Reactor Design

Syngas- and H2-based fuels from solid waste feedstocks are essential for decarbonizing chemical production and
reducing dependence on fossil resources. A combined pyrolysis-reforming prototype (300 g/h waste feedstock
input) with a fluidized Ni/Al2O3 catalyst was designed to elucidate feedstock effects on reforming efficiency,
catalyst stability, and system reliability. Pine sawdust (pine), dried municipal sewage sludge (sewage sludge),
and refuse-derived fuel (RDF) were used to generate producer gas. Pine enabled stable pyrolysis–reforming for 6
h, yielding 45–52 vol% H2 and 33–34 vol% CO, with minimal tar (0–2 g/Nm3) and the lowest C1–C5 hydrocarbon
concentrations in the producer gas. Sewage sludge also sustained 6 h of operation but produced lower H2 (39–45
vol%) and CO (19–20 vol%), higher tar (25–35 g/Nm3) and C1–C5 concentrations, as the catalyst activity was
suppressed by Ni sulfidation and, probably, coking. RDF trials were stopped after 2 h due to severe coking at the
reformer inlet and tar condensation on equipment walls (not the catalyst bed), the lowest H2 (34–37 vol%) and
CO (14–17 vol%) concentrations and insufficient tar (~47 g/Nm3) and C1–C5 (26–31 vol%) reforming.
Regardless of the feedstock, class 4 polyaromatic tar compounds were consistently the most abundant tar species.
C1–C5 hydrocarbon concentrations exhibited a strong empirical correlation with quantified tar concentration
(adjusted R2 = 0.951), enabling real-time process monitoring and control. Catalyst testing showed no statistically
significant effect of feedstock on differences in catalyst porosity or Ni loss due to attrition. Based on these
findings, a feedstock-specific technology development roadmap was proposed, focusing on the research of un­
addressed issues in the development of robust, scalable pyrolysis–reforming systems tailored to diverse waste
streams.

We formulate a fixed-parameter three-regime instability operator for open, non-equilibrium systems and present a conservative tokamak-plasma test protocol. The operator, denoted ∆Φ(t), aggregates baseline-normalized deviations along structural (S), informational (I), and coherence/phase-memory (C) axes, with non-negative weights satisfying α + β + γ = 1. The framework is designed to distinguish three operational regimes: stable baseline dynamics, metastable pre-instability, and macroscopic collapse. The operator is not proposed as a new plasma-physics law, a replacement for magnetohydrodynamics, or a universal physical constant. It is a deterministic diagnostic layer whose value must be assessed by locked-parameter, archival validation. The revised manuscript separates what has already been explored in EEG-type regimetransition data from what remains a proposed tokamak validation protocol. The EEG component is treated as external methodological evidence that a phase-memory/structure-informationcoherence operator can be implemented on high-dimensional physiological time series. The tokamak component is not presented as completed plasma-data validation. Instead, we define an explicit archival test on L-H transitions, edge-localized-mode-like bursts, and disruptions using standard diagnostics such as Mirnov coils, equilibrium reconstruction, reflectometry, electroncyclotron-emission channels, soft-X-ray channels, bolometry, and cross-channel coherence. Failure conditions are stated in advance: if the fixed operator does not improve lead time, false-alarm performance, calibration, or robustness over declared baselines and null models, the cross-domain claim fails for that event class or machine. The objective is therefore narrow and falsifiable: to test whether a locked phase-memory instability observable adds reproducible diagnostic value beyond single-channel or memoryless baselines in tokamak archival data.

A highlevel overview of a closed fuel cycle architecture, strategic rationale, and proposed fast spectrum programme. A Concept Fast Spectrum Reactor Architecture for a UK Closed Nuclear Fuel Cycle to 2101

Concept Programmes for a UK Fast Burner Reactor Fleet and a UK Fast Breeder Fleet



Executive Summary

The United Kingdom stands at a strategic crossroads in its civil nuclear programme. For decades, the nation has accumulated a substantial legacy of nuclear materials—most notably a ~140‑tonne separated plutonium stockpile, tens of thousands of cubic metres of Magnox swarf and residues, and a growing inventory of AGR and PWR spent fuel. At the same time, the UK is committing to a new generation of large reactors (Hinkley Point C, Sizewell C) and small modular reactors, all of which will produce additional spent fuel for many decades.

