Mouldable and printable composite material for the sequestration of environmental carbon dioxide; and panels and frame system or other structure produced

Abstract

A composite material for the sequestration of carbon dioxide. Preferably the composite comprises a metal oxide and polyethylene glycol (PEG). Preferably the metal oxide comprises calcium oxide. Pre

Description

[0002] CO2 emissions are unevenly distributed across towns and cities in the UK. Construction accounts for 40% of greenhouse gases and transport accounts for 24% of greenhouse gases. Over the course of a day, transport (rail, roads, airports, ports), housing and office buildings continuously emit CO2. The problem arises due to the concentration of CO2 being released into our atmosphere.

[0003] In the UK overall, there is a significant volume of fuel related carbon emissions in the rail, aviation and maritime industry that negatively affect the environment and overall sustainability. Referring to Figure 1, the greenhouse gas emissions by proportion of the total domestic Greenhouse gases emissions in 2020 are shown and it can be seen that transport accounts for 24% of the total emissions.

[0004] The present invention seeks to address the problem of greenhouse gas emissions and to alleviate the disadvantages of the prior art. Introduction

[0005] Mineral carbonation is a process where alkaline earth metal oxides, such as calcium oxide and magnesium oxide, combine with carbon dioxide (CO2) to form stable carbonates. The thermodynamic stability of products from the direct mineral carbonation makes this reaction an attractive system for the reduction of carbon emissions [1,2], The process can go on either through gas-solid (dry) route or aqueous (wet) route [3], The mineral carbonation process has also the advantage of being an exothermal process, thereby decreasing the energy consumption and the costs involved, in contrast to other technologies [4], Moreover, the gas-solid carbonation process was reported to be energy intensive, involving slow kinetics when compared to the other route [5], even though still economical [4], In this context, the aqueous route seems a better option for mineral carbonation, which is associated with optimization of process parameters and maximum extent of carbonation can be achieved through acceptable kinetics [6]. Although the mineral carbonation technology is quite attractive, the difficulty in the use of minerals is that these processes are expensive and energy-intensive pre-treatments are necessary to perform the reaction with CO2 [3], The use of alkaline solid residues has been demonstrated to overcome slow carbonation and high-energy consumption found in mineral use. This approach enables on-site applications in the future and improves the environmental quality of the solid residue [7], Bobicki et al. collected and reviewed various research works carried out on mineral carbon sequestration of industrial wastes and the related process routes [3]. BRIEF SUMMARY OF THE PRESENT INVENTION

[0006] The present invention accordingly provides a composite material for the sequestration of environmental carbon dioxide. Preferably, the composite material of the present invention is based on an active component for example, a metal oxide such as calcium oxide (CaO) and a non-reactive component such as polyethylene glycol (PEG) mixed in different ratios to sequester and stably fix CO2 from the environment.

[0007] The present invention provides composite material based on an active component for example, a metal oxide such as, for example, calcium oxide (CaO) and a non-reactive component such as polyethylene glycol (PEG) mixed in different ratios to sequester and stably fix CO2 from the environment. Several different binary and ternary mixtures were produced and tested. However, the present invention and the technology on which it is based can function quite broadly provided that the nonreactive component (in this case PEG) allows for the diffusion of gas (including CO2) into the composite where it is able to react with the active component (CaO). Therefore, different types of non-reactive substances could be used as well as polymers such as PEG in various polymerization states and molecular weights. Considering ternary mixtures, CaO, PEG and other polymers can be mixed into the composite to add functionality including color, thermal sensitivity, elasticity, rigidity etc depending on the final application.

[0008] According to the present invention, the composite material is based on an active component for example, a metal oxide such as calcium oxide (CaO) and a non-reactive component such as polyethylene glycol (PEG) mixed in different ratios to sequester and stably fix CO2 from the environment. In accordance with the present invention, the composite material can be formed from any metal Oxide capable of being converted into its respective carbonate by fixing CO2 including, for example, Cobalt Oxide, copper oxide and Nickel oxide.

[0009] The term “fixing CO2” is to be understood to mean that CO2 from the surrounding environment is absorbed in the composite material and subsequently fixed by thermodynamically favoured reaction.

[0010] In accordance with the present invention, the Composite material is formed by reacting a metal oxide with Polyethylene glycol and any PEG alternative for example, any of the following: . Polyethylene glycol 400, PEG 2000, PEG 3350, PEG 4000, PEG 6000, PEG 8000 and any PEG alternative. The composite material of the present invention also includes a binder, for example any of the following binders: ® Povidone (Polyvinylpyrrolidone, PVP) « Hydroxypropyl cellulose (HPC) » Microcrystalline cellulose (MCC) » Gelatin ® Starch ® Carbomers and / or ® Sodium carboxymethyl cellulose (NaCMC). The composite material of the present invention also comprises an emulsion polymer, for example any of the following emulsion polymers: « Nitrile ® Ethylene-vinyl acetate * Styrene acrylic emulsion; and / or ® Styrene-butadiene (latex). The composite material of the present invention may also comprise other binders, for example, any of the following binders: ® Natural rubber » Gums ® Tanins ® Asphalt ® Resin ® Bitumen « Lignin • Cellulose ® Chitisoan ® Zein ® Sodium silicate: and / or ® Alkali-activated binders.

