High-purity Production Research Articles

Reactive Separation of Ammonia from Wastewater Nitrate via Molecular Electrocatalysis

Selective electrochemical conversion of nitrate to ammonia with ammonia capture can simultaneously remediate nitrate-polluted wastewater and supplement Haber-Bosch ammonia production. Homogeneous molecular catalysts remain underexplored in wastewater treatment and, more generally, in reactive separation processes. Despite the tunable reactivity of molecular catalysts, two barriers prevent their widespread implementation for wastewater nitrate treatment and ammonia recovery. The first barrier is the lack of reports of reaction activity and selectivity of nitrate reduction molecular catalysts in real wastewaters. The second barrier is the need to separate the catalyst, catalytic product, and treated wastewater. In this study, we employ electrochemical stripping in several configurations as a reactive separation unit process to address both barriers to implementation. Using the homogeneous molecular nitrate reduction catalyst Co(DIM), we demonstrate >70% removal of nitrate from municipal wastewater treatment plant secondary effluent with >98.5% selectivity to ammonia, leading to the generation of a high-purity ammonia product (ammonium sulfate). These experiments constitute a novel demonstration of molecular catalysis for nitrate reduction in real wastewater and highlight electrochemical engineering opportunities in reactive separations to valorize wastewater resources. This work advances environmental research toward United Nations Sustainable Development Goals (SDGs) for Clean Water (SDG 6) and Responsible Consumption and Production (SDG 12).

Industrial Electrocatalytic Oxidation - The Future of «Green Chemistry»

From the point of view of "green chemistry", the relevance and prospects of the electrooxidation of organic compounds is confirmed by numerous scientific data on the practical use of methods developed and introduced into production for obtaining demanded chemical and pharmaceutical preparations. The advantages of electrochemical methods for converting organic substrates into products of low-tonnage chemical industry and pharmaceutical chemistry are shown. The reactions of electrooxidation of alcohol groups of synthetic and natural compounds, mediated by catalytic systems based on inexpensive TEMPO-like nitroxyl radicals, which provide numerous key synthetic advantages over other oxidation methods, are considered. It has been shown that oxidation reactions can be carried out under mild conditions, without the use of environmentally harmful reagents and toxic solvents, without large economic investments and with the maximum yield of high-purity target products with the formation of little or no waste. Further fundamental and technological research is recommended in order to develop effective electrocatalytic systems for use in industrial electrooxidation.

Design framework for dimethyl ether (DME) production from coal and biomass‐derived syngas via simulation approach

AbstractA comprehensive thermodynamic study was conducted to evaluate the comparative efficacy of methanol and dimethyl ether (DME) synthesis using CO2 rich syngas feed. The first part of our study included assessing the relative performances of the methanol synthesis system, two step DME synthesis system, and one step DME synthesis system in terms of the COx conversion and product yield (methanol/DME) based on the Gibbs free energy minimization approach. The wide range of composition of CO2‐enriched syngas feed produced by the coal and biomass gasification was simulated using Aspen Plus and the following evaluation parameters were analyzed for a broad parameter range: reaction temperature (180–280°C), reaction pressure (10–80 bar), stoichiometry number (SN) (0–11), and CO2/(CO2 + CO) molar feed ratio (0–1) for isothermal as well as adiabatic conditions. Based on the equilibrium yield, one‐step DME synthesis was discovered as the most viable process to utilize the co‐gasification derived syngas effectively. In the second part of our study, the overall process efficiency was inspected through the process design of 1 tonnes per day (TPD) DME plant inclusive of heat integration, resulting in significant CO2 abatement and DME production with high product purity and minimum energy consumption. Consequently, one‐step DME production via CO2‐enriched syngas obtained through the coal or biomass gasification process is identified as the leading technology based on energy utilization and CO2 abatement.

