The creation of knowledge and its effective transfer to users is our cherished mission. We are working in the areas of Multiphase reactors particularly Trickle-Bed Reactor,bubble/Slurry bubble column reactors, Motionless mixers etc. In this era of globalization there is a growing awareness that environment protection and economic development must go together.

Prof. Nigam has published more than hundred research papers in international journals. Recently, he has published a book titled 'Three phase sparged reactors', Gordon and Breach, 1996, in association with Prof. A. Schumpe (Germany). The high impact and significance of Prof. Nigam's work can be judged from the extensive citations it has received in research literature, research monographs, Perry's handbook of Chemical Engineers and textbooks. His students (graduate and undergraduate) have won various national awards such as CSIR young scientist award, best paper award of IIChE and INAE Innovative students Projects award (B.Tech).

He has served as a member of Scientific Advisory Committee of Ministry of Petroleum & Natural Gas, Government of India. He is also a member of different Research Advisory Committees such as Fertilizers Association of India, Engineers India Limited, Indian Oil Corporation Limited and Regional Research Laboratories of CSIR. He had also served as honourable Council Member of All India Council of Technical Education, GOI. Prof. Nigam's international reputation has brought him the various Fellowships from prestigious international organizations such as Alexander von Humbolt Foundation, Deutscher Akademischer Austauschdienst, British Council, French Government, Cambridge University (U.K), University of Saskatchewan, Canada and Rensselaer Polytechnic Institute, Troy. He has large numbers of research cooperation with prestigious foreign institutions.

Prof. Nigam is researching several promising possibilities to develop a cleaner and greener technology for trickle bed reactors. A novel reactor configuration for the countercurrent operation of trickle bed reactor has been proposed. The pressure drop is lower and liquid holdup is higher increasing the overall performance of the reactor due to improved wetting of the catalyst. Trickle bed reactor mostly operates under prewetted conditions; there is very little possibility that contact angle difference will play a role there. The reasons for the hysteresis is that while retracting, the edges of the liquid rivulets, which flow down the porous solid packing are held up by the pores of the packing and are not allowed to retract. While advancing, there is no such barrier and on the contrary these pores will help in spreading. An innovative experimental setup has been designed, which is simple and easy to fabricate called as Sliding Tackle to Counter Pinning. This equipment can be used to measure pinning forces, which are very difficult to measure otherwise, which will be of immense use in petroleum refining industries where porous catalyst is the heart of the technology development.

He is very actively involved in the academia and industry interaction for the energy conservation in Fertilizer industry. He has proposed an innovative design of heat exchanger called as 'Coiled Flow Inverter' based on novel concept of flow inversion. The proposed innovative device has potential for the multi-functional applications in the process industry such as, inline mixer, chemical reactors, separation process, and cryogenic applications.

He has also introduced a new class of Static mixers 'Four Zone Axial Mixers'. These mixers intend to homogenize feed streams subject to variations in concentration or temperature. A general design approximates the axial mixing performance of a CSTR without need for moving parts. The residence time distribution closely approximates an exponential distribution. The devices do very little mixing in the radial direction and thus behave like a completely segregated stirred tank. They may be used advantageously in series with a conventional static mixer.

Trickle Bed Reactors

Coiled Flow Inverter:A Novel Device for Process Intensification

Another problem industry faces is with mixing at low Reynolds numbers; we have been looking into different inline mixers and have developed a novel inline mixer named as “COILED FLOW INVERTER” (CFI) whose performance is practically of Plug Flow. This property of the device provides potential to be exploited for many applications not only in process industry but also in other fields. We have shown the superiority of CFI with respect to conventional inline mixers & heat exchangers. Some schools in Europe (ECPM Strasbourg, TU Dortmund and TU Eindhoven) have started working on our CFI device for polymerization & extraction processes. We are also engaged in demystifying the physics of fluid flow in complex three dimensional flows using CFD, RTD and other modeling& simulation tools.

The developed CFI device at IIT Delhi has received global attention including German company Bayer for following applications in process industry.

                                                                                            Different Application Areas of CFI

Green Technology

The development of Environmental friendly Technology for the removal of Heavy metals from Spent Catalyst obtained from Fertilizer & Petroleum refining industries. The developed chelation technology for metal extraction at our school have also been now applied for recovery of metals from electronic waste.

In order to achieve above goals considerable efforts were placed to generate research funds and createfacilities including the construction of a three storied building which housed the following facilities:

(i)      Pilot plant facility to test coiled flow inverter as heat exchanger

(ii)    Pilot plant facility for trickle bed reactor operating upto 40 atms and 120⁰C

(iii)   State of art laboratory for spent catalysis (GCMS, TGA, BET,TOC and BOM CALORIMETER)

(iv)  High pressure & high temperature bubble column reactor       

(iv)  Computational facilities for CFD modelling & simulation