[0011] In another aspect of the present invention, there is provided a method of preparing a composite material for the sequestration of environmental carbon dioxide, based on a metal oxide and Polyethylene Glycol ( PEG), the method comprising the steps of heating the PEG to at least its melting point so that the PEG is melted to form melted PEG in order to obtain a liquid and adding the metal oxide to the molten PEG in a precalculated ratio.

[0012] Preferably, the method also comprises the step of mixing the metal oxide in the melted PEG and dispersing by stirring in order to obtain a homogeneous system, most preferably, the metal oxide is intimately dispersed in the melted PEG by stirring.

[0013] Preferably, the method also comprises the step of pouring the homogenous dispersion on a support and cooling until a solid composite material is formed on the support.

[0014]

[0015] In another aspect, the present invention also provides a panel comprising said composite material for the sequestration of environmental carbon dioxide.

[0016] The inventors prepared composite materials at different weight to weight (w / w) ratios comprising calcium oxide (CaO) and polyethylene glycol (PEG) for the fabrication of matrices adapted to sequestrate and stably fix the environmental carbon dioxide (CO2) by carbonation of the CaO under ambient conditions (i.e. 20 to 25 °C (68-77 °F; 293-298 K), 1 atm pressure). The composite after heating to 70 °C showed moldability, can be colored with dyes and worked into different forms very easily. By moldability, this means shaping the liquid or pliable raw material using a rigid frame called a mold. This mold is made using a pattern or model of the final object using a hollowed-out frame that is filled with our heated liquid composite that is then cooled in the frame adopting this shape. The use of PEG allows for the passage of ambient CO2 from the environment into the composite to react with the CaO.

[0017] The experimental results demonstrated high performance environmental CO2 sequestration in both controlled and open environment conditions showing this composite material can be used successfully in controlled industrial applications as well as in human living spaces for the stable removal of CO2.

[0018] The present invention has the advantage of providing a composite material and a panel comprising said composite material to remove atmospheric carbon dioxide which has the significant advantage of contributing to achieving an international strategy to prevent global warming from exceeding 2°C (3.6°F) and to achieving Net Zero targets.

[0019] Accordingly, the present invention provides composite material based on calcium oxide (CaO) and polyethylene glycol (PEG) mixed in different ratios [8], Many ratios of CaO to PEG are possible and even different ratios of PEG of different polymer length have been tested. Binary mixtures (w / w) include: CaO to PEG 2000 1:1, 1:2, 1:3, 1:4, 1:5, 1:10, 1:15, 1:20,9:1. Ternary mixtures include CaO to PEG 400 to PEG 2000 5:3:2, 10:9:1; and CaO to PEG 2000 to PEG 8000 1:1:1, 1:4:2, 2:2:1, 1:5:5, 1:10:5, 1:15:7.5, 1:20:10. The composite material is adapted to sequester and stably fix CO2 in the composite by longterm carbonation of CaO as shown in the schematic below: CaO + CO2 CaCO3 Scheme 1

[0020] The composite material of the present invention has a low melting point, from 5 up to 70 °C, depending on the molecular weight of PEG used (from 400 to 10000), along with moldability into different forms and the possibility of addition of natural and synthetic pigmentations, thus making this material applicable for the built environment where the reduction of CO2 emissions is desirable in the low-carbon economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Embodiments of the invention are further described hereinafter with reference to the accompanying drawings, in which:

[0022] Figure 1 is a pie-chart showing the respective proportions of contribution to overall greenhouse gas emissions from various sources;

[0023] Figure 2 is a photo of an Experimental set up for the determination of the absorption properties of the composite material; Figure 2 shows the four samples (from Sample A, Sample B, Sample C and Sample D) having different CaO / PEG w / w ratios as well as the blank Sample (no CaO) exposed to indoor open environment for 140 days;

[0024] Figure 3 (a) and (b) are photos showing examples of coloration for the composite material: Figure 3 (a) is a photo showing the composite material molded in cylindrical shapes without dye (left) and after addition of Sudan Black B dye (right); the cylinders of the composite material are approx. 2 cm (height) x 1 cm (width) Figure 3 (b) and 3(c.) are a photos of the composite material comprising various dyes; From left to right in the photos shown in Figure 3(b) and Figure 3(c.), respectively, there is shown, test tubes comprising the following dyes: no dye; 50% Sudan Black B + 50 % Nile Red; only Sudan B; only Nile Red. Samples were exposed to normal light and the test tubes are shown in Figure 3(b) and Samples were exposed to UV light with the results as shown in the test tubes in Figure 3(c.) Cylinders are approx. 2 cm (height) x 1 cm (width) Figure 4 (a) is a photo showing a plan view of the glass chamber used for recreating a controlled environment and testing the four composite samples at different CaO + PEG ratio and the blank (only PEG) as reference; Figure 4 (b) is a photo showing a perspective view of the glass chamber used for recreating a controlled environment and testing the four composite samples at different CaO + PEG ratio and the blank (only PEG) as reference;

