PSA oxygen generators at hospitals not a panacea, says Moloy Banerjee

In an interview with Jyoti Mukul, Moloy Banerjee, head of gases-South Asia, Linde South Asia, talks about capacity building and the merits of setting up PSA plants to meet medical oxygen demand

Industrial gas producers had to quickly ramp up their medical oxygen production capacity in India due the devastating second wave of Covid-19. Among those supplying a sizeable percentage of medical oxygen was Linde Plc through its subsidiaries Linde India and Praxair India. In an interview with Jyoti Mukul, Moloy Banerjee, head of gases-South Asia, Linde South Asia, talks about capacity building and the merits of setting up pressure swing adsorption (PSA) plants to meet medical oxygen demand. Edited excerpts:

What were the challenges when demand for oxygen increased over the last year, especially since the second Covid wave was not expected? 

During the first wave, the demand went up by about 3.5 times. We were supplying up to 1,000 tonne a day during the peak, which was mid-September last year. During the second wave, we were supplying close to 3,000 tonne. The main difference between the two waves is the Covid infection rate. Consequently, oxygen dem­and went up pretty sharply during the second wave. So, the challenge was to adjust to the abruptness with which it went up.

With the government deciding on oxygen quota, did the companies feel restrained and under pressure?

The government actively got involved during both the waves, which was helpful because there was a lot of conflicting push and pull from every state and hospital. There are distress calls, but then capacity is limited. So, we were trying to figure out where we needed to prioritise and where we didn’t. The empowered group dealing with oxygen did a great job of helping the companies prioritise. They were issuing allocation orders and telling us how much oxygen to supply to different states. Our challenge was also logistics — how to shift the oxygen from main production centres in the east to Maharashtra and north India. What was needed more was liquid oxygen production because that can be transported in tankers.

Are you planning to expand the oxygen production capacity in India?

We are planning to set up an additional 1,000-tonne-a-day separation capacity to beef up oxygen, nitrogen and argon production, with about 75 per cent of that being oxygen capacity. We have already started work on the first plant in the south and then we will follow it up with additional air separation units in the west and the north. We are also actively discussing with ISO container suppliers and the government. The government has given us timelines in terms of how long we need to plan and hold on to these assets.

With oxygen plants being installed at hospital sites, do you think demand for medical oxygen from players like you will come down?

The PSA (pressure swing adsorption) oxygen generator is not a panacea, or a solution to all problems. When a hospital is treating Covid patients and when the demand goes up, it ramps up to 7-11 times. The PSA generator is only going to provide the X amo­unt; the 9-10x still needs to be provided by liquid oxygen. And when Covid subsides, economic considerations will come to the forefront for hospitals. That’s the whole risk about putting in PSA oxygen generators. But the situation is still evolving.

The second issue with PSA oxygen generators is that they use technology that uses molecular sieves, which degrade over time. When you buy a PSA plant, it performs well in the first year but the performance keeps going down over a period of time. This is a genuine problem, which hospitals that bought PSA generators in the first wave are facing. I have heard they are only getting 70 per cent capacity, and their purity has come down from 90 per cent to 80-85 per cent. The solution that Linde offers is that we own and operate plants at the hospitals, so they do not have to worry about degrading performance as we keep topping up the sieves. I don’t think PSAs are going to make a big dent. If they had to, then you would have seen them everywhere in the world.

Did you have to use your overseas oxygen manufacturing capacity or tankers for oxygen supply to India?

Liquid medical oxygen is moved in ISO tanks, which need to be imported. We approached our customers, Tata Steel and ITC, and told them we needed to bring in more ISO tanks to de-bottleneck the liquid oxygen supply chain. Both companies came forward and said they would support us. We also started using the Railways to truck the liquid. A lot of other companies also stepped in and started importing ISO tanks. This is the best way to ramp up distribution.

If we were moving ISO containers through sea, we would load them with liquid oxygen as well. In a lot of cases, they were brought in by air, wherein it is not possible to load them with liquid oxygen. So, not a very significant overseas oxygen capacity was utilised; nor is it pragmatic to do so. What we did utilise was our links and association with the ISO container industry to mobilise these tanks. Linde is an extensive user of these ISO tanks across the ASEAN region, and also in Europe and other places.