Device for the utilization of calcium carbonate from mussel shells for the production of stone paper

Abstract

Device (1) for producing stone paper (11) from CaCO3-containing mussel shells (2) and polyethylene (5).

Description

Stone paper, also called mineral paper, is an environmentally friendly alternative to conventional wood-based paper. It consists mainly of calcium carbonate = CaCO 3( about 80 % by weight) derived from limestone and a small proportion of high density polyethylene (HDPE) as binder.The high density polyethylene (HDPE) required for making stone paper is traditionally obtained from fossil raw materials. However, there are alternative production methods that reduce the dependence on fossil raw materials and can contribute to a more durable supply chain. One such alternative is the production of HDPE from the gasification of biomass. In this process, biomass is converted to synthesis gas (a mixture of hydrogen and carbon monoxide) which is then catalytically processed to hydrocarbons, including the building blocks for polyethylene production.Another new approach is to produce HDPE from carbon dioxide (CO 2), which is obtained from industrial sources such as power plant flue gases, in combination with hydrogen produced by water electrolysis. This process has the potential to provide low carbon output circulation management through the use of CO 2 as a raw material.However, other waste plastics can also be used, which only have to function as binders for the shell shells containing CaCO 3-. However, thermoplastics which are obtained, for example, from sugar cane waste can also be used.This unique composition (CaCO 3 & Plastic) imparts exceptional properties to stoneware such as durability, water resistance, fire resistance and recycleability, making it an ideal choice for various applications, including:• Print and writing materials: books, notebooks, brochures and posters all benefit from their tear-resistant and water-repellent nature.• Packaging: For environmental-friendly packaging solutions such as shopping bags, food containers and labels.• Exterior and industrial applications: Due to its durability and environmental resistance, stone paper is used for cards, banners and water resistant labels.One of the most important advantages of stone paper is its lasting manufacturing process. In contrast to conventional paper production, which requires large amounts of water and chemical treatments, little water is consumed in the production of stone paper and no toxic chemicals such as bleaches and acids are required.The process begins with cracked calcium carbonate which is ground to an ultrafine powder. This powder is then mixed with HDPE and heated to about 220°C so that the binder melts and mixes with the calcium carbonate particles. The molten mixture is then extruded into thin sheets, cooled and cut into the desired size and shape.As global environmental regulations become more stringent and demand for sustainable materials increases, the stone paper market experiences considerable growth. In 2023, the market has been estimated to be about 800 million Euros and is expected to reach as many as 2030 billion Euros.This demand push is driven by industries seeking environmentally friendly alternatives for packaging, printing and other applications.Stone paper offers numerous environmental advantages compared to conventional wood-based paper:• No timbering: unlike conventional paper, no trees or other wood-based materials are needed to produce stone paper, thereby preserving forests and varieties.• Water saving: Conventional paper production is very water intensive and consumes thousands of liters per ton of paper. In contrast, the production of stone paper consumes much less water, which significantly reduces water consumption and environmental pollution.• Lower CO 2- footprint: The carbon dioxide emissions (CO 2) associated with the production of stone paper are drastically lower than that of conventional paper. On average, the production of a ton of stone paper produces only about 5% of the CO 2- emissions as compared to the production of a corresponding amount of conventional paper. While in the production of conventional paper about 1.8 to 2.5 tons of CO 2 are discharged per ton, in the production of stone paper only about 0.1 tons of CO 2 are discharged per ton of stone paper produced.• Lower energy consumption: Unlike traditional papermaking, which requires complex chemical processes and energy intensive pulping, the production of stone paper requires less energy, which further minimizes environmental impact.• No toxic chemicals: Conventional paper requires bleaches and other chemicals which contribute to environmental pollution. In the production of stone paper, such fabrics are not needed, resulting in a cleaner and safer process.• Waste Avoidance and Recycleability: Stone paper is fully recyclable and can be further processed into new stone paper products, thereby reducing landfill waste and promoting cycle management.A disadvantage of the technologies known hitherto for producing stone paper is that very large amounts of limestone from quarries have to be used, which can only be made available by very extensive recovery methods.In the following, the required outlay for conveying limestone from quarries is of importance:If there is a stone break, after very extensive and long test and test procedures.The process chain is initially composed of the removal of cover layers, which require considerable preliminary work as a room.The recovery is then carried out, for the most part by explosion and / or by the use of cable saws. Thereafter, the usable rock is transported to a processing