[0025] Figure 5 is a graph showing the absorption trend of the sample Composite materials A, B, C, D having different CaO / PEG w / w ratios and for the sample blank after exposure to open indoor environment for 140 days; The tested samples A, B, C, D and the blank sample have the following w / w compositions: Composite A = 1 / 1 (CaO / PEG); Composite B = 1 / 2 (CaO / PEG); Composite C = 1 / 3 (CaO / PEG); Composite D = 1 / 4 (CaO / PEG); Blank = (only PEG);

[0026] Figure 6 (a) is a photo of the non-flammable composite material in contact with an open flame. As can be seen from the photo, the composite material is not burning when in contact with the open flame; Figure 6(b) is a photo of the composite material in contact with water. As can be seen from the photo, there is no toxic vapour or explosion when the composite material is in contact with water; Figure 6(c.) shows the composite material in contact with skin. As can be seen from the photo, there is no skin irritation or toxic effects from contact with the skin.

[0027] Figure 7 is a photo of 10 samples numbered from 1 through to 10 with samples 1-5 having been produced using Active PEG 2000 and Samples numbered 6-10 having been produced using Active PEG 8000;

[0028] Figure 8 is a graph and associated table of results associated with the composite weight change associated with each of the samples 1-10 shown in Figure 7;

[0029] Figure 9 is a photo shown the composite material comprising a bonding agent -The ternay mixtures are CaO:PEG 2000:PEG 8000 2:10:5 plus a bonding agent. The two bonding agents tested are S.B.R Bond (a commercial latex based bonding agent) and methylcellulose. Both are added to the ternary mixtures above in the amounts indicated. At the top are photos of the composite with bonding agents. At the bottom are measurement of weight changes over time,

[0030] Figure 10 shows absorption trends under controlled environment along the time of the four composite samples at different CaO + PEG ratios and the blank (only PEG) used a reference,

[0031] Figure 11 includes Figures 11 (a), 11(b) and 11 (c.) in which Figure 11 (a) is a front view of a frame and panel comprising the composite material of the present invention; Figure 11 (b) is a top section view of the frame and panel comprising the composite material of the present invention; and Figure 11 (c.) is a side section view of the frame and panel comprising the composite material of the present invention;

[0032] Figure 12 is an alternative embodiment of the frame and panel of the present invention and includes Figures 12 (a), 12(b) and 12 (c.) in which Figure 12(a) is a front view of a frame and panel comprising the composite material of the present invention; Figure 12(b) is a top section view of the frame and panel comprising the composite material of the present invention; and Figure 12(c.) is a side section view of the frame and panel comprising the composite material of the present invention;

[0033] Figure 13 shows a colour change in the frame and panel of the present invention and includes Figures 13 (a), 13(b) and 13 (c.) in which Figure 13(a) is a front view of a frame and panel comprising the composite material of the present invention; Figure 13(b) is a top section view of the frame and panel comprising the composite material of the present invention; and Figure 13(c.) is a side section view of the frame and panel comprising the composite material of the present invention;

[0034] Figure 14 is a plan view of a plurality of the frame and panel system of Figures 11-13 showing that the framing system is modular and can be arranged in various configurations and sizes and with a plurality of the individual frame and panel units arranged in any configuration; and

[0035] Figure 15 is a plan view of the frame and panel system of Figures 11-14 comprising a logo or other written material which can be printed onto the panel in the frame and panel system of the present invention.

[0036] Referring initially to Figure 11 of the drawings, there is shown a frame and panel system comprising frame 1, glass 2, panel comprising the composite material 3 of the present invention, perforated mesh 4, spacer 5, fixing means 6, air gap 7. The frame and panel system is adapted to be mounted to a wall / substrate 8.

[0037] As shown in Figure 12, the frame and panel system comprise of an alternative embodiment where a perforated sheet 9 is added to the outside face of the panel system adding durability in extreme environments and allowing air to reach both sides of the composite material 3 of the present invention.

[0038] As shown in Figure 13, the frame and panel system comprises a panel comprising composite material in a frame.

[0039] Referring now to Figure 14, the framing system is modular and can be arranged in various configurations and sizes.

[0040] Referring now to Figure 15, a logo or other written material can be printed onto the panel in the frame and panel system.

[0041] Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise. 1. DETAILED DESCRIPTION 1.1 DETAILED DESCRIPTION OF THE DRAWINGS

[0042] A number of aspects of the present invention will now be described more particularly, with reference to the accompanying drawings and the following Examples. In the drawings, like reference numerals refer to like features.

[0043] Referring initially to Figure 11 of the drawings, there is shown a frame and panel system comprising frame 1, glass 2, panel comprising the composite material 3 of the present invention, perforated mesh 4, spacer 5, fixing means 6, air gap 7. The frame and panel system is adapted to be mounted to a wall / substrate 8.

[0044] As shown in Figure 12, the frame and panel system comprises of an alternative embodiment where a perforated sheet 9 is added to the outside face of the panel system adding durability in extreme environments and allowing air to reach both sides of the composite material 3 of the present invention.

