In the continuation of this theme the author will now highlight the different alternatives that the paintings are looking for other alternatives to be produced without dependence on oil.
by Julián Restrepo*
Oil is a non-renewable raw material that is still widely implemented in different applications, including paints. In the first part of this article we saw how the consumption of this input grows while the reserves are reduced and also how the damage to the planet that is caused by its implementation increases.
Previously mentioned were some environmental problems that originated as a result of the use of oil and their relationship with the role played by the paint industry here. Global warming, climate change and ozone depletion were assessed in the previous article. We continue now with the formation of "Photochemical Smog" and the role of our industry.
The formation of "Photochemical Smog" or "summer smog" (since, in the northern hemisphere, it usually occurs in the summer months), which is mostly formed by the so-called "tropospheric ozone", "environmental ozone" or "bad ozone". "Photochemical smog" is air pollution in the form of clouds that has a brown to black coloration (also called "brown clouds"), observed mainly in urban areas. This type of smog was first described in Los Angeles in the 40s, and usually occurs in cities with a lot of traffic, warm and sunny, and with little movement of air masses [10].
In this case it is important to understand the differences between the two types of ozone: While the so-called "good ozone" ("stratospheric ozone"), is a natural atmospheric layer that is responsible for protecting us from UV rays, the so-called "bad ozone" is anthropogenic, since it is ozone that is created in the troposphere (it is located in the lowest area of the atmosphere, at the level of living beings), through a complex series of photochemical reactions, between nitrogen oxides (NOx) and volatile organic compounds (VOCs),1 which leads to the formation of ozone, HNO3, peroxiacyl-nitrate (PAN) and other polluting compounds.
In this sense it is important to bear in mind that ozone is an oxidizing and toxic compound that, in sufficient concentration, can cause respiratory problems to human health (from about 150 micrograms per cubic meter) and living beings (in vegetation, from 30 parts per billion), and also, contributes to "Global Warming".
These characteristics of ozone have led to the appearance, for example, in the European Union of a regulation on ozone in ambient air (Directive 2002/3/EC), which establishes the new Community legal regime on ground-level ozone in the lower atmosphere.
Based on the above, we can construct the following table as a summary of the environmental problems in which the paint industry participates:
Consequently, it would already be clear that, paints or better, the organic solvents used in the formulation of solvent-based paints only have an important participation in the environmental problem of the generation of "photochemical smog", while their participation in phenomena such as "Global Warming", "Climate Change" or "Depletion of the ozone layer" is much more moderate than what was thought.
The use of solvents for the manufacture of paints today can be very common for our generation and the previous ones, but perhaps not for future ones, based on the following reflection:
In addition to the environmental aspects, toxicity and other risks involved in the use of organic solvents, these are flammable substances, so they have a risk of fire and inflammation, both at the stage of manufacture and use of the paints that use them. So it is increasingly clear to understand why there is a stronger pressure to reduce the use of this type of compounds. We must bear in mind that the function of the solvent in the formulation is basically to facilitate the process of manufacture, application and formation of film, but due to their nature, these do not remain in the composition of the final coating and evaporate into the environment (so we could consider them as a "useful fool"). The point is that, as we have discussed, we are deliberately pouring into the atmosphere a material that is toxic, flammable, and also, with its use, and that is what will surely surprise future generations the most, we are causing an environmental problem.
Also, taking into account the aspects of Environmental Sustainability, we must consider the sources or natural resources from where we obtain organic solvents, since currently the main source is oil, and although there are several advances in the issue of solvents obtained from renewable sources, also called "green solvents", "renewable solvents", "benign solvents" or "alternative solvents", in many cases, the analyses of their true impact have not been carried out with sufficient scientific rigor or simply have not been carried out, which (trying to round off the idea), would result in the fact that we are not sure that these "new solvents" are really more benign for the environment, simply because it comes from renewable sources.
Consider, for example, the fact that, in the case of the approach to the solution to current environmental problems, agri-food alternatives are sought to obtain bio- or agro-fuels, where there is now the problem of competition between food in favor of fuels, which has led to the increase in food prices, disfavoring the poorest classes and therefore, further complicating the balance between what would be most advantageous to us, depending on the so-called Sustainable Development.