The current proposed strategy—immobilisation of plutonium and long‑term geological disposal of high‑activity wastes—addresses the symptoms of the problem but not its underlying structure. It is a linear, once‑through model that treats valuable fissile material as waste, expands the burden on the future Geological Disposal Facility (GDF), and leaves the UK dependent on imported uranium for the long term.

This document proposes a different path: a closed fuel cycle anchored in West Cumbria, centred on a cluster of fast spectrum reactors co‑located with a modernised reprocessing and fuel fabrication campus at Sellafield–Moorside. This is not a theoretical exercise. It is a practical, phased, technically grounded programme that uses the UK’s existing assets—its plutonium inventory, its legacy Magnox residues, its nuclear workforce, and its regulatory capability—to build a sustainable, sovereign, and economically rational nuclear future.

A Concept Architecture to consider Fast Spectrum Breeders for a Closed Fuel Cycle

The core proposition is simple: The UK may be able to convert a £3 billion legacy liability into a £10–17 billion energy asset while reducing long‑term disposal costs and establishing a closed fuel cycle for the future.

The architecture rests on three pillars:

A 50 GWe fleet of PWR/EPR/SMR reactors generating electricity and spent fuel.
A reprocessing and fuel fabrication capability at Sellafield, rebuilt for 21st‑century requirements.
A fast spectrum reactor fleet—initially burners, later complemented by breeders—to destroy legacy materials and sustain long‑term fuel supply.
This is a coherent, circular system. Without fast reactors, reprocessing economics weaken. Without reprocessing, fast reactors lack feedstock. Together, they form  self‑reinforcing capabilities for a future benefits.

Why Fast Spectrum Reactors may be necessary

Fast spectrum reactors (FSRs) are the only technology capable of:

Destroying plutonium and minor actinides
Reducing long‑lived radiotoxicity by orders of magnitude
Converting waste into fuel
Closing the nuclear fuel cycle
Reducing the size, heat load, and cost of the GDF
A 600 MWe fast burner reactor destroys roughly 1–1.2 tonnes of plutonium per year. A fleet of 6–8 burners can eliminate the UK’s legacy plutonium within a politically realistic timeframe while simultaneously processing actinides from ongoing PWR/SMR operations.

Breeders are not required immediately. However they do become relevant only once the UK’s reactor fleet is large enough that fuel independence becomes a strategic objective—likely from the 2060s onward.

where he has taught since 1964. He received his doctorate in chemical engineering in 1963 from the University of Oklahoma, where he was Dr. Perry's first doctoral student. Dr. Green has won several teaching awards at the University of Kansas, and he is a Fellow of the American Institute of Chemical Engineers and an Honorary Member of the Society of Petroleum Engineers. He is the author of numerous articles in technical journals. The late Robert H. Perry served as chairman of the Department of Chemical Engineering at the University of Oklahoma and program director for graduate research facilities at the National Science Research Foundation. He was a consultant to various United Nations and other international organizations. From 1973 until his death in 1978, Dr. Perry devoted his time to a study of the cross impact of technologies within the next half century. The subjects under his investigation on a global basis were energy, minerals and metals, transportation and communications, medicine, food production, and the environment.

This paper presents the Sanim Advanced Dual-Core Reactor (SADCR), a hypothetical nuclear energy system designed to combine nuclear fission and magnetic confinement fusion within a unified containment structure. The goal of the design is to generate large-scale electrical power while reducing the accumulation of long-lived radioactive waste through in-situ neutron transmutation. The SADCR integrates a modified pressurized water fission reactor with a high-field tokamak fusion core operating in close proximity inside a carbon-boron composite containment vessel. In this configuration, the fission reactor provides reliable baseline power and contributes neutron flux that supports fusion plasma stability. In return, the fusion reactor produces high-energy neutrons that can transmute long-lived fission products into shorter-lived or stable isotopes. Key innovations proposed in this design include dual-core thermal coupling, cross-core emergency cooling systems, magnetic siphon redundancy for plasma containment power, and gamma-energy harvesting using thermoelectric systems. The reactor also incorporates advanced structural materials such as carbon-boron composites and tantalum-lined alloys to improve radiation tolerance and thermal performance. Although the reactor described is theoretical, first-principles physics calculations are used to estimate energy output, neutron flux, and potential waste reduction pathways. The proposed system illustrates how hybrid fission-fusion reactors could potentially improve nuclear energy sustainability while addressing long-term waste management challenges.