[0045] As shown in Figure 13, the frame and panel system comprises a panel comprising composite material in a frame.

[0046] Referring now to Figure 14, the framing system is modular and can be arranged in various configurations and sizes.

[0047] Referring now to Figure 15, a logo or other written material can be printed onto the panel in the frame and panel system. EXPERIMENTAL SECTION AND EXAMPLES Exemplary Compositions will now be set out in the following Examples. 2. Experimental section 2.1. Fabrication of the composites

[0048] CaO in powder, PEG 400, PEG 2000, PEG 10000, Nile Red, Oil Red O, Sudan Black B, and hydrochloric acid were purchased from Sigma Aldrich. All chemicals used for the preparation were in reagent grade purity. For the synthesis of the composites in different CaO / PEG ratios, PEG 2000 pellets, with a melting point between 52 - 54 °C, were ground by means of mortar and pestle. The CaO powder was subsequently added and thoroughly mixed by hand. Then the mixtures were melted at 70 °C under constant stirring inside a glass container until the PEG was completely melted. The mixture was then subsequently poured into appropriate containers and molds in order to obtain the desired shapes for further characterization. We prepared four composites having 1 / 1, 1 / 2, 1 / 3, and 1 / 4 CaO / PEG w / w ratios, respectively [8],

[0049] To make the composite into filament for 3D printing applications we mixed a ternary mixuture of CaO, PEG 2000, and polylactic acid (PLA) to obtain the best extrusion efficiency. Specifically, we melted at 75 °C a mixture of 1 / 4 CaO / PEG w / w ratio and we subsequently added pellets of PLA under constant stirring. At this temperature, the PLA was not melted due to its higher melting point (200 °C). After mixing, we slowly cooled down under constant stirring the ternary mixture in order make the PLA pellets covered with the composite. The final ternary mixture was 1 / 3 composite / PLA w / w ratio.

[0050] To vary the consistency of the composite, we mixed PEG 400, liquid at room temperature, in different ratios with PEG 2000 and PEG 10000, with a melting point between 61 - 66 °C, respectively. For color, dyes were added to the composite during the melting step and mixed thoroughly. 2.2 Fabrication of composite with reagents for glass and frame applications.

[0051] The inventors mixed various ratios of calcium oxide, PEG 2000, PEG 8000, S.B.R Bonding agent and Blue Iron Oxide. We mixed 2g CaO, 10g PEG 2000, 5g PEG 8000. Specifically, we heated it in pot on an electric plate until fluid consistency. While the mixture was cooling, the inventors then added 2ml Aqueous styrene-butadiene emulsion polymer (S.B.R Bonding agent) and mixed thoroughly and poured on glass slide to cool down. We observed the weight change in the lab for the absorption of carbon dioxide.

[0052] The inventors mixed various ratios in a similar sequence except to pour in a disk mold to test the strength of the composite at various thicknesses. The inventors mixed the ratios as follows:

[0053] Fig A: 1g CaO, 10g PEG 2000 and 1.5ml Aqueous styrene-butadiene emulsion polymer.

[0054] Fig B: 2g CaO, 10g PEG 2000 and 2.5ml Aqueous styrene-butadiene emulsion polymer.

[0055] Fig C: 1g CaO, 10g PEG 2000, 5g PEG 8000 and 1.5ml Aqueous styrene-butadiene emulsion polymer.

[0056] Fig D: 2g CaO, 10g PEG 2000, 10g PEG 8000 and 2.5ml Aqueous styrene-butadiene emulsion polymer.

[0057] For glass and frame sample (21.5 cm x 26.8 cm x 1cm) the inventors melted a mixture of 10g CaO, 50g PEG 2000. Specifically, the inventors heated it on an electric plate and pot until fluid consistency. While the mixture was cooling, the inventors then added 200ml Aqueous styrene-butadiene emulsion polymer (S.B.R Bonding agent) and mixed thoroughly. Finally, the inventors added Blue Iron Oxide powder to the mixture, mixed thoroughly, poured into the glass and frame to cool down and set. Over time, the panel changes colour from blue colour associated with the Blue Iron Oxide to white as CO2 is fixed in the composite forming calcium carbonate.

[0058] The inventors mixed various ratios of calcium oxide, PEG 2000, PEG 8000, Methylcellulose. The inventors mixed 2g CaO, 10g PEG 2000, 5g PEG 8000. Specifically, the inventors heated it in pot on an electric plate until fluid consistency. While the mixture was cooling, the inventors then added 2g Methylcellulose and mixed thoroughly and poured on glass slide to cool down. The inventors observed the weight change in the lab for the absorption of carbon dioxide.

[0059] 2.3 A framing system is used to hold the composite absorbing carbon dioxide in the environment (indoor and outdoor). The inventors tested the framing system with various frame thicknesses, framing materials (steel, aluminum, wood, alloys, plastics) and a glass front with various thicknesses (single glass 1mm, double glazed unit consisting of 4mm toughened, 18mm argon cavity, 6.4 laminated glass, double glazed unit consisting of 6mm toughened, 16mm argon cavity, 6.4 laminated glass). The framing system consists of a ventilation gap exposing the composite to carbon dioxide in the environment.