Intensification of biodiesel production by hydrodynamic cavitation: A critical review

Biodiesel, with its nature of clean, biodegradability, and renewability, is an ideal substitute for fossil diesel. This critical review focuses on the advances in process intensification of biodiesel production by the emerging hydrodynamic cavitation (HC) technology. The recent progress in HC reactors and HC-assisted biodiesel production are summarized and discussed. Several key operating factors (i.e., reactor structure, cavitation intensity, temperature, molar ratio of alcohol to oil, catalyst, and duration) and the economic feasibility are analyzed. It is found that HC can effectively enhance acid- and alkali-catalyzed production processes by using various edible and non-edible oils (e.g., waste cooking oil) as feedstocks, and have economic practicability for industrialization. HC can achieve as high as over 99% yields in a short time, and the quality of the high-purity products meets EN 14214 and ASTM D6751 standards. Although the process simulation and life cycle cost analysis (LCCA) validated that the economics of HC process is far superior to that of conventional mechanical stirring at large scales, the experimental research at pilot or industrial scales is absent, and the amplification effect of both the reactor and process is unclear. Moreover, the investigations on the cavitation flow mechanism, structural optimization and design of HCRs, and feasibility (e.g., life cycle analysis (LCA), LCCA, and LCA-LCCA), have to be focused on in the future. At last, the strengths, weaknesses, opportunities, and threats (SWOT) of the HC process are evaluated by a SWOT matrix, which may hopefully provide some inspiration for the future development of this novel technology.

Accelerated Synthesis of Borophane (HB) Sheets through HCl-Assisted Ion-Exchange Reaction with YCrB4

We present an enhanced method for synthesizing sheets of borophane. Despite the challenges associated with low efficiency, we discovered that incorporating hydrochloric acid into the ion-exchange reaction significantly improved the production yield from 20% to over 50%. After a thorough examination of the reaction, we gained insight into the underlying mechanisms and found that the use of hydrochloric acid provides two key benefits: accelerated production of borophene and isolation of high-purity products. This method has the potential to pave the way for the production of novel topological 2D materials with potential industrial applications.

Nd-Gd–Platinum doped TiO2 nanotube arrays catalyst for water splitting in Alkaline Medium

The utilization of a highly efficient electrocatalyst for the hydrogen evolution reaction (HER) plays an important role in energy conversion in regard to the development of hydrogen-based clean energy sources. The HER in alkaline media by co-doped lanthanide-platinum TiO2 Nanotube Arrays (TNTA) catalyst electrodes has yet to be studied. Here, we report the robust fabrication of an electrocatalyst and its prominent performance in catalyzing the HER. The catalyst electrode consisted of TiO2 nanotube arrays doped with rare earth metals (neodymium (Nd) and gadolinium (Gd)) and a small loading of Pt metal as double-layer nanotube arrays. This material was obtained by a two-step electrochemical anodization method using a small amount of fluoride salt and a short time of mechanical growth. Additionally, an in situ doping strategy that utilized a hydrothermal treatment for the ternary and quaternary ions of Nd, Gd and Pt was performed, while retaining the anatase phase. The Nd-Gd-TNTA catalyst electrode produced a current density of −47.522 µA cm−2 and exhibited a low activation energy of approximately 2.15 kJ/mol. The Nd-Gd-Pt-TNTA catalyst electrode is the best candidate for supporting the HER and advancing water splitting techniques for high-purity hydrogen production in alkaline media.

Performance and ANN-based optimization of an advanced process for wet CO2-to-Methanol using a catalytic fluidized bed reactor integrated with separators

