WO2023126577A1

WO2023126577A1 - An equipment and a method for scavenging of ions and molecules from fluid

Info

Publication number: WO2023126577A1
Application number: PCT/FI2022/050875
Authority: WO
Inventors: Jenna TASKINEN; Elmeri LAHTINEN; Mikko HÄNNINEN
Original assignee: Weeefiner Oy
Priority date: 2021-12-30
Filing date: 2022-12-29
Publication date: 2023-07-06

Abstract

According to an example aspect of the present invention, there is provided a hybrid scavenger system for scavenging of metal ions and complexes and non-metal anions and cations from fluid. The hybrid scavenger system comprises granular active material with adsorbent properties, ion exchange properties or both and at least one laser sintered porous body comprising functional groups, wherein said laser sintered body is arranged upstream or downstream or in both positions in relation to the granular active material and flow of the fluid.

Description

AN EQUIPMENT AND A METHOD FOR SCAVENGING OF IONS AND

MOLECULES FROM FLUID

FIELD

[0001] The present invention relates to collection of ions and molecules from fluid using a hybrid scavenger system containing at least one laser sintered porous body with a chemical functionality and granular active material, typically granular ion exchange material. Said system has selective properties for collecting chosen ions or molecules from a fluid flow and releasing the collected ions or molecules upon specific elution treatment.

BACKGROUND

[0002] Ion exchange resins and their macroporous, granular form have been industry standard for decades and are described for example in documents US2366007 and US4246386A. The equipment for traditional operation and use of granular ion exchange material is described for example in US2810692. There exist different technical solutions for various operation/regeneration modes, ion exchange material behavior during operation or operating parameters. Examples for these can be found in US3595784 and EP2711340A1.

[0003] Small particle size (powdered) ion exchange resins can be easily manufactured by grinding the commercially available large particle size resins (see for example EP0026574A1). It has been shown that even a thin layer of powdered resin can provide a dramatic improvement in the ion exchange reaction compared to conventional resins. Traditionally, the powdered resins are used as a pre-coat applied on septum or filter (US3250702).

[0004] Metal scavenging can be seen as subspecies of ion exchange where selected (dissolved) metals are recovered from complicated water streams containing different metals in various concentrations. US 2016310871 Al relates to a scavenging unit having two porous partitions and between them a scavenging chamber filled with a scavenging medium for removing metal ions from a liquid. The porous partitions are not laser sintered or tailored for scavenging metal ions and have smaller particle sizes than a particle size of the scavenging medium.

[0005] Novel technology for metal scavenging using laser sintered porous body is described in EP3648859A1. By utilization of laser 3D printing technique, namely selective laser sintering, unique internal structure, physical and metal scavenging properties are achieved.

[0006] However, methods based on contemporary ion exchange resins do not provide an efficient and scalable solution with a fast scavenging rate and low operating costs for low concentration fluids. In addition, the removal of the collected ions or molecules from the scavenging material, and thus regeneration or reuse of the material, is generally dissatisfactory.

[0007] Alternative methods, such as coagulation, sedimentation, ultra-filtration or reverse osmosis, do not provide the sought after selectivity for the recovery process, generate notable amounts of waste material but also render the removed material into difficult or entirely unusable form. Furthermore, the operating costs and infrastructure requirements for the above methods are considerable and thus make them infeasible for many applications.

[0008] There exists therefore a need for an equipment for scavenging of ions and molecules, such as metal ions and metal complexes and non-metal anions and cations, from various fluids, wherein said equipment is efficient, scalable, easy to regenerate and applicable also for low concentration fluids, while providing low operation costs.

SUMMARY OF THE INVENTION

[0009] The invention is defined by the features of the independent claims. Some specific embodiments are defined in the dependent claims.

[0010] The present invention is based on the concept of using a novel equipment, a hybrid scavenger system, for selective recovery or removal of dissolved ions and molecules from fluid. The system combines the most advantageous features of laser sintered scavengers or porous bodies and granular ion exchange and/or adsorbent materials and optionally powdered ion exchange material into an equipment that is performing better compared to the sum of its components.

[0011] According to a first aspect of the present invention there is thus provided a hybrid scavenger system for scavenging of ions and molecules, in particular metal ions and complexes and non-metal anions and cations, from fluid, the hybrid scavenger system comprising a section of granular active material with adsorbent properties, with functional groups providing ion exchange properties or both, and at least one laser sintered porous body comprising functional groups, wherein said laser sintered body is arranged upstream or downstream or in both positions in relation to the section of granular active material and flow of the fluid.

[0012] According to a second aspect of the present invention there is provided a method for scavenging of ions and molecules from fluid using the hybrid scavenger system of the invention, wherein the method comprises the steps of: feeding the fluid through the system until the designed scavenging capacity is reached, and eluting scavenged ions or molecules using a separate elution solution, which simultaneously regenerates the system enabling immediate reuse of the system.

[0013] Embodiments of the invention comprise hybrid scavenger systems, which comprise or consist essentially of: (i) a section of granular active material and a laser sintered porous body arranged upstream of the section of granular active material; or (ii) a section of granular active material and a laser sintered porous body arranged downstream of the section of granular active material; or (iii) a section of granular active material and laser sintered porous bodies arranged both upstream and downstream in relation to the granular active material and flow of the fluid.

