Principles of green chemistry in the paint and coating industry

Melissa Peron e Sá Carneiro de Sousa, Luiz Claudio Mandarino Freire, Ricardo Luiz Fernandes Oliveira |Petrobras Distribuidora S/A
Green Chemistry (also known as Ecochemical or Sustainable Chemistry) is an emerging area designed to develop eco-friendly products or production processes. In recent years, through the adoption of activities in these new areas, interest in chemical innovation has been successfully harmoned with the objectives of sustainable environmental development and the feasibility of industry and the economy.
this paper introduces the general principles on green chemistry, including the historical concepts and 12 principles related to the subject. The paper also analyzes the products of two coating industries under the principle of green chemistry: propylene from glycerin produced in biodiesel plants, and sugar from lilac cellulose, which is then produced by ABE fermentation. We apply some of the 12 principles of green chemistry to these processes because they are related to the coatings industry. Finally, we have come to some conclusions and made some suggestions for further study.
green chemistry
can be defined as a chemical route from renewable resources. The historical approach adopted is to deal with the use of these by-products, which, whenever possible, bring additional revenue to production1. Green chemistry is directly related to the triangle of sustainable development (see figure 1), i.e. environmental, economic and social issues form the three pillars of the triangular structure.History of Green Chemistry
The Green Chemistry Movement began in the early 1990s and is concentrated in the United States, Britain and Italy, introducing new values and ideas for different chemical activities and related areas of the chemical industry and economic activity. This proposal was soon extended to the International Union of Pure and Applied Chemistry (IUPAC) and the Organization for Economic Cooperation and Development (OCDE) to develop guidelines for the development of green chemistry on a global scale2.several countries have initiated initiatives on green chemistry, such as the
Inter-School Alliance for Environmental Chemistry, founded in
1993 (Italy); (United States);
. Green Chemistry Program of the United States Environmental Protection Agency (United States);
. Green Chemistry Network (United Kingdom), established by the Royal Society of Chemistry in 1998;
. Other initiatives in Germany, Australia, Canada, Japan, Spain, Sweden and Russia3.in Brazil, brazil's Green Chemical Network Structure (RBQV) is being implemented, as shown in Figure 2.The mission of Brazil's Green Chemistry Network is to promote and develop technological innovation in green chemistry and Brazil's medium- and long-term scientific skills, with the aim of reducing environmental impact and achieving sustainable environmental, social and economic development1.strategic themes of the Structure of the Brazilian Green Chemistry Network (RBQV) are bio-refining (thermochemistry and biochemical routes), ethanol chemistry, glycochemistry, petrochemicals, phytochemistry, CO2 conversion and renewable energy1.12 Principles of Green Chemistry
After hosting the United Nations Conference on Sustainable Development (Rio 92), Paul T. Anastas, a member of the United States Environmental Protection Agency (EPA), proposed 12 principles for green chemistry, listed below.
1． Prevention
better prevent waste generation, rather than treating or cleaning it after it has been generated.2． Atomic economy
method should be designed to maximize the conversion of atoms from raw material molecules used in the process into target products.
3． Less hazardous chemical synthesis
regardless of its usefulness, synthesis methods should be designed to use and produce substances that are virtually or completely toxic to human health and the environment.4． Design safer chemicals
chemicals should be designed to achieve the desired functionality while minimizing toxicity.5． Safer solvents and additives
in possible, do not use auxiliary substances (e.g. solvents, separators and other substances) and, if possible, non-toxic substances.6． Energy efficiency
should minimize the energy needs of chemical processes from an environmental and economic perspective. If possible, the synthesis method should be performed at room temperature and atmospheric pressure.7． The use of renewable raw
as long as technically and economically feasible, raw materials should be renewable, not consumed at once.8． Reduction of derivatives
in possible, unnecessary derivativeization (with closed syringes, protection/protection, temporary changes in physical/chemical processes) should be minimized or avoided, as these steps require additional reagents and can produce waste. 9． Catalysis
catalysts, not a large number of reactants. 10． Degradation Design
chemicals should be designed to degrade into harmless degradation products after completing their functions and cannot be permanently present in the environment. 11． Real-time pollution prevention
need to further develop analytical methods for real-time, online monitoring and control before hazardous substances are generated. 12． Chemicals that are themselves safer for accident prevention
substances and forms used in the chemical process should be chosen to minimize the likelihood of chemical accidents, including releases, explosions and fires. Applications of Green Chemistry
We have selected two related products for the coatings industry, propylene glycol and butanol, which are used in many areas of the chemical industry, particularly in the coatings sector. propylene glycol
propylene glycol (1,2-propylene glycol) is a tasteless, colorless oily liquid that absorbs moisture and is easily mixed with water, ketones and chloroform. This raw material is used in the production of pharmaceutical products, food, cosmetics, pesticides, solvents, detergents and coatings, etc.5. In the Brazilian market, propylene glycol is used in the production of a wide range of products, including polyester resins, engine coolants, latex paints, heat transfer fluids, de-icing agents, mesh cleaners, lubricants, plasticizers and additives in cement grinding. It can also be used in pharmaceuticals, personal care products, cosmetics, food and animal food6. in the field of coatings, propylene glycol is an important solvent for water-based inks used in the construction field and can also be used as an intermediate for the production of aolic acid resins for color paints and varnishes6. Propylene glycol helps protect the coating, helps with surface corrosion, provides stability as an antifreeze, protects buildings and weather resistance, and ensures floor quality and aesthetics in high-traffic areas7. this study explores the petrochemical route and the chemical route of glycelycerol. petrochemical route
industrial production of propylene glycol using petrochemical route is a hydration process using epoxy propane. the temperature of the non-catalytic process used by different manufacturers is approximately 473.15K and 15 standard atmospheric pressures5, and the catalytic process can be performed at lower temperatures (423.15K to 453.15 K) with ion exchange resins or a small amount of sulphuric acid or alkali. The final product contains 20% 1,2-propylene glycol, 1.5% 1-propylene glycol and a small amount of other polypropylene glycol.
