process is conducted in benzene, the worst environmental impact is obtained. Finally, recycle of the solvent for the best batch case was assessed. This improved the batch process to make it comparable with the continuous process. Conclusions: The continuous production of vitamin D3 leads to an interesting alternative to the industrial process. Continuous manufacturing of vitamin D3 is faster, requires fewer steps, and uses less solvents compared with the industrial synthesis. However, although the environmental impact of this continuous process is already lower than that of the batch processes, the continuous process can still benefit from further optimization, particularly the introduction of a recycle loops for the solvents methyl tert-butyl ether and acetonitrile.

The vitamin D3 flow-chemical process is a good route for exercising circularity in chemistry; as the complex chemistry of this reaction limits the highest yield to only 25%, a recycling operation becomes mandatory. In this context, this research applies, for the first time, a circular economy assessment to a flow chemistry process, including reaction and separation. This is undertaken on the example of the photo-flow-chemical synthesis of vitamin D3, previously developed by our group. In the research reported here, we develop a separation process to recycle the unreacted starting material 7-dehydrocholesterol after the photo-flow irradiation. We use acetonitrile for separation, instead of methanol, in the industrial process. In just one run, 90% of vitamin is extracted using dry acetonitrile as a separation solvent at 30 °C. A cumulative extraction efficiency of >99% is achieved after a second extraction step. The acetonitrile separation process connects directly to the subsequent vitamin crystallization using the same solvent. This eliminates the need to evaporate methanol in the industrial process; rather, the product is obtained just by cooling down. The Material Circular Indicator has been used as a central metric, and we needed to redefine this circularity metrics proposed by the Ellen MacArthur Foundation's CE100 program to the world of flow chemistry. Rather than being able to take the parameter of lifetime and utility used in the original C100 definition, the frequency and dose of usage of medicinal products are taken here, both of which are connected to chemical productivity and waste generation. To explore the application of this adapted methodology to other pharmaceutical production processes, the results for the proposed vitamin D3 flow-chemical process are compared with five processes for producing vitamins, painkillers, and an antibiotic. It is shown that the vitamin D3 flow chemistry process with the new separation achieves a Material Circular Indicator of 0.94, a recycled fraction mass above 0.95, and an energy demand reduction by a factor of 2.

Six of the most promising lab-scale synthesis process methodologies for N-doped carbon dots (NCDs) are selected and compared in terms of green chemistry and circular and EcoScale/Good-Manufacturing-Practice metrics. We compare a new innovative route, the low-temperature plasma-enabled synthesis of carbon dots, e.g., from citric acid and monoethanolamine, to more-established literature processes, such as thermochemical processes, from the same or other materials. Along with this study, the advantages and disadvantages of each method are depicted in manifold sustainability facets. It is shown how recycling/reuse of nonconverted starting materials and solvents can improve the sustainability profile. In addition, safety constraints, cost analysis, and energy consumption are considered. The analysis showed that the thermal process from citric acid and monoethanolamine gives the best performance with regard to the sustainability assessment chosen here. It has a material circularity indicator of 0.971, with an EcoScale factor of 56% and an E-factor of 5.56. In continuation of those results, the paper shows how the low-temperature plasma using the same materials and the same recycling strategy can be improved to come closer to the performance of its thermal counterpart. It has the best energy efficiency, while lacking so far in mass efficiency. From this study, we learned more about which of these methods are most promising for scaling-up and industrial manufacturing of N-doped carbon dots.

Process intensification commonly enables reaction acceleration and therefore continuous-flow/PAT is urgently needed. The low volumes typical for micro-flow pose challenges for online sampling operations in analytics. In this paper, a very fast process is combined with a modified ultra-high-performance liquid chromatography (UHPLC) system allowing for very fast sampling and analysis. Low-volume online sampling according to the needs posed by PAT for pharma quality control, is introduced here for UHPLC analysis of the photo-Claisen rearrangement in micro-flow. Chances and challenges are critically reviewed, including the reproducibility and robustness of the sampling. Furthermore, the ability and speed of the chosen set-up in order to capture process changes and adjust the process parameters properly is investigated. With the applied online sampling system, it was possible to perform, almost unattended and spending 12 times less sampling volume, a full factorial analysis of all relevant reaction conditions (243 experiments) in three days. Such quality-in-the-process-line (QuIProLi) online sampling avoided random errors due to automation. (C) 2018 Elsevier Ltd. All rights reserved.