[0014] Considerable advantages are obtained by the invention. First, the hybrid scavenger system has the ability to induce higher selectivity towards desired ions or molecules while maintaining high capacity and required physical properties. Second, the scavenger system of the invention provides faster kinetics for recovery and scavenging of ions and molecules from feed fluid, including unparalleled ion exchange rate and thus utilization of capacity, optionally with further improvement compared to the use of powdered ion exchange material (lower pressure drop, higher capacity).

[0015] Third, high scavenging capacity induced by the hybrid arrangement (defined as comprising a section of granular active material with adsorbent properties, with functional groups providing ion exchange properties, or both, and at least one laser sintered porous body comprising functional groups, arranged upstream or downstream or in both positions in relation to the section of granular active material and flow of the fluid) enables longer elution intervals compared to scavenger systems consisting of a single laser sintered porous body. In addition, high capacity will enable smaller equipment size and longer operation cycles, which will reduce the cost and improve the lifetime of the system. Further, in some embodiments the hybrid scavenger system efficiently traps solid particles into the structure, allowing good scavenging performance to continue without notable increase in backpressure. In some embodiments, the hybrid scavenger system comprises a scavenging enhancing internal structure that allows increasing the metal scavenging performance of the laser sintered scavenger while allowing solid particles to efficiently pass through the scavenger.

[0016] Further features and advantages of the present technology will appear from the following description of some embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] FIGURES 1A and IB illustrate an example of the overall structure of a hybrid 4D scavenger with upstream laser sintered porous body, designed for flow and suspended solids control, middle section with granular ion exchange material, designed for additional scavenging capacity, and downstream laser sintered porous body, designed for flow and residence/hydraulic retention time control in accordance with at least some embodiments of the present invention;

[0018] FIGURE 2 presents an example of the internal structure of the suspended solids controlling upstream laser sintered porous body with alternately plugged channels. Dark grey bars represent the upstream flow channels, light grey bars represent the downstream flow channels while semi-transparent area between and around the channels represents the sintered porous material enabling horizontal fluid flow through channel walls (horizontal wall flow).

[0019] FIGURE 3A illustrates the top view of a porous body with laser sintering controlled flow channels and FIGURE 3B shows the split view of a CAD designed zig-zag flow channels of the porous body.

EMBODIMENTS

[0020] DEFINITIONS

[0021] As known to those skilled in the art, the terms “selective laser sintering” and “laser sintering” define manufacturing technique that uses a laser as the power and heat source to sinter powdered material, aiming the laser automatically at points in space defined by a 3D model, binding the material together to create a solid structure. As used herein, the above-disclosed manufacturing technique, i.e. selective laser sintering or laser sintering, is used to create porous solid structures comprising functional groups.

[0022] As used herein, the terms such as “hybrid scavenger”, “hybrid 4D scavenger” and “hybrid scavenger system” refer to the scavenging system according to the present invention, which comprises at least two different scavenging materials.

[0023] In the present context, the terms “upstream” and “downstream” define the position of a component in relation to each other and to the flow of the fluid stream. For example, in a stream of fluid, the component that is first interacting with the fluid, is considered to be located upstream, compared to any following component in the system. Conversely, any component after the said first component, is considered to be located downstream in relation to the first component.

[0024] The hybrid scavenger system efficiently removes metal ions and metal complexes as well as non-metal anions and cations from various fluids. The hybrid scavenger system may also remove any suspended material from said fluids.

[0025] The “active material” or “granular active material” is selected from ion exchange materials and adsorbents. The active material may thus comprise functional groups with ion exchange properties, adsorber properties or both. Correspondingly, the granular active material comprises adsorbent properties, functional groups providing ion exchange properties or both.

[0026] Ion exchange materials typically belong to group of strong cation exchange resins (SAC), weak cation exchange resins (WAC), strong base anion exchange (SBA), weak base anion exchange (WBA) or chelating exchange resins. More specifically, the functional groups in the active materials may belong to group of carboxylates, primary amine or ammonium, secondary amine or ammonium, tertiary amine or ammonium, sulphates, sulfonic acids, phosphonic acids, diethanolamines, thioureas, thiols, thiouronium, ethylenediaminetetraacetic acid or any combination of these.

[0027] Adsorbents include but are not limited to activated carbon, graphene, inorganic metal oxides, inorganic metal hydroxides, zeolites, aluminas, chitosan, lignin and other mostly carbon containing biobased materials or any combinations of these. [0028] Metal ions typically include but are not limited to cations and anions containing transition metals (groups 3-12 in periodic table), lanthanides and actinides. In some embodiments, alkaline and alkaline earth metal cations from groups 1 and 2 may be targeted. In some embodiments, other metal and metalloid ions from groups 13-16 may be targeted. In some embodiments, halogen ions from group 17 may be targeted.

[0029] In some preferred embodiments, cations or anions of toxic or environmentally harmful metals or metalloids vanadium, chromium, nickel, copper, zinc, cadmium, arsenic, antimony, mercury and/or lead may be targeted.

[0030] In some preferred embodiments, cations or anions of typical battery metals such lithium, cobalt, nickel, zinc, copper or manganese may be targeted.

[0031] In some preferred embodiments, cations or anions of precious metals ruthenium, rhodium, palladium, silver, osmium, iridium, platinum or gold may be targeted.

[0032] In some preferred embodiments, cations or anions of rare earth elements may be targeted.

[0033] If applicable, metal complexes of the above-mentioned metals may also be scavenged by the hybrid scavenger system of the invention.

[0034] Target non-metal anions include but are not limited- to nitrate, nitrite, sulfate, hydrogen sulfate, sulfite, hydrogen sulfite, carbonate, hydrogen carbonate, hypochlorite, cyanide, perchlorate, phosphate, phosphite, hydroxide, thiosulfate, acetate, formate and oxalate.