Large-scale green processes to produce methanol from massive industrial sources of CO2 with a certain amount of water are increasingly attractive for carbon neutralization. In this study, an advanced CO2-to-Methanol (CTM) process, consisting of a turbulent fluidized bed (TFB) reactor, separators, and other units, was developed, analyzed from start-up to steady state, and optimized for high-purity methanol production (98.5–99.9 wt%) from a wet CO2 source (1.3 MtCO2/year with 1.35 mol% H2O). A two-stage flash drum with direct feeding of wet CO2 into a flash drum was applied to the developed CTM process to remove water and enhance unconverted gas recovery. At a methanol purity of 99.9 wt%, the advanced CTM process increased the methanol yield (0.15–0.31%), production capacity (5700–10100 tMeOH/year), and net CO2 reduction (0.0009–0.0033 kgCO2/kgMeOH) but decreased production cost (3.7–7.4 $/tMeOH) compared to the conventional CTM process under various of reactor temperatures (478–538 K) and pressures (40–90 bar). During the start-up process, the CTM process indicated the peaks in the methanol molar fraction and flow rate as the TFB reactor performed the stable profile of solid temperature (548–553.75 K) and volume fraction (∼0.249). In the performance assessment, the main units (compressor, TFB reactor, and distillation column) accounted for 96, 95, and 82.5% of capital expenditure (CAPEX), operating expenditure (OPEX), and energy consumption, respectively. Meanwhile, lowering the price of the annual CO2 and H2 increased CAPEX and OPEX contributions from 10.92 (present) to 28.64% (in 2050). To optimize the process using an artificial neural network (ANN) model, three main objectives and four main operating variables were selected as features through data analysis. The ANN model precisely predicted process performances (>99% accuracy) could reduce the computational cost by 900-fold compared to the process simulation. For methanol purity of 98.5–99.9 wt%, the CTM process should be operated in the optimum domain with a reactor pressure of 57.18–75.74 bar, reactor temperature of 493.62–506.32 K, reflux ratio of 1.02–1.08, and reboiler ratio of 1.32–1.38. The results are useful for designing, operating, and decision-making processes for producing various grades of green methanol from wet CO2 sources.

Research Progress and Trends in Iron Metal Purification Processes

Traditional industrial pure iron can no longer meet the requirements of many core industries, such as aerospace, electronic information, and military industries. Thus, high-purity iron has attracted considerable interest. Pyrometallurgy, hydrometallurgy, and electrometallurgy provide extensive research platforms for purifying and developing novel processes for producing high-purity iron. In this paper, we review latest research advances in high-purity iron purification methods and production processes and summarize the merits of each purification method. Moreover, we propose a production process that ensures the production of high-purity iron while reducing carbon emissions. In this process, iron ore is leached using a hydrometallurgical process, high-purity iron is obtained by electrolysis from clean energy sources, such as photovoltaics and wind power, and the purity of iron is increased to over 5N with a pyrometallurgy process.

Process Simulations of High-Purity and Renewable Clean H2 Production by Sorption Enhanced Steam Reforming of Biogas

Renewable clean H2 has a very promising potential for the decarbonization of energy systems. Sorption enhanced steam reforming (SESR) is a novel process that combines the steam reforming reaction and the simultaneous CO2 removal by a solid sorbent, such as CaO, which significantly enhances hydrogen generation, enabling high-purity H2 production. The CO2 sorption reaction (carbonation) is exothermic, but the sorbent regeneration by calcination is highly endothermic, which requires extra energy. Biogas is one of the available carbon-neutral renewable H2 production sources. It can be especially relevant for the energy integration of the SESR process since, due to the exothermic sorption reaction, the CO2 contained in the biogas provides extra heat to the system, which can help to balance the energy requirements of the process. This work studies different process configurations for the energy integration of the SESR process of biogas for high-purity renewable H2 production: (1) SESR with sorbent regeneration using a portion of the produced H2 (SESR+REG_H2), (2) SESR with sorbent regeneration using biogas (SESR+REG_BG), and (3) SESR with sorbent regeneration using biogas and adding a pressure swing adsorption (PSA) unit for hydrogen purification (SESR+REG_BG+PSA). When using biogas as fuel (Cases 2 and 3), these configurations were studied using air and oxy-fuel combustion atmospheres in the sorbent regeneration step, resulting in five case studies. A thermodynamic approach for process modeling can provide the optimal process operating conditions and configurations that maximize the energy efficiency of the process, which are the basis for subsequent optimization of the process at the practical level needed to scale up this technology. For this purpose, process simulations were performed using a steady-state plant model developed in Aspen Plus, incorporating a complex heat exchanger network (HEN) to optimize heat integration. A comprehensive parametric study assessed the effects of biogas composition, temperature, pressure, and steam to methane (S/CH4) ratio on the process performance represented by the selected key performance indicators, i.e., H2 purity, H2 yield, CH4 conversion, cold gas efficiency (CGE), net efficiency (NE), fuel consumption for the sorbent regeneration step, and CO2 capture efficiency. H2 with a purity of 98.5 vol % and a CGE of 75.7% with zero carbon emissions can be achieved. When adding a PSA unit, nearly 100% H2 purity and CO2 capture efficiency were achieved with a CGE of 77.3%. The use of oxy-fuel combustion during regeneration lowered the net efficiency of the process by 2.3% points (since it requires an air separation unit) but allowed the process to achieve negative carbon emissions.