This paper presents the Sanim Advanced Dual-Core Reactor (SADCR), a hypothetical nuclear energy system designed to combine nuclear fission and magnetic confinement fusion within a unified containment structure. The goal of the design is to generate large-scale electrical power while reducing the accumulation of long-lived radioactive waste through in-situ neutron transmutation.The SADCR integrates a modified pressurized water fission reactor with a high-field tokamak fusion core operating in close proximity inside a carbon-boron composite containment vessel. In this configuration, the fission reactor provides reliable baseline power and contributes neutron flux that supports fusion plasma stability. In return, the fusion reactor produces high-energy neutrons that can transmute long-lived fission products into shorter-lived or stable isotopes. Key innovations proposed in this design include dual-core thermal coupling, cross-core emergency cooling systems, magnetic siphon redundancy for plasma containment power, and gamma-energy harvesting using thermoelectric and photoelectric systems. The reactor also incorporates advanced structural materials such as carbon-boron composites and tantalum-lined alloys to improve radiation tolerance and thermal performance. Although the reactor described is theoretical, firstprinciples physics calculations are used to estimate energy output, neutron flux, and potential waste reduction pathways. The proposed system illustrates how hybrid fission-fusion reactors could potentially improve nuclear energy sustainability while addressing long-term waste management challenges. 1.INTRODUCTION The evolution of nuclear power to get energy has followed two tracks: fission reactors, now in their fourth generation, and fusion experiments such as ITER, which aims to demonstrate net energy gain. Despite advances, both face fundamental limitations. Fission produces long lived nuclear waste requiring storage, while fusion requires monumental external energy input for plasma ignition and lacks inherent fuel breeding.

This paper presents a staged development roadmap for a compact, aneutronic fusion reactor based on the proton-boron (p-¹¹B) fuel cycle and field-reversed configuration (FRC) confinement. The target system is designed for integration into a mobile exoskeleton platform, requiring a net electrical output of 50 kW continuous and 500 kW burst, with a total mass below 150 kg. A four-stage program spanning 15 years is outlined, progressing from basic confinement validation to a fully integrated engineering prototype. Key technical challenges-including achieving the high ion temperatures (150-300 keV) required for appreciable p-¹¹B reactivity, plasma heating, energy conversion, thermal management, and radiation shielding-are addressed with specific mitigation strategies, such as direct energy conversion, liquid metal cooling, and cryogenic loops for high-temperature superconductors. Monte Carlo simulations are used to validate shielding effectiveness, with all simulation-based results verified through the pHCA and BPA diagnostic frameworks, which are derived from the proclian hierarchical constraint algorithm and the Bauhaus proclian algorithm-both validated against experimental FRC data. A contingency battery pack ensures continued system development independent of fusion core breakthroughs. The paper argues that while the reactor remains at low technology readiness levels, a disciplined, phased approach can make such a system feasible within a 15-year horizon, provided that the fundamental plasma temperature requirements are met through advanced heating and confinement techniques.

The nuclear fusion threshold, Coulomb barrier energy, critical density, and chain reaction conditions are derived entirely from the universal closure condition C = g², without nuclear equation-of-state models or empirical fitting. The barrier energy Ec = (α · αs/2) mpc² is expressed purely in terms of the electromagnetic and strong coupling constants with no free parameters — a result with no equivalent in standard fusion physics. Nuclear density, the D-T viability ratio of 20.6, and a minimum ignition radius of 3–4mm follow from the same geometry.

As chemical processes grow in complexity and demand more robust control strategies, understanding the transient dynamics of reactors becomes increasingly critical. This article presents a practical approach to dynamic simulation of chemical reactors with a focus on continuous stirred tank reactors (CSTRs) through phase plane analysis, nullcline computation and system trajectory visualization using Python. By integrating rigorous mathematical modeling with clear graphical insight, the study reveals how nullclines help identify multiple steady-states, assess stability and anticipate unsafe conditions like thermal runaway. The methodology, which is extendable to plug flow reactors (PFRs), packed bed reactors (PBRs) and fluid catalytic cracking units (FCCUs), offers process engineers a powerful design and diagnostic tool grounded in modern computation.

