Cost analysis of oil cake-to-biodiesel production in packed-bed micro-flow reactors with immobilized lipases.

Biodiesel production depends to a great extent on the use of cheap raw materials, since biodiesel itself is a mass product, not a high-value product. New processing methods, such as micro-flow continuous processing combined with enzymatic catalysis, open doors to the latter. As reported here, the window of opportunity in enzyme-catalyzed biodiesel production is the conversion of waste cooking oil. The main technological challenge for this is to obtain efficient immobilization of the lipase catalyst on beads. The beads can be filled into tubular reactors where designed packed-bed provide porous channels, forming micro-flow. It turns out, that in this way, the immobilization costs become the decisive economic factor. This paper reports a solution to that issue. The use of oil cake enables economic viability, which is not given by any of the commercial polymeric substrates used so far for enzyme immobilization. The costs of immobilization are mirrored in the earnings and cash flow of the new biotechnological process.

Visible-Light-Mediated Selective Arylation of Cysteine in Batch and Flow.

A mild visible-light-mediated strategy for cysteine arylation is presented. The method relies on the use of eosin Y as a metal-free photocatalyst and aryldiazonium salts as arylating agents. The reaction can be significantly accelerated in a microflow reactor, whilst allowing the in situ formation of the required diazonium salts. The batch and flow protocol described herein can be applied to obtain a broad series of arylated cysteine derivatives and arylated cysteine-containing dipeptides. Moreover, the method was applied to the chemoselective arylation of a model peptide in biocompatible reaction conditions (room temperature, phosphate-buffered saline (PBS) buffer) within a short reaction time.

Micro-flow photosynthesis of new dienophiles for inverse-electron-demand Diels-Alder reactions. Potential applications for pretargeted in vivo PET imaging.

Pretargeted PET imaging has emerged as an effective two-step in vivo approach that combines the superior affinity and selectivity of antibodies with the rapid pharmacokinetics and favorable dosimetry of smaller molecules radiolabeled with short-lived radionuclides. This approach can be based on the bioorthogonal inverse-electron-demand Diels-Alder (IEDDA) reaction between tetrazines and trans-cyclooctene (TCO) derivatives. We aimed to develop new [18F]TCO-dienophiles with high reactivity for IEDDA reactions, and favorable in vivo stability and pharmacokinetics. New dienophiles were synthesized using an innovative micro-flow photochemistry process, and their reaction kinetics with a tetrazine were determined. In vivo stability and biodistribution of the most promising 18F-radiolabeled-TCO-derivative ([18F]3) was investigated, and its potential for in vivo pretargeted PET imaging was assessed in tumor-bearing mice. We demonstrated that [18F]3 is a suitable dienophile for IEDDA reactions and for pretargeting applications.

Energy-Efficient Routes for the Production of Gasoline from Biogas and Pyrolysis Oil-Process Design and Life-Cycle Assessment.

Two novel routes for the production of gasoline from pyrolysis oil (from timber pine) and biogas (from ley grass) are simulated, followed by a cradle-to-gate life-cycle assessment of the two production routes. The main aim of this work is to conduct a holistic evaluation of the proposed routes and benchmark them against the conventional route of producing gasoline from natural gas. A previously commercialized method of synthesizing gasoline involves conversion of natural gas to syngas, which is further converted to methanol, and then as a last step, the methanol is converted to gasoline. In the new proposed routes, the syngas production step is different; syngas is produced from a mixture of pyrolysis oil and biogas in the following two ways: (i) autothermal reforming of pyrolysis oil and biogas, in which there are two reactions in one reactor (ATR) and (ii) steam reforming of pyrolysis oil and catalytic partial oxidation of biogas, in which there are separated but thermally coupled reactions and reactors (CR). The other two steps to produce methanol from syngas, and gasoline from methanol, remain the same. The purpose of this simulation is to have an ex-ante comparison of the performance of the new routes against a reference, in terms of energy and sustainability. Thus, at this stage of simulations, nonrigorous, equilibrium-based models have been used for reactors, which will give the best case conversions for each step. For the conventional production route, conversion and yield data available in the literature have been used, wherever available.The results of the process design showed that the second method (separate, but thermally coupled reforming) has a carbon efficiency of 0.53, compared to the conventional route (0.48), as well as the first route (0.40). The life-cycle assessment results revealed that the newly proposed processes have a clear advantage over the conventional process in some categories, particularly the global warming potential and primary energy demand; but there are also some in which the conventional route fares better, such as the human toxicity potential and the categories related to land-use change such as biotic production potential and the groundwater resistance indicator. The results confirmed that even though using biomass such as timber pine as raw material does result in reduced greenhouse gas emissions, the activities associated with biomass, such as cultivation and harvesting, contribute to the environmental footprint, particularly the land use change categories. This gives an impetus to investigate the potential of agricultural, forest, or even food waste, which would be likely to have a substantially lower impact on the environment. Moreover, it could be seen that the source of electricity used in the process has a major impact on the environmental performance.

