Connect with us

Features

Sri Lanka’s gas tragedy: the untold story

Published

on

By Deshai Botheju, Ph.D.
M.Sc.Tech.(Norway), M.Sc., B.Sc.Eng. (1st Hons., UoM), AIChE, AMIE(SL)
deshaibotheju@acses.org

Recent explosions and gas leak accidents related to domestic LP gas cylinders have created an environment of fear, anxiety, and social unrest throughout the country. More than 400 explosions and gas leak incidents have been reported during the first week of December 2021. In addition, a large number of observations have been made with respect to leaking gas cylinder valves.

The reported accidents and incidents can be divided into four major categories: (a) Sudden gas explosions inside houses and building, (b) Sudden explosions associated with the gas cooker, (c) Major gas leaks and resulting damages associated with the regulator and the hoses, (d) Minor gas leaks from the cylinder valve, regulator, or the hoses. The number of accidents reported during a single week has far exceeded the typical gas-related accidents happening within a typical year. Something must have gone terribly wrong for Sri Lankan LP gas consumers. Unconfirmed reports now indicate potential deaths, associated with some of these gas explosion accidents.

What is LPG?

Liquefied Petroleum Gas, abbreviated LPG, is an energy carrier derived during crude oil refining or natural gas processing. In petroleum industry terminology these are called gas condensates and are byproducts often generated during the production of liquid fuels (gasoline, diesel, and kerosene) or natural gas (methane). The key components of typical LP gas are propane (an alkane gas containing three carbon atoms – C3H8) and butane (an alkane gas containing four carbon atoms – C4H10). In addition, small amounts of propylene, methane, pentane and other minor constituents can be present. LP gases do not originally have a clearly recognizable distinct odour. Therefore, in order to identify any gas leaks, methyl mercaptan (CH3SH), or a similar odour generating component, is added to LP gas before commercial use. Table 1 provides a useful comparison between propane and butane, with respect to key physical or chemical properties.

Depending on the refinery process, or intended use, LP gas can have a widely varying propane and butane composition. Under normal atmospheric pressure, butane has a higher boiling point of minus 0.5 degrees Celsius (-0.5) compared to propane’s minus 42 degrees Celsius (-42) boiling point. That means in colder climates, where the ambient temperature could go below 0 degrees Celsius, the LP gas must mostly contain propane in order to use that as a fuel gas (otherwise it wouldn’t flow as a gas, as butane would remain in the cylinder as a liquid). Therefore, the butane content is greatly reduced in LP gas used in colder climate countries, typically less than five percent of the volume. For tropical countries, like Sri Lanka, having a high butane content is just fine, as the year-round temperature is almost always above zero degrees Celsius (except for some rare occasions in locations at higher altitudes). Further, butane is a much safer gas to use. This is due to its much lower vapour pressure (31 pound per square inch) compared to that of propane (124.5 psi). Therefore, the containment integrity requirements shall be much stricter for propane use, compared to butane. (figure I)

Composition changes and pressure effects

Unlike compressed gas cylinders, LP gas cylinders are not filled with 100 percent gas. Instead, a new cylinder would contain the liquids, hence the name LP gas, to about 85 percent volume. Only the remaining 15 percent ullage volume (the volume left empty in a tank for the liquid to expand) contains actual gas. These two phases (liquid and gas) are in equilibrium. The pressure within this gas filled ullage is the equilibrium pressure of the corresponding liquid mixture (of propane and butane). This equilibrium pressure can be predicted based on the ambient temperature and the composition of the liquid phase. Table 2 provides the values of these equilibrium pressures (in pounds per square inch gauge or psig) for different propane-butane mixtures at the temperature of 32 degrees Celsius (which is quite close to the typical ambient temperature in Sri Lanka). (Figure II)

As can be seen from Table 2, at 32 oC temperature, a mixture of 80 percent butane and 20 percent propane has an equilibrium pressure of 53.6 psig. This was the composition used in Sri Lanka for a long time. All appliances (including gas cookers), pressure regulators, hoses, hose connectors, gas cylinder valves and cylinders have been accustomed to this pressure condition. In other words, our consumer gas utility system has been calibrated at this pressure condition. Nevertheless, gas cylinders themselves are manufactured to tolerate a much higher pressure.

If the butane-propane composition is suddenly changed to 50 % butane and 50 % propane, now the increased propane content leads to a much higher equilibrium pressure of 89.4 psig. It is obvious that this is a very significant pressure increase from the previous condition.