Rational Construction of Ultrahigh Thermal Stable MOF for Efficient Separation of MTO Products and Natural Gas

Considering the important application foundation of propylene (C3H6) and ethylene (C2H4) production, as well as methane (CH4), in petrochemical industries, this report comprehensively investigated an innovative MOF material (Zn-BPZ-SA) that was synthesized by 3,3′,5,5′-tetramethyl-4,4′-bipyrazole (H2BPZ) and squaric acid (H2SA) for separating methanol-to-olefins (MTO) products (C3H6/C2H4 mixtures) and natural gas (C3H8/C2H6/CH4 mixtures). Zn-BPZ-SA with great resistance toward water and exceptional thermal stability (520 °C), can preferentially adsorb C3H8 and C3H6 rather than C2H6 and C2H4, and in particular, reveals high C3H6 and C3H8 uptakes of 46.6 and 48.0 cm3 g–1 under the crucial low pressure (10 kPa, 298 K). The experimental and simulated transient breakthroughs for C3H6/C2H4 binary mixtures and C3H8/C2H6/CH4 ternary mixtures demonstrated that the MOF can separate these mixtures with long breakthrough time differences, yielding high-purity (>99.95%) products with high productivities: C2H4 (21.9–142.8 L kg–1) and CH4 (34.9–73.0 L kg–1). The excellent separation abilities can be attributed to the rich accessbile O/N and methyl binding sites scattered at the pore surfaces in framework.

Experimental investigation on performance evaluation of PEM electrolysis cell by using a Taguchi method

Proton exchange membrane (PEM) electrolysis cells play a vital role in high-purity and sustainable hydrogen production by utilizing the DC power from renewable energy sources and can help minimize harmful greenhouse gasses. The performance of PEM electrolysis cells can be improved significantly by optimizing the operating and design conditions. In the present study, experiments have been conducted to investigate the influences of the operational parameters (cell voltage, temperature, and water flow rate) on the performance of the PEM electrolysis cell with a total surface area of 9 cm2. Design of experiment and Taguchi method were also applied to the experimental system to optimize PEM electrolysis cell operating parameters. Cell voltage, temperature, and water flow rate are the three main control factors that have been varied between 1.6 and 2.4 V, 40–80 °C, and 16.5–30.6 mL/min, respectively. The results were analyzed using analysis of variance (ANOVA) and the signal-to-noise (S/N) ratios by Minitab software for the optimal operational factors. The results show that the best electrolysis cell performance is obtained at a temperature of 80 °C, cell voltage of 2.4 V, and water flow rate of 16.5 mL/min. The maximum current and hydrogen flow rate for the optimal combinations of the input factors were 17.398 A and 152.019 mL/min, respectively. At the highest cell performance, LHV (low heating value) and HHV (high heating value) energy efficiencies were calculated as 59.6% and 70.4%, respectively. The cell voltage has considerably affected the current and hydrogen flow rate with contributions of 91.91% and 90.81%, respectively. The water flow rate has a minimal effect, with contributions of 1.04% and 1.25%, respectively. Our results indicated that the current and hydrogen flow rate reflecting the cell performance increased with increasing the cell voltage, the temperature and decreasing the water flow rate. Therefore, the ideal combination of operating factors is essential to provide the best cell performance and lower operational costs.