Visible Light-Induced Trifluoromethylation and Perfluoroalkylation of Cysteine Residues in Batch and Continuous Flow.

We report a visible light-induced trifluoromethylation and perfluoroalkylation for cysteine conjugation using Ru(bpy)3(2+) as photocatalyst and inexpensive RFI as coupling partner. The protocol allows the introduction of a variety of perfluoro alkyl groups (C1-C10) and a CF2COOEt moiety. The reaction is high yielding (56-94% yield) and fast (2 h in batch, 12 examples). Process intensification in a photomicroreactor accelerated the reaction (5 min reaction time) and increased the yields (8 examples). Quantum yield investigations support a radical chain mechanism.

Accelerated gas-liquid visible light photoredox catalysis with continuous-flow photochemical microreactors.

In this protocol, we describe the construction and use of an operationally simple photochemical microreactor for gas-liquid photoredox catalysis using visible light. The general procedure includes details on how to set up the microreactor appropriately with inlets for gaseous reagents and organic starting materials, and it includes examples of how to use it to achieve continuous-flow preparation of disulfides or trifluoromethylated heterocycles and thiols. The reported photomicroreactors are modular, inexpensive and can be prepared rapidly from commercially available parts within 1 h even by nonspecialists. Interestingly, typical reaction times of gas-liquid visible light photocatalytic reactions performed in microflow are lower (in the minute range) than comparable reactions performed as a batch process (in the hour range). This can be attributed to the improved irradiation efficiency of the reaction mixture and the enhanced gas-liquid mass transfer in the segmented gas-liquid flow regime.

Membrane microreactors: gas-liquid reactions made easy.

Getting phases together: Membrane microreactors provide new opportunities for gas-liquid reactions. The advantages of this microreactor concept are a large interfacial area, a greater flexibility with regard to flow rates, and the opportunity to immobilize a catalyst on the membrane.

Transfer of the epoxidation of soybean oil from batch to flow chemistry guided by cost and environmental issues.

The simple transfer of established chemical production processes from batch to flow chemistry does not automatically result in more sustainable ones. Detailed process understanding and the motivation to scrutinize known process conditions are necessary factors for success. Although the focus is usually "only" on intensifying transport phenomena to operate under intrinsic kinetics, there is also a large intensification potential in chemistry under harsh conditions and in the specific design of flow processes. Such an understanding and proposed processes are required at an early stage of process design because decisions on the best-suited tools and parameters required to convert green engineering concepts into practice-typically with little chance of substantial changes later-are made during this period. Herein, we present a holistic and interdisciplinary process design approach that combines the concept of novel process windows with process modeling, simulation, and simplified cost and lifecycle assessment for the deliberate development of a cost-competitive and environmentally sustainable alternative to an existing production process for epoxidized soybean oil.

Recent changes in patenting behavior in microprocess technology and its possible use for gas-liquid reactions and the oxidation of glucose.

The miniaturization of continuous processes has been of increasing interest in the past decade, and microreaction technology and flow chemistry have moved from academic and industrial research to commercial applications. With industry taking up such innovations, this trend is also reflected in the patenting behavior of companies active in this area. This review is a continuation of the review paper on microreactor patents published by Hessel et al. and indicates major changes in patenting trends since 2006. Moreover, a different patent database search algorithm is presented, which complements the algorithm explained in the previous review. In addition, the preservation of intellectual property is analyzed for multiphase reactions and particularly solid-catalyzed gas-liquid reactions in microreactors, which play an important role in the chemical and pharmaceutical industries and are reactions that benefit largely from microprocessing. Among other results, we show that the number of patents has increased in this field, with solid-catalyst design and deposition, control of the flow pattern, and ensured stable flow as the main challenges.