[0035] In some embodiments, targeted non-metal anions are nitrate, nitrite, sulfate, sulfite, phosphate and/or phosphite.

[0036] As stated above, it has been found that a hybrid scavenger system according to the present invention provides a high selectivity towards desired ions and molecules while maintaining high capacity and required physical properties for scavenging of metal ions and complexes and non-metal anions and cations from fluid.

[0037] The hybrid scavenger system of the invention comprises a section of granular active material with adsorbent properties, with functional groups providing ion exchange properties, or both, and at least one laser sintered porous body comprising functional groups, arranged upstream or downstream or in both positions in relation to the section of granular active material and flow of the fluid.

[0038] In one preferred embodiment, the structure of the hybrid scavenger system comprises or consists of three different components or sections (Fig. 1):

• An upstream laser sintered scavenger or porous body, comprising polymer powder and active material or consisting solely of the active material

• A middle section, comprising granular active material, located between the laser sintered scavengers

• A downstream laser sintered scavenger or porous body, comprising polymer powder and active material or consisting solely of the active material

[0039] In one embodiment the upstream or downstream or both of the laser sintered scavengers or porous bodies, comprise of at least 30 % of active material, preferably of at least 50 % of active material, more preferably of at least 70 % of active material, defined as the weight percentage of the active material compared to total weight of the material.

[0040] Typically, in a laser sintering process, powdered material, in particular sinterable polymer powder, typically nylon or polyamide, is sintered to create the structure of the porous body. In the manufacturing process of the laser sintered scavengers, polymer powder may be mixed with the active material, typically an ion exchange resin, for example in a 50:50 ratio, before laser sintering. However, it has been found that the proportion of the active material in the laser sintered scavenger may be adjusted to at least 30 % of active material, preferably at least 50 % of active material, more preferably at least 70 % of active material, by weight of the mixture of the polymer powder and the active material.

[0041] In one embodiment, the structure of the hybrid scavenger system thus comprises or consists of three different components or sections:

• An upstream laser sintered scavenger or porous body, comprising polymer powder and at least 30 % of active material, preferably at least 50 % of active material, more preferably at least 70 % of active material, by weight of the laser sintered scavenger

A middle section, comprising granular active material, located between the laser sintered scavengers A downstream laser sintered scavenger or porous body, comprising polymer powder and at least 30 % of active material, preferably at least 50 % of active material, more preferably at least 70 % of active material, by weight of the laser sintered scavenger

[0042] In some embodiments, the hybrid scavenger system consists of an upstream laser sintered porous body or scavenger and a section of granular active material.

[0043] In some embodiments, the hybrid scavenger system consists of a section of granular active material and a downstream laser sintered porous body or scavenger.

[0044] In another embodiment, the structure of the hybrid scavenger system consists of upstream and downstream laser sintered scavengers or porous bodies, optionally separated by an empty space, wherein said upstream and downstream laser sintered scavengers are different from each other.

[0045] In some embodiments, the volumetric ratio between the laser sintered scavenger(s) and the granular active material is between 1 :500 and 1 :0.1, preferably between 1 :50 and 1 :0.5 or most preferably between 1 :20 and 1 :1, depending on the application.

[0046] In some embodiments, the hybrid scavenger system comprises an empty space between the upstream laser sintered scavenger and the section of granular active material. In an embodiment, wherein the hybrid scavenger system is arranged in a column-shaped reactor, said empty space is typically 0-200 % of the height of the granular active material section, preferably 20-150 % and most preferably 50-100 %, depending on the application.

[0047] In some embodiments, the granular scavenger may be separated from the laser sintered scavenger(s) by a semi-permeable membrane, fabric, foam, or corresponding porous material to prevent granular material intrusion to the flow channels of the up- or downstream laser sintered scavenger.

[0048] Typically, the hybrid scavenger system is arranged in a column or columnshaped reactor. However, also other reactor forms in addition to column-shaped reactors may be applicable, such as containers, barrels, square-shaped reactors, cylinders, tube reactors with horizontal flow, scrubber type reactors or turbine type reactors, reactors with horizontal flow, scrubber type reactors or turbine type reactors.

[0049] Preferably, for low flow rate applications, the laser sintered porous body of the hybrid scavenger system are manufactured so that the width and height ratio, defined by dividing the width of the sintered porous body with the height of the sintered porous body, of the system is typically between 0.01 to 1 , preferably between 0.05 to 1 and most preferably between 0.1 to 1.

[0050] Preferably, for high flow rate applications, the laser sintered porous body of the hybrid scavenger system are manufactured so that the width and height ratio, defined by dividing the width of the sintered porous body with the height of the sintered porous body, of the system is typically between 100 to 1, preferably between 25 to 1 and most preferably between 10 to 1.

[0051] Bulk density (pbuik) of the upstream and downstream laser sintered scavengers (porous bodies) is typically between 0.1 and 0.9 kg/dm³, preferably between 0.3 and 0.8 kg/dm³ and most preferably between 0.45 and 0.7 kg/dm³, defined as ratio between the weight measured using a calibrated balance (M) and calculated volume of the scavenger defined by the CAD-model (V), excluding any designed interior (flow) structure (V) according to formula pbuik = M/V.

