Introduction:
We
are surrounded by chemicals, in everything from shampoo and clothes to tarmac
and concrete. A sound management of chemicals is needed to avoid harm on humans
or environment. To obtain this, chemicals may have to be substituted, new
methods chosen or waste water treatment improved. To decide what action needs
to be taken, knowledge about the chemicals is a must. To safeguard the
environment, knowledge about the ecosystem risking exposure is also important.
We assess the environmental hazard of chemicals and the risk for the for the
environment. We have experience from developing criteria for suppliers and
finding alternatives with less environmental impact.
A Definition of Sustainable Chemistry
"Sustainable
chemistry is a scientific concept that seeks to improve the efficiency with
which natural resources are used to meet human needs for chemical products and
services. Sustainable chemistry encompasses the design, manufacture and use of
efficient, effective, safe and more environmentally benign chemical products
and processes."
Sustainable
chemistry is also a process that stimulates innovation across all sectors to
design and discover new chemicals, production processes, and product
stewardship practices that will provide increased performance and increased
value while meeting the goals of protecting and enhancing human health and the
environment.
Sustainable Chemical Management
The
Rise of Green Chemistry, Compared to environmental chemistry, which emphasizes
avoiding chemical processes and solutions that harm nature, green chemistry is
primarily concerned with developing technology that helps prevent pollution and
reduce consumption of non-renewable resources.
Benefits of Sustainable chemical
management
When
green chemistry is applied to the formulation of industrial solvents,
sustainable chemical management is one of the primary areas of emphasis, as it
helps accomplish the dual goal of green chemistry simultaneously: stop chemical
pollution, and minimize the use of non-renewable resources. For companies that
implement solvents that achieve the goal, three important benefits can emerge:
lower waste disposal cost, reduced solvent purchases, and the promotion of a
good business image.
1. Lower Waste Disposal Cost
Chemicals
that are sustainable in the sense of being re-useable inherently lower waste
disposal cost. Instead of entering the waste trap, the chemicals get recycled
and help preserve room in the trap. The trap will eventually fill or need to be
emptied before at capacity to remove a certain chemical, but reusable chemicals
help reduce the frequency at which the trap is purged.
2. Reduced Solvent Expense
Chemicals
that are reusable also reduce solvent expense. For example, if a parts washing
system is designed to recycle a degreaser for reuse in the parts washing
system, the recycled degreaser would be used at least twice. Using rudimentary
math, implementing this type of solvent could foreseeably reduce solvent
expense by an estimate of roughly 50 percent.
3. Good Business Image
At
a time when advancing environmental consciousness and improving safety in the
workplace with eco-friendly solutions are sweeping goals, consumers and
businesses like to support companies and organizations that have decided to “go
green.” Companies that use sustainable solvents that green chemistry pioneers
can put the feather of sustainable chemical management in their cap, use it to
improve public relations, and even use it for marketing purposes.
Benefits of Sustainable Chemistry
Ø The environmental and
societal benefits of sustainable chemistry include:
Ø Avoiding the use of
persistent, bio-accumulative, toxic, and otherwise hazardous materials;
Ø Using renewable resources
and decreasing consumption of non-renewable resources,
Ø Minimising negative
environmental impacts of chemical processing and manufacturing;
Ø Providing technologies
that are economically competitive for and advantageous to industry.
WHY SUSTAINABLE CHEMICAL USED IN TEXTILE INDUSTRY?
Conventional
chemical processes based on fossil fuels are unsustainable. Green reactions are
sustainable, more efficient resources, easier to use eco-friendly. They are
assessed by twelve principles, the most important being the amount of waste
generated. The textile industry is considered as the most ecologically harmful
industry in the world. Recently a number of steps have been taken to make
textile processing greener. These include use of greener fibre, greener dyes
and auxiliaries, greener solvents, eco-friendly, optimised and efficient
processing, bio-processing, recycling of textile, water and chemicals and
elimination of hazardous chemicals.
Green
chemistry is the chemistry thatDoesn't hurt nature,
Ø Reduce or eliminate the
use or generation of hazardous substances,
Ø Provides more eco-friendly
alternative,
Ø Prevents formation of
waste,
Ø Creates new knowledge
based on sustainability i.e. sustainable chemistry
Ø Takes a life cycle
approach to reduce the potential risks throughout the production process. Life
Cycle analyses (LCAs) enable a manufacturer to quantify how much energy and raw
materials areused, and how much solid, liquid and gaseous waste is generated, at
each stage of the product's life.
The
conventional chemical manufacturing processes are unsustainable because:
Mostly
carbon-based products are derived from fossil fuels, petroleum and coal which
have limited supply.Large amounts of waste increasing burden on the
environment.Environmental chemistry studies the effect of environmental
pollutants, whereas green chemistry deals with new sciences and technologies to
prevent the formation of any waste. In developing countries, although there is
growing awareness about the ill effects of pollution, promotion of continual
introduction of environmentally friendly products a methodology in the chemical
industry needs to be developed further. Usage of non-conventional technologies
is highly popular in India. First in this list is the usage of microwaves.
Further, the microwave chemists are turning their attention toward
microwave-assisted dry-media reactions in order to minimize solvent usage, an
added advantage to already established microwave chemistry. In addition to
microwave-assisted reactions, ultrasonic and photochemical reactions are also
used as non-conventional reaction technology. The strict application of the
Euro norms and the drive for switchover to Compressed Natural Gas as an
alternative fuel are some of the examples of the endeavours made by India
towards creating a greater eco-friendly environment.
ADVANTAGE OF SUSTAINABLE CHEMIALS
Prevent waste: Design chemical syntheses to prevent waste, thereby
eliminate/minimise waste treatment processes. It is better to prevent waste
than to treat or clean up waste after it is formed.
Maintain atom economy: There should be few, if any, wasted atoms.Use safe chemical
synthesis methods.
Use low toxic products: Use fully effective but safe or non-toxic chemicals and
products.
Choice energy efficient processes: Prefer ambient temperature and
pressure reactions.
Use renewable feedstock: Use non-depleting renewable agricultural products or the
wastes of other processes and not products derived from fossil fuels.
Omit derivation steps: Follow least number of sequential chemical steps, and
choose direct reactions.
Catalysis: Catalytic reactions generate minimum waste – its little amount can
carry out a single reaction many times. Gold is an outstanding catalyst for
oxidation processes.
Safer solvents and auxiliaries: Use aqueous or other safe media.
Degradation
of chemical products: Choose chemicals degradable to harmless substances.
Real time analysis: Minimise/eliminate by-products by real-time monitoring and
control.
Safety: Assure minimum chemical accidents.
Water can be saved in dyeing in the following ways:
Ø Reuse dyehouse water.
Ø Reduce reprocessing.
Ø Optimise rinsing and
soaping processes.
Ø Reduce Liquor ratio.
The application of enzymes in various stages of textile processing may be
listed as follows:
Desizing: amylase, lipase.
Scouring: pectinase, cellulose.
Bleaching: oxidoreductase. xylenes.
Dyeing: oxidoreductase.
Finishing: cellulose, oxidoreductase, lipase.
Composting:cellulose, protease, nylons, polyesters.
Delignification, decolourisation of dyes: laccases.
Conclusion and Future Trends
Sustainable
chemical management provides a technical solution to many environmental
problems. It is effective due to design stage efforts, starting at the
molecular level lets one to design out the hazardous properties and to design
in environmentally appropriate features.
Written By Arif Morshed Khan