[0060] The composite changes colour in the carbon dioxide environment. The inventors tested various colours (Blue to white, Green to white, Red to white etc.). The colour change signals to the viewer that decarbonization has taken place.

[0061] The glass outer surface assists in fire performance for Building Regulations. Tests to be completed.

[0062] When the composite material is saturated with carbon dioxide in the framing system, the composite material panel is replaced with a new panel of composite material. The system according to the present invention provides a continuous decarbonization of the environment. Carbon dioxide concentrations are unevenly distributed across cities, towns and infrastructure due to exhaust emissions. This includes high concentrations of CO2 emissions in train stations, roads, bus stops, airports, petrol stations, taxi ranks, bridges, housing and office buildings, ports and shipping industry.

[0063] The inventors have tested the recyclability of composite saturated with carbon dioxide. The waste composite panel is recycled and repurposed after use.

[0064] Recyclability section 3.7 - below. 90% of the composite can be recycled to make new CO2 absorbing panels by separating and recovering it. A remaining 10% of the composite can be repurposed such as e.g., aggregate filler, wall panel or moldable products such as plant pots etc.

[0065] The framing system is modular and can be arranged in various configurations and sizes as shown in Figure 14.

[0066] The framing system face has a variety of panel types. Figure 12 shows a perforated panel (steel, aluminum, vinyl) front of various perforated sizes.

[0067] The panel system with composite in frame is shown in Figure 13.

[0068] The panel system with logo, advertising, motif, message, lettering, design as shown in Figure 15. 2.4. Tests in indoor open environment

[0069] The composite mixtures with varying ratios of CaO to PEG 2000 and weights as shown in Table 1, were placed into glass petri dishes of diameter 3.6 cm and allowed to stand open without any imposed environmental control in a typical laboratory environment for several days. The samples were then tested by determining the increment in weight due to the sequestration of CO2 by the materials. In parallel to the composites, we prepared a blank obtained by using the only PEG 2000. Sample Materials composition (w / w) Initial weight (mg) CaO PEG Composite A 1 1 4240 Composite B 1 2 4117 Composite C 1 3 4334 Composite D 1 4 4518 Blank - 1 4227 Table 1. Composition of the composite materials and blank employed for the CO2 sequestration tests. 2.5. Tests under controlled atmosphere

[0070] The composite mixtures in different ratios were tested under controlled environmental conditions in addition to a blank sample, made only by PEG, as a control. Four molded samples and the blank of known weights, as shown in Table 2, were thus placed into a sealed chamber of 0.340 L volume with applied controlled flow of carbon dioxide and let them interact with the chamber environment for 130 days. The chamber, shown in Figure 4(a) and (b), was designed to recreate a dynamic environment. The weight of the samples was tested at different intervals of time to assess the sequestration of carbon dioxide by the samples, as shown in Table 3. The results were also plotted to have a clear view of the absorption trend related to the tested samples, as shown in Figure 10. 2.6 Acid test for carbonates

[0071] IM hydrocloric acid (HCI) was added to composites that were either freshly prepared or exposed over time to CO2 in order to test for the presence of CaCOs. A small of amount of composite was removed from a sample by scraping with a spatula and placed onto a glass slide. HCI was then added and the release of CO2 gas was noted. 3. Results and discussion 3.1. The moldability and consistency of the CaO / PEG w / w ratios

[0072] Tests samples with varying ratios of CaO to PEG were prepared. Ratios with a greater amount of CaO with respect to PEG 2000, resulted in composites materials showing several drawbacks during the melting and consequent cooling processes since the final materials were too brittle to be worked into geometrical shapes. Therefore in subsequent preparations the 1:1 ratio of CaO to PEG 2000 used was the maximum amount of CaO used.

[0073] The inventors also explored how the mixture of CaO with different molecular weights of PEG resulted in composites of differing consistency. The inventors carried out tests of moldability at room temperature of the composite in order to obtain a final composition able to act as paint or coating on different surfaces. For this purpose, the inventors achieved an optimal moldability by mixing PEG 400, liquid at room temperature, in different ratios with PEG 2000 and PEG 10000, with a melting point between 61 - 66 °C, respectively. The possibility of using three different supports in a ternary combination allowed the fabrication of several polymeric matrices of "tunable" consistency ranging from creamy to greasy features. The wide range of different molecular weights PEG available in the market together with the possibility of taking advantage of others several polymeric supports can pave the way for many possible applications of this material in very different situations and environments where efficiency and adaptability are strongly required. The inventors noted that after exposure of the soft composites to environmental CO2, the composites became hard and sometimes brittle. 3.2. Acid test for carbonates

[0074] To verify the formation of CaCOs in our composites we treated samples with 1 M HCI. We tested the initial components used to fabricate the composite, freshly prepared composites along with the samples exposed to the open environment. Effervescence was observed only for the composites exposed to CO2, while the blank and initial components did not react with HCI. The effervescence is a common process occurring when carbonates react with strong protic acid such as HCI and it is associated to the development of carbonic acid that decomposes into water and CO2, responsible of the effervescence. This is also a simple way to reverse the capture of CO2 in such composites through the application of strong acids. 3.3. Test of adding colorants and scents

[0075] The inventors also assessed the capability of the composite to be colored and scented. The additives were placed into the melted PEG and CaO mixtures under mechanical stirring for a few seconds to reach the best homogeneity. The melted composite was then molded into cylinders (Fig. 2a). This resulted in composites of varying color. The colors changed over time coincident with the change in weight. Fluorescent dyes were also active in the molded composite (Fig. 2b). The scents released by the composite were also apparent.