The Dawn of Deterministic Autonomy: Synthesizing Nuclear Physics and Global Logistics

The global maritime industry currently stands at a transformative precipice, characterized by the "Maritime Trilemma"—the seemingly irreconcilable conflict among high energy-density requirements, the mandate for zero-emission operations, and the need for economic scalability. As traditional hydrocarbon-based propulsion systems face obsolescence under the weight of CO2 taxes and environmental degradation, the search for a successor has largely focused on stochastic solutions such as green ammonia or hydrogen, which are frequently hampered by low volumetric efficiency and infrastructure bottlenecks. This research introduces a radical ontological shift in maritime engineering: Deterministic Autonomous Maritime Propulsion (DAMP).

At the core of this framework lies the Generation-IV Thorium Molten Salt Reactor (TMSR), a technology that replaces human-centric safety with "Physics-First" determinism. By utilizing liquid-fuel salts, the TMSR leverages inherent safety mechanisms—such as negative-temperature reactivity feedback and passive decay-heat removal (RVACS)—that ensure reactor stability through thermodynamic laws rather than active intervention. This technical foundation is uniquely suited for Level 4 Autonomy, where the vessel operates entirely independent of human interaction. The synthesis of advanced reactor kinetics, specifically the modeling of the "drifting precursor effect" in circulating fuels, allows for a control architecture that is both mathematically verifiable and operationally resilient.

The results of this study underscore a profound breakthrough in power conversion: the adoption of a Recompression sCO2 Brayton Cycle. With a thermal efficiency exceeding 47.28%, this system drastically reduces the total volume and mass of the propulsion plant compared to conventional steam Rankine cycles, thereby maximizing cargo displacement for commercial viability.

Furthermore, the introduction of the "Nuclear Citadel" shipbuilding model—utilizing composite Sandwich Plate Systems (SPS)—provides a robust structural barrier against collisions and piracy, ensuring the survivability of the reactor compartment even in extreme capsizing or impact scenarios.
Beyond technical specifications, this work explores the geopolitical and economic dimensions of the "Thorium Opportunity." With massive reserves located in strategic nations such as Turkey, India, and Brazil, thorium offers a path to "Strategic Autonomy," allowing these nations to emerge as leaders in a zero-emission global economy. Through the "Fuel-as-a-Service" (FaaS) business model, the economic risks of nuclear adoption are mitigated, transforming the shipowner’s capital expenditure into predictable operational costs.

Ultimately, this research serves as more than a technical blueprint; it is a vision for the future of sovereign energy and autonomous trade. By aligning the IMO MASS Code with goal-based nuclear standards, the DAMP framework provides the scientific and regulatory roadmap necessary to realize "Thorium Green Lanes"—bilateral corridors of zero-emission, autonomous global logistics.

The corrosion failure of a crucible made of 95 wt% Zr in tin ore smelting applications was investigated. The Zr crucibles degraded after a high-temperature firing process involving alkaline fusion such as Na 2 CO 3 , NaOH and sulfur. An analysis was conducted to determine the corrosion failure mechanism and the strength degradation. The research was conducted by taking samples of zirconium metal crucibles that had undergone either 1000 min of accumulated firing or 100 cycles of firing, and then comparing them to new ones. Micro-Vickers hardness testing and tensile testing were carried out. SEM observed microstructures, while XRD analysis was conducted to observe phase composition. The results showed that pitting and cracking damage caused a decreased tensile strength (UTS) by 52% while the strain decreased by 22%. The deposition of several oxygen atoms, based on EDS results confirmed by XRD as a ZrO 2 compound, causes the material to embrittle and makes the crucible unable to maintain its original shape.

