Research Projects

The proposal envisages the development of a novel pincer catalytic pilot-scale process for the production of precious C4 specialty chemicals such as n-butanol, 1-butene and 1,3-butadiene with high selectivity starting from inexpensive, feed-agnostic ethanol. The continuously changing feedstock landscape in petroleum refineries coupled with the recent shale-gas boom has severely influenced the global production of 1,3-butadiene, an invaluable building block for synthetic rubber, and nylon. Polybutadiene Rubber PBR and Styrene Butadiene Rubber SBR are high volume synthetic rubber catering to the fast growing tire industry. The Lebedev and Ostromislensky processes were key sources of butadiene up to 1970s, before being replaced by petroleum-based routes. Recently there has been a surge in industrial R&D interest in the bio-ethanol to bio- butadiene process owing to both environmental and economic concerns. While much efforts have been dedicated to turning the Lebedev and Ostromislensky processes into technologies capable of competing financially with current butadiene production methods, there has been very little efforts to design alternate technologies. In this context, the current proposal that envisages the two-step process for conversion of bio-ethanol to bio-butadiene via bio- butanol with excellent selectivity and high yield offers immense promise. At IITG, we have formulated efficient catalytic systems that transform bio- ethanol selectively to bio-butanol on a lab scale in a batch reactor. The catalytic system comprises of a pincer-metal catalyst at a very low loading 0.025 mol% or lower in the presence of base loadings as low as 2.5 mol%. One of the striking features of this process developed is the low operating temperature (ca. 100-170 C) and the relatively short reaction time 30 minutes. The n-butanol productivity is very high ca 10000 TONs with no compromise on selectivity (ca. 98%). The process has been protected by filing a patent (Indian Patent Granted. Grant Number: 477312) and a part of these results among others have been published recently (Chem. Commun., 2025, 61, 2906., Catal. Sci. Technol., 2020, 10, 8347 and 2023, 13, 1763). Based on this, novel bis(iminopyridine) and 2,6-bis(benzimidazole-2-yl) pincer-Ru catalysts with polar anchoring groups will be synthesized. While the pincer framework would impart the selectivity towards the ethanol upgradation, the polar groups would assist in anchoring the pincer-catalyst onto inert solid supports to render them the necessary recyclability. In comparison to ethanol, n-butanol as a fuel blend offers lower vapour pressure, higher energy density and reduced corrosiveness, and hence is easier to manage and transport without the need for costly infrastructure changes. These features have propelled n-butanol as a promising alternative to ethanol in the future of biodiesel. Akshai has demonstrated the ability of pincer iridium complexes immobilized on solid surfaces to catalytically dehydrogenate alkanes which in stark contrast to traditional heterogeneous catalysts, operate at relatively low temperatures (ca. 200 °C) and are recyclable. Akshai has 4 US patents in dehydrogenation technologies in addition to authoring 1 Chemical Review and about 10 publications. Based on this knowledge, novel bis(iminopyridine) and 2,6-bis(benzimidazole-2-yl) pincer-Ir catalysts with polar anchoring groups will be synthesized to generate selective and recyclable catalysts for the dehydration of butanol to butene and its dehydrogenation to butadiene and hydrogen. Under the able guidance of Dr. Raksh Vir Jasra who has decades of expertise in developing chemical processes, a process will be developed for producing 1kg of n-butanol, 0.8kg of butene and 0.7kg of butadiene/day using a 100 g fixed-bed microwave reactor. Further, using the expertise of Prof. Dipankar Bandyopadhyay in fluid dynamics, attempts will be made to develop advanced microfluidic reactors for large-scale production.