Making Oxygen — The last resort to buy time

18 min readMay 8, 2021

If you do something as a last resort, you do it because you can find no other way of getting out of a difficult situation or of solving a problem.

24th April 2021. It was a little past 9 pm on a Saturday night.

That night I was really disturbed. The massive shortage in medical oxygen supply in India was all over the news. The clips of open cremations in New Delhi and patients waiting desperately outside the hospital left me restless. I found it hard to sit idle. There should be something I/ we can do to try helping in some way. I wondered if a quick small scale medical oxygen production can be built and open sourced so that the local engineers or anyone from anywhere can build it up from scratch.

I immediately removed my 11th & 12th standard chemistry books as I vaguely remembered learning something about the production process of Nitrogen and Oxygen years back. Along with a couple of searches on the internet, I soon realised the production of medical oxygen is a highly industrialized or sophisticated process to produce at a DIY level. Upon sharing this on my social media, some of my great friends and kind people from the internet came forward to help.

We categorized the medical oxygen requirement for COVID patients as
Stage 1: Highly critical at ICU. Patients on life-support.
Stage 2: Severe. On supplemental support.
Stage 3: Waiting outside the hospital or isolated at homes.

Hospitals prioritize the support of available medical oxygen to the patients in Stage 1 & 2 as it is highly vital for them. But many lives were lost while waiting for beds and oxygen, and watching those incidents of the loved ones in desperation to find any possible means to buy time to keep their father, mother, husband, wife, grandpa, grandma alive until they get hospital admission and oxygen became the reason for us to put together a quick DIY set-up for patients outside the hospital or at homes to buy time or give basic oxygen support until they find another solution.

So, here we are showcasing a quick way to produce good quality oxygen for patients at home or anywhere. Please consider using this method as your last resort when you are left with no options. Additionally, we are sharing our complete findings of the problem and the study of medical oxygen for anyone who is willing to innovate better solutions for the future. We attempted to make this blog post as a one stop solution to understand medical oxygen as a whole.

I’m Giriprashad from Erode, TN, and this wouldn’t have been possible without the support of my friends Kishor Avhad (Nashik), Deep Thakar (Satara), Alex Dhalayan (Chennai), Saurabh Shinde (Mumbai), Kalpak Kadam (Pune) and Ahan Majumder (Mumbai). A special thanks to Mr. Visweswara ‘Chakri’ Gudla, R&D Manager at HYMETH ApS Hydrogen, Denmark for sharing his expertise in electrolysis.

Here are the specific parts of this writing if you’d like to jump to any:

Problem Identification
Current Methods/ Technologies
Producing Oxygen: The Electrolysis way
Other quick solutions
Our next phase

IMPORTANT NOTE:

The following is an extensive research and comprehension of the oxygen crisis. We realise not everyone will have the time when, for some, time is the one that their loved ones are running out. If you’re in such a situation, please reach me on twitter, instagram or linkedin for quick understanding and help. And for others who need this piece as a document, it can be downloaded here.

Problem Identification

So what are we told about why there is medical oxygen shortage?

The outwardly prominent reason is the inadequacy in medical oxygen production in India. Which is true but there are more components to the shortfall. Apart from putting together a solution, we spent a great amount of time understanding the macroscopic view of the problem.

Primary reasons:

Production shortage: The daily production capacity of oxygen in India is 7127 MT (metric tonnes) per day. The Central government had said India was consuming less than 60%, as of 12th April 2021, about 3842 MT of its daily oxygen production for medical use. Also, there were stocks in excess of 50,000 metric tonnes. On April 21st, an official of the Central government told the Delhi High Court that the daily demand for just medical oxygen in the country had risen to 8,000 metric tonnes. Hence, there was a move that shifted every oxygen production for medical use and yet we face the shortage because of the tsunami of surging cases than anywhere in the world.