Glyglyceride chemical route
from the production of propylene glycol from glycerol produced by biodiesel, in the presence of a metal catalyst (based on copper, nickel or palladium) and hydrogen, glycerol catalytic hydrogenation; 5 shows the overall reaction to the production of propylene glycol, another product is 1,3-propylene glycol, by-products are glycol, methanol and water. brazil, propylene glycol is not produced on an industrial scale. Research is still on a smaller scale, and Brazilian companies have a potential market for developing this technology because of the large amount of glycelyceel that is obtained from the production of biodiesel. According to the National Authority for Oil, Gas and Biofuels (ANP), production of yellow glycerine, which is 80 per cent high, was about 300,000 tonnes in 2012. The data are based on 2012 biodiesel production data from the National Authority for Oil, Gas and Biofuels (chemical measurement reaction: 10 per cent production of crude glycerine and 80 per cent production of yellow glycerine). The green chemical principles used to produce propylene glycol using the glycelyceride chemical route: Principle
2: Atomic Economy
Principle 2, based on the reaction to produce propylene glycol (Figure 5), are calculated as follows:
if another reaction is taken into account Species 1,3-propylene glycol, the efficiency can be greater, 1,3-propylene glycol also has commercial value, can be used as a monomer in polyester production or as a polyurethane, lubricant and pharmaceutical products production chaining agent 10. 5: The total reaction of glycelycerides to the production of propylene glycol and ethylene glycol.
Principle 4: Designing Safer Chemicals
In order to apply this principle, an investigation was conducted into the use and disposal of propylene glycol by companies associated with THEIVESP (Industrial Paints and Coatings Union of the State of S?o Paulo). 25 of the 55 member companies associated with SITIVESP responded to the request. Forty-eight percent (12) of these companies use propylene glycol in the production of coatings and resins, and only two companies can still use propylene glycol at the end of the process. In this case, the product is stored in a bucket and then sent out for recycling. can therefore be proved under principle 4 that propylene glycol can be considered a safe product because it does not damage the environment and its waste can be reused. principle 6: Energy efficiency design
principle 6 can also be easily proved. The route of using glycelor consists of three basic steps: yellow glycelor purification at temperatures below 473.15 K 11, dehydration of 12 glycelycerides at temperatures of about 573.15 K to produce ketones, and finally 13 between temperatures of 473.15 K and 573.15 K, ketones and hydrolol. , on the other hand, the first step in the route of using epoxy propane is the high-temperature decomposition of tartan oil (i.e. the process that occurs at temperatures of 973.15 K to 1173 K)14 to produce propylene. An oxidation or chlorination reaction (temperatures from 298.15 K to 473.15 K) then occurred to produce epoxy propane 15, followed by propylene propylene hydration at about 473.15 K. This temperature is a non-catalytic process. In the case of process catalysis, the temperature should vary between 423.15 K and 453.15 K5. the process of producing propane through epoxy is higher, mainly because it is pyration of tartan oil, which means more energy consumption than propylene glycol produced through the glycelium chemical route. principle 7: The use of renewable raw materials
it can be observed that principle 7 also applies, since the glycelic used comes from glycelor extracted from biodiesel plants as raw materials for the production of propylene. As an example, we give the following reaction (Figure 6), where glycerine is a by-product of biodiesel production. exchange reaction is a chemical reaction that occurs under catalytic action by plant or animal oil esters (triglycerides) and alcohols (methanol or ethanol). The reaction products are fatty acids methyl or ethyl esters and glyceroid. At the end of the process, the catalyst is removed by reacting with hydrochloric acid. Figure 6 shows the ester exchange reaction 12 via the methanol route. 6: Ester exchange reaction via methanol route.
butanol
are four isomers (positive butanol, iso butanol, butanol, and statin), the first two commonly used as solvents used in resins and varnishes. Ordanol, also known as n-butanol, is the most commonly used solvent and can be mixed with alcohols, ketones, aldehydes, ethers, glycols, aromatics and fatty hydrocarbons, and also has a relatively high solubility in water. , also known as iso butyl alcohol, is an alcohol with a boiling point of 381.15K. Low relative molecular quality alcohols, such as butanol, are often commonly used solvents in protective coatings and colorants. acetate is the most important ester used in coating formulations and their derivatives because they are excellent solvents for many natural and synthetic resins such as acrylics, polyurethanes and nitrate cellulose, and are also commonly used as solvents for varnishes, wood varnishes and various commonly used coatings. acetate is widely used as a volatile solvent in the production and construction of various paints and as an inhibitor for coatings16. acrylates obtained from butanol are usually polymerized to form acrylic co-polymers and thyme co-polymers. They are used to produce resins, water-based inks, paper coatings, impregnated and decorative materials, and adhesives17. can be produced by fermentation or petrochemical routes, as explained below. Petrochemical route produces butanol
isobutanol and orthobutanol by carbide synthesis (CO-H2), a process that involves a propylene-based synthesis process that produces cortisone or isobutylate, followed by hydrogenation reduction to produce alcohol, as shown in Figure 7. 7: Block diagram of butanol production in petrochemical routes.
two Brazilian companies, Elekeiroz and Oxiteno, use petrochemical routes to produce butanol. According to the Yearbook of the Brazilian Chemical Industry Association, the Elekeiroz plant produced 150,000 tons/year in 2011, while the Oxiteno plant produced 10,000 tons/year 18.