[0076] The possibility of using natural dyes without "harmful properties" is an important advantage for the development of environmental "zero impact" materials able to find applications in the field of green technologies. 3.4. Printable filament Several filaments to be used for 3D printing have been made as described hereinabove. 3.5. Tests in indoor open environment

[0077] For the tests in indoor open environment, we made four samples of composite and one blank following the w / w ratios illustrated in Table 1. After solidification of the composite, we determined the initial weight and then we exposed all samples to the environment for up to 140 days. The inventors periodically assessed the variation in weight due to the CO2 absorbed and consequently fixed to the CaO dispersed into the polymer (PEG), according to the reaction in scheme 1. In parallel to the composite, we prepared a blank using only PEG 2000 in order to verify the total inactivity of the support towards the sequestration of the CO2.

[0078] The composites exposed to the open environment resulted in an increase in weight for all materials, with no such trend associated to the blank in line with the expectation a certain amount of reacted CaO would result in increased weight of the composite. The increase in weight was observed over several days until finally a plateau was reached after 100 days signifying the saturation of the available CaO and consequent end of the carbonation process. The oscillations in weight in the range of 7 - 20 days of the pure polymeric support (blank) may be due to the variation of environmental humidity, confirming the capability of PEG 2000 of reversibly absorbing and releasing water. In this period, the inventors observed the increment in weight of the composites was always increasing but the increment ratio may have been affected by the humidity present in the environment and the quantity absorbed by the polymer (PEG). The dispersion of CaO particles inside the PEG along with the porosity of the composite allowed the diffusion of CO2 inside the bulk. The result was thus a long-term absorption capability of the composite, a very important and promising characteristic in the vision of possible application of this technology. Fig. 10 shows the variation in weight related to the four samples and the blank after exposure to indoor open environment for 140 days. 3.6. Tests under controlled atmosphere

[0079] The composite mixtures in different ratios were tested under controlled environmental conditions in addition to a blank sample, made only by PEG, as a control. Four molded samples and the blank of known weights, as shown in Table 2, were thus placed into a sealed chamber of 0.340 L volume with applied controlled flow of carbon dioxide and let them interact with the chamber environment for 130 days. The chamber, shown in Figure 4 (b) and (c), was designed to recreate a dynamic environment. The weight of the samples was tested at different intervals of time to assess the sequestration of carbon dioxide by the samples, as shown in Table 3. The results were also plotted to have a clear 5 view of the absorption trend related to the tested samples, as shown in Figure 10.

[0080] Test on CaO + PEG samples Sample 1 Sample 2 Sample 3 Sample 4 Sample W CaO PEG CaO PEG CaO PEG CaO PEG PEG | CaO: PEG w / w ratio 1 1 1 2 1 3 1 4 Blank | Initial weight (mg) 1782 1648 1552 1395 1309 Table 2. Initial weight of the four composite samples at different CaO + PEG ratios and the 10 blank (only PEG) used a reference. Test on CaO + PEG samples Sample 1 Sample 2 Sample 3 Sample 4 Sample W CaO PEG CaO PEG CaO PEG CaO PEG PEG | CaO:PEG w / w ratio 1 1 1 2 1 3 1 4 Blank Change in weight (mg) after exposure to CO2 atmosphere 1782 1648 1552 1395 1309 22 / 07 / 2015 5.00 p.m. -24 / 07 / 2015 15.00 p.m. 1785 1650 1553 1398 1307 Weight increment (mg) 3 2 1 3 -2 Total weight increment (mg) .............................. ........................................... 1 3 -2 Weight increment (%) 0.17 0.12 0.06 0.22 -0.15 Total weight increment (%) .................... Ui .................................... 0.06 0.22 -0.15 Change in weight (mg) after exposure to CO2 atmosphere 1785 1650 1553 1398 1307 24 / 07 / 2015 15.30 p.m. - 27 / 07 / 2015 11.00 am. 1789 1653 1555 1401 1308 Weight increment (mg) 4 3 2 3 1 Total weight increment (mg) 7 00 5 00 3 00 6.00 ■1 00 Weight increment (%) 0.22 0.18 0.13 0.21 0.08 Total weight increment (%) 0.39 0.30 0.19 0.43 -0.08 Change in weight (mg) after exposure to CO2 atmosphere 1789 1653 1555 1401 1308 27 / 07 / 2015 11.15 am. - 03 / 08 / 2015 10.00 am. 1797 1658 1561 1411 1307 Weight increment (mg) 8 5 6 10 -1 Total weight increment (mg) 16.00 10.00 9.00 16.00 -2.00 Weight increment (%) 0.45 0.30 0.39 0.71 -0.08 Total weight increment (%) 0.84 0.61 0.58 1.14 -0.15 Change in weight (mg) after exposure to CO2 atmosphere 1797 1658 1561 1411 1307 03 / 08 / 2015 12.00 p.m. - 31 / 08 / 2015 12.00 p.m. 1815 1672 1569 1422 1304 Weight increment (mg) 18 14 8 11 -3 Total weight increment (mg) 33 00 24 00 17 00 27 00 -5.00 Weight increment (%) 1.00 0.84 0.51 0.78 -0.23 Total weight increment (%) 1.84 1.45 1.09 1.92 -0.38 Change in weight (mg) after exposure to CO2 atmosphere 1815 1672 1569 1422 1304 31 / 08 / 2015 12.00 p.m. - 30 / 09 / 2015 2.00 p.m. 1831 1681 1575 1429 1303 Weight increment (mg) 16 9 6 7 -1 Total weight increment (mg) 49.00 33.00 23.00 34.00 -6.00 Weight increment (%) 0.88 0.54 0.38 0.49 -0.08 Total weight increment (%) 2.72 1.99 1.47 2.42 -0.46 Change in weight (mg) after exposure to CO2 atmosphere 1831 1681 1575 1429 1303 30 / 09 / 2015 2.00 p.m. - 25 / 11 / 2015 2.00 p.m. 1853 1696 1583 1436 1303 Weight increment (mg) 22 15 8 7 0 Weight increment (mg) 71.00 48.00 31.00 41.00 -6.00 Weight increment (%) 1.20 0.89 0.51 0.49 0.00 Total weight increment (%) 3 92 2 88 1 98 291 •0 46 Table 3. Absorption trend under controlled environment along the time of the four composite 15 samples at different CaO + PEG ratios and the blank (only PEG) used a reference. 3.7 Recyclability (circular economy &repurpose)