[0052] Porosity (cp) of the upstream and downstream laser sintered scavengers is typically between 10 and 90 %, preferably between 20 and 70 %, and most preferably between 30 and 50 %, defined through porous body bulk density (pbuik), excluding any designed interior (flow) structure, and polymer mixture particle density (pparticie), defined as the mass of a unit volume of particles, according to formula cp = 1 — (pbuik / pparticie).

[0053] Preferred porosity and bulk density of the laser sintered scavengers are used to control the chemical performance and flow performance of the laser sintered scavenger, with these parameters not connected to the particle size of granular material in preferred embodiments.

[0054] The sinterable polymers typically comprise any one or several of polyamide, polypropylene, polyurethane, polystyrene, polylactic acid, polyetheretherketone, polyethylene terephthalate, polycarbonate, polyaryletherketone, polyetherimide and other thermoplastic polymers.

[0055] In some embodiments, the sinterable polymer itself can be the active component providing scavenging functionality similar to that provided by separate active materials such as adsorbent or ion exchange resin. [0056] Manufacturing method of the laser sintered scavenger enables manufacturing different internal structures, which can either allow solid particles to efficiently be trapped into the structure, allowing good scavenging performance to continue without notable increase in backpressure, or scavenging enhancing internal structure that allows increasing the metal scavenging performance of the laser sintered scavenger while allowing solid particles to efficiently pass through the scavenger.

[0057] In some embodiments, the laser sintered scavenger section(s) have parallel, alternately plugged channels, manufactured by first designing the alternately plugged channels into a CAD model used for controlling the laser sintering during manufacturing, enabling horizontal fluid flow through channel walls (wall flow), allowing greater surface area for fluid to pass through the scavenger while providing space for solid particles to be trapped without notable increase in the pressure drop (Fig. 2). It should be noted that the alternatively plugged channels differ from CAD designed flow channels that go through the entire body of laser sintered scavenger.

[0058] The suspended solid particles that are efficiently passed through the scavenger system with CAD designed alternatively plugged channels typically possess particle size of less than 30 pm.

[0059] In some embodiments, the laser sintered porous body has scavenging enhancing internal structure, manufactured by controlling the laser sintering process by changing the hatching distance parameter, defined as the distance between adjacent laser passes during sintering process, from typical 0.25-0.35 mm to 0.5-1.5 mm, preferably between 0.6-1.4 mm and most preferably between 0.7-1 mm, allowing greater surface area for fluid and solid particles to pass through the scavenger and thus leading to lower pressure drop and better scavenging performance (Fig 3A, Example 2).

[0060] The suspended solid particles that are efficiently passed through the scavenger system with hatching controlled structure typically possess particle size of less than 100 pm.

[0061] In some embodiments, the at least one laser sintered porous body (scavenger section), either upstream or downstream laser sintered scavenger section or both, may have scavenging enhancing internal structure, CAD designed flow channels, allowing greater surface area for fluid and solid particles to pass through the scavenger and thus leading to lower pressure drop for the whole assembly (Fig. 3B). The scavenging enhancing internal structure comprising flow channels is manufactured by designing the flow channels into the CAD model used for controlling the laser sintering during manufacture.

[0062] Low pressure drop over the system will reduce the required energy to transport the fluid through the scavenging system. The operating and capital costs of the pumping system are reduced with lower pressure drop scavengers.

[0063] In another embodiment, the upstream or downstream scavenger or both are composed of material having a particle size ranging from 10 to 400 pm, defined by laser diffraction methods using for example Malvern Mastersizer 3000 particle size analyzer according to ISO 13320:2020. Thus both the polymer powder material and the optional active material included in the upstream and/or downstream scavenger have a particle size within the above mentioned range.

[0064] In another embodiment, the granular active material section of the scavenger systems contains material having a particle size ranging from 0.1 to 3 mm, defined by laser diffraction methods using for example Malvern Mastersizer 3000 particle size analyzer according to ISO 13320:2020.

[0065] In some embodiments, the upstream laser sintered porous body may have flow controlling design and/or parallel, alternately plugged channels enabling horizontal fluid flow through channel walls (horizontal wall flow), for suspended solids resistance and faster scavenging kinetics. Thus in some embodiments the upstream laser sintered scavenger section has a honeycomb structure, i.e. parallel, alternately plugged channels with porous walls enabling horizontal wall flow and capacity for trapping undissolved particulate matter, thus lowering the pressured drop induced by accumulating solids (Fig. 2). The structure resembles diesel particulate filters structure with alternately plugged channels. The upstream laser sintered porous body with a honeycomb structure with horizontal wall flow channels effectively decreases accumulations of solid particles and thus reduces the pressure drop of the hybrid scavenger system. Accumulation of solid particles is a known problem also in ion exchange, where solid impurities may have detrimental effects for the ion exchange performance but also for the durability of the active material.

[0066] Inorganic, organic or oil fouling may also reduce the lifetime and scavenging performance of the active material by attaching to the surfaces of the material and therefore blocking the chemically active sites of the material. In some embodiments, the upstream laser sintered scavenger operates as protection against organic or inorganic fouling, thus improving the lifetime and scavenging performance of all downstream scavenging components.

[0067] In some embodiments, the upstream laser sintered scavenger is prepared from hydrophilic material and operates as protection against fouling by polar or moderately polar inorganic or organic impurities, thus improving the lifetime and scavenging performance of all downstream scavenging components.

[0068] In some embodiments, the upstream laser sintered scavenger is prepared from hydrophobic material and operates as protection against fouling by oil or other non-polar impurities, thus improving the lifetime and scavenging performance of all downstream scavenging components.