In this work, a microfluidic flow-through electrochemical reactor for wastewater treatment is presented which simultaneously minimizes ohmic drop and mass transfer limitations, two of the most important bottlenecks in electrochemical wastewater treatment. A proof-of-concept comparison versus a state-of-the-art flow-by commercial reactor revealed that the proposed reactor greatly outperforms the commercial system. The novel system requires only 2.4 Ah dm -3 (vs. 11.4 Ah dm -3 ) and 12.5 kWh m -3 (vs. 75.0 kWh m -3 ) to completely mineralize 100 mg dm -3 of clopyralid spiked in a lowconductive (1 mS cm -1 ) matrix with both systems using diamond anodes. The microfluidic flow-through configuration represents a promising approach to the development of cost-effective electrochemical technologies for wastewater treatment.

📘 Modeling of Chemical Kinetics & Reactor Design — A Cornerstone for Modern Chemical Engineers
Modeling of Chemical Kinetics & Reactor Design by A. Kayode Coker continues to stand out as one of the most influential resources in reaction engineering since its publication in 2001. It remains widely referenced across academia and industry, consistently ranking among the top performing chemical engineering publications on ResearchGate.
This book offers a comprehensive and practice driven exploration of how chemical reactions behave and how reactors should be designed to achieve safe, efficient, and economically optimized operation. It guides readers from foundational kinetics and reaction mechanisms into advanced modeling of batch, CSTR, PFR, catalytic, and multiphase reactors. The text also provides clear methodologies for analyzing kinetic data, fitting parameters, validating mechanisms, and translating laboratory results into full scale industrial reactor designs.
One of the book’s greatest strengths is its ability to bridge theory with real world engineering. The industrial case studies drawn from petroleum refining, petrochemicals, gas processing, polymerization, and environmental systems show how kinetic modeling directly informs design decisions, troubleshooting, optimization, and scale up. Engineers working in complex process environments often find these examples invaluable.
The book also anticipated the rise of computational modeling. Its algorithm friendly approach to solving differential equations, performing sensitivity analysis, and validating models makes it a natural companion for today’s engineers who rely on simulation tools and custom modeling workflows.
More than two decades later, the book continues to attract strong engagement from researchers and professionals. Its ResearchGate Research Interest Score places it above 98% of all chemical engineering items, underscoring its enduring relevance in graduate education, industrial practice, and advanced research.

The aim of this work is to present in a systematic way a novel general methodology to develop the design equations (heat and mass balances) for networks of ideal reactors, that is, Plug-Flow Reactors (PFRs) and Continuous Stirred Tank Reactors (CSTRs). In particular, after introducing the general definition of conversion to be used for reactor networks, several case studies of interest in chemical engineering are presented as topic-examples of application: (i) adiabatic-stage reactors with recycle, (ii) adiabatic-stage reactors with split, (iii) adiabatic-stage reactors intercooled by reactants and (iv) adiabatic-stage reactors with interstage distributed feed. More generally, the presented methodology can also be applied to develop the design equations for complex networks of interconnected reactors, not restricted to those considered in the present work. The motivation behind the present study lies in the fact that, to the best of our knowledge, a systematic development of the design equations of single reactors in reactor networks is currently missing in the open literature as well as in the reference textbooks of chemical reaction engineering and reactor design.

This paper describes the systematic revamp of a Benfield CO₂ removal unit at a high-throughput ammonia plant, emphasizing simulation-driven diagnostics and customized engineering solutions. The initiative was prompted by persistent operational challenges, including excessive steam consumption, elevated CO₂ slippage, and ongoing mechanical degradation—all of which had undermined energy efficiency, plant reliability, and overall performance. These issues were further compounded by hydraulic constraints in both the absorber and stripper, leading to unstable operation, solvent carryover, and increased cooling water demand.

A systematic upgrade strategy was applied, combining validated process simulation with detailed hydraulic and mechanical assessments to diagnose performance bottlenecks. Improvement options were ranked using a cost-benefit framework to ensure impactful and economically viable implementation.

The revamp yielded significant benefits: restored hydraulic stability, reduced CO₂ slippage, lower steam usage, and improved energy efficiency—all of which contributed to maximizing ammonia and urea production and enhancing long-term reliability.

Although implemented in an ammonia facility, the systematic methodology and solutions are broadly applicable to aging Benfield units in refineries and petrochemical complexes facing similar operational constraints.

