By Okoti Gilbert, Kenya Sugar Board
The ultimate objective of the Kenya National Climate Change Council is to stabilize industrial pollution concentrations in the atmosphere at levels that prevent dangerous human interference with the climate system, while allowing ecosystems to adapt naturally and enabling sustainable industrial best practices. This article focuses on green chemistry technology in sustainable industry, with a particular emphasis on its impact on the sugar processing sector.
The Kenyan sugar industry has undergone tremendous development and now produces a vast array of chemical products, including paper, fertilizers, pesticides, polymers, and CFCs. While many of these products have improved our quality of life, aspects of their manufacturing processes have had harmful effects on the environment.
To address waste management challenges, a range of environmental regulations has imposed stringent controls on the emission, discharge, and disposal of waste associated with sugar manufacturing. As a result, sugar industries have been compelled to implement standards that control the amount of gas released into the air, liquid waste discharged into water, and solid waste sent to landfills.
Green Chemistry Technology
The characterization of environmental problems often follows a simple equation: a hazardous chemical is released into the environment in some quantity, resulting in exposure and, ultimately, environmental risk. Green chemistry technology seeks to reduce these hazards and thus environmental risks by designing chemical products and processes that minimize or eliminate the use and generation of hazardous substances.
The 12 Principles of Green Chemistry can be summarized as follows: It is better to prevent waste than to treat or clean up waste after it has formed. Whenever practicable, synthetic methodologies should be designed to use or generate substances that possess little or no toxicity to human health and the environment.
Significance of Green Chemistry to the Kenyan Sugar Processing Industry
The sugar processing industry is not typically associated with pollution and waste; however, there are several potential areas of environmental concern that must be addressed before they reach problematic levels. The industry must recognize that waste is increasingly unacceptable and develop strategies to address it, including:
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Effluent treatment
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Better process control and recycling
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Improved process design
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Adoption of alternative processes
The first two approaches address pollution prevention through cleaner and reduced effluent, while the latter two—central to green chemistry—challenge the industry to re-evaluate and redesign processes. Better process design can reduce waste, while alternative processes may eliminate waste altogether.
The Kenyan sugar industry has begun to utilize waste as feedstock or sustainable resources for other industries. For example, biochar technology is being adopted for organic fertilizer production, ethanol is produced from molasses, and bagasse is used in briquetting systems.
The 12 Principles of Green Chemistry can guide the sugar processing industry in developing new processes that address its environmental challenges. Below are two representative examples of how environmental challenges within the Kenyan sugar processing industry are being identified and addressed.
Example of Materials Change: Elimination of Lead in Polarimetry
Lead subacetate has been routinely used to determine the purity of optically active sucrose solutions. However, the National Environment Management Authority (NEMA) determined that lead-containing waste cannot be discarded without proper treatment. Alternatives such as clarification using aluminum salts or membrane ultrafiltration were identified, but widespread adoption has been hampered by high costs.
Example of Process Change: Cane Juice Analysis by Near Infrared
While the previous example illustrates a positive material change, new procedures can sometimes outperform traditional methods both economically and environmentally. The development of Near Infrared (NIR) techniques for cane juice analysis is one such example. NIR analysis eliminates the need for harsh chemicals used in polarimetry, reduces labor costs, and is simpler and less time-consuming. With further modifications, NIR could be used for in-line monitoring, reducing personnel demands and aligning with the 12th principle of Green Chemistry.
Summary and Conclusions
Green chemistry aims to reduce hazards and environmental risks by designing chemical products and processes that minimize or eliminate the use and generation of hazardous substances. In addition to meeting market demands for renewable raw materials and feedstocks, the Kenyan sugar industry can address its own processing and production methods to maintain or increase yields while reducing waste production, handling, and disposal.
By incorporating the 12 Principles of Green Chemistry, the sugar industry can offer not only its core food product, but also environmentally friendly and cost-effective materials and consumer goods. Through these efforts, the industry can remain competitive and sustainable while contributing to a cleaner environment.