Jonathan McDonoughNewcastle University | NCL · School of Engineering
Jonathan McDonough
PhD MEng (Hons) AMIChemE
3D printing, reactor engineering, flow chemistry, fluidization, carbon capture
About
25
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Introduction
Interests: flow chemistry, reaction engineering, meso-OBRs, microreactors, fluid mechanics, process intensification, green chemistry, 3D printing, fluidization
Publications
Publications (25)
![Figure 4 -(a) Thermosyphon & (b) heat pipe (Reproduced from [74])](profile/Jonathan-Mcdonough-2/publication/270293304/figure/fig2/AS:989956344406017@1613035393734/a-Thermosyphon-b-heat-pipe-Reproduced-from-74_Q320.jpg)
The mesoscale oscillatory baffled reactor (meso-OBR) is a novel technology for reaction engineering and screening applications. The meso-OBR exhibits high degrees of plug flow at low and moderate net flow rates (0.3–8 mL/min). For example, central and integral baffle configurations give good plug flow at net flows of Ren = 4.3–34 for ψ = 4–8 and ψ...
The mesoscale oscillatory baffled reactor (meso-OBR) is a novel screening platform that does not require significant optimisation of the operating conditions, making it ubiquitous. Although it is known that micromixing performance influences the observed reaction kinetics, the micromixing of meso-OBRs has not previously been characterised. Therefor...
This review provides an overview of the current state of additive manufacturing in the context of process engineering. The results and opinions from a wide range of public domain reports has been compiled, and used to formulate a new perspective in the ways additive manufacturing has been exploited for heat transfer, and what some of the future opp...
Carbon capture (CC) will play a predominant role in decarbonising the energy, industry, and transportation sectors in the short to medium timeframes to meet the 2050 Net Zero target. Adsorption is a promising CC technology that uses solid-adsorbents rather than liquid-absorbents to strip CO2 from flue gas streams. In this study we developed a small...
Additive manufacturing has enabled the production of more advanced reactor geometries, resulting in the potential for significantly larger and more complex design spaces. Identifying and optimising promising configurations within broader design spaces presents a significant challenge for existing human-centric design approaches. As such, existing p...
Processes involving the manufacture of fine/bulk chemicals, pharmaceuticals, biofuels, and waste treatment require plug flow characteristics to minimise their energy consumption and costs, and maximise product quality. One such versatile flow chemistry platform is the coiled tube reactor subjected to oscillatory motion, producing excellent plug flo...
The development of new manufacturing techniques such as 3D printing have enabled the creation of previously infeasible chemical reactor designs. Systematically optimizing the highly parameterized geometries involved in these new classes of reactor is vital to ensure enhanced mixing characteristics and feasible manufacturability. Here we present a f...
Hydrotalcites are a promising candidate for capturing CO2, but their strong inter-particle forces produce significant agglomeration and poor fluidisation quality in micro-fluidised bed technology. Therefore, in this study we performed detailed hydrodynamic experiments using the pressure drop characterisation approach to identify viable MFBR designs...
We derive a model entirely from first principles to explain the Leidenfrost self-propulsion phenomenon in a quantitative way, where the deformable nature of the liquid has been taken into account. Experiments show a good agreement with our model, suggesting this model supersedes the limited scaling analysis previously given in the literature. Our a...
When a liquid is dropped on a surface significantly hotter than the liquid's boiling point, a vapor film forms beneath the droplet creating an insulation layer sufficient enough to prevent the droplet from rapidly boiling. This phenomenon is known as the Leidenfrost effect, and enables droplets to survive for up to several minutes before fully evap...
We used the stereolithography printing technique to fabricate a toroidal fluidized bed at the smallest scale ever achieved (50 mm diameter with 10 mm annular width). In toroidal fluidization, most of the kinetic energy of the fluidizing gas is used to induce swirling of the particle bed meaning higher gas velocities can be used without entrainment....
Additive manufacturing enables the fabrication of geometries previously unavailable via conventional means. Here, a helically coiled channel containing a secondary helical coil insert was 3D printed, and operated in a net flow with superimposed oscillation. This ‘coil-in-coil’ geometry exhibited exceptional plug flow quality at low Reynolds numbers...
When a liquid is oscillated in a tube containing a helical coil, there are two key flow phenomena: vortex-shedding and “swirl”. Together, they cause plug flow to be achievable over a wide range of conditions in this design. When an additional small cylindrical rod is placed in the centre of the helical coil, a new dual vortex regime is realised. Th...
