Green chemistry and its twelve fundamental principles Essay

Climate change is recognized as a major environmental menace affecting the ecosystem globally. The rapid industrialization of the world's economy has resulted in the expansion of human-caused greenhouse gases such as carbon dioxide (CO2), nitric oxide (N2O), water vapor (H2O), and methane (CH4) [1]. In November 2015, carbon dioxide level in the atmosphere was estimated to be 402.23 ppm the highest level in 650,000 years (http//climate.nasa.gov/evidence/). The exponential rise in global warming can be attributed mainly to human activities such as deforestation, agriculture, and decomposition of waste in landfills [2, 3]. Combustion of fossil fuel [4], exhaust emission from transport, and manufacturing of manure for farm animals produce huge volumes of greenhouse gases (http//climate.nasa.gov/causes/). The use of conventional chemical processes in the mining of oil, coal, and mineral increase the amount of atmospheric greenhouse gases, challenging governmental agencies and cooperate bodies to find alternative green chemical processes which can reduce pollution and make the environment safer for sustainable living [5].
Chemical research in the past decades has shifted focus from conventional pollution control mechanisms to innovative and much greener technological waste reduction right from source [6, 7]. Green chemistry is the design of chemical products and processes that are inherently safer to the environment [6-8]. Green chemistry specifically acts as the culture and methodology for chemists and engineers to achieve sustainability [9]. The green concept was launched by Paul Anastas in the United States Environmental Protection Agency (EPA) to design innovative chemical technologies to eliminate pollution [6, 9, 10]. The twelve fundamental principles written by Anastas and Warner [8] demonstrates the breadth and concepts of green chemistry (Table 1). Apart from the United States EPA, the United Kingdom, Canada, Italy, Japan, India, Brazil, China and Australia have initiated green network programs to promote research and development for sustainable chemistry practices (http//advancinggreenchemistry.org/).
Recently, supercritical fluid carbon dioxide, a much safer solvent form of CO2, has been employed in biocatalysis [11-14], asymmetric catalysis of functionalized tetrahydroquinolines [15], pretreatment of lignocellulose biomass [16], and for extraction of essential oils [17-20]. Deep eutectic solvents [21, 22] and ionic liquids [23, 24] are other green solvents gaining roots in organic synthesis, biocatalysis, and other chemical extraction methodologies. The use of renewable feedstocks for chemical products and bioenergy generation cannot be overlooked [25-27]. Modern analytical extraction techniques which uses little solvents such as single-drop extraction, membrane-based extractions, sorption-based methods, and fluid-phase partitioning methods have been reviewed [28-30]. Moreover, in the last decade, green chemistry research, education, and networking platforms have been gaining popularity, mostly in developed countries, leaving many developing countries behind. However, some application of green technologies have been reported in a few developing countries [31, 32], although this approach is still in its infancy. Using Ghana as a focus, we discuss the disadvantages of conventional chemical process technologies, and argue for the incorporation of green chemistry principles into research, chemical industries, and education to reduce or eliminate waste production. The possible challenges, opportunities, and ways to promote green chemistry in Ghana have been addressed in detail.