Green Chemistry and Catalysis

Basic principles of green chemistry include prevention, less hazardous chemical synthesis, safer chemicals designing, use of inexhaustible or renewable feedstocks, derivatives reduction, catalysis, degradation, analysis for pollution prevention, safer solvents and auxiliaries etc. These principles allow scientists and engineers to preserve and benefit the economy, people and the planet by innovative ways to reduce waste and conserve energy. They are also helpful in discovering replacements for harmful substances.

Waste reduction, also known as source reduction, is the method of using less material and energy to reduce waste generation and preserve natural resources. Some of the ways to reduce waste include:

·         Using reusable materials

·         Purchasing wisely and recycling

·         Composting

·         Restraint the use of paper

Reuse is defined as the practice of using a material over and over again in its present form. It is the second preferred waste management alternative after waste reduction method.

Recycling is the process of collecting waste and processing those materials and turning them into new products instead of throwing them away as trash.

Hazardous waste management is the process of collecting, treating, and discarding of waste material. This waste material when improperly handled, can cause significant harm to human health and to the environment. The improper storage and disposal of hazardous waste frequently pollutes surface water and groundwater supplies which results in water pollution and can also be a source of threatening land pollution.

An analytical method or technique is a method which is used to determine the concentration of a chemical compound or element in a sample. There is a very broad variety of methods used for analysis which afford different degrees of sample devising and instrumentation. 

As there is a growing interest in green chemistry it needs modern views on analytical extractions. Reduced solvent utilization, safer solvents, and cheap energy demands should be balanced with former analytical issues. 

The Green Chemistry provides:

·         A huge range of challenges to those who follow chemistry in trade,

·         An equal range of opportunities in new chemistry, to boost the economic science of chemical producing substances (which doesn’t involve materials that are toxic to the surroundings).

The green chemistry deals with the applying of environmentally friendly chemical compounds within the varied areas of our life like industrial uses (from plastics to prescription drugs). However, these industries have the potential to significantly harm the environment. Thus Green chemistry serves to look after environmentally benign chemicals and chemical processes.

Green Chemistry controls environmental pollution by using different kinds of green alternatives to conventional methods:

• Solvent free reactions
• Microwave assisted solvent free Organic Synthesis
• Green Organic Analysis
• Qualitative Inorganic Analysis
• Quantitative Analysis using flower petal extracts

Environmental eco-friendly and sustainable methods to be used in daily life:

• Biodegradable Plastics
• Eco-friendly Paint
• Green Bleaching agents
• New Lighting technologies
• Biofuels

In the pharmaceutical industries, there is a need for consideration of the waste product as a number of by-products are produced. Thus innovative strategies on chemistry are the core for pharmaceuticals, so the main point is gathering technology and chemistry to improve lives of patients and minimize environmental impact. Green chemistry also plays a major in developing innovatory drug delivery methods which are less toxic and more useful, effective with minimum side effects and could help millions of patients

In the past years, for the production of Adipic acid industrially, benzene is used as a beginning material (Benzene is one of the basic chemicals for industrial reactions and a solvent). It is known that it derives mainly from the refining processes of the petrochemical industry. Later the starting material became cyclohexanone or a mixture of cyclohexanone and cyclohexane. For the oxidation process it was used nitric acid, producing toxic fumes of nitric oxides, which are also responsible to the greenhouse effect and the destruction of the ozone layer in the stratosphere. It was certain that the method had to be changed again with more environmentally cordial reactions.

Green food production often suggested the organic farming practices a few centuries ago. This type of organic farming uses a small area of land for crops and another area for grazing cattle. Farm entities were almost always independent with no use of pesticides/ herbicides and the only manure was used as fertilizer.

Primary, secondary, and tertiary processing techniques are discovered to produce value-added foods and ingredients. Primary processing techniques like cleaning, sorting, and milling are used as first step in processing.

• Managing nutrient cycles in crop and cattle with green techniques
• Reduce carbon footprint
• Environmental performance of organic farming

One of the most encouraging technological approaches to reduce environmental footprint in food processing is the use of enzymes. Enzymes speed up reaction rates. Food enzymes provide advantages in

• Specificity
• susceptibility
• non-toxicity
• high activity at low concentrations
• ease of inactivation

The biosynthesis of nanoparticles has been suggested as a worthwhile and environmentally affable alternative to physical and chemical methods. One of the green chemistry approaches is plant-mediated synthesis of nanoparticles that connects nanotechnology with plants. Novel methods of ideally synthesizing nanoparticles:

• temperature
• neutral pH
• low costs and
• environmentally friendly trend

Considering these objectives, nanomaterials have been synthesized using many routes. However, for many important aspects of synthesis with environmental considerations, involves the choice and study of nontoxic capping and reducing agents, the selection of safe solvents and therefore the evolution of energy-efficient artificial strategies.

