Green Chemistry: Innovation for a Sustainable Future
These same principles can also be applied to most other industrial activities that derive from chemical processes, making them more environmentally benign by-products, using renewable resources, and avoiding the use of non-renewable materials. Green chemistry is defined as a science-based innovation to design chemical products and processes that reduce or eliminate the use and generation of hazardous substances.
Definition and Principles
Green Chemistry, also known as sustainable chemistry, is a chemical philosophy encouraging the design and manufacture of chemical products in a way that reduces environmental pollution and promotes human health. Green Chemistry is an essential aspect of more sustainable chemistry.
It is about designing chemical products that are safe and non-toxic for the environment and human health, which in turn contributes to the implementation of sustainability at all levels. Innovations in existing technology will inevitably be furthered and will play a role in maintaining and improving both the standard of living and the human/environment relationship.
These innovations will further accelerate the drive towards more Europe-centered research and initiatives.
There are many ways chemists can make the reactions they perform in the lab safer and less polluting. As a guide, chemists can employ the well-established set of principles of green chemistry to make the necessary changes in the laboratory.
Green chemistry, the design of chemical manufacturing processes and industrial applications in order to reduce emissions of toxic substances and the amount of hazardous waste, is far more than just environmental policy; it is also a philosophy and a way of doing business.
The 12 Principles of Green Chemistry provide a conceptual framework and the required guidance of fundamental drivers needed to achieve low-impact and zero-waste processes. They include the design of processes that prevent waste, the promotion of atom economy, the use of safer chemicals and solvents, and the design for degradation.
They encourage the use of renewable resources and the manufacture of products that are designed for energy efficiency and the careful analysis of the synthetic design, which could prevent the generation of pollution from feedstock and result in products that are ultimately benign.
This also means considering the life cycle of a wide range of chemicals, including both petroleum-based and renewable feedstock raw materials, through the end production of materials and products, to recycling and final clean-up. By investigating structures of the future, it will be possible to contribute positively and creatively from a societal, environmental, and commercial perspective.
We need to define the desired final properties and outputs and then focus on developing the corresponding chemistries; to some extent, the tools for the future stem from understanding the vision of the future itself.
Historical Development
Sustainability in chemistry is a fairly recent invention that came into being in the late eighties with the coining of the term environmentally benign synthesis. The core ideas of synthetic methodologies that are benign by design predate this novel term, but the field picked up significant momentum in the early nineties upon the first publication of a 'green' chemistry research article in a major journal.
As the field of green chemistry grew, some key publications helped to define the newly formed community and garnered widespread attention, causing rapid evolution in this area of research. The pre-automotive era saw the need for a green substitute to the hampering pollution caused by the excretion of horses.
In particular, the disastrous side effects of chemical warfare during the First World War and increasing awareness of environmental pollution led to enormous increases in the funding for academic basic research, specifically related to clean technologies.
Parallel to the emergence of environmental movements, there was a notable surge in the research and development of green chemistry. As the focus shifted to the importance of hazardous waste remediation, an international workshop on hazardous waste in 1987 exposed various hazards resulting from chemical products and crop protection agents.
Environmental organizations and industrial groups pressured regulatory agencies to act upon this hazardous threat by demanding that manufacturers stop meddling with nature and instead fight waste output.
In addition to the generally increased research subsidies and environmental legislation, the following list of significant guiding initiatives and legislative documents solidified the ground on which green chemistry operates today. In light of these critical historical developments, it is evident that fundamental changes in public perception and awareness have influenced the evolution of the principles and practices of green chemistry.
Importance of Green Chemistry
Green Chemistry contributes significantly to reducing the ecological footprint of different production processes presently employed by industry. In a broad perspective, the Green Chemistry methodologies will lead to more sustainable processes aiming to achieve less negative ecological impacts.
The more adherence to the principles of Green Chemistry in a specific process, the more optimal solutions are implemented to decrease the toxicity of the ingredients, which leads to a lower environmental impact and less volume of generated waste.
Thus, the ramifications of adopting Green Chemistry principles would be in the domain of waste minimization, pollution prevention, and reducing the negative ecological impact and problems that result in human health, competitiveness of the industry in the market, economic growth, and social conflicts as well.