[0069] If desired and needed, the hydrophobicity/hydrophilicity of the material of the laser sintered scavenger may thus be adjusted according to the fluid to be treated, by selecting suitable polymer powder and active material for laser sintering.

[0070] In some embodiments, the downstream laser sintered porous body enables the flow and pressure control which allows the optimization of feed residence/hydraulic retention time inside the hybrid scavenger system. The downstream laser sintered scavenger also provides accurate control over the reaction kinetics and allows for smaller size of the whole unit due to the faster reaction kinetics. Conversely, in counter-flow regeneration, the upstream (top) laser sintered porous body will act as pressure/flow control system to ensure optimal residence/hydraulic retention time for the regenerant. This allows more efficient scavenging or regeneration, which in turn realizes in notably lower chemical consumption.

[0071] Moreover, the structure of the above described hybrid scavenger system allows unique flow properties within the system. Material density inside the hybrid 4D scavenger will induce highly efficient mixing and fluid movement at the microscopic level, which will improve the film diffusion and thus the kinetics of scavenging reaction. Local pressure differences between the fixed particles inside the laser sintered porous body will increase the film diffusion increasing the rate of scavenging reaction.

[0072] Method for scavenging ions and molecules [0073] As stated above, the present invention also relates to a method for scavenging of ions and molecules from fluid using the hybrid scavenger system according to the invention.

[0074] In said method the fluid is fed through the hybrid scavenger system until the designed scavenging capacity is reached, scavenged ions and molecules are eluted using a separate elution solution, which preferably simultaneously regenerates the system enabling immediate reuse of the system.

[0075] In another embodiment, the hybrid scavenger system is conditioned by pumping conditioning solution through the system prior to a next scavenging cycle.

[0076] In another embodiment, the hybrid scavenger system is regenerated by pumping regeneration solution through the system after the elution cycle.

[0077] In some embodiments, the space velocity, defined as the quotient of the entering volumetric flow rate of the fluid divided by the volume of the hybrid scavenger system which indicates how many scavenger volumes of feed fluid can be treated in a unit time, is between 10 and 10 000 1/h, preferably between 30 and 5000 1/h and most preferably between 50 and 2000 1/h.

[0078] In some embodiments, the elution, conditioning and regeneration solution are independently selected from sulphuric acid, nitric acid, hydrochloric acid, formic acid, ascorbic acid, acetic acid, sodium hydroxide, potassium hydroxide, sodium fluoride, sodium chloride, sodium bromide, sodium iodide, potassium fluoride, potassium chloride, potassium bromide, potassium iodide, urea and its derivatives, thiourea and its derivatives, ammonia, ammonium chloride and ammonium hydroxide.

[0079] In some embodiments, the elution cycle is performed by feeding the elution solution in opposite direction to the scavenging flow direction, i.e. in opposite direction to the flow of the fluid.

[0080] In some embodiments, the regeneration cycle is performed by feeding the regeneration solution in opposite direction to the scavenging flow direction.

[0081] In another embodiment, the elution and regeneration cycles are performed by feeding the corresponding solutions in the same direction as the scavenging flow direction. [0082] In some embodiments, the temperature of the feeding fluid is typically between 20 and 90 °C.

[0083] In some embodiments, the regeneration cycle is performed after 5 - 50 operation cycles, preferably after 5 - 30 operation cycles and most preferably after 5 - 10 operation cycles.

[0084] The hybrid structure of the above-described hybrid scavenger system provides several process design benefits, including but not limited to low chemical consumption due to fast reaction kinetics and compact scavenger size, which allows even smaller fluid volumes to be treated effectively. Moreover, the modular structure allows easy maintenance of the system as well as combining different material easily in the same system, which is an advantage compared to using the different scavenging materials separately.

[0085] Compared to traditional use of powdered resins, the hybrid scavenger system of the present invention provides in particular the following advantages:

• No need to use coated polymers or supports which increases the active material amount and broadens the application scope notably

• More efficient regeneration and reuse of the resins

• Recovery of the scavenged ions or molecules as separate fraction

• No need to maintain constant flow or pressure to keep the pre-coat from falling of the filter element

• Notably improved flow rate compared to standard pre-coat system

[0086] Finally, in some embodiments the hybrid scavenger system may be operated even without external power supply. The fluid can be passed through the hybrid scavenger system by gravitational force or if needed or desired, by pumping.

[0087] It is to be understood that the embodiments of the invention disclosed are not limited to the particular structures, process steps, or materials disclosed herein, but are extended to equivalents thereof as would be recognized by those ordinarily skilled in the relevant arts. It should also be understood that terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting. [0088] Reference throughout this specification to one embodiment or an embodiment means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Where reference is made to a numerical value using a term such as, for example, about or substantially, the exact numerical value is also disclosed.

[0089] As used herein, a plurality of items, structural elements, compositional elements, and/or materials may be presented in a common list for convenience. However, these lists should be construed as though each member of the list is individually identified as a separate and unique member. Thus, no individual member of such list should be construed as a de facto equivalent of any other member of the same list solely based on their presentation in a common group without indications to the contrary. In addition, various embodiments and example of the present invention may be referred to herein along with alternatives for the various components thereof. It is understood that such embodiments, examples, and alternatives are not to be construed as de facto equivalents of one another, but are to be considered as separate and autonomous representations of the present invention.

[0090] Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided, such as examples of lengths, widths, shapes, etc., to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.

EXPERIMENTAL

[0091] Example 1. Comparative metal scavenging from water using different scavenger types (granular ion exchange material, laser sintered scavenger and hybrid 4D Scavenger).