Microwave-promoted Synthesis of Novel Bioactive N-based Heterocycles

Abstract: Our environment is in a continuous state of change, which, in turn, demands sustainable, eco-friendly, and safer chemistry techniques. This, in turn, has led to the green chemistry principles coming into the picture in recent years. Over the years, microwave heating has evolved as a green protocol in organic synthesis. The advantages of the safe and environment-friendly MW heating approach include a simple experimental setup, products of high purity with high yields, solvent-free reactions, short reaction times, elimination of the side products, and a decrease in the rate of by-product formation. Heterocycles, especially nitrogen heterocycles, are important not only because they are present in natural products, but because they have widespread applications in pharmaceutical industries as well. These N-heterocycles are part of many biologically active molecules. In the present review, the focus has been laid on the developments in MW-mediated synthesis of biologically important N-heterocycles in the last 2 years (2020-21).

Coupling Ferrocyanide-Assisted PW/PB Redox with Efficient Direct Seawater Electrolysis for Hydrogen Production

Direct seawater electrolysis is a promising approach for grid-scale hydrogen mass production. However, the low energy efficiency and detrimental anodic chlorine electrochemistry unlock its practical potential. Here, we present an efficient chlorine-free hydrogen production by coupling the rapid electrode reaction of ferrocyanide-assisted Prussian white (PW)/Prussian blue (PB) redox with an onset potential of 0.87 VRHE. The chloride oxidation in our cells is avoided by low cell voltages, enabling high-purity hydrogen production. Operando spectroscopic analysis coupled with theoretical calculations validates that the addition of the [Fe(CN)6]3–/4– redox mediator in the electrolyte can reduce the PB to PW instantaneously, thus completing the cycle of PW/PB redox and making the system recyclable. The assembled electrolyzer exhibited unprecedented performance for direct seawater electrolysis (pH = 8.5), achieving a current density of 320 mA cm–2 at 1.7 V. Therefore, the electricity consumed per cubic meter of H2 produced in the electrolyzer is 3.8 kWh at 200 mA cm–2, and 42% lower energy equivalent input relative to commercial redox-free seawater electrolysis. This work offers a cost-competitive and energy-saving strategy for producing high-purity H2 directly from unlimited seawater.

An Interesting and Highly Efficient Route to 2-(Arylethynyl)Selanyl-Azoles: Fe3O4-Serine-CuI Nanocomposite Catalyzed Three-Component Coupling Reaction of Azoles, Se Powder, and Alkynes

2-(arylethynyl)selanyl-azoles are important and vital compounds that both azoles and aryl ethynyl selenides presented in their structure. In this article, we have constructed copper (I) iodide supported on the surface of magnetic Fe3O4 nanoparticles functionalized with Serine [Fe3O4-Serine-CuI] and evaluated its catalytic behavior in the preparation of 2-(arylethynyl)selanyl-azoles though one-pot three-component coupling reaction of azoles, Se powder and alkynes under ecofriendly conditions. The structure of Fe3O4-Serine-CuI nanocatalyst is well analyzed by several spectroscopic techniques like: FT-IR, SEM, EDX, TEM, MAP, XRD, TGA, VSM, ICP-OES techniques. High reusability and well characterization of Fe3O4-Serine-CuI nanocatalyst, high purity and yields of products, ecofriendly conditions, and simple operation are several considerable advantages this catalytic system.