Green Chemistry provides a technical method of handling hazardous and harmful substances, and also preserving non-renewable resources. From an economic point of view, there are four mechanisms by which Green Chemistry practices are growing; it includes lowering the costs of compliance, competitiveness of the industries, avoiding fines and penalties, gaining a larger share of the global marketplace, and achieving breakthroughs in utilizing biomass.
With several tools that are currently in research and development for the design of safer products and more efficient and less hazardous chemical processes, Green Chemistry will supplement the financing for end-of-pipe waste treatment. With the ultimate goal of benefiting society and improving both human and environmental health, Green Chemistry seeks to make this entire life cycle of a chemical more sustainable.
Environmental Benefits
The prime focus of adopting a green chemistry strategy is the reduction of environmental pollution through the measurable minimization of hazardous substances released to the environment. It is generally agreed that the reduction of hazardous substances is a minimum requirement for achieving a sustainable future with regard to ecosystem health and biodiversity.
This may be accomplished through preferential selection of chemicals and chemical processes that reduce pollution at the source and simultaneously conserve natural resources, thereby achieving the goals of environmental management and conservation.
More specifically, the avoidance of synthetic routes that produce waste, such as the use of solvents, reagents, and processing conditions that generate hazardous products, would achieve the two goals mentioned above. One of the strategies toward resolving industrial environmental problems is to develop processes that minimize waste. Since most waste is hazardous, the manufacturing of such products is beneficial in achieving the goal of green chemistry.
Another environmental benefit of green chemistry is the long-term replacement of finite fossil resources with renewable biological resources supplied by plants, which absorb CO2, a greenhouse gas that is considered to be one of the major contributors to global warming.
Therefore, substituting synthetic chemicals derived from petroleum and natural gas-based feedstock with renewable chemicals is one of the benefits of green chemistry. Also, as many of the chemical and pharmaceutical products on the market have been identified as hazardous, as well as their precursors, it is not only the products that are being banned, but also those with precursors that are not so hazardous but are susceptible to undergo metabolic transformation to lead to the production of hazardous end products.
By using safer chemistry, the chances of synthesizing such types of hazardous products could be minimized. Mitigative action in the chemical and pharmaceutical industry regarding public health should be resolved in part through sustainable chemistry innovations, such as green chemistry.
The level of environmental cleanliness strongly influences the quality of air, water, soil, aquatic, and terrestrial ecosystems, and therefore all forms of life on Earth. Consequently, proactive chemistry already breeds several wins for the environmental front.
This kind of innovation and responsible management of natural resources is also a gateway tool to promote and protect biodiversity and the ecosystem as well, even without addressing or enforcing any environmental policies and regulations.
Economic Advantages
Implementing green chemistry principles offers significant economic advantages. Companies that adopt these practices can make use of feedstocks more efficient. This, in turn, reduces manufacturing costs, waste, and makes recycling operations unnecessary.
By minimizing waste, a company can see a clear increase in profitability. Companies that engage in green marketing and product innovation have also capitalized on new market opportunities that require contributing to green chemistry research, development, and design that offer economic, as well as environmental, advantages.
As companies shift to using new feedstocks and sustainable processes, such as using biomaterials instead of oil-based materials, new jobs and new research and development activities are created. The industry can also engage in public and private partnerships to create regional green chemistry hubs that advance green chemistry science and technology, build workforce capacity, and increase economic development for communities.
By developing more sustainable products and processes, a manufacturer can also minimize potential fines. For example, a company that has minimized the waste from its production process via an optimized synthetic route to a select catalyst is less subject to liabilities than a company that continues to generate a waste-to-product ratio.
Further, consumers are increasingly becoming attracted to more sustainable options and have expressed a willingness to pay more for products provided that the additional price is linked to some environmental attribute of that product, service, or activity.
Real, observable concern for environmental impact and clear benefits related to environmental impact make the difference in consumer choices. As people become more aware of green products and as sustainability is even easier to demonstrate and verify with numerical credibility, the demand for greener products will only further increase in the marketplace.
As more and more governments are placing an expanded scope on renewable products, including biobased products, an early understanding of green chemistry's potential for commercial applications would facilitate the passage of new and enhanced regulations. By understanding what green chemistry is and how it is created, innovative companies can adapt to new regulations in order to deliver innovative, greener products.