The Role of the Paint Industry
In this context, what role does the paints and coatings industry play? Well, this is how, for several years, the VOC content of paints has been reduced, in fact there are coating systems completely absent of organic solvents, and if you also consider, the fact that many manufacturers of raw materials in the industry already work under concepts of eco-efficiency, sustainable processes or in the reduction of many of the toxic and polluting products used in their processes, this shows the outstanding role of this industry in the development of more environmentally friendly processes and products.
Likewise, a review of the role of one of the most familiar solvents that surrounds us is observed, in fact it is the solvent of nature and is called the "universal solvent" (which is not of organic origin and therefore does not constitute a VOC!): Water. Thus, it is observed that new and diverse aqueous systems have managed to replace many traditional solvent-based systems, even in industries as demanding as automotive. This shows the significant adaptability of the coatings industry in facing the challenges it faces.
We can briefly analyze some examples of companies that have integrated concepts of high product quality and low environmental impact, as well as concepts of eco-efficiency, innovation and sustainability: the multinational paint company PPG Industries stands out, which is one step ahead in ecological mentality, since it considers sustainability as one of its pillars for a long time.
Many of the innovations introduced by this company, in recent years, have represented for its customers a competitive advantage, as well as for the environment, since it has been, for example, one of the pioneers in the launch of paints with low voCs [13].
Likewise, the multinational Monsanto has developed polyurethane resins from processes absent from phosgene (used in the conventional process); for its part, the German Degussa (now BASF), has developed successful commercial products from "design solvents", such as "ionic liquids", for use in the production of various dispersants, surfactants and plasticizers.
Conclusions
Although various environmental pollution phenomena can also occur naturally, such as the presence of ozone in the troposphere by descending stratospheric ozone, the natural ozone hole or natural emissions of VOCs, NOx and CO, as well as more complex phenomena such as "climate change" and "global warming", in this paper the effect of human action on these phenomena has been discussed, that is, the anthropogenic effect caused by the natural acceleration of these and especially the role of the paints and coatings industry, which only shows an important role in the formation of photochemical smog.
The fact that modern chemistry depends so intimately on oil and its derivatives, and that these reserves are becoming scarce, in societies more eager for means of transport, energy sources, the search for comfort and "new sensations", make it necessary, in a context of "global climate change", to search for alternative sources, such as renewable natural resources, which allow such chemicals to be obtained; in this case we are talking about renewable raw materials to obtain organic solvents. But it is clear that changing the sources from which these solvents are obtained does not solve the problem of contamination caused by them. To achieve an adequate balance, we must review the sources of where we obtain the solvents we use, as well as the use we make of them.
In this sense, therefore, there are those who affirm that "the use of solvents distinguishes a technological society", since in the case of paints, organic solvents are not part of the coating formed, and therefore go to the atmosphere causing an environmental problem: Not only money is lost by the deliberate dumping of a material for which the consumer is paying and that will not be part of the paint you apply, but it is a material that has associated various risks of toxicity, flammability and for the environment.
This is how, from the point of view of the so-called "Green Chemistry", we can affirm that, the best solvent is the one that does not exist! This is how we have seen a decrease in the VOC content of conventional paints, in favor of solvents more benign to the environment.
References
[12] (a) Montreal Protocol Manual with Text and Explanations (http://www.unep.ch/ozone/spanish/Publications/MP-Handbook-07-es.pdf); (b) http://es.wikipedia.org/wiki/Protocolo_de_Montreal
[13] http://es.ppgrefinish.com/es/acerca-de-ppg/ppg-industries/. You can also visit the PPG Industries corporate website: www.ppg.com, "Bringing innovation to the surface".
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8. They come mainly from the volatilization of organic compounds into the atmosphere, such as fuels, but one of their main sources are organic solvents, used in the paints and coatings industry.
9. Because much of the paint industry has already largely replaced the use of CFCs.
* M.Sc. Ph.D. Julián A. Restrepo R., Factory Service of PPG Industries Colombia, [email protected]
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