Sorption-enhanced steam gasification of biomass for H2-rich gas production and in-situ CO2 capture by CaO-based sorbents: A critical review

The sorption-enhanced steam gasification of biomass (SEBSG) is considered a prospective thermo-chemical technology for high-purity H2 production with in-situ CO2 capture. Fundamental concepts and operating conditions of SEBSG technology were summarized in this review. Considerable industrial demonstration units have been conducted on pilot scales for large-scale availability of the SEBSG process. The influence of process parameters such as reaction temperature, Steam/Biomass (S/B) ratio, feedstock characteristics, cyclic CO2 capture capacity of CaO-based sorbents, and catalysis, were critically reviewed to provide theoretical recommendations for industrial operation. Bifunctional materials that have high catalytic activity and CO2 capture activity are crucial for ensuring high H2 production in the SEBSG. The application of density functional theory (DFT) and reactive force field molecular dynamic (ReaxFF MD) simulations on microcosmic reaction mechanisms in the SEBSG process, such as pyrolysis, WGS and reforming reactions, and CO2 capture of CaO-based materials are comprehensively overviewed. Several research gaps, like the exploitation of more efficient and low-cost bifunctional material, integrated process economics and revelation of well-rounded mechanisms, need to be filled for the following large-scale industrial applications.

Molecularly Imprinted Polymers with Shape-Memorable Imprint Cavities for Efficient Separation of Hemoglobin from Blood.

Efficient separation and purification of hemoglobin from blood and other complicated biological fluids still remains a big challenge. Molecularly imprinted polymers (MIPs) of hemoglobin are potential choices; however, they suffer from severe problems including difficult template removal and low imprinting efficiency like other protein-imprinted polymers. Herein, a novel MIP of bovine hemoglobin (BHb) was designed in which a peptide crosslinker (PC), instead of the commonly used crosslinkers, was used. The PC, a random copolymer of lysine and alanine, adopts an α-helical conformation at pH 10 but transits to a random coil conformation at pH 5. The introduction of alanine residues lowers the pH range at which the PC undergoes helix-coil transition. The imprint cavities in the polymers are shape-memorable due to the reversible and precise helix-coil transition of the peptide segments in the polymers. They can be enlarged by lowering pH from 10 to 5, thus allowing complete removal of the template protein under mild conditions. When the pH is adjusted back to 10, their original size and shape will be recovered. Therefore, the MIP binds the template protein BHb with high affinity. Compared with the MIP crosslinked with the commonly used crosslinker, the imprinting efficiency of the PC-crosslinked MIP is significantly improved. In addition, both the maximum adsorption capacity (641.9 mg/g) and imprinting factor (7.2) are much higher than the BHb MIPs reported previously. The new BHb MIP also exhibits high selectivity toward BHb and good reusability. Thanks to the high adsorption capacity and high selectivity of the MIP, when it was applied to extract BHb from bovine blood, BHb in the blood sample was extracted almost completely, and high purity product was obtained.

Selection of eco-efficient downstream separation configuration for isopropanol–butanol–ethanol purification process

Nowadays, renewable and cleaner biofuel requirements increase with the increase in economic, environmental, and social concerns. Biobutanol is a preferable alternative fuel due to its outstanding properties compared to other alcohol-based biofuels. Two alternative downstream process configurations are designed in this study to obtain high-purity alcohol products from isopropanol–butanol–ethanol (IBE) fermentation broth with the same feed flowrate and compositions. In process configuration 1, the excess amount of water in the fermentation broth is mainly taken away using a preconcentration column. In process configuration 2, an extractor-extractive distillation hybrid system is used to remove the excess amount of water from the system. The results show that the first configuration is superior with a 62% reduction in total annual cost (TAC). Besides economic superiority, process configuration 1 is also quantitatively better than process configuration 2 in terms of gas emissions and energy demand to purify butanol. As a result, process configuration 1 is found as an eco-efficient downstream separation sequence for IBE purification process.