Key Innovations in Green Chemistry
Over the past 25 years, green chemistry has made significant strides in addressing several metrics that showcase industries' need to be more sustainable. A critical shift occurring within green chemistry is the utilization of renewable feedstocks to supplement and replace our ideals surrounding non-renewable feedstocks.
Viewing chemicals as intermediates, industries can begin to utilize biomass as a way to reduce their costs and long-term dependence on increasingly hostile markets. Green catalysis and catalytic processes are equally pivotal tools in the reduction of energy and waste streams of conventional research potential.
By definition, catalysis is the art of speeding up a chemical reaction without being consumed in the process. The catalyst is continually recycled after each utilization. This focus has played a critical role in academic and industrial research, as the development of increasingly effective catalysts can minimize energy usage and reduce the formation of hazardous waste by-products.
Having high solution phase concentrations can be equally helpful in aiding catalytic transformations. This can be exemplified by the use of peroxide radicals to assist in bleaching dyes, and/or with the aid of transition metals to initiate the propagation of radical initiators during curing reactions. Industry is driving rapid change, and research into continuous flow reactions rather than batch chemistry is becoming increasingly important.
This specialization in catalysis greatly reduces the residence times of reactants to the catalyst and minimizes the formation of by-products that generally increase with prolonged reaction times. It is important to continuously engage in fundamental and applied research to promote and drive the green chemistry manufacturing innovation platform.
The challenges of the present and future must be continuously tackled with new developments and eco-friendly solutions. Cutting-edge research will aid in developing reliable, scalable solutions that can be universally adopted in industrial practice.
Renewable Feedstocks
Among the many facets of green chemistry, an important area of investigation assesses the impact of using renewable feedstocks, i.e., bio-based resources, in replacement of their fossil-based counterparts.
This is sometimes viewed as the first industrial step in the transition from using fossil feedstock within refineries to the concept of biorefinery, where the range of products and by-products (fuels, chemicals, and materials) will be expanded once oil has been replaced, in some cases, by a liquid and/or gaseous stream from a biological route.
In the case of chemicals production, replacing oil-based raw materials, which often require fine petrochemical synthesis whereby much of the feedstock is converted into waste rather than value-added products, with biobased resources, much of which end up as waste albeit lower value raw material, can often result in more efficient use of the carbon content in the process.
For a more comprehensive introduction to the use of renewable feedstocks, the reader is referred to some key documents published by the US Department of Energy: Top Value-Added Chemicals from Biomass Volume 1—Results of Screening for Potential Candidates from Sugars and Volume 11—Results of Screening for Potential Candidates from Lignocellulosic Feedstocks, both methodologies published in the Action Plan, the Multi-Year Plan, and the proceedings of biannual conferences and journals, beginning with an international conference in 2007 called Biorefining, in which different forms of bioethanol and biodiesel were discussed.
Some details of that event are given in a magazine issue. For one thing, utilizing a side product of sugar production, the low calorific value bagasse, for partial replacement of starch in the brewery route allowed enriched extraction of high value protein.
Catalysis
One of the key innovations in green chemistry is the development of catalysis as an enabling science, which facilitates chemical transformations with minimal waste of energy and resources. Catalysts work by providing a "shortcut" or alternative pathway to the reaction, so that the rate of the reaction can be greatly enhanced and the reaction can be performed under more practical conditions and often with higher selectivity.
These advantages are particularly interesting for the development of more sustainable industrial processes, as they enable waste and energy consumption to be significantly reduced. Typical advantages that catalysis can bring to sustainable organic reactions include shorter reaction times, lower temperatures, fewer by-products and waste generation, reduced energy consumption through fine-tuning of the reaction mechanisms, improvement of selectivity, and reduction of the amount of toxic solvents used in the processes.
In recent years, there have been extremely significant advances in the field of catalytic materials. Novel catalytic materials, especially nanostructured and nanoparticle catalysts and/or catalytic supports, and the development of the relevant preparation and characterization protocols have been made available.