In this study, we investigated enzymatic pre- treatment of grease trap waste (GTW) as an environmentally beneficial procedure for biodiesel production. Different enzymes, both commercial and newly designed industrial enzymes, were used to reduce the free fatty acids (FFA) level of GTW through an esterification reaction. The process conditions were optimized using response surface methodology with central composite design parameters. A set of 30 experiments, for both batch and continuous flow reactors, were designed to identify the optimal process conditions in which the highest conversion of FFA is achieved. Within the range of the selected operating conditions, the optimized values of reaction temperature, catalyst quantities, ethanol to oil molar ratio, and reaction time for the batch reactor, in which FFA level was reduced to 31.5 %, were found to be 70 °C, 4.5 wt%, 3:1, and 25 min respectively. A significant improvement in the reduction of FFA, of which FFA amount is only 9.9 %, was obtained in the flow reactor when using the commercial enzyme (T = 57 °C, catalyst loading 4.85 %, ethanol to oil ratio 2:1, t = 25 min). In addition to achieving higher conversion, the continuous-flow experiments saved time since the entire series of experiments were completed in

To design an integrated continuous crystallization setup that is directly coupled to a photochemical synthesis in flow, the crystallization of vitamin D3 was studied in detail. Because of the high solubility of the vitamin in the reaction solvent tert-butylmethyl ether, a solvent swap to acetonitrile was necessary. While other methods use a multistep procedure, with the proposed approach, crystalline vitamin D3 can be obtained within one crystallization step. The influence of crystallization parameters, such as the initial concentration of vitamin D3, stirring as well as cooling temperature, rate, and time, on the obtained results in terms of yield, crystal shape, polymorphism, and particle size distribution are discussed in detail.

The development of a pilot-scale synthesis of the rufinamide precursor in flow chemistry is reported. Complex steps such as Taylor-flow, segmented flow, and high-temperature processing at high pressure (high-p,T) are successfully combined, overcoming the mixing and heat transfer issues of the scale-up. The cascaded multistep process operates essentially solvent-free in just 3 m2 giving a productivity of 47 g/h (>400 kg/year), which increases in a factor of 7 the lab-scale productivity previously reported as a scale-up proof-of-concept. The publication also includes an economic study of the feasible implementation of this technology for a possible manufacturer, as well as an outline on business development strategies how to implement such kind of disruptive technology.

The development of a pilot-scale synthesis of the rufinamide precursor in flow chemistry is reported. Complex steps such as Taylor-flow, segmented flow, and high-temperature processing at high pressure (high-p,T) are successfully combined, overcoming the mixing and heat transfer issues of the scale-up. The cascaded multistep process operates essentially solvent-free in just 3 m2 giving a productivity of 47 g/h (>400 kg/year), which increases by a factor of 7 the lab-scale productivity previously reported as a scale-up proof-of-concept. This publication also includes an economic study of the feasible implementation of this technology for a possible manufacturer, as well as an outline on business development strategies of how to implement such a disruptive technology., The development of a pilot-scale synthesis of the rufinamide precursor in flow chemistry is reported.

A new reactor design for photosynthesis in microflow is presented based on spatial overlap of a laser beam through a capillary tube. A conical Archimedean spiral facilitates exposure of the entire volume of the reaction solution to the irradiation beam. In this fashion, photo-high-p,T intensification of the photolysis of 7-dehydrocholesterol is achieved using either a pulsed ultraviolet (UV) laser excitation (in the order of femtoseconds) alone or in tandem with a conventional UV lamp. The goal is to control the kinetics of the side photoreactions under pulsed photolysis, as well as to reduce the reaction time and enhance the vitamin D3 yield. Three kinds of effects are targeted: a) Utilizing a very large and spatially homogeneous photon flux inside the flowing solution; b) the novel process window of combining photo- with thermal intensification to promote the final, irreversible thermal step to vitamin D3; and c) the use of sub-ps laser pulses to supply excitation energy on a timescale shorter than the formation of side photoproducts. Finally, photo-processing with the laser alone is compared to the tandem irradiation by the laser-UV lamp.