plant according to its use. Here, the feed material is comminuted by means of crushers or mills and classified via sieves or, if appropriate, separators.Here, according to the invention, the use of shell shells as CaCOs carrier lends itself as a promising alternative in stone paper production, because shell shells have a similar chemical composition, inter alia with respect to CaCO 3, to lime products from quarries. Moreover, mussel shells must be treated as waste, the disposal of which is associated with considerable costs.In parallel with the continuous increase in world population, demand for mussel products is increasing, with China, India, Chile, Spain, and Italy leading to market. Worldwide, mussel production reached about 2.3 million tons in 2022, approximately 600,000 tons in Europe. More recent publications report even far more waste occurrences from mussel shells: "10 million tons of waste from oyster, mussel, jakobsha and mussel shells are produced worldwide, the disposed shells are frequently thrown into the sea or disposed of at landfills where they alter soils, waters and marine ecosystems" (Appl. Sci. 2023, 13 (1), 623). This immense amount of waste is to be considered non-compostable waste which can cause many environmental problems, with additional odour nuisance in the decomposition of the organic matter.Other sources report much higher mussel consumptions introduced in the nutritional circulation: marine mussel production by direct trapping has remained relatively constant (1.78 million tons per year) for the 1970s, but marine mussel aquaculture production has increased from 1.18 million tons per year in time 1970-1974 to 13.47 million tons per year in time 2010-2015 (Global Production of Marine Bivalves. Trends and Challenges. SpringerNatur 2018, pp 7-26).This amount of waste arises solely by considering shell shells which would have to be disposed of for nutritional reasons. However, very large rates of invasive, toxic mussel shell populations are also known worldwide. Here, one must mention the "zebra and quagga mussel". These compete with common species for resources and thus interfere with the natural balance of aquatic ecosystems, so enormous efforts to combat this species of mussel are known. The chemical composition likewise corresponds to the greatest possible extent to the composition of limestone from quarries. It is thus possible to use these abovementioned nutritionally and also the invasive waste products intelligently and thus to avoid the described disadvantageous accompanying phenomena.Further advantages, details and features of the invention will also become apparent from the following description of the drawing 1. FIG. 1 is a simplified representation of the apparatus for utilizing CaO 3 as a basis for the production of stone paper;In Fig. 1, (1) shows an apparatus for producing stone paper consisting of calcium carbonate and polyethylene. (2) depicts a reservoir of shell shells. In (3), the preparation of the shell shells (purification & grinding) is first carried out. In (4) polyethylene (5) is then added and these starting materials are thoroughly mixed. Via (6), this mixture is introduced into a pelletizer (7). These pellets are then shaped into stone paper with heat being supplied in an extruder (8). If necessary, this stone paper may optionally be coated in (9) by adding whitener (10) such as titanium dioxide, zinc sulfide white or other known additives to obtain a white surface. The surface treatment of stone paper with TiO 2 also offers the possibility of improving compatibility with printing inks and of improving ink absorption and adhesion to the paper. In (11), the product "stone paper" (11) is then available for a variety of applications.Of course, the examples described must be modified and supplemented in many ways without departing from the basic idea of the invention. Thus, the invention also relates to the method of producing stone paper from mussel shells containing CaCO 3- and polyethylene. Of course, other CaCO 3- containing wastes, such as egg and / or screw shells and a variety of other plastics, are also usable as binders for the CaCO 3- containing wastes.List of reference characters1 Apparatus for producing paper from mussel shells and polyethylene 2 reservoir for mussel shells waste 3 preparation of mussel shells 4 mixers for mussel shell powder (CaCO 3) and polyethylene 5 addition of polyethylene to mussel shell powder 6 prepared mixture for producing stone paper 7 pelletizer 8 extruder 9 coating apparatus 10 coating agent, e.g. TiO 211 stone paperReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Cited Non-Patent LiteratureAppl. Sci. 2023, 13 (1), 623

[0015] Global Production of Marine Bivalves. Trends and Challenges. SpringerNatur 2018, pp 7-26

[0016]

Claims

Device (1) for the production of stone paper (11) from mussel shells (2) containing CaCO 3- and polyethylene (5).Device according to claim 1, characterised in that the starting materials CaCO 3 of shell shells and polyethylene (5) are mixed in a mixer (4).Device according to preceding claims, characterized in that the mixture from mixer (4) is processed via line (6) in a pelletizer (7).Device according to preceding claims, characterized in that stone paper (11) is produced in an extruder (8) from mussel shells (2) containing CaCO 3- and polyethylene (5).Device according to preceding claims, characterized in that the stone paper (11) produced is optionally surface-treated in a coating apparatus (9).Device according to preceding claims, characterised in that the surface treatment in (9) is effected with a whitener (10), such as titanium dioxide, zinc sulphide white or other additives.