[0092] The different scavengers were compared by pumping liquid containing 15 mg L ¹ of Ca as well as 5 mg L ¹ of Cd, Cu, Ni, Pb and Zn at 0.3 dm³ min ¹ through the scavenger units (volume of 0.03 dm³) and by measuring the recovery efficiency of said metals defined as percentage of reduction in metal concentration in the feed solution after passing through the scavenger. The results are shown in Table 1.

Table 1. Metal scavenging performance difference between granular ion exchange material, laser sintered porous body and hybrid 4D scavenger

[0093] As can be seen from the above results, the exceptional scavenging performance of the hybrid 4D scavenger of the invention is obvious. The granular active material displays lowest selectivity towards heavy metals whereas the laser sintered scavenger displays the most selective recovery (i.e. low Ca recovery with high Cd, Zn and Cu recovery). The hybrid 4D Scavenger demonstrates notably increased heavy metal recovery when compared to granular ion exchange material.

[0094] This example demonstrates how assembling the different components into a hybrid 4D Scavenger results in notable and even unexpected performance increase in metal recovery.

[0095] Example 2. The effect of the internal structure to the flow properties

[0096] The effect of the internal structure to the flow properties was tested by passing small particle containing water through the porous body. The overall suspended particle size in water was 0.2 - 3000 pm with 35 % between 0.1 and 5.0 pm, measured using laser diffraction. The tested objects were cylindrical objects with 40mm of diameter and 20mm of height. Around 5 dm³ of the suspended material containing (3 g/dm³) solution was pumped through the porous bodies with different flow channel types (Sintering controlled, CAD designed, No channels) at the rate of 50 dm h ¹. The results are shown in Table 2. Table 2. Internal structure design effect (flow channels) on pressure drop over the system.

[0097] The porous body with flow channels prepared using control of the sintering process (hatching) showed lowest pressure increase after the treatment. The body with CAD designed structure for increased solids resistance displayed 4-5 times higher pressure drop by the solid material accumulation to collection channels as designed. As expected, the body without any designed flow channels displayed over 10-fold increase in the pressure drop compared to body with laser sintering controlled internal structure.

Example 3.

The different scavengers for nutrient recovery were tested by pumping liquid containing 63 mg L ¹ nitrate (NCh ), 53 mg L ¹ phosphate (PO4² ) and 64 mg L ¹ sulfate (SO4² ) at 0.25 dm³ min ¹ through the scavenger units (volume of 1.0 dm³) and by measuring the recovery efficiency of nutrients, defined as percentage of reduction in effluent concentration after passing through the scavenger compared to the feed solution. The results are shown in Table 3.

Table 3. Nutrient scavenging performance difference between granular ion exchange material, laser sintered porous body and hybrid scavenger

[0098] Hybrid arrangement improved the nutrient scavenging properties notable compared to both granular resin and scavenger comprising of only laser sintered material. [0099] Example 4.

[00100] The effect of single missing component of the hybrid scavenger was tested by observing the backpressure and scavenging behaviour after removing one component at the time from complete system with upstream and downstream laser sintered porous bodies and middle section with granular active material. The volume of the remaining components was scaled up to correspond original hybrid arrangement.

Table 4. Backpressure and metal scavenging performance difference when one component of the hybrid scavenger is missing.

[00101] The different scavengers were compared by pumping liquid containing 15 mg L ¹ of Ca as well as 5 mg L ¹ of Cd, Cu, Ni, Pb and Zn at 0.3 dm³ min ¹ through the scavenger units (volume of 0.03 dm³) and by measuring the recovery efficiency of said metals defined as percentage of reduction in metal concentration in the feed solution after passing through the scavenger. Missing upstream sintered porous body induced poor flow distribution and hence lower scavenging performance but also worse suspended solids resistance. Missing granular material caused notable increase in the backpressure and lower overall capacity while missing downstream sintered porous body induced too high flowrate and thus lower scavenging performance.

[00102] Example 5.

[00103] The effect of different components to effective capacity compared to capacity of the full hybrid scavenger setup was tested by pumping liquid containing 100 mg L ¹ of Ni at 0.5 dm³ min ¹ through the scavenger units (volume of 0.1 dm³) and by measuring the recovery efficiency of said metal defined as percentage of reduction in metal concentration in the feed solution after passing through the scavenger. Effective capacity was measured as the amount of liquid treated with Ni recovery efficiency of over 75 %. This amount of liquid was then divided by the volume of the scavenger unit to obtain the effective capacity as bed volumes. The test displayed the superior performance of the hybrid arrangement. Without being bound by the theory, by combining the hybrid scavenger system components in a way that granular resin with slower reaction kinetics is allowed to be utilized for removal of bulk of the dissolved Ni, while the sintered porous body with faster reaction kinetics is utilized for effectively removing the smaller concentration remaining after the granular material, higher effective capacity for the system is obtained. This leads to system with higher effective capacity than what would be just the sum of the components separately.

Table 5. Effective capacity defined as treated bed volumes of different components of the scavenger system as well as the effective capacity of the whole system.

Scavenger setup Effective Capacity (

Sintered Scavenger 548

Granular Resin 382

Hybrid Scavenger

592

[00104] While the forgoing examples are illustrative of the principles of the present invention in one or more particular applications, it will be apparent to those of ordinary skill in the art that numerous modifications in form, usage and details of implementation can be made without the exercise of inventive faculty, and without departing from the principles and concepts of the invention. Accordingly, it is not intended that the invention be limited, except as by the claims set forth below.