Containment integrity

Increased propane content leads to a significant increase in gas pressure inside the cylinder. This is because propane has a much higher equilibrium vapour pressure compared to butane (see Table 1). Now, the whole utility system on the part of the customers faces a containment integrity problem. In other words, gas leaks are likely to happen from many of the system components. Table 3 elaborates potential impacts of this pressure increase on different system components. Figure 1 further illustrates potential leak sources and pathways associated with the gas cylinder valve. (Figures III and IV)

What happens during a gas leak?

Propane and butane are flammable and combustible gases, when mixed with air (or oxygen). Within the approximate volume percentages of 2 to 10 percent (within LEL- Lower explosive limit and UEL – Upper explosive limit), these gases can create an explosive gas mixture when exposed to air; see Table 1. Outside of this volume percentage range, the gas would not ignite. However, at higher gas concentrations, the gas cloud can still pose an asphyxiation hazard to humans as it displaces breathable oxygen in air.

Even a minor gas leak in the cylinder valve, regulator, or any other component (see Table 3 and Figure 1) can lead to the accumulation of the gas inside a building, over several hours. Note that both propane and butane gases are higher in density compared to air (heavier than air; see specific gravity values shown in Table 1). Which means, when a gas leak occurs the explosive gas cloud accumulates close to ground level (rather than moving upward and dissipating). This situation is more likely to occur at night when doors and windows are closed, with consequently little or no ventilation. If the leaked cloud of gas reaches the concentration of LEL within that surrounding (for example a kitchen), then it is a bomb waiting to be triggered at any time. The only thing required is a small spark, which may occur when an electrical switch makes contact (on or off), or even due to static electricity present in the atmosphere, or due to an actual flame such as lighting a match. At that moment, an explosive combustion reaction occurs within the flammable gas cloud and the energy released is transmitted as a pressure wave accompanied often by a fireball. This is a typical atmospheric gas cloud explosion. Secondary damage can occur due to projectiles (broken glass for example), prolonged fires, collapsing roofs and walls.

Change management failure

Changing an existing LP gas composition without a detailed safety assessment is an act of sheer negligence bordering on absurdity. It’s a fundamental process engineering principle to follow a comprehensive Management of Change (MoC) protocol before making this kind of, or even far less consequential, change to a product, process, or an operating procedure. Even a Process Engineering Trainee can explain this to production management. As part of an MoC process, it is absolutely necessary to conduct a dedicated risk assessment or a standard safety study such as ‘HAZards and Operability’ (HAZOP). Had such HAZOP been conducted in this case, many of the problems we have indicated in Table 3 could have been identified in advance, avoiding calamity in consequence.

Cost factor and energy contents

The heat energy contents of propane and butane are respectively 49.58 and 47.39 megajoules per kilogram (MJ/kg). However, the density of liquid propane and butane are 0.51 and 0.58 kilograms per litre (kg/L) respectively. That means due to the lower density of propane compared to butane, propane has a slightly lower energy content when based on volume (25.3 and 27.5 MJ/L respectively). Propane burns with a slightly higher flame temperature compared to butane (1980 vs 1970 oC). In certain gas burners, propane could burn with slightly higher efficiency compared to butane (with less deposition of carbon).

If calculated based on the heat energy content delivered (measured by BTU-British Thermal Units), propane is often a cheaper energy commodity compared to butane in the world energy market. Therefore, an LP gas mixture rich in propane can be cheaper. LP gases with more propane are also easier to procure. While per BTU price is cheaper, if calculated based on metric ton price, one can be misled to believe that propane is more expensive than butane. This becomes a false assumption if all gas pricing and market economics are based on the value of BTUs (energy) delivered to the customer (customer is made to pay for the heat energy content delivered to them, and not for the weight of the gas). Also note that the exact price of a certain LPG shipment can be very different from the typical spot prices prevailing in the world energy market.

Safety culture issue

Every organisation has a certain safety culture. Without going into detailed academic definitions of the safety culture concept, we can still try to understand different characteristics of good (positive) safety cultures in comparison to bad (negative) safety cultures.

In a good safety culture Management of Change protocols are always followed; when an accident or an incident occurs, it will always be investigated to the fullest extent and all lessons to be earned are extracted; transparency and honesty are always maintained; instead of finger pointing, their own faults are admitted; no attempts are made at concealing information; safety is always given priority over marginal economic gains. In contrast, the complete opposite of these is to be expected of an organisation with a negative safety culture.