Herewith a new process concept for synthesis is presented which combines both UV-photoirradiation and high-p,T intensification (photo-high-p,T) in continuous flow. The application of this procedure to Vitamin D3 synthesis promotes thermal shifting of the equilibrium from the reaction intermediate to the product. This is enabled by microreactors which allow operation under harsh conditions such as the high temperature used here. This provides, to our best knowledge, a new kind of process combination (novel process window). As a result, in less than 1 min, 42% conversion of 7-dehydrocholesterol can be achieved giving a 17% yield and 40% selectivity of Vitamin D3. This approach enhances productivity by up to 2 orders of magnitude compared with the current capillary based vitamin D3 synthesis, because, under the microflow conditions, photochemistry can be performed at fairly high concentration and up to 20 times faster.

A continuous tandem in-line evaporation-crystallization is presented. The process includes an in-line solvent-swap step, suitable to be coupled to a capillary based cooler. As a proof of concept, this setup is tested in a direct in-line acetonitrile mediated crystallization of Vitamin D3. This configuration is suitable to be coupled to a new end-to-end continuous microflow synthesis of Vitamin D3. By this procedure, vitamin particles can be crystallized in continuous flow and isolated using an in-line continuous filtration step. In one run in just 1 min of cooling time, ∼50% (w/w) crystals of Vitamin D3 are directly obtained. Furthermore, the polymorphic form as well as crystals shape and size properties are described in this paper.

Esterification–chlorination of glycerol provides chlorohydrin esters in high yields. A ratio of reagents close to equivalence can be used, so that atom economy of the reaction is optimized. The reaction can be carried out using either classical or microwave heating, and no solvent is required. 2-Chloro-1-(chloromethyl)ethyl esters can be obtained in high regioisomeric relationship when either low or moderate temperature is used. In contrast, microwave irradiation allows the use of higher reaction temperatures that render mixtures of both regioisomers in variable relationships. Kinetic control of the process is proposed for classical heating, and experimental results are analyzed with the aid of ab initio calculated values. Non-thermal phenomena can be used to explain the high efficiency of microwave irradiation at low temperature.

Allyl esters can be obtained by a Finkelstein-rearrangement–elimination reaction of 2-chloro-1-(chloromethyl)ethyl esters induced by NaI. Sodium iodide can be used below equivalence using a reductive agent as sodium thiosulfate. High yields are obtained with most of the diverse esters studied. The method described avoids the use of allyl alcohol as a reagent. 2-Chloro-1-(chloromethyl)ethyl esters are prepared from glycerol, the main by-product of biodiesel industry. The effectiveness of iodine as reagent to hydrolyze allyl esters is also confirmed. This work was supported in part by a Grant-in-Aid for the Secretaría de Estado de Política Científica y Tecnológica of the Spanish Ministry of Education and Culture (Contract grant number: CTQ2006-07451/PPQ). The authors are grateful to the Comissionat per a Universitats i Recerca del Departament d'Innovació, Universitats i Empresa de la Generalitat de Catalunya and to the European Social Fund (ESF) for the FI grant of Marc Escribà Gelonch.

Eight allyl esters of fatty acids were synthesized in moderate to high yields with a novel two-step procedure using glycerol as a starting material. The two-step methodology avoids the use of allyl alcohol. The first step consisted of heating at 80 degrees C for 48 h a 2:1:5 mmol mixture of glycerol, a fatty acid, and chlorotrimethylsilane in a solvent-free medium. The crude compound was then dissolved in butanone and heated at 115 degrees C in the presence of NaI. A tandem Finkelstein rearrangement-elimination reaction occurs, producing the corresponding allyl ester. The activity of these esters against Cydia pomonella (L.) (Lepidoptera: Tortricidae) eggs was tested in the laboratory by topical application of one 0.1 microL drop. All of the compounds showed a concentration-mortality response and caused 100% mortality at the highest concentration tested (10 mg/mL). There was an inverse relationship between the alkyl chain length and the ovicidal activity of the allyl ester; the LC(50) and the LC(90) of the two compounds that have the longer alkyl chains were significantly higher than those of the rest of the compounds. The ovicidal and IGR activities of this kind of compound appear to be unprecedented.