[00105] The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of also un-recited features. The features recited in depending claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of "a" or "an", that is, a singular form, throughout this document does not exclude a plurality.

INDUSTRIAL APPLICABILITY

[00106] At least some embodiments of the present invention find industrial application in various water intensive industries, such as municipal water treatment, process, mining and recycling industries. Quick adaptation of the technology can be expected because of the improved performance and lower operating and capital costs compared to currently available metal scavenging solutions. [00107] The invention can be further understood with reference to the following embodiments:

1. A hybrid scavenger system for scavenging of ions and molecules from fluid comprising:

- a section of granular active material with adsorbent properties, with functional groups providing ion exchange properties, or both;

- at least one laser sintered porous body comprising functional groups, wherein the laser sintered porous body/bodies is/are arranged upstream or downstream or in both positions in relation to the section of granular active material and flow of the fluid.

2. The hybrid scavenger system according to embodiment 1, wherein at least one laser sintered porous body has a bulk density, which is between 0.1 and 0.9 kg/dm³, preferably between 0.3 and 0.8 kg/dm³ and most preferably between 0.45 and 0.7 kg/dm³, defined as a ratio between the measured weight and calculated volume of the scavenger.

3. The hybrid scavenger system according to embodiment 1 or 2, wherein the volumetric ratio between the at least one laser sintered porous body and the granular active material is between 1 : 100 and 1 :0.1, preferably 1 :50 and 1 :0.5 or most preferably between 1 :20 and 1 :1.

4. The hybrid scavenger system according to any one of the preceding embodiments, wherein the at least one laser sintered porous body is manufactured with hatch distances between 0.5- 1.5 mm, preferably between 0.6- 1.4 mm and most preferably between 0.7-1 mm.

5. The hybrid scavenger system according to any one of the preceding embodiments, wherein the functional groups in the laser sintered porous body and in the section of granular active material are selected from the group consisting of carboxylates, primary amine or ammonium, secondary amine or ammonium, tertiary amine or ammonium, sulphates, sulfonic acids, phosphonic acids, diethanolamines, thioureas, thiols, thiouronium, ethylenediaminetetraacetic acid and any combinations of these.

6. The hybrid scavenger system according to any one of the preceding embodiments, wherein the system comprises an upstream arranged laser sintered porous body, which has parallel, alternately plugged channels enabling horizontal fluid flow through channel walls (wall flow) and trapping undissolved particulate matter.

7. The hybrid scavenger system according to any one of the preceding embodiments, wherein the at least one laser sintered porous body has scavenging enhancing internal structure, wherein the scavenging enhancing internal structure is manufactured by using hatch distance parameters between 0.5- 1.5 mm or comprises CAD designed flow channels. 8. The hybrid scavenger system according to any one of the preceding embodiments, wherein the granular active material has a particle size ranging from 0.01 to 3 mm, defined by laser diffraction methods according to ISO 13320:2020X.

9. The hybrid scavenger system according to any one of the preceding embodiments, which comprises a laser sintered porous body arranged upstream in relation to the granular active material, a section of granular active material, and a laser sintered porous body arranged downstream in relation to the granular active material.

10. A method for scavenging of ions and molecules from fluid using the hybrid scavenger system according to any one of embodiments 1-9, comprising the steps of:

- feeding the fluid through the system until the designed scavenging capacity is reached; and;

- eluting scavenged ions or molecules using a separate elution solution, which simultaneously regenerates the system enabling immediate reuse of the system.

11. The method according to embodiment 10, wherein the fluid is fed through the system with a space velocity, defined as the quotient of the entering volumetric flow rate of the fluid divided by the volume of the hybrid scavenger system, which is between 10 and 10 000 1/h, preferably between 30 and 5 000 1/h and most preferably between 50 and 2 000 1/h.

12. The method according to embodiment 10 or 11, which comprises a step of performing an additional regeneration cycle after the elution step by feeding regeneration solution into the hybrid scavenger system.

13. The method according to any one of embodiments 10 to 12, which comprises a step of performing a conditioning cycle by feeding conditioning solution into the hybrid scavenger system prior to feeding the fluid through the system.

14. The method according to any one of embodiments 10 to 13, where the elution, regeneration or conditioning solutions are selected independently from sulphuric acid, nitric acid, hydrochloric acid, formic acid, ascorbic acid, acetic acid, sodium hydroxide, potassium hydroxide, sodium fluoride, sodium chloride, sodium bromide, sodium iodide, potassium fluoride, potassium chloride, potassium bromide, potassium iodide, urea and its derivatives, thiourea and its derivatives, ammonia, ammonium chloride and ammonium hydroxide and any combination of these.

15. Use of a hybrid scavenger system according to any one of embodiments 1 to 9 for removing metal ions and complexes and non-metal anions and cations from fluid CITATION LIST

Patent Literature

US 2,366,007 (D’Alelio G. F„ 1944)

US 4,246,386 (Howell, et al., 1981) US 2,810,692 (Calmon, C„ 1957)

US 3,595,784 (Butterworth, D. J., 1971)

EP 2 711 340 Al (Yoden, M. et al, 2020)

EP 0 026 574 Al (Pirotta M. G. et al, 1981)

US 3,250,702 (Levendusky, J. A. et al, 1966) EP 3648859A1 (Haukka M. et al, 2019)

US 2016310871 Al (Hooper , S. et al, 2016)

Non Patent Literature

Yarnell, P. A. (2000), POWDERED RESINS: CONTINUOUS ION EXCHANGE, Glasgow, DE, USA, Academic Press

Claims

CLAIMS:

2. The hybrid scavenger system according to claim 1, wherein at least one laser sintered porous body has a bulk density, which is between 0.1 and 0.9 kg/dm³, preferably between 0.3 and 0.8 kg/dm³ and most preferably between 0.45 and 0.7 kg/dm³, defined as a ratio between the measured weight and calculated volume of the scavenger.