Application of basic Chemical Engineering Principles to understand the chemical kinetics and reactor design. C ourse Outcomes Students will be able to ◾ Understand the basic laws of Reaction Engineering,kinetics and design of reactors. ◾ Understand the kinetics of multiple reaction and multiplereactiondesign. ◾ Comprehend and to apply temperature and pressure effects in reactor design.

Recebido em 13/1/04; aceito em 27/1/05; publicado na web em 30/6/05 CONSTRUCTION AND PERFORMANCE STUDIES OF A CPC TYPE PHOTOCHEMICAL REACTOR. A CPC (Compound Parabolic Concentrator) reactor was projected and constructed aiming to promote the degradation of the organic matter present in considerable volumes of aqueous effluents, under the action of solar radiation. The essays were done using a model effluent which consists of a mixture of fragments of a sodium salt of lignosulphonic acid possessing a mean molecular weigth of 52,000 Daltons, and a real effluent, from a chip board industry. The volume of effluent in each test was about 50 L. The tests involved heterogeneous (TiO 2 P25 Degussa and formulations made from the association of TiO 2 with a photosensitiser), and homogeneous (thermal and photochemical Fenton reactions) catalysis of the effluents. The results demonstrate the viability of application of this kind of reactor even when the load of organic pollutants is high.

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In this research, the neutronic parameters of the typical reactor core with 300 MW electrical power were calculated in order to choose an optimal material for the core barrel and baffle. The core barrel belongs to the lower core support structure because it houses a reactor core. Other lower core support structures are attached to the core barrel, which transmits the weight of the core to the reactor vessel. Core baffle forms the interface between the core and the core barrel. The core barrel is made of low carbon, chromium-nickel stainless steel because it is situated in a corrosive environment (primary coolant comprises boric acid), and the material should not get oxidized. Since different materials can be chosen as baffles and barrels of the core, it is necessary to investigate the effects of these materials on different neutronic parameters of the core. In this regard, the typical reactor core was completely simulated by the MCNP code. The core of the reactor consists of 121 fuel assemblies with a 15x15 square arrangement. At first, various neutronic parameters of the reactor core, including the effective multiplication factor, neutron flux, and radial Power Peaking Factor (PPF) for the reference core were calculated by considering SS-304L as the material of Barrel and Baffle, and the obtained results were validated. Then, various alloy materials including 0Cr18Ni11Ti, 18Cr10NiTi, SS-347, SS-409, Inconel-718, Inconel-625 and 08X18H10T were considered as the material of the core barrel and baffle. According to the results, SS-304L leads to the most effective multiplication factor, Inconel-625 leads to the most thermal to fast neutron flux ratio, while, 08X18H10T leads to the lowest PPF. Finally, by performing optimization on various neutronic parameters of the reactor core, the alloy 08X18H10T was introduced as the optimal material for the core barrel and baffle.

Bioelectrochemical systems (BESs) have great potential in renewable energy production technologies. BES can generate electricity via Microbial Fuel Cell (MFC) or use the electric current for the synthesis of valuable commodities in Microbial Electrolysis Cells (MECs). The number of various reactor configurations and operational protocols increasing rapidly although, the industrial scale operation is still facing difficulties. This article reviews the recent BES related to literature, with special attention to electrosynthesis and the most promising reactor configurations. We also attempted to clarify the numerous definitions proposed for BESs. The main components of BES are highlighted. Although the comparison of the various fermentation systems is we collected useful and generally applicable operational parameters to be used for comparative studies. A brief overview to link the appropriate microbes to the optimal reactor design is given.

Wheat is the world's second most produced grain because of its high consumption rate, easy growth, multipurpose use and important role in the human diet. Every year, abundant amounts of wheat hull are obtained after shell process of the wheat as a waste material. Wheat hull, a by-product of the food industry, has low economic value. The utilization of wheat hull ash in various areas of industry can contribute to both financial and waste management strategies. In the present study, wheat hull ash that contains a high proportion of silica (43.22%), was utilized for barium and calcium silicate production. The wheat hull ash based barium and calcium silicate had a BET surface area of 30 and 54 m/g, respectively. There has been no research on barium and calcium silicate production from wheat hull. So, this study will present originality on this area.