We describe here the first example in which glycerol has been transformed into chlorohydrin esters using an ionic liquid and hydrated aluminium chloride. The method avoids using Crown-18 ether, which was needed to obtain a similar yield when KCl was used. Alkyl and aryl acids can be used, although yields are very dependent on the carboxylic acid used.

The anticipated worldwide increase in biodiesel production will result in an accumulation of glycerol for which there are insufficient conventional uses. The surplus of this by-product has increased rapidly during the last decade, prompting a search for new glycerol applications. We describe here the synthesis of dissymmetric chlorohydrin esters from symmetric 1,3-dichloro-2-propyl esters obtained from glycerol. We studied the influence of two solvents: 1,4-dioxane and 1-butanol and two bases: sodium carbonate and 1-butylimidazole, on the synthesis of dissymmetric chlorohydrin esters. In addition, we studied the influence of other bases (potassium and lithium carbonates) in the reaction using 1,4-dioxane as the solvent. The highest yield was obtained using 1,4-dioxane and sodium carbonate. This work was supported by a Grant-in-Aid from the Secretaría de Estado de Política Cientifíca y Tecnológica of the Spanish Ministry of Education and Culture (contract Grant No.: CTQ2009-14699- C02-01). The authors are grateful to the Comissionat per a Universitats i Recerca del Departament d’Innovació, Universitats i Empresa de la Generalitat de Catalunya and to the European social Fund (EFS) for the FI grant of Carmen Solarte Orozco.

Vegetable oils and fats are important renewable raw materials for use by the biodiesel industry. One drawback of this industry is the large amounts of glycerol produced as a by-product. Consequently, crude glycerol is moving from a by-product to a residue. New industrial applications for this substance are required. A conversion of this by-product to allyl esters using various fatty materials in a two-step process is reported: After a simultaneous alcoholysis–chlorination reaction of vegetable oils and fats without a solvent, allyl esters were synthesized in a high yield by a rearrangement–elimination reaction using n-butanol as a solvent. All the reactions could be carried out using conventional heating or microwave irradiation with comparable results. Microwave irradiation allows for an important reduction in the reaction time. This work was supported in part by a Grant-in-Aid for the Secretaría de Estado de Política Científica y Tecnológica of the Spanish Ministry of Education and Culture (Contract grant number: CTQ2006-07451). The authors are grateful to the Comissionat per a Universitats i Recerca del Departament d’Innovació, Universitats i Empresa de la Generalitat de Catalunya and to the the European Social Fund (ESF) for the FI grant of Marc Escribà Gelonch

Nowadays, continuous chemical processes (‘flow chemistry’) using micro process technology are becoming highly competitive, both for cost (better selectivity, higher productivity) and sustainability (low environmental impact) reasons. The first needs true process intensification and the second, among others, new eco-efficient starting and product materials. In this context, a new application for glycerol is reported with increasing industrial interest and tested here under highly intensified conditions. Starting from prior batch processing experience, it is reported about the transfer to a continuous process to transform dichloropropyl pivaloate, prepared from glycerol, into 3-chloro-2-hydroxypropyl ester. The continuous microreactor based process has up to three orders-of-magnitude reduced reaction times (5760×) by virtue of exploiting unusual experimental conditions in organic chemistry (Novel Process Windows), i.e. superheated pressurised processing much above the boiling point. The yields are fully comparable with the ones obtained under batch conditions, but with (expected) loss in selectivity through enhanced diproduct formation. This principally enables the new continuous process to target much higher productivities; however this also results in a more complex reaction mixture therefore the ease of separation and commercial value of the second product will decide its exploitation. Beyond such benefits for the individual reaction under investigation, this is among the very first reports about a superheated reaction with a distinct selectivity issue with two known byproduct pathways, and thus provides the first respective generic information after an upheavalled reporting on capillary- or microreactor-based superheated processing, so far mostly done for less complex reactions.