[0081] The composite material was collected after sequestration of carbon dioxide had saturated in the composite. This saturation end point was assessed by no further weight gain over time. The mixture of CaCOs, PEG 2000 and colour dye was ground down to powder form. The mixture was heated on an electric plate in a pot until viscous. The mixture was removed from the heat and aqueous styrene-butadiene emulsion polymer was added and the mixture was mixed thoroughly. The mixture was then poured into a disk mold to cool down and set. In accordance with the present invention, the mixture of CaCOs, PEG 2000 and aqueous styrene-butadiene emulsion polymer forms a composite adapted to sequester carbon dioxide and for use, in an inert state, as a panel, brick or other moldable product. 4. Conclusions

[0082] Four samples of composite materials (Sample composites A, B, C and D) were prepared by mixing CaO and PEG 2000 in different w / w ratios (1:1, 1:2, 1:3, 1:4) and are adapted to sequestrate and stably fix the environmental CO2. The composites A, B, C and D when heated to 70 °C and stirred were then poured into molds. Each of the composite materials A, B, C and D allow composite materials to be formed in different shapes and when molten, the composite materials A, B, C and D can be coloured by including a dye in the composition. Bonding agents can also be added to change the consistency of the composite

[0083] The inventors also carried out further experiments with compositions of PEG with different molecular weights to create the composite with is pliable and spreadable at room temperature. The ratios tested were 3 to 2 PEG 400 to PEG 2000 and 9 to 1 PEG 400 to PEG 10000, by weight. To activate these were then mixed 1 to 1 by weight with CaO. The inventors successfully obtained different compositions ranging from creamy to greasy consistency able to be spread on various surfaces due to the inclusion of the low molelcular weight PEG. The sequestration efficiency of the composite was assessed by exposing the composite to the indoor open environment and under controlled atmosphere inside a test chamber. The experimental data related obtained by exposing the composite material in different CaO / PEG w / w ratios highlighted the capability of sequestering and stably fixing the environmental CO2 by the composite, and the quantity of gas absorbed by the material increased in relation to the increment of CaO / PEG ratio.

[0084] Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this 5 specification (including any accompanying claims, abstract and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and / or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features 10 disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. References [1] Huijgen, W. J. J.; Comans, R. N. J. Carbon Dioxide Sequestration by Mineral Carbonation Literature Review Update 2003-2004; Energy Research Centre of the Netherlands, 2005. [2] Huijgen, W. J. J.; Comans, R. N. J. Carbon Dioxide Sequestration by Mineral Carbonation Literature Review; Energy Research Centre of the Netherlands, 2003. [3] Bobicki, E.R., Liu, Q., Xu, Z., Zeng, H., 2012. Carbon capture and storage using alkaline industrial wastes. Prog. Energy Combust. Sci. 38, 302-320. [4] Zevenhoven, R., Teir, S., Elonev, S., 2008. Heat optimisation of a staged gas-solid mineral carbonation process for long-term CO2 storage. Energy 33, 362-370. [5] Mazzotti, M., Abanades, J.C., Allam, R., Lackner, K.S., Meunier, F., Rubin, E., etal., 2005. Mineral carbonation and industrial uses of carbon dioxide. In: IPCC Special Report on Carbon Dioxide Capture and Storage. Cambridge University Press, Cambridge, UK (Chapter 7). [6] Huijgen, W.J.J., Comans, R.N.J., 2005. Carbon Dioxide Sequestration by Mineral Carbonation: Literature Reviews Update 2003-2004. Energy Research Centre of The Netherlands, Petten, the Netherlands. [7] Pan, S.Y., Chang, E.E., Chiang, P.C., 2012. CO2 capture by accelerated carbonation of alkaline wastes: a review on its principles and applications. Aerosol Air Qual. Res. 12, 770-791. [8] Bezerra Correia Terencio, T., Bavastrello, V., Nicolini, C., 2012. Calcium Oxide Matrices and Carbon Dioxide Sensors. Sensors 12, 5896-5905.

