Dr Sadhana Rayalu, former Chief Scientist, CSIR-NEERI, played a key role in developing reduced emissions firecrackers. She is now Adjunct Professor at LITU, Nagpur. Dr Rayalu gave an email interview to Sophiya Mathew. How are green crackers different from conventional ones? Reduced emissions firecrackers, popularly known as green crackers, were developed to address environmental concerns and to protect livelihoods linked to the fireworks industry. Green crackers are “environmentally benign by design”, with a reduced chemical and environmental footprint. The term gained formal recognition in October 2018 from the Supreme Court. Green crackers are similar to conventional firecrackers in having typical pyrotechnic composition consisting of a fuel, oxidiser, and an optional binder to give structural integrity for special effects of light and sound. However, unlike conventional firecrackers, green firecrackers are based on the usage of reduced chemicals, and have potential for generating fewer emissions in the presence of multifunctional additives. What were the key pollutants targeted? Do green crackers emit more ultrafine particles, as studies suggest? The reduction in particulate matter and gaseous emissions is to the tune of 30–35%. Green firecrackers do not emit more ultrafine particles, and the findings are substantiated and reported in peer-reviewed high-impact factor publications. Is manufacturing green crackers more cost-effective? How? Green firecrackers are indeed cost-effective. The usage of oxidisers (potassium nitrate, strontium nitrate) and fuel (aluminium) has been relatively reduced in green firecrackers compared to conventional firecrackers, and substituted with low-cost multifunctional additives. This reduces emissions, and consequently has a positive impact on the cost of the green firecrackers. Is it possible to go completely ‘green’ where firecrackers are concerned? Extensive research is being carried out across the world for further reducing emissions and using eco-friendly chemicals and additives. Second-generation firecrackers meeting 45-50% particulate matter emissions reduction have been developed by TANFAMA (Tamil Nadu Fireworks and Amorces Manufacturers Association, an industry group based around Sivakasi), and Laxminarayan Innovation Technological University (LITU, a state university in Nagpur). The scientific approach or innovations for meeting 45-50% particulate matter emissions reduction include usage of hybrid oxidisers or additives or fuel, and of biodegradable ingredients. What next for the technology of green firecrackers and its applications? Efforts are in progress to establish a Centre of Excellence at LITU, Nagpur, on Green Pyrotechnics and Combustion Products to leverage existing infrastructure and expertise for exploiting the export potential of reduced emissions firecrackers (green firecrackers) and repurposing low explosive pyrotechnics traditionally used in civilian applications like fireworks. It is proposed to use low-explosive pyrotechnics for multisectoral applications including green combustion products (biomass pellets, eco-engineered coal, incense sticks), green processes (hydrogen, carbon capture), waste management, industrial products and devices (airbags), agriculture, and military applications.
