Industry consumes large quantities of solvents. These solvents, thanks to their ability to dissolve or disperse other chemical substances, are mainly used in separation processes where the solvent selectively dissolves a product from a mixture, or to reduce viscosity in some production processes (e.g., in paints and coatings). Solvents also appear in cosmetic formulations, in cleaning products, in medicines, in adhesives…
Traditional solvents
Many solvents have traditionally been used in industry: hydrocarbons (aromatics such as toluene or xylene, aliphatics, etc.), esters (such as ethyl, methyl or butyl acetates), alcohols (such as methanol, isopropanol), ketones (such as acetone, methyl ethyl ketone or cyclohexanone), glycols (such as butyl glycol or propylene glycol), halogenated (such as methylene chloride), etc….
They have a synthetic origin and most of them are derived from crude oil or olefins (ethylene and propylene, mainly). They are usually very well introduced in the market and are widely available and usually cheaply priced (compared to other raw materials used in the different formulations). They have very high solvency powers, usually with fast evaporation and meet all the expectations of the finished product manufacturers.
Why do we need alternative solvents?
However, many of these conventional organic solvents are flammable substances, harmful to the environment or to human health. This has put them under the spotlight of many regulations that have limited or hindered their use, for example by classifying some of them as carcinogenic or toxic for reproduction.
This is why the chemical industry is increasingly looking for alternative solvents offering greater protection to people and the environment, and less hazardousness, in order to have a safer use and to avoid restrictions imposed by the different laws in force.
A further advantage of reduced hazardousness is implicit in terms of product labelling.
Special hydrocarbons
The use of hydrocarbons in the chemical industry tends towards specialisation. A few years ago, the same solvent was used for almost everything. Instead, nowadays, special hydrocarbons are sought after; the right hydrocarbon for each case. Thus, some of the alternative solvents, although still hydrocarbons, incorporate improvements in odour emission, are safer for people or have a lower inflammation. These improvements, while better complying with current regulations, can optimise the performance of these alternative solvents.
Such hydrocarbons include dearomatised hydrocarbons and isoparaffins, among others.
Environmentally friendly solvents
Other alternative solvents are the so-called ecological solvents or green solvents. These are crude oil derivatives or synthetics that are less flammable and less aggressive and offer specific properties for specific applications. These are compounds generating less waste and, at the same time, less toxic than those currently in use. As a result, they are less hazardous to human health.
Environmentally friendly solvents include, among others, dibasic esters and propylene carbonate.
Renewable solvents
These are alternative solvents very similar to environmentally friendly solvents, but with the big difference that their origin is not from petrochemicals. For example, they are derived from glycerine (exclusively obtained from GMO-free vegetable oils). They are therefore harmless to human and environmental health: they are non-toxic, non-bioaccumulative, non-mutagenic, non-reprotoxic and do not cause skin irritation. They are also safe to store and handle.
These products have aroused growing consumer interest due to current market trends, which are increasingly oriented towards sustainability and the protection of our planet and its inhabitants.
Solvent mixtures as an alternative
Sometimes finding alternative solvents is not straightforward. There are some substances that, due to their unique characteristics, cannot be directly replaced by another one, instead it is necessary to make mixtures of solvents in which each of them can provide some of the original solvent’s characteristics.
Due to the hazardous nature of many of these products, many companies tend to buy these mixtures already prepared in order to avoid their handling and optimise costs. Quimidroga has been offering for many years the possibility of making tailor-made solvent mixtures in all types of formats.
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