This has led to the possibility of further advancements in many chemical processes. In addition to novel inorganic catalysts, particular attention has been given to the development of catalysts based on standard and improved biocatalysts.
Biocatalysis represents both an enabling science for the field of sustainable chemistry and a resultant sector of fast-growing interest. This is because it harnesses the beauty of nature and the efficacy of living cells to perform chemical transformations with high precision and selectivity, potentially even in water as the sole reaction media.
The fast technological improvements allow for more and more complex operations to be incorporated and developed. This is having an impact in many areas, from environmental chemistry to medical chemistry, from sustainability to technology and beyond.
Applications of Green Chemistry
Our place in the global ecosystem is an issue that has significantly captured the public mood. The word 'green' has not only infiltrated our lifestyles but has also infiltrated our language and even our homes. Interior decorators now offer green paints, which have a low toxic burden, and many buildings have been audited for conforming to environmental and energy-saving specifications.
If we adopt the same environmentally friendly outlook aimed at ridding our homes of toxic substances, then should we do likewise with our chemical activities, particularly as toxic chemicals have been known to produce nuclear winters disastrous for human life? Green chemistry has many virtues, but on the most practical level, it is a treasure trove of product innovations.
Some of the biggest changes will occur in the materials and energy business. Energy is produced by burning fossilized plants, by dividing nuclei, and by harnessing wind, wave, tide, and sun. Green chemistry becomes involved in the latter two ways.
Green chemistry lies at the heart of proposed electricity-producing solar cells as well as solar cells of an entirely different kind, which release hydrogen, which can be used to power trucks and cars. In addition, biomaterials can be converted into established utilities. Some synthetic polymers are notorious for sticking around and causing pollution.
Green chemistry is busy converting biodegradable wood cellulose into textiles, whereas newer methods see us using bacterial polyesters as biodegradable plastics. Green chemistry is also looking at oil-derived biodegradable polyesters and a waterborne precursor to a new class of resins that can be used in the production of new bioplastics.
In the little-known field of bioplastics, biodegradable and non-biodegradable bioplastics are seen as key future applications of green chemistry. Green chemistry is providing radical new applications for the flavor and fragrance industry as well.
Pharmacists are now screening new green compounds for synthesis and commercial use. The use of green chemicals in agriculture can bring about some dramatic changes, not least in pest control. Research is ongoing in HFC reduction and in identifying less harmful pesticides. There are useful derivations of free radical reactions that might help the chemist to achieve this. Special focus has been on the use of supercritical carbon dioxide as a commercial solvent and on enzyme technologies.
Green Energy Production
The urgent need for sustainability is observed particularly in the world energy situation. Due to predictable energy scarcity, the quest for technological innovation that supports sustainable energy production and enhances industrial input/output efficiency, and thus sustainability, is becoming more and more urgent.
At present, advanced greenhouse gas-generating technology contributes significantly to the energy production industry. The fossil fuel-based systems have supplied about 86% of the US energy over the past decade.
It may also lead to greenhouse gases and other environmental contaminants. Due to global warming, the generation of greenhouse gases from the combustion of fossil fuels is a much-researched topic. Merging green chemistry into energy industries has shown strong potential to solve some of these long-due problems, reduce greenhouse gases, and improve energy efficiency. The use of green chemistry techniques in energy production is being discussed in this subsection.
According to their indefinitely expressed potential, renewable energy sources such as solar, wind, geothermal, hydropower, and bioenergy are fascinating energy sources. The 'green diffusion' of renewable energy is supported by a significant financial investment.
A fruitful, smart energy storage and transformation concept increases the need for renewable energy. In the electricity of today, both refrigeration and lighting need to be informed. A significant selection of current energy transitions is underway.
The target is that the electric sector will be inherently carbon neutral by 2015 outside the heating and cooling sector. Green chemistry can be integrated throughout the various components of the value stream already present within the green energy industry.
The different sub-components are addressed in the following sections. Past successes and failures have been evaluated and documented. The formalized steps are used for all successful case studies taken from these reports, and there are typical steps included in the design of the green chemistry process. A brief overview is now given of how green chemistry can be built in several common components of green energy.