Investigation and compensation

Any investigation into the recent series of unfortunate gas related accidents in Sri Lanka must not stop at merely identifying plausible physical causes. Such investigation must definitely look deeper into related organisational factors, and make necessary recommendations to bring about much needed organisational reforms in the form of enhancing safety culture. In addition, more systematic safety management requirements and stricter regulatory reforms must be recommended to avoid repetition of this kind of ‘organizationally rooted accidents’. Failing to do so may lead to greater disasters of higher magnitude in future. Prompt compensation to those who faced harm must be a priority. Even more urgent is to recall every single gas cylinder delivered with hazardous pressure conditions, irrespective of whether the gas has been used or not. As explained before, LP gas cylinders will retain the same high pressure condition until the last drop of liquid is vaporised. Therefore, unused as well as almost fully used gas cylinders will pose the same level of leaking hazard.

(Facts presented in this article are based on information available on the public domain. The analyses and opinions are based on the author’s experience in the industry, and do not reflect the opinions of any institution.)



Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Features

Babies made using three people’s DNA are born free of hereditary disease

Published

on

By

Eight babies have been born in the UK using genetic material from three people to prevent devastating and often fatal conditions, doctors say.

The method, pioneered by UK scientists, combines the egg and sperm from a mum and dad with a second egg from a donor woman.

The technique has been legal here for a decade but we now have the first proof it is leading to children born free of incurable mitochondrial disease.

These conditions are normally passed from mother to child, starving the body of energy.

This can cause severe disability and some babies die within days of being born. Couples know they are at risk if previous children, family members or the mother has been affected.

Children born through the three-person technique inherit most of their DNA, their genetic blueprint, from their parents, but also get a tiny amount, about 0.1%, from the second woman. This is a change that is passed down the generations.

None of the families who have been through the process are speaking publicly to protect their privacy, but have issued anonymous statements through the Newcastle Fertility Centre where the procedures took place.

“After years of uncertainty this treatment gave us hope – and then it gave us our baby,” said the mother of a baby girl. “We look at them now, full of life and possibility, and we’re overwhelmed with gratitude.”

The mother of a baby boy added: “Thanks to this incredible advancement and the support we received, our little family is complete.  “The emotional burden of mitochondrial disease has been lifted, and in its place is hope, joy, and deep gratitude.”

Mitochondria are tiny structures inside nearly every one of our cells. They are the reason we breathe as they use oxygen to convert food into the form of energy our bodies use as fuel.

Defective mitochondria can leave the body with insufficient energy to keep the heart beating as well as causing brain damage, seizures, blindness, muscle weakness and organ failure.

About one in 5,000 babies are born with mitochondrial disease. The team in Newcastle anticipate there is demand for 20 to 30 babies born through the three-person method each year.

Some parents have faced the agony of having multiple children die from these diseases.

Mitochondria are passed down only from mother to child. So this pioneering fertility technique uses both parents and a woman who donates her healthy mitochondria.

The science was developed more than a decade ago at Newcastle University and the Newcastle upon Tyne Hospitals NHS Foundation Trust and a specialist service opened within the NHS in 2017.

Graphic showing a red circular representation of an embryo with unhealthy, oval, mitochondria inside that has the nuclear material - a joined pair of circles - removed. The next step is blue representing a healthy donor with healthy mitochondria and their nuclear material is also removed. Step three shows the nuclear material removed in step 1 being placed inside the healthy embryo

There was a case of epilepsy, which cleared up by itself and one child has an abnormal heart rhythm which is being successfully treated.

These are not thought to be connected to defective mitochondria. It is not known whether this is part of the known risks of IVF, something specific to the three-person method or something that has been detected only because the health of all babies born through this technique is monitored intensely.

Another key question hanging over the approach has been whether defective mitochondria would be transferred into the healthy embryo and what the consequences could be.

The results show that in five cases the diseased mitochondria were undetectable. In the other three, between 5% and 20% of mitochondria were defective in blood and urine samples.

This is below the 80% level thought to cause disease. It will take further work to understand why this occurred and if it can be prevented.

Getty Images An orange sausage shaped blob on a blue grainy background
A picture of a mitochondrion taken with a microscope – there are up to half a million in a fertilised egg. [BBC]

Prof Mary Herbert, from Newcastle University and Monash University, said: “The findings give grounds for optimism. However, research to better understand the limitations of mitochondrial donation technologies, will be essential to further improve treatment outcomes.”

The breakthrough gives hope to the Kitto family.

Kat’s youngest daughter Poppy, 14, has the disease. Her eldest Lily, 16, may pass it onto her children.

Poppy is in a wheelchair, is non-verbal and is fed through a tube.

“It’s impacted a huge part of her life,” says Kat, “we have a lovely time as she is, but there are the moments where you realize how devastating mitochondrial disease is”.