3. The hybrid scavenger system according to claim 1 or 2, wherein the volumetric ratio between the at least one laser sintered porous body and the granular active material is between 1 : 100 and 1 :0.1, preferably 1 :50 and 1 :0.5 or most preferably between 1 :20 and 1 :1.

4. The hybrid scavenger system according to any one of the preceding claims, wherein the functional groups in the laser sintered porous body and in the section of granular active material are selected from the group consisting of carboxylates, primary amine or ammonium, secondary amine or ammonium, tertiary amine or ammonium, sulphates, sulfonic acids, phosphonic acids, diethanolamines, thioureas, thiols, thiouronium, ethylenediaminetetraacetic acid and any combinations of these.

5. The hybrid scavenger system according to any one of the preceding claims, wherein at least one laser sintered porous body is manufactured with hatch distances between 0.5- 1.5 mm, preferably between 0.6-1.4 mm and most preferably between 0.7-1 mm.

6. The hybrid scavenger system according to any one of the preceding claims, wherein at least one laser sintered porous body has scavenging enhancing internal structure, wherein the scavenging enhancing internal structure is manufactured by using hatch distance parameters between 0.5 -1.5 mm.

7. The hybrid scavenger system according to any one of the preceding claims, wherein at least one of the laser sintered porous bodies has parallel, alternately plugged channels enabling horizontal fluid flow through channel walls (wall flow) and trapping undissolved particulate matter.

8. The hybrid scavenger system according to any one of the preceding claims, wherein the system comprises an upstream arranged laser sintered porous body, which has parallel, alternately plugged channels enabling horizontal fluid flow through channel walls (wall flow) and trapping undissolved particulate matter.

9. The hybrid scavenger system according to any one of claims 1-6, wherein the at least one laser sintered porous body has scavenging enhancing internal structure, which comprises CAD designed flow channels.

10. The hybrid scavenger system according to any one of the preceding claims, wherein the granular active material has a particle size ranging from 0.01 to 3 mm, defined by laser diffraction methods according to ISO 13320:2020X.

11. The hybrid scavenger system according to any one of the preceding claims, which comprises a laser sintered porous body arranged upstream in relation to the granular active material, a section of granular active material, and a laser sintered porous body arranged downstream in relation to the granular active material.

12. The hybrid scavenger system according to any one of the preceding claims, wherein the upstream arranged laser sintered porous body, the downstream arranged laser sintered porous body or both comprise polymer powder and active material or consist solely of the active material, wherein the active material comprises ion exchange materials, adsorbent materials or both.

13. The hybrid scavenger system according to claim 11, wherein the upstream arranged laser sintered porous body, the downstream arranged laser sintered porous body or both comprise at least 30 wt% of active material, preferably at least 50 wt%, more preferably at least 70% of active material, based on the weight of the mixture of the polymer powder and the active material, or consist solely of the active material.

14. The hybrid scavenger system, where the upstream or downstream scavenger or both are composed of material having a particle size ranging from 10 to 400 pm, defined by laser diffraction.

15. A method for scavenging of ions and molecules from fluid using the hybrid scavenger system according to any one of claims 1-14, comprising the steps of:

- feeding the fluid through the system until the designed scavenging capacity is reached; and

16. The method according to claim 15, wherein the fluid is fed through the system with a space velocity, defined as the quotient of the entering volumetric flow rate of the fluid divided by the volume of the hybrid scavenger system, which is between 10 and 10 000 1/h, preferably between 30 and 5 000 1/h and most preferably between 50 and 2 000 1/h.

17. The method according to claim 15 or 16, which comprises a step of performing an additional regeneration cycle after the elution step by feeding regeneration solution into the hybrid scavenger system.

18. The method according to any one of claims 15 to 17, which comprises a step of performing a conditioning cycle by feeding conditioning solution into the hybrid scavenger system prior to feeding the fluid through the system.

19. The method according to any one of claims 15 to 18, where the elution, regeneration or conditioning solutions are selected independently from sulphuric acid, nitric acid, hydrochloric acid, formic acid, ascorbic acid, acetic acid, sodium hydroxide, potassium hydroxide, sodium fluoride, sodium chloride, sodium bromide, sodium iodide, potassium fluoride, potassium chloride, potassium bromide, potassium iodide, urea and its derivatives, thiourea and its derivatives, ammonia, ammonium chloride and ammonium hydroxide and any combination of these.

20. Use of a hybrid scavenger system according to any one of claims 1 to 14 for removing metal ions and complexes and non-metal anions and cations from fluid.

21. The use according to claim 20, wherein the non-metal anions are selected from nitrate, nitrite, sulfate, sulfite, phosphate and phosphite.

22. The use according to claim 20, wherein the metal ions are selected from ions of alkaline metals, alkaline earth metals and rare earth elements.

23. The use according to claim 20, wherein the metal ions are selected from calcium, vanadium, chromium, nickel, copper, zinc, cadmium, arsenic, antimony, mercury, lead, lithium, cobalt, manganese, ruthenium, rhodium, palladium, silver, osmium, iridium, platinum and gold.