Biodegradable Polymers
One of the most significant problems related to conventional plastics is their resistance to biodegradation, representing a direct departure from the innovative principles of green chemistry. In recent years, the environmental problems caused by petroleum-based plastics have created an urgent need for biodegradable materials.
A variety of approaches have been reported to produce biodegradable polymers from more sustainable resources. The derivation of renewable polymers from the microbial fermentation of sugars has attracted particular attention. Increasing the utilization of crops and lignocellulosic materials for bioplastics could have beneficial effects, such as more favorable climatic impacts, energy savings, decreased reliance on petroleum feedstocks, landfill minimization, and the prospect of more localized waste management practices.
Biodegradable polymers and plastics represent an important development of green chemistry. They do not elicit the environmental problems created by conventional plastics since they can be gradually mineralized in the presence of suitable microorganisms into elements such as water, carbon dioxide, and biomass.
These materials can find several potential applications. For example, biodegradable polymers and plastics could be used as flexible films in packaging fields, for manufacturing shopping and waste bags, agriculture films, blown foils for food packaging, and to prepare foams. Additionally, they can be employed in several markets including textiles, automobiles, toys, agriculture, and horticulture.
To date, volumes of production and market shares of biodegradable polymers and plastics remain very limited compared to those of petroleum-based products. However, according to some prognoses, these figures should increase in the near future, thanks also to the increasing consumer demand for safer and cleaner products.
One of the major drawbacks of biodegradable polymers such as PLA is their high production cost, so several studies are now ongoing to improve their carbon footprint, processability, performance, and compo-stability. In particular, PLA is considered a versatile material that has recently attracted a growing interest in its modification strategies.
Challenges and Future Directions
Green chemistry aims to contribute to building a sustainable future by improving the composition and performance of chemicals and materials. However, the field continues to face considerable barriers that hinder it from fulfilling its potential.
Among these hurdles are regulatory challenges, including the necessity of revised policies to better support green chemistry. Uncertainty in funding for fundamental basic science and the urgent needs for green development also pose significant challenges.
One clear target, in our opinion, is to increase the scope of where the international community interacts for academic, industrial, and governmental management collaboration, such as fostering the development of regional innovation clusters in green chemistry to parallel clusters for basic science and engineering innovation. At NTU, we will launch clusters of international research in green chemistry and future technologies that chemically save energy, reduce emissions, and remove toxic and dangerous components from manufactured items and modern infrastructure.
We will also make it a priority to identify R&D opportunities in sustainable materials and processes. For example, we lack the true next-generation majority feedstocks for chemically created items, high purity, and select chemicals, so they can be discarded without contaminating modern infrastructure.
Innovations in chemistry, however, can generate such feedstocks from benign renewable sources if we invest in R&D, education, and knowledge dissemination. Collaboration in the context of education is also an important future direction.
There is an urgent need to transform the chemistry workforce so these skilled employees can identify and promote the business values of green chemistry. Innovation in the scale-up from science and training of the workforce must become a research focus. New tools that are applied to R&D and stakeholder perception in this sense are also needed.
A central question that few studies have directly examined is how marketplace and stakeholder perspectives on public perception can affect a given field or technology, such as green chemistry, in addition to using merchant assets to understand the social context in which scientific research is done.
Academics, industry, and government should all play a role in addressing these grand challenges in green chemistry-related priorities of R&D. In a real sense, we can address these challenges only if we contribute together to achieving advances in green and sustainable chemistry.
The field is only a part of a community dedicated to converting basic science to world welfare. The current state of green chemistry manifests an ongoing journey. Rapid and visionary scientific advances, committed to sustainability and improving the human condition through chemistry, can only be achieved if scientists collaborate and work toward an integrated research and development program.
We must also engage in the larger societal dialogue surrounding innovation, energy, and environmental sustainability, which we believe is crucial to set the path forward, recognizing the interconnections among not just different forms of research, but among scientific research, education, economic development, and public policy. Only by forming this powerful relationship among science, education, industry, and society can the national program in green and sustainable chemistry fulfill its mission.
Regulatory Hurdles
Regulatory implementation is an important constraint for green chemistry. The existing legal framework may act to block the re-emergence of practices that were once common in the US. Policymakers need to support not only the commercial or practical development and dissemination of green technologies but also the research and development of green chemistry experimentation.