Transportation: Many local industries, foreign countries and companies have come forward to support India with oxygen supply. Distribution is the problem, a leading oxygen manufacturer in India, Inox Air Products who produces 2000 MT a day, said so. The next major hurdle is the logistical and transportation challenge. Getting the oxygen from plants to patients till date remains a great hurdle as the production plants in India are unevenly distributed. Hence, reaching the end of hospitals is taking days, sometimes weeks. Maharashtra, Gujarat, Jharkhand, Odisha, Tamil Nadu, Karnataka, Kerala and West Bengal account for nearly 80% of India’s total dedicated oxygen production. Delhi, Madhya Pradesh and Bihar suffer a lot with the increase in daily cases as they’ve no significant production capacities of their own and they have to wait and get only the excess from the oxygen producing states.
Storage: Say now that oxygen reached hospital, the capacity to store and administer to patients is infact become inadequate. The medical oxygen has to be stored in special cryogenic vessels as liquid, later converted to gas while administering to the patients, or in cylinders as gas. The requirement of cryogenics tanks and tankers, gas cylinders has gone over 5 folds as of now. Infact, there are conversations and trials around converting existing Nitrogen, Argon and some even seeing the possibility of conversion of CNG tanks to store and distribute medical oxygen.
People: Yes, there is a shortfall of people working in production, assembly and distribution as the infection/ positivity rate is spiking in many oxygen producing states. Manufacturers are clocking their capacity at its peak while trying to keep its people safe and uninfected.

The solution to the above problems is to ramp up the hospital infrastructure to have its own, atleast backup, on-site plant so that it is not subject to the challenges of logistics and transport because manufacturers cannot have the capacity that can cater to sudden demand that is ten times higher.

“Other” reasons:

Forecast: While Kerala still manages to have excess oxygen production despite the surge, the rest of the country falls short. Was there any deliberate ignorance over the second wave or this is all a sudden overnight surge — well, I leave that to one’s own judgement.
New Plants: India has six years of experience building Pressure Swing Adsorption (PSA) oxygen plants. It takes just four to six weeks to install a PSA oxygen generator at a hospital at an average cost of Rs 1.25 Cr based on the central government’s outlay of Rs 201 crore for 162 oxygen plants. The health ministry admitted only 33 of the 162 PSA oxygen plants it had commissioned had been installed.

I think it is irrelevant to speak of “other” reasons when we can come together to solve our problems on our own.

List of items that are under serious demand

We found the following to be in demand at hospitals during our investigation:

Items for ICU

For Oxygen supply

Oxygen concentrator along with flow meter, regulator, connectors and tubings
Medical Oxygen
Vacuum Pressure Swing Absorption (VPSA) and Pressure Swing Absorption (PSA) oxygen plants, Cryogenic oxygen Air Separation Units (ASUs) producing liquid/gaseous oxygen
Oxygen Canister
Oxygen filling systems
Oxygen storage tanks
Oxygen generator
ISO containers for shipping oxygen
Cryogenic road transport tanks for oxygen
Oxygen cylinders including cryogenic cylinders and tanks
Parts of the above to be used for manufacturing equipment related to the production, transportation, distribution or storage of oxygen
Any other device from which oxygen can be generated — this is where our DIY solution lies

Other ICU items

Ventilators
a. Ventilator with compressors
b. All accessories and tubings
c. Humidifiers
d. Viral filters
e. Should be able to function as high flow device and come with nasal cannula
High flow nasal cannula device
a. With all attachments
b. Nasal cannula for use with the device
Helmets for use with non-invasive ventilation
Non-invasive ventilation oronasal masks for ICU ventilators
Non-invasive ventilation nasal masks for ICU ventilators

Current Methods/ Technologies

What is Medical Oxygen?

It is a colorless, odorless and tasteless gas that is a breathed in (inhaled) gas extracted from the atmosphere. Many people think that oxygen is easily available since the air is oxygen and we breathe it. But the ambient air around us consists of only 21% oxygen and the rest is a mixture of nitrogen, carbon dioxide and other gases.

Medical oxygen is a high purity oxygen that is used as first aid resuscitation for emergencies like COVID-19, anesthesia, life support for patients who can’t breathe on their own. In order to develop pure oxygen, Oxygen plants employ a specialized technique to separate the oxygen from the air, often by collecting air in its gaseous form and liquefying it at cold temperatures (Ridle, 2018).

Why is it needed?