Nanotechnology is increasingly being utilized to create advanced materials with improved or new functional attributes. Converting fertilizers into a nanoparticle-form has been shown to improve their efficacy but the current procedures used to fabricate nanofertilisers often have poor reproducibility and flexibility. Microfluidic systems, on the other hand, have advantages over traditional nanoparticle fabrication methods in terms of energy and materials consumption, versatility, and controllability. The increased controllability can result in the formation of nanoparticles with precise and complex morphologies (e.g., tuneable sizes, low polydispersity, and multi-core structures). As a result, their functional performance can be tailored to specific applications. This paper reviews the principles, formation, and applications of nano-enabled delivery systems fabricated using microfluidic approaches for the encapsulation, protection, and release of fertilizers. Controlled release can be achieved using two main routes: (i) nutrients adsorbed on nanosupports and (ii) nutrients encapsulated inside nanostructures. We aim to highlight the opportunities for preparing a new generation of highly versatile nanofertilisers using microfluidic systems. We will explore several main characteristics of microfluidically prepared nanofertilisers, including droplet formation, shell fine-tuning, adsorbate fine-tuning, and sustained/triggered release behavior. Volker Hessel and Nam Nghiep Tran acknowledge support from the ERC Grant Surface-COnfined fast modulated Plasma for process and Energy intensification (SCOPE) from the European Commission with Grant No. 810182

Ionic liquids (diimidazol-1-ium esters) prepared from wastes, crude glycerol and carboxylic acids are investigated as potential phase change materials (PCM). The ionic liquids (IL) with best thermophysical properties were those with also better production yield (higher than 75%). The chemical composition of those IL was with R1 being (CH3)3CCO, CH3(CH2)14CO or C2H3CO; R2 being BIM+; R3 being BIM+; and X- being 2 Cl‾. Phase change of state (solid-liquid) of this IL was 85 ºC, 264 ºC and 128 ºC, which means potential application in different fields such as domestic hot water, solar cooling and industry, respectively. The measured melting enthalpy 328 kJ/kg, 408 kJ/kg, and 660 kJ/kg is much higher in all cases than the usual found in commercial PCM (100 kJ/kg), therefore, these ILs synthetized in this study are proper candidates to be used as PCM because of the huge amounts of energy that they are able to store and their low cost. Moreover, biobPCM are sustainable materials since its obtaining process is based on oil. The work is partially funded by the Spanish government (ENE2015-64117-C5-1-R (MINECO/FEDER) and CTQ2015-70982-C3-1-R (MINECO/FEDER)). The authors would like to thank the Catalan Government for the quality accreditation given to the research groups GREA (2014 SGR 123), Agricultural Biotechnology (2014 SGR 1296) and DIOPMA (2014 SGR 1543). Dr. Camila Barreneche would like to thank Ministerio de Economia y Competitividad de España for Grant Juan de la Cierva, FJCI-2014-22886.The research leading to these results has received funding from the European Union’s Seventh Framework Program (FP7/2007–2013) under grant agreement n° PIRSES-GA-2013-610692 (INNOSTORAGE) and from the European Union’s Horizon 2020 research and innovation program under grant agreement No 657466 (INPATH-TES).

As part of our continued effort to achieve the synthesis of halohydrin esters from polyols by a sustainable method, here we report on a multicomponent inorganic acid-mediated solvent-free synthesis. The synthesis was designed to ensure few waste materials. Using this approach, the process shows a low E-factor and a high reaction mass efficiency. The new process involves the preparation of a reaction mixture containing either a fatty acid or fatty material, glycerol or diol, a halide salt and H3PO4. This mixture is heated at 100 °C for 48 h, yielding up to 88% of halohydrin ester. The process also allows recovery of pyrophosphate salts, compounds that have various applications in agriculture, and in the pharmaceutical, chemical and food industries. This work was supported in part by a Grant-in-Aid from the Secretarı´a de Estado de Polı´tica Cientı´fica y Tecnolo´gica of the Spanish Ministry of Education and Culture (Contract grant number: CTQ2009-14699-C02-01).