Regulatory harmonization across continents is essential in the global economy. When green chemistry is heavily regulated in a European or North American setting and is integrated into various products, the role of labeling becomes very integral to the market success of new chemicals or chemical products.
All companies want to export, but for large companies selling in a global economy, they must be able to transpose regulatory impositions into a global marketplace; they must re-engineer any products for multi-jurisdictional systems to reduce costs globally.
For companies devising regulatory strategies for new chemicals such as bio-derived chemicals or catalytic ammonia production, much of the material to carry out regulatory compliance work is not concentrated, strategic, checklist-driven substance management; it is scattered across R&D laboratories, design engineering departments, safety assessment departments, and intellectual property offices.
Until all of this information can be assembled, it will be impossible to ascertain how much time, effort, and cost will be involved, although the development of advanced strategies that mitigate risks and lead to compliance and expected profits are fodder for companies hoping to address these difficulties using comprehensive product stewardship.
Policymakers can approach such challenges, either when they pertain to existing chemicals or new chemicals, by integrating early on in such systemic processes to help research potential new regulatory strategies, including creating public-private partnerships to fund such work during crisis situations. Policymakers should also examine means to facilitate partnership models for industries and academia so that both can benefit from collaborative research and development to ensure a bottom-up regulatory implementation strategy.
Governments can also fund or steer other systems to help improve access to markets for green chemistry innovations by enabling pre-commercial procurement systems operating in a manner that is consistent with international trade agreements.
Research and Development Priorities
For both the present and the future, there are a number of highly valuable research and development (R&D) topics where innovation will result in an important and sustainable advantage. Obviously, developing new processes and products crucially depends on an intimate knowledge of the markets of interest.
Below is a non-exhaustive list of high-priority R&D areas that illustrate the promise, challenges, and opportunities to move away from the traditional approaches to current practice by embracing sustainability.
It is important to relate the nanotechnologies and biotechnologies for practical innovations; they would almost always be used in combination as a package of solutions for promoting sustainability. Lastly, all of these areas are so broad and complex that they require highly interdisciplinary programs for significant advancements likely requiring millions or even billions of euros of additional funding that are hardly obtainable from existing R&D funding for nanotechnology because the expertise to meet these challenges is rare.
Fundamentally, green and sustainable chemistry is about the development of new processes and the whole suite of new products that arise from the use of more environmentally friendly methods. Broadly speaking, such new processes can be grouped into sustainable systems, via 'alchemy' or via new technologies.
A program specifically addressing the supply chain can currently be considered but not necessarily the only option for future government investment, as the technology is more incremental and only partially sustainable as it does not necessarily drive down the selectivity to equi-molarity.
This syllabus is largely a future market pull, so it is feasibility study based or basic feasibility and doing more of the same and more of the existing UK base at synthesizing new discovery. Given the complexity of many of these subsystems and their dependencies, it is hardly necessary to spell out that an interdisciplinary approach for each of these research areas is required.
The study of the products and processes investigated further will require more in-depth consultation with the end-user industrial community because adequate representation was not shown in the scoping study to date. Interests cover the chemical supply of the new products of various kinds of hedge funds, synthetic and human receptor ligands, potential hydrogen carriers, or for refining oil and gas and catalysts generally.
Green chemistry funding and investment should also cover coordination and basic research and interdisciplinary areas in the possible future program. In addition, a case exists for inorganic chemistry and nanotechnology. Multi-institutional and multinational collaborations and thus funding at a variety of scales should be encouraged.
Collaboration must extend to industry and UK regions and to other government and non-governmental funding agencies. It is important that funding bodies and advisory bodies are made aware of and review green chemistry funding recommendations that have been ratified by industry; thus, it is essential to get industry representation on all committees related to green chemistry strategy and funding. New interdisciplinary projects will provide novel options.
In this way, it is hoped that scientific discoveries will be made. This requires funding over the long term and cannot be left to industry. Universities should create exciting new careers for young and emerging chemists, displacing in part those attracted to medicine, dentistry, and other fields. There should be money for undergraduates and for postgraduates in these interdisciplinary areas of study. There should be encouragement for the more mature chemist to reskill. This will complement and enhance the maturity of the system.