The threat posed by climate change, and the contamination of major cities, means that the population is increasingly aware of, and worried about, the consequences of the treatment given to the environment, the excesses to which we submit it, and the possibility that these excesses may lead to difficult and irreversible situations.
There is an increasing consensus regarding the need to put into practice industrial processes that do not endanger or compromise our future capacity to satisfy current and future needs. As such, sustainable development is an absolute necessity and the governments of the majority of countries are attempting to put into place measures to ensure that its implementation becomes reality.
The sustainability of any industrial process is based on four main pillars, namely management of the waste produced, management of the water consumed, management of any gaseous emissions, and optimization of its energy requirements.
Management of the waste produced
Optimal waste management is that which leads to the generation of no waste. Or, otherwise, that which generates the lowest possible quantity of waste. The prevention and minimization of waste production is the basic objective to be achieved as first option as minimizing the quantity of waste generated is the best way to reduce the environmental impact.
However, in practice it is very difficult to completely avoid waste production. Consequently, alternatives that allow this waste to be reused must be found. This results in a reduction in the consumption of some raw materials while providing an efficient outlet for the waste.
If the waste generated cannot be reused, the next step involves attempting to recycle it, in other words, using it for another application. If none of these options are possible, and prior to final disposal of the waste, it is recommended to attempt to recover all the energy possible using processes such as gasification, pyrolysis, or incineration.
Management of the water consumed
Another key aspect as regards the sustainable development of an industrial process concerns water management. As we have seen for the case of solid waste, the most satisfactory option is not to generate wastewater. However, this extreme is usually not feasible. Consequently, generation of the smallest possible volume of wastewater should be the priority. With regard to the wastewater produced, the most sustainable option comprises an exhaustive treatment that allows a sufficient quality for the water to be reused to be achieved. Recovery of water from the waste flow for reuse also minimizes the consumption of water external to the process. The current state-of-the-art of numerous technologies makes this management alternative a real possibility. However, if the wastewater generated is not used for whatever reason, it still needs to be treated to remove the contaminants prior to being discharged, thus meaning that its discharge has no type of environmental impact.
Management of gas emissions
The industrial process must avoid any situation that results in an emission of contaminant gases into the atmosphere. The most sustainable, and often the cheapest, alternative is to modify the process in order to avoid, or at least minimize, the production of contaminant gases. However, this option is not always viable.
When the generation of contaminant gases cannot be avoided completely, efforts must be made to treat them. Fortunately, several highly competitive techniques that allow contaminant gases to be converted into harmless gases are available.
Optimization of energy consumption
Sustainability and the economy go hand in hand as far as energy consumption is concerned. Indeed, all optimization strategies lead to the same objective, namely reducing nett energy consumption as far as possible. This overall objective can be achieved by working on different aspects. For example, by modifying processes that are not efficient from an energy viewpoint and even replacing them with other, more efficient designs. It is also possible to combine different processes used in the same industry to take advantage of possible synergies. The energy that needs to be dissipated in one process may be of use in another operation for which energy needs to be supplied. Possible cogeneration options, where a waste with sufficient calorific value or a residual energy source can be used to generate electrical energy, can also be explored. The operation of a cogeneration system results in a lower nett energy consumption.
Thus, the adoption of measures to economize resources, whether material or energetic, improves the productivity of the industrial process while making it environmentally more sustainable. Indeed, it brings together the intangible respect for the environment with a likely cost saving. Moreover, the legislation currently being adopted by the majority of governments is tending to ensure that the cheapest option often turns out to be the most environmentally sustainable.[/vc_column_text][/vc_column][/vc_row]