Oxygen is a crucial treatment for the patients suffering with Covid-19. The virus directly affects the respiratory system of the patient causing shortness of the breath. The primary function of the respiratory epithelial cells that are situated in the respiratory tract, is to protect the airways tract from infections and pathogens. The SARS-CoV-2 coronavirus has the ability to infect these epithelial cells which leads the body’s immune system to release cells that trigger inflammation. When the immune response continues, this stops the regular transfer of the oxygen to the lungs, leading to build up fluid as well. These complications make it difficult to breathe.

How is it administered to patients?

Infected or damaged lungs are less effective at allowing the oxygen to pass from the environment to the bloodstream. One of the main reasons patients are admitted to hospital is to receive supplemental oxygen. This can be administered through a number of ways through the nose using plastic tubing or via a loose-fitting face mask. Only high quality medical-grade oxygen is given to the patient with critical condition. This oxygen contains at least 82% of pure oxygen and is free from any contamination.

According to the WHO data about 75% of the COVID patients requiring hospitalization can be classified as “severe” and 25% can be classified as “critical”. In order to estimate the medical oxygen required per patient can be calculated by WHO recommended flow rate of oxygen for each category as shown in the table.

Sample calculation of oxygen requirement based on severity

This sample scenario is based on the WHO guided O2 requirement per patient. There are other factors affecting the flow required per patient according to the health of the person and the severity condition of the patient.

How is it produced?

Presently, there are mainly three types ways to produce medical oxygen:

Air Separation Units (ASU) : Commercial scale
These units are used to produce nitrogen, oxygen and argon as gases and/ or liquid products. Cryogenic air separation process is the preferred technology since it is cost effective and produces very high purity oxygen and nitrogen. Here, the first step is to filter, compress and cool the incoming air. Next it removes impurities in particular, residual water vapor and carbon dioxide. Next additional heat is transferred to a heat exchanger which brings the air feed to cryogenic temperature. Which is then followed by the cryogenic air separator/ product purification process where it separates the air into the desired product.
Pressure Swing Adsorption (PSA) : Medium scale
PSA is a process in which the air is passed through an internal filtration system which has a large total surface area to separate nitrogen from the air and concentrate the remaining oxygen. An PSA is a medium scale industry in which it consists of an air compressor, dryer, filters, dual separation chambers, a reservoir and controls. This plant can generate oxygen anywhere between 2Nm3/hr to 200 Nm3/hr.
Oxygen concentrator : Small/ patient scale
Oxygen concentrators are self-contained, electrically powered medical devices designed to concentrate oxygen from air (WHO, 2020). According to Dr. Shahid Barmar, concentrators suck in atmospheric air, filter other gases, compress oxygen and dispense it through cannula. Oxygen concentrators can supply from 0.1 LPM. There are different types of concentrators ranging from 3, 5, 8 and 10 LPM. 1 litre of oxygen provided to patients raises 24% of oxygen percentage in the lungs. 2 liters raises 28% while 10 liters rise to 60%.

The major oxygen manufacturers in the country include Inox Air Products, Linde India, Atul Oxygen Company, Aims Industries, P K Carbonics, Vinayak Air Products, Scoop Industries, Hiltone, Raj Gas Industries, Kashmir Gases, Universal Air Products, Popular Carbonic, Raigad Carbides, Taiyo Nippon Sanso India, Phoenix Gases, Essem Gases, Rukmani Metals and Gaseous, Kolhapur Oxygen & Acetylene, Goyal MG Gases and Assam Air Products. (Jacob, 2021)

How are they stored?

Oxygen can be stored in cylinders, a vacuum insulated evaporator or a manifold cylinder bank.

Cylinders: have a black cylindrical, and are made of steel. The gauge pressure indicates how much gas is present in the cylinder. It can be connected to manifolds of central/sub-central pipeline distribution systems, or directly connected to patients with flowmeters and tubing.
Vacuum-insulated evaporator: VIE is a huge thermos flask that is used to store liquid oxygen on site of large hospitals which stores from 20 tonnes to 35 tonnes of liquid oxygen. Later, through the evaporator, it is supplied to the patients.
Manifold cylinder gas system: A manifold gas system has two banks of at least 10G size (46.5 kg) cylinders. This system is usually used by small hospitals which do not have VIE. It is also used as a backup at large hospitals when a VIE is getting filled.

How is it supplied?