A review on biodegradable polylactic acid (PLA) production from fermentative food waste - Its applications and degradation

Due to its low carbon footprint and environmental friendliness, polylactic acid (PLA) is one of the most widely produced bioplastics in the world. Manufacturing attempts to partially replace petrochemical plastics with PLA are growing year over year. Although this polymer is typically used in high-end applications, its use will increase only if it can be produced at the lowest cost. As a result, food wastes rich in carbohydrates can be used as the primary raw material for the production of PLA. Lactic acid (LA) is typically produced through biological fermentation, but a suitable downstream separation process with low production costs and high product purity is also essential. The global PLA market has been steadily expanding with the increased demand, and PLA has now become the most widely used biopolymer across a range of industries, including packaging, agriculture, and transportation. Therefore, the necessity for an efficient manufacturing method with reduced production costs and a vital separation method is paramount. The primary goal of this study is to examine the various methods of lactic acid synthesis, together with their characteristics and the metabolic processes involved in producing lactic acid from food waste. In addition, the synthesis of PLA, possible difficulties in its biodegradation, and its application in diverse industries have also been discussed.

Research Progress on the Typical Variants of Simulated Moving Bed: From the Established Processes to the Advanced Technologies

Simulated moving bed (SMB) chromatography is a highly efficient adsorption-based separation technology with various industrial applications. At present, its application has been successfully extended to the biochemical and pharmaceutical industrial sectors. SMB possesses the advantages of high product purity and yield, large feed treatment capacity, and simple process control due to the continuous operation mode and the efficient separation mechanism, particularly for difficult separation. Moreover, SMB performs well, particularly for multi-component separation or complicated systems’ purification processes in which each component exhibits similar properties and low resolution. With the development of the economy and technology, SMB technology needs to be improved and optimized to enhance its performance and deal with more complex separation tasks. This paper summarizes the typical variants or modifications of the SMB process through three aspects: zone variant, gradient variant, and feed or operation variant. The corresponding modification principles, operating modes, advantages, limitations, and practical application areas of each variant were comprehensively investigated. Finally, the application prospect and development direction were summarized, which could provide valuable recommendations and guidance for future research in the SMB area.

Manufacturing of CD34 + HPC-enriched, high-purity mononuclear cell products from umbilical cord blood.

The purpose of this study was to explore methods of selectively enriching CD34 + haematopoietic progenitor cells (HPC) in mononuclear cell (MNC) preparations, and to outline a procedure for cryopreservation and thawing of manufactured material. Density gradient centrifugation of umbilical cord blood was achieved using Ficoll-Paque™ media at 1.077g/mL and 1.065g/mL densities and Leucosep preparation tubes. Post-process samples were analysed for CD34 + and MNC content. Finally, MNCs were frozen down at a concentration of 8.5 × 106 cells/mL in CryoStor CS10 using an Asymptote VIAFreeze controlled rate freezer at a rate of - 2°C per minute, then thawed and analysed for viability and recovery. Processing with 1.065g/mL media selectively depleted non-HPC cell types, producing an approximately fourfold increase in CD34 + frequency (M ± 1SD = 1.4 ± 1.3%, P < 0.01) relative to the pre-process sample (M ± 1SD = 0.4 ± 0.3%), whereas 1.077g/mL media produced only a twofold enrichment (0.7 ± 0.6, P < 0.01). This was not accompanied by any significant forfeit of CD34 + recovery (79 ± 32% vs. 78 ± 32% respectively; P = 0.87). The MNCs generated by the 1.065g/mL procedure were of greater purity (96 ± 2%) than in the 1.077g/mL procedure (80 ± 7%, P < 0.01). Post-thaw, MNC viability was 95 ± 1% and CD34 + viability was 98 ± 1%. Ultra-pure MNCs rich in CD34 + HPCs can be generated with a simple, inexpensive modification to Ficoll-Paque™ media. These products can be easily cryopreserved using a simple controlled rate freezing procedure.