BBC/Josh Elgin Kat Kitto, sitting on a grey corner sofa wearing a black vest top, with her daughter Lily who is wearing white. Kat is feeding Monty, a ginger coloured long-haired dog, who is sitting on Lily's legs
Kat Kitto (R) in black top with her daughter Lily and Monty the dog [BBC]

Despite decades of work there is still no cure for mitochondrial disease, but the chance to prevent it being passed on gives hope to Lily.

“It’s the future generations like myself, or my children, or my cousins, who can have that outlook of a normal life,” she says.

The UK not only developed the science of three-person babies, but it also became the first country in the world to introduce laws to allow their creation after a vote in Parliament in 2015.

There was controversy as mitochondria have DNA of their own, which controls how they function.

It means the children have inherited DNA from their parents and around 0.1% from the donor woman.

Any girls born through this technique would pass this onto their own children, so it is a permanent alteration of human genetic inheritance.

This was a step too far for some when the technology was debated, raising fears it would open the doors to genetically-modified “designer” babies.

Prof Sir Doug Turnbull, from Newcastle University, told me: “I think this is the only place in the world this could have happened, there’s been first class science to get us to where we are, there been legislation to allow it to move into clinical treatment, the NHS to help support it and now we’ve got eight children that seem to free of mitochondrial disease, what a wonderful result.”

Liz Curtis, the founder of the Lily Foundation charity said: “After years of waiting, we now know that eight babies have been born using this technique, all showing no signs of mito.

“For many affected families, it’s the first real hope of breaking the cycle of this inherited condition.”

[BBC]

Continue Reading

Features

Western proxy war in Ukraine could be approaching dangerous tipping point

Published

on

President Donald Trump in a meeting with President Volodymyr Zelensky. (NBC News)

Fast-breaking developments in US-Russia relations and US-Ukraine ties could very well be pointing to the wasting war in the Ukraine theatre currently approaching a dangerous tipping point. The US has reached the crucial decision to equip Ukraine with the necessary lethal arms to counter Russia’s ongoing missile and drone strikes on it and if implemented could mark a qualitatively new phase in the conflict between the West and Russia in Ukraine, which could have serious implications for regional and even world peace.

‘We want to make sure Ukraine can do what it wants to do, US President Donald Trump is quoted as saying following a recent meeting he had with NATO chief Mark Rutte in Washington, subsequent to indicating that the US will be sending ‘top of the line weapons’ to Ukraine through NATO countries. Such weaponry could include Patriot air defence systems which are generally seen as an effective answer in particular to Russia’s air strikes on Ukraine.

Meanwhile, Ukrainian President Volodymyr Zelensky is on record that he had thanked the US President for his ‘willingness to support Ukraine and to continue working together to stop the killings and establish a lasting and just peace.’

Going ahead, the West would need to bear in mind that the supplying of exceptionally lethal arms to the Ukraine through its mediation could be seen by the Putin regime as hostile acts directed at the Russian state. That is, the West would be considered as involving itself physically in the ongoing hostilities between Russia and the Ukraine, necessitating the West, and more specifically NATO countries, to brace for Russian military strikes on them. Needless to say, such an eventuality would bode ill for international stability and peace.

Accordingly the West would need to assess very finely the consequences of its decisions on the Ukraine front. While the US President’s recent statements on these questions could be seen by some as mere rhetoric Trump is also on record as having indicated that his patience is wearing thin with Putin over the central issue of bringing peace to the Ukraine.

Inasmuch as Trump needs to trod gingerly going ahead so must Putin. In the event of full scale hostilities breaking out between the East and West in the Eastern European theatre no camp would stand to gain; this ought to be plain to the main antagonists, since they are evenly matched in terms of military capability. Even if the conflict in the Ukraine stagnates at a proxy stage, the costs for both sides would be staggering in human and material terms. Russia would need to recollect Afghanistan and the US would need to take itself back to the numerous proxy wars it fought in the then Third World.

However, although there are great uncertainties and perils for the world in the event of the current proxy war in the Ukraine degenerating into a more frontal East-West military confrontation in Europe, President Trump could be considered as holding the ‘Trump card’ to force a negotiated end to the present crisis.

This ‘Trump card’ takes the form of the economic strife which may descend upon the world in the event of the Trump administration going fully ahead with its ‘reciprocal tariff’ based trade wars with the majority of countries.

The US under President Trump may not be the most popular major power but it continues to be critical to the world’s current economic health. However much unpalatable it may be, the truth is that the economic vibrancy and prosperity of the US are key to many a country’s material survival. This is on account of the multiple economic linkages between the US and the rest of the world. The weaker the economy the greater is its dependence on the US and its largesse. For example, Sri Lanka knows this only too well.