Green energy (also known as renewable energy) comes from natural sources like wind, water, and daylight. It is environmentally friendly than other forms of energy and doesn’t contribute to Global warming. These energy resources are renewable in the environment.

• Biofuels and bioenergy
• CO2 capture, storage and utilization
• Energy storage and network

Most commonly used renewable power technologies are solar, wind, biogas, geothermal, biomass and emerging technologies like wave and tidal power. There are both environmental and economic benefits of using renewable energy which include:

• Generating energy that produces no greenhouse gases from fossil fuels  
• reducing some types of air pollution
• Diversifying energy supply and reducing vulnerability on imported fuels
• Creating fruitful development and jobs in manufacturing, installation, and more

A green economy is defined as an economy that focuses at reducing environmental risks and ecological shortage, and that aims for feasible development without degrading the environment.

Principles of Green Economy:

• enables all people to create and enjoy success
• promotes impartiality within and between generations
• safeguards, restores and invests in nature
• geared to support sustainable utilization and production
• Guided by integrated, liable and resilient institutions.

Green synthesis is systematic protocol for the synthesis of various biologically active compounds with various molecular structures. The chemical reactions which are under microwave, ultrasound irradiation follows a green chemistry approach by

• decreasing reaction time
• development in product yield
• enhancement in rate of reaction
• reducing formation of waste

This technology is nature-friendly by eliminating the use and generation of hazardous chemicals and utilization of renewable raw materials. 

Catalysis is defined as the process by which a substance speeds up a chemical reaction without being consumed or altered. Substances that can fulfil this remarkable feat are termed as catalysts. Apart from accelerating reactions, catalysts also have another important property i.e, they can influence the selectivity of the chemical reaction. Catalysts can be gases, solids or liquids but most commonly used industrial catalysts are liquids or solids.

Classification of catalysts:

• Homogeneous catalysts
• Heterogenized homogeneous catalysts
• Heterogeneous catalysts
• Biocatalyst

Agriculture plays a unique and important role in sustainability, providing food at a rational cost to current and future generations. Sustainable agriculture refers to the farming practices that understand and are also conscious about the effects farming has on an ecosystem. In order for agriculture to be sustainable, it must have the objective of sustaining groups, farmers, and resources. 

Rules for sustainable agriculture:

• it also has to be profitable
• must not sacrifice the quality of life of farmers, the families of farmers, and farm communities as a whole
• must take into consideration the feasibility of each of its practices, making sure to preserve the resources used

Bio-separation is defined as the method of purifying biological product on large-scale. The aim of bio-separation is to refine molecules, cells, and components of cells into refined fractions. It is usually recognized that the industrial success of biotechnology products extremely keen on product development and application of high-powered separation and purification ways.

Analytical techniques embrace a stimulating of activity ways, isoelectric focusing, and mass spectrum analysis. Among separation and purification ways:

• liquid-liquid distribution
• displacement action
• dilated bed sorption
• membrane action
• simulated moving bed action  

Bio-based products are those goods which are made from renewable biogenic material (also called “biomass”). The most commonly used types of biomass are:

·         sugar

·         starch

·         plant oils

·         wood and natural fibres

Bio-based products generally provide an alternative to conventional petroleum derived products and include a varied range of offerings such as grease, detergents, inks, fertilizers and bioplastics.”

Bio catalysis is defined as the use of natural substances like enzymes from biological sources or whole cells to speed up chemical reactions. Enzymes have crucial role in the catalysis of many reactions that include production of alcohols from fermentation and cheese by breakdown of milk proteins.

Recent advances in the field of scientific research have helped to understand the structure and functional activities of enzymes, which results an increase in their stability, activity, sustainability, and substrate specificity. At present, there are hundreds of different bio catalytic processes that have been executed in various industries like pharma, chemical, food, and agro-based industries. In embracing bio catalysis as a mainstream technology for chemical production, we will be introducing a technology that is

• Greener
• reduces pollution and cost
• creates greater sustainability

Biofuels are those which are derived from newly dead or living plant material and animal waste. The frequently used biofuels are ethanol and biodiesel. Biofuels are divided into four “generations,” or categories based on the raw materials used to produce them. They are:

·         First generation - food related sources

·         Second generation - non-food sources

·         Third generation - algae

·         Fourth generation – other sources

Some energy sources, such as sun and wind are considered sustainable because   they are renewable. Biofuels are also considered renewable because you can grow biomass feedstock again and again to produce biofuels continuously. The biofuels is considered as one of best source of alternate energy to overcome the future energy demand. Alternate energy is the best option with respect to the environmental pollution.

Future Trends in Green Chemistry includes the following:

• Supramolecular Chemistry
• Catalysts and Oxidation Reagents
• Biometric Multifunctional Reagents
• Non Covalent Derivatization Techniques
• Combinatorial Green Chemistry
• Green Nano chemistry