Oxygen is either supplied via pipeline or cylinders. The pipeline for the supply of oxygen extends from VIE and manifold cylinders via degreased, sealed and steam-cleaned copper piping to the wall outlets.

Producing Oxygen: The Electrolysis way

There are three major methods to produce medical oxygen, as mentioned before, at commercial, medium and small scales. But we are resorting to the electrolysis method of producing oxygen — something that is entirely different and simple — for the purpose of single patient use. The very method is used to create a hospitable breathable environment for astronauts in space crafts and sailors in some submarines where oxygen is produced by splitting water. We found this method to be ideal and repeatable for basic setup for everyday people to be able to put together using ordinary everyday components like buckets and water bottles at homes or outside hospitals.

What is Electrolysis?

Basically, current is used to break down a compound or a solution into its component molecules. Such breakdown does not happen spontaneously or naturally so an external energy is required to do so. This is a basic chemical decomposition process of an electrolyte solution by passing direct electric current (DC) power supply. In our case, electrolyte solution is water and caustic soda (NaOH) — substance that makes the pure water a conducting medium when current is applied. So, by passing current, the water is split into its respective components i.e., hydrogen and oxygen.

This method is meant for only as your last option to give basic oxygen support to buy time

Safety instructions

Only pure water such as RO water or distilled water should be used
Hydrogen gas should be vented out at an elevated height or open area

Requirement

Basic science understanding
20 litres of RO water
1x 20 L paint bucket
1x PVC pipes of diameter 2" — 3", length 1.5 m
2x PVC end caps of selected diameter
2 kg Caustic Soda (NaOH) — Not the cooking soda
AC-DC convertor (220vac to 48vdc @10A)
Stainless Steel (SS) electrodes — any small SS screws, sheets or rods
Plastic tubes — ones that are used in fish tanks
Inhaler mask
Copper wires

Design and Assembly

We designed the below setup using paint buckets, PVC pipe and water bottles:

Please follow the following instructions to setup a DIY electrolysis kit:

Take a 20L paint bucket or a plastic tub with its lid and wash them thoroughly. This is the electrolysis container of the kit. Fill little over 3/4th of the bucket with about 15L+ of RO water and 1kg of caustic soda.
Cut two PVC pipes of lengths 2ft and 1ft and drill two small wire sized holes at 10” from one side on each pipe. Punch two holes of size 2” or 3” on the bucket’s lid based on your PVC pipe diameter at a comfortably equidistant from the centre of the lid. These pipes act as a channel for suspending the electrodes and the passage of gases.
Electrodes here can be anything from Stainless Steel (SS) screws, rods or sheets of 1ft length. Do not use thick copper wires or iron as electrodes as they will be easily oxidised at anode and form impurities while producing oxygen. Suspending these electrodes inside the pipes could be tricky based on the availability of the SS material options and size. In our case, we used screws and silicone sealant to keep the screws in place and seal the wire holes. Make sure to connect/ solder the wires to the electrodes and then seal the electrodes inside the pipes. Suspend 10” of the electrode inside the lid and 2” above the lid for the wiring connection.

Insert the cut PVC pipes upto 8” into the bucket and seal the top of these pipes with end caps. Drill a plastic tube sized holes on the caps to direct the gas passage.
Connect the power supply wire with a AC-DC convertor (220vac to 48vdc @10A) and then the positive, negative terminals to anode and cathode respectively. Make sure to use good quality thick copper wires to conduct high current. Please note that Hydrogen gas is produced at cathode so it has a tall PVC channel to disperse properly and Oxygen gas at anode with a small channel.
Take two 1L water bottles-one for humidifier and other for oxygen storage-and drill two small holes of size that of the plastic tubes on the bottle caps. Fill the humidifier bottle with half litre of RO water and use only an empty bottle for oxygen storage. Make the tubing connections as shown in the working of the electrolysis process.
Before turning on the power supply, please double-check the power connections for error and the passage of the tubings in the setup to ensure the right gas and avoid leakage.
An estimated 5L of oxygen can be produced from 15L of pure/ RO water. The produced oxygen is to be administered to the patient through an inhaler mask which channels air and this oxygen. Thereby increasing the oxygen concentration of the inhaled air for the patients. The rate of the oxygen output is yet to be calculated. If the oxygen bubbling looks slow, try adding more soda or increasing the supply current. But one can assure the potential of this setup to increase the oxygen concentration of the inhaled air to essentially be a secondary support for patients.
Refill new water and add soda when the container gets empty or seems to accumulate impurities.

