Interview with the Amar Flow Reactors Team (Prof Dalvi)

I am a chemical engineer. I did my bachelor's from UDCT (now the Institute of Chemical Technology). I have a master's in process engineering from the University of Twente (NL) and a Ph.D. in chemical engineering from the University of Texas at Austin, USA. My academic work mostly focuses on developing technologies that are imperatively decentralized (like solar heat and power, solar desalination, valorization of agricultural and municipal waste, open-source process simulation software, etc). The purpose is to enable low-skilled youth to earn a decent, dignified living by monetizing readily available resources.

I also consult with chemical, pharmaceutical, and allied industries. This is mostly related to the concept to commercialization work. I provide support for analyzing laboratory data to develop chemical kinetics models, using this data to do in-silico technoeconomic evaluation of processes and equipment and providing support for scaleup and commercialization. I have acquired expertise in downstream processes including crystallization, filtration, and drying – I have invented a novel algorithm for solving population balance equations for batch crystallizations.

I started working on flow reactors at Amar in May 2021. I was very excited by the great variety of options available for reactor and ancillary equipment selection. This has allowed me to engage all my intellectual faculties towards creative problem solving which I enjoy very much. It is also especially satisfying to see ideas being converted to products that find an industrial application.

The Amar team is exhibiting at Stall S1 at the FCS2023 on the 14th and 15th of September 2023. The talk is titled “Making Profits Flow”. It focuses on when and how to go for flow technology. A running theme in the talk is the need for a multidisciplinary team of engineers, scientists, and economists that gel well together and have learned to speak each others’ language. To give an example of how subtle misunderstandings can be: a process engineer will refer to the size of a reactor by its inner diameter while a mechanical engineer will use the outer diameter. For high pressure vessels, where the thickness is considerable, this can lead to disastrous miscommunication unless the team is constantly talking to each other.

You are right that bulk chemicals (with the exception of the wet phosphoric acid process) have been manufactured in continuous mode. It is very hard to imagine methanol or ammonia or sulfuric acid being manufactured in batch. The largest use of stirred tanks in series is in the alkylation reactors in modern refineries. So continuous manufacturing is nearly a century old.

What is new is continuous manufacturing for fine chemicals – and this is primarily due to economics. Fine chemical manufacturers normally produce according to market demand: in campaigns that can last a few months. They prefer to use equipment that can be readily repurposed for manufacturing a wide variety of chemicals. Hence the emphasis on large stirred vessels and batch distillation units. This remained the case as long as the chemical sector was small, demand was intermittent and cash flows were low. Also, the emphasis of chemical manufacturers was bringing new products to market quickly rather than efficiently. All this seems to have changed in the last ten years with chemical demand showing healthy growth and it has been helped along by the efforts of companies like Amar and others who now provide the chemical industry with viable partners with whom to build flow technology solutions.

Amar has developed new configurations in passive flow reactors (both plate and tubular) and actively agitated reactors (both internally and externally agitated). The passive flow systems work well where the reactants have low viscosities and are either miscible or where the kinetic energy of the fluid is high enough to supply the work of creating interfacial area. If we are faced with viscous flows or slurries we have to go for actively agitated systems. We will announce each type of reactor very soon.

In addition, at Amar we are developing a series of intensified reactor ancillaries including pulseless multipurpose pumps, active dampners and pressure regulators for difficult fluids (like high temperature viscous slurries).

The most common type of chemistry we have tried is nitrations. These are particularly hazardous to carry out in stirred tanks but can be executed readily in passive flow reactors. The era of industrial incidents caused by nitration reactors is rapidly drawing to a close. We also have had considerable success with very fast reactions like nBuLi reactions – which can be carried out at close to 0oC in flow against -40oC in stirred tanks. At the other end of the operational spectrum, we have carried out high temperature high pressure reactions (like amidations) very conveniently in flow.

At Amar we do supply glass microchannel reactors but we get very few enquires for them. Microchannel reactors or rather microfluidic devices are excellent for and are finding increasing application in rapid screening of chemical and biochemical systems including ideas like organ-on-chip. This could be an area we will venture into in the future, but right now our focus is commercial flow technology.

One of the delights of working in Amar is that the queries are very seldom repetitive. The use cases in fine chemicals are so vast and varied that we are never bored.

Very much so. But it is not only the price: which is, of course, a fraction of what the established players charge. At Amar we offer complete end-to-end support for concept to commercialization. Our very sharp, multidisciplinary team is responsive and regularly makes visits to the clients’ sites for fact-finding, installation, commissioning and post-sales preventive maintenance.

This brings me back to the theme of the talk. You must get a multidisciplinary team of scientists and engineers comfortable with each other and support each other in executing complex projects. A toxic work culture is the death of flow technology.

If anyone is thinking of flow, please consider our team at Amar. Think of us as your partners in flow. We would love to talk to you about your particular project and suggest ways in which we can help. We work with your comfort and you will find our commitment is equal to or exceeds yours.

Please contact at sales@amarequip.com for any kind of queries or concerns.