The Trump administration is on record that it would be imposing what are described as ‘secondary tariffs’ on those countries whose economic operations are even indirectly benefiting Russia and if implemented could bring about crippling economic hardships for quite a few countries.

Major economic powers, China and India, are fully aware of these consequences. This is the reason why they would prefer not to undermine current economic arrangements between them and the US and between the latter and the rest of the world.

The above positions should not be misunderstood to mean that the rest of the world should be in a subservient relationship with the US. There is no question of the US exercising some sort of suzerainty over the rest of the world. This is not the case but in international relations the primacy of economics over politics may need to be recognized; economic realism needs be a cornerstone of foreign policy.

It would be quite some time before the BRICS grouping reaches the commanding heights of the world economy. Right now, it would be self-defeating, given the US’ continued economic power, for the South in particular to gloss over the might of the West and depend lopsidedly on the BRICS powers for its entire economic sustenance and survival. Indeed, a Non-aligned foreign policy remains best for the South.

It does not follow from the above considerations that the West could continue to turn a blind eye to the dangers posed to it and the world from the Ukraine conflict. Immense caution and foresight would need to go into its moves to arm Ukraine with its more sophisticated and exceptionally lethal weaponry. A cornered enemy in the battlefield, suffering overwhelming losses, cannot be expected to be continually discreet. With its patience relentlessly wearing thin it could unleash its Weapons of Mass Destruction, thus driving the world to the brink of destruction.

Accordingly, it is hoped that better counsel would prevail over all concerned and that differences would be resolved at the negotiating table. May be harsh economic realities would come to dictate terms and propel the quarters concerned to give cool rationality rather than the avarice born of self-aggrandizement a chance in their dealings with each other.

Continue Reading

Features

Shah Rukh Khan – secret to looking young

Published

on

I’m sure the whole of Sri Lanka is eagerly looking forward to the arrival of Bollywood heartthrob Shah Rukh Khan, due in Colombo, next month, for the grand opening of the City of Dreams.

What makes Shah Rukh Khan standout is not only his acting prowess but also his looks.

At 59-plus, he looks absolutely great … or, let’s say, simply awesome.

Generally, people in their late fifties, or even in their mid-fifties, look frail, and some can’t even walk steadily.

So, what is Shah Rukh Khan’s secret to looking young, and, remember, he will be hitting 60 on 2nd November, 2025!

Yes, diet, is given top priority where Shah Rukh Khan is concerned.

While many of us need around four meals a day, Shah Rukh focuses on two main meals a day – lunch and dinner – and avoids snacking or elaborate dishes.

His meals often include sprouts, grilled chicken, broccoli, and sometimes dhal. And don’t we all love dhal!

While he enjoys sharing meals with others when he’s with family or travelling, even if it means indulging in richer dishes, like biryani or parathas, his core diet remains consistent, he says.

Wonder what would be his menu during his very short stay in Sri Lanka! Perhaps traditional Indian foods like tandoori chicken and mutton biriyani, roti, parathas, food cooked with ghee! He also likes the drink lassi, I’m told.

Perhaps, we should also ask him to check out some of our dishes, as well … a good rice and curry menu, with dhal!

It isn’t diet alone that has given Shah Rukh his young look but, he says, exercise, too, has played an important part, especially where his physique is concerned.

Young Shah Rukh Khan in the early ‘90s

Shah Rukh refers to his fitness journey during the pandemic, saying during the pandemic he decided to work hard on his body.

He focused on building a strong physique, and, by exercising consistently, he achieved a body he is proud of today.

Another factor responsible for his leaner, healthier body, and a sharper appearance, is that he has completely quit smoking

This major lifestyle change has also helped him maintain a leaner, healthier body, and a sharper appearance, he says.

Strangely, his sleep routine is totally different to what experts say. We are told that we need between seven and nine hours of sleep per night for optimal health.

Shah Rukh admits he has an unusual sleep schedule and this generally happens when he has a busy shooting schedule.

He usually goes to bed around 5.00 am and sleeps for about four–five hours. Even though it’s not ideal, he manages it around his busy shooting schedule.

In fact, Shah Rukh is a night person and usually loves working in the night. He also loves night shoots. He had said, “I usually head to bed around 5.00 am. On shooting days, I wake up by 9 or 10 in the morning. After coming back home late at night — sometimes around 2.00 am — I take a shower and get a workout in before I finally sleep.”

On the work front, he will be seen next in the movie ‘King’, due for a grand release in 2026.

Shah Rukh Khan continues to inspire millions with his commitment to fitness and I hope Sri Lankans will take a cue from this Bollywood heartthrob and maintain a leaner, healthier body.

Continue Reading

Trending