Here is a quick look into our first prototype:

Linking another video of a similar electrolysis setup:

Limitations & Precautions

Oxygen quality: The quality of the produced oxygen depends on the quality of water and electrolyte that is used (we use caustic soda i.e., Sodium Hydroxide in our case). If only pure water and good quality Potassium or Sodium Hydroxide are used, then we will produce only oxygen at the anode. This will give us more than 90 to 95% oxygen purity. If there is Chlorine in the water, basically if salt water is used, then Chlorine gas will be produced which is a harmful gas to breathe. Hence, use only RO water or bottled drinking water.
The oxygen will need to be passed through pure water again through a water column/ humidifier so that it is good to use with required moisture content while the aerosols of the electrolyte (caustic soda) carried by the oxygen from the electrolysis process are removed. Hence, it is mandatory to use pure water/ RO water in the container and the water column/ humidifier to get chlorine free and almost contaminant free oxygen output.
Dispersion Hydrogen gas: Combination of hydrogen and oxygen is an explosive mixture and can easily ignite. So, proper dispersion of this gas is important. If operating the setup in open air, then it is easy to vent the Hydrogen gas as it is a very light gas. It will move upwards immediately when produced, so an open space with some wind blowing like close to window, balcony, terrace and parking lot. Avoid any flammable or ignition sources within 5 m distance of the setup. In our design, we added a tall PVC line with perforations/ holes to dilute the Hydrogen concentration and disperse the gas easily without causing much stress to the user.
Power Consumption: It consumes a great deal of power to produce a unit volume of oxygen. Yet this is the quickest way to produce oxygen at DIY level for temporary support compared to the commercial efficient methods. So, this is ignorable considering the time we are able to buy for our loved ones.
Output & Heating issue: Please keep in mind that this is relatively a slow process and the output volume of oxygen is dependent on the Amperes of current, electrode surface area and electrolyte concentration. Since the purpose is to increase oxygen concentration during breathing, this will do a decent job. Then, the heating issue of the water used in the container due to the electrolysis process. Instead of going for further sophistication to cool down the container at the moment, one may use a jugaad method to cool down. A cold wet towel can be wrapped around the container.

Our Next Phase

Current Goal

Is some basic setup for everyday people to make at home for backup. We are yet figuring out if there could be a way to store the produced oxygen in a surge tank/ container and supplied to patients at a constant rate. That’s why we conceptualized the below schematic diagram of an ideal case setup having an oil-free compressor and few other modifications. Nonetheless, we think we can go ahead without the compressor at the moment, and the oxygen produced from electrolysis can be supplied to the patient’s mask.

Schematic diagram of our ideal case electrolysis setup for oxygen production

We are currently focused on studying and measuring the performance parameters and the output quality. In fact, we are looking for help in tools like oxygen flowmeter & concentration meter and in materials like carbon electrodes to be able to produce a high quality oxygen.

What is our End Goal?

There is still so much work to perfect the existing electrolysis design and work to make it compact & portable, and get it to the hands that need help. That is our priority.

We see the end goal, not just for us, is to develop backup oxygen generators at hospitals

We are optimistic about making a localised solution like the one developed by Oxikit. This directs us to build portable DIY oxygen concentrators and then reach hospital level.

Final Thoughts

Realistically speaking, the horrific surge in COVID cases is going to drop within a quarter like Aug-Sep-Oct of last year. And there are already many news and improvements around medical oxygen production & imports. So, essentially, it is a matter of a few weeks by then the current infrastructure will cope with the demand & supply.

Then, why do we need to do this?

Because, we believe this is a spark. We simply cannot be a by-stander to another pandemic, politics or whatsoever to kill innocent lives. This spark is to make us all “rethink” everything. Our homes, offices, hospitals, food supply, material production. Everything.

An intervention is needed from all of us. At all fronts.

May love and kindness rule the world.

And ain’t easy to finish such a long blog. Thank you for your time.

Images, references and other useful links can be found in this folder.