Claims

1. A composite material for the sequestration of environmental carbon dioxide wherein the composite material is adapted to sequester and stably fix CO2 from the environment.

2. A composite material as claimed in claim 1 based on based on a metal oxide and polyethylene glycol (PEG) mixed in different ratios.

3. A composite material as claimed in claim 1 wherein the metal oxide comprises calcium oxide (CaO).

4. A composite material as claimed in claim 1 wherein different types of non-reactive substances are used to form the composite material as well as polymers such as PEG in various polymerization states and molecular weights.

5. A composite material as claimed in claim 1 wherein CaO, PEG and other polymers can be mixed into the composite to add functionality including color, thermal sensitivity, elasticity, rigidity and other desired properties depending on the final application.

6. A composite material for sequestering carbon dioxide from the environment comprising calcium oxide (CaO) and polyethylene glycol (PEG) combined in the ratios in the range of a: b to x: y.

7. A composite material as claimed in claim 1 wherein Binary mixtures (w / w) include: CaO to PEG 2000 1:1, 1:2, 1:3, 1:4, 1:5, 1:10, 1:15, 1:20, 9:1.

8. A composite material as claimed in claim 1 wherein Ternary mixtures include CaO to PEG 400 to PEG 2000 5:3:2, 10:9:1; and CaO to PEG 2000 to PEG 8000 1:1:1, 1:4:2, 2:2:1, 1:5:5, 1:10:5, 1:15:7.5, 1:20:10.

9. A composite material as claimed in claim 1 formed by reacting a metal oxide with Polyethylene glycol and / or any PEG alternative for example, any of the following:« Polyethylene glycol 400, PEG 2000, PEG 3350, PEG 4000, PEG 6000, PEG 8000 and any PEG alternative.

10. A composite material as claimed in any preceding claim wherein the composite material also comprises a binder, for example any of the following binders:® Povidone (Polyvinylpyrrolidone, PVP)® Hydroxypropyl cellulose (HPC)® Microcrystalline cellulose (MCC)® Gelatin® Starch® Carbomers and / or® Sodium carboxymethyl cellulose (NaCMC).

11. A composite material as claimed in any preceding claim wherein the composite material also comprises an emulsion polymer.

12. A composite material as claimed in claim 11 wherein the emulsion polymer may comprise any of the following emulsion polymers:® Nitrile® Ethylene-vinyl acetate® Styrene acrylic emulsion; and / or® Styrene-butadiene (latex).

13. A composite material as claimed in any preceding claim wherein the composite material comprises a binder, for example, any one or more of the following binders:* Natural rubber® Gums® Tanins® Asphalt® Resin® Bitumen® Lignin® Cellulose« Chitisoan« Zein® Sodium silicate; and / or® Alkali-activated binders.

14. A method of preparing a composite material as claimed in claim 1 for the sequestration of environmental carbon dioxide, based on a metal oxide and Polyethylene Glycol ( PEG), the method comprising the steps of heating the PEG to at least its melting point so that the PEG is melted to form melted PEG in order to obtain a liquid and adding the metal oxide to the molten PEG in a precalculated ratio.

15. A method as claimed in claim 14 wherein the method also comprises the step of mixing the metal oxide in the melted PEG and dispersing by stirring in order to obtain a homogeneous system.

16. A method as claimed in claim 15 wherein the metal oxide is intimately dispersed in the melted PEG by stirring.

17. A method as claimed in any of claims 14 to 16 wherein the method also comprises the step of pouring the homogenous dispersion on a support and cooling until a solid composite material is formed on the support.

18. A panel formed from the composite material of any one of claims 1 to 13.

19. A method for preparing a composite material as claimed in claim 1 comprising the following steps: mixing PEG 400, liquid at room temperature, in pre-determined ratios with PEG 2000 and PEG 10000, with a melting point between 61 - 66 °C, respectively.

20. A method for preparing a panel for absorbing carbon dioxide in the environment (indoor and outdoor), the method comprising the following steps: pouring a homogenous dispersion of metal oxide and PEG on a support in the form of a panel and cooling until a solid composite material is formed on the support panel.

21. A method for preparing a framing system comprising the steps of: molding a panel formed from the composite material claimed in claim 1 and providing a frame structure for the panel.

22. A Panel formed of the composite material as claimed in any one of claims 1 to 13.

23. A panel and frame system comprising a panel as claimed in claim 22.

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