Additive manufacturing could be used to facilitate the rapid fabrication and testing of small-scale fluidized beds for use in screening applications, such as adsorbent screening for carbon capture. In this work, experiments were performed in order to map the different flow regimes produced in small-scale (Dh = 3–15 mm) gas-solid fluidized beds that...
Flow in helical tubes exhibits plug flow characteristics above a critical flow rate due to the formation of Dean vortices. In this study, we report the novel use of oscillatory flow inside coiled tubes to achieve high degrees of plug flow at lower flow rates. The plug flow enhancement appeared to ‘switch-on’ then ‘switch-off’ as the oscillation int...
Up to 25% of the total European Union (EU) CO2 emissions that contribute to global warming are from industry, and while improved energy efficiency and process integration continues to play a role in minimizing these, it is carbon capture (CC) that in future will contribute most to mitigation, until nuclear energy and renewable technologies take ove...
There are numerous potential benefits of conducting chemical reactions in the absence of solvent. For instance, the risk of environmental release of the solvent is eliminated and there is the potential for intensification via increased reaction rates reducing the required reactor volume. It was previously shown that two configurations of the mesosc...
Oscillatory baffled reactors (OBRs) are able to generate plug flow at laminar net flow conditions, providing appropriate oscillation conditions are selected. Mesoscale OBRs containing helical baffles exhibit wider “operating windows” (i.e. a broader oscillation intensity range) for plug flow than other baffle designs. It has been hypothesised that...
Oscillatory baffled reactors (OBRs) operate through the superposition of an oscillatory motion on to a net flow in a tube fitted with baffles. The baffles disrupt the boundary layer at the tube wall, whilst oscillation results in improved mixing through the formation of vortices. OBRs are therefore intensified reactors capable of achieving plug flo...
Fluidic oscillators of the bistable amplifier type are one example of fluidics that has found new interest in a wide range of applications. Fluidic oscillators use internal feedback to induce periodic oscillations. By operating these devices with multiple outlet channels, periodic flow switching between the channels leading to dual stream pulsation...
There is limited information available regarding fluidic oscillator design for liquid phase applications. In this paper, the results of a simple parametric study investigating the effects of seven geometrical parameters on the flow-switching frequencies produced in 3D printed single feedback loop bistable oscillators are reported for a variety of g...
In this study, a heat pipe was integrated with a mesoscale oscillatory baffled reactor for the passive temperature control of an exothermic reaction. The thermal/chemical performance of this new Heat Pipe Oscillatory Baffled Reactor (HPOBR) was compared to a conventional jacketed OBR (JOBR) using central composite experiment designs for an iminatio...
Process development often involves the optimisation of a process or the study of reaction kinetics in order to improve product yields and selectivities whilst increasing process robustness. Flow chemistry offers superior heat/mass transfer properties, better controllability and reduced processing volumes compared to conventional batch screening. Ad...
Questions
Question (1)
Hi,
I performed an in-situ 1H-NMR study of the reaction between benzaldehyde and n-butylamine to form an imine some time ago, but I am currently struggling to explain some of the behaviours of the observed peaks.
Although I have been able to identify all of the peaks belonging to the reactants and products (and possibly the intermediate), I can't seem to find any clear literature/background theory that explains the following behaviours:
-Peak movement: the peaks belonging to the n-butylamine reactant shift to higher δ over time, towards their corresponding δ in the imine product. At first I thought this was due to the butylamine's conversion to the imine, but I don't see this behaviour with the benzaldehyde (these peaks only decrease in intensity whilst the imine product peaks increase). I was wondering if the movement of the peaks could be explained by the butylamine's involvement in the reaction mechanism, but I haven't been able to find any decent literature to support/explain this.
-Broad (+ moving) peak. I also observe a broad (δ 3.45-3.8) peak that shifts to higher δ over time whilst decreasing in intensity. Again, I am unsure of the interpretations of moving peaks over time and I am also unsure about the potential explanations for broad 1H-NMR peaks - I believe one explanation is hydrogen exchange occurring on the same time scale as the NMR acquisition time.
If anybody has any potential suggestions for these in-situ behaviours, or any useful literature/background theory, I would be really grateful.
Thanks
Jonathan
