Prevent air pollution by suppressing oil vapor emissions

According to the oil vapor recovery facility installation work manual (2020, Ministry of Environment of Korea), the Enforcement Regulations of the Air Environment Conservation Act were enacted in 2007 and Stage II installation standards were established. and installation has been completed. In this process, each local government supported the subsidy to encourage the expansion of the installation, and it is still expanding.

If you look at the case of the United States, it is going in the opposite direction, so it is necessary to look at this. In the United States, the federal government enacted the Clean Air Act in 1990, making stage II installation compulsory. As a result, it has been actively expanded in 27 states. Since it was implemented 17 years earlier than Korea, the efforts of the federal government on environmental pollution are commendable. Even now, there is no such law in underdeveloped or developing countries, so it can be said that there is a huge difference in perception. Above all, the installation cost in the United States ranges from $20,000 to $60,000, and the annual maintenance cost is $3,000.

However, in the 2000s, a major change in perception occurred in the United States. It happened as cars started to be equipped mostly with Onboard Refueling Vapor Recovery (ORVR). The purpose of ORVR was to improve fuel efficiency by attaching a device called a canister between an automobile engine and a fuel tank to absorb oil vapor and reuse it as fuel. As a result, the effect of preventing oil vapor generated from the fuel tank from being discharged to the outside was also obtained. The problem started with reports of this canister causing compatibility issues with Stage II. In particular, studies have emerged that Stage II, which operates a vacuum pump, causes a malfunction in the canister or generates more oil vapor.

Finally, in 2012, the federal government recognized this and passed a law requiring the decommission of Stage II facilities. As a result, most of Stage II have been removed or are in the process of being removed, with the exception of some states. There are, of course, states that want to keep or do more analysis before deciding.

The important thing is that in 2012, the United States decided to decommission the Stage II 10 years ago, and Korea is still expanding it.

In most cases where a canister is not attached to a gasoline vehicle, Stage II should be maintained, but it is presumed that most automobiles operating in Korea are also equipped with this device, so wouldn't it be reasonable to decommission through analysis?

Another reason that it is difficult to expand blindly is that decommission also incurs a cost. If the installation costs a lot of money and the decommission cost has to be put in again soon after, this is a very unreasonable policy, and it will be criticized as a hasty policy.

Fortunately, in the decommissioning conditions suggested by the Environmental Protection Agency of the State of Pennsylvania, USA, there is a provision that the vacuum suction type must be decommissioned and the pressure balancing type does not need to be decommissioned. In fact, stage II, which causes compatibility problems with the canister, is mostly vacuum suction type, so it is a reasonable policy.

In Korea, we have not investigated which method is mainly installed, but at least measures to prohibit the installation of the vacuum suction type seem necessary. And since the US policy cannot always be said to be the correct answer, it seems necessary to investigate whether there is a malfunction or compatibility problem in the pressure balancing equation. If the degree is not severe, it is right that Stage II is further expanded. This is because the oil vapor is full of substances that are very harmful to the human body, including a group 1 carcinogen called benzene.

Oil vapor emitted from gas stations is a toxic substance that is very harmful to the human body, and since gas stations are operating near large-scale residential areas, efforts have been made to solve this problem from the very beginning. A representative among them is the oil vapor recovery system called Stage II(Phase II).

This stage II recovery facility refers to an oil vapor recovery system that sucks oil vapor from the vehicle's tank and sends it to the gas station's underground tank when refueling the vehicle. With this facility, there is almost no odor when refueling the car. This is because the fuel gun for refueling has two pipes, one to expel oil and one to suck in oil vapor.

Basically, it is true that this system provides very beneficial effects for the health of gas customers and those who work at gas stations. In addition, it provides the effect of preventing oil vapor from spreading in all directions near the gas station and directly spreading to the residents of large cities.

However, the problem is that the recovered oil vapor is not liquefied immediately after being collected into an underground tank. If it is still in a gaseous state without being liquefied, the temperature rises and the kinetic energy of the gas is accumulated, and eventually it is discharged to the outside through the ventilation pipe.

It would be good to seal it so that it does not discharge to the outside, but the oil vapor has a high risk of explosion and cannot be kept sealed. Therefore, the ventilation pipe is always developed to the outside, and the oil vapor is always discharged to the outside. This structure is the same for all gas stations around the world.

Therefore, a liquefaction system must be added for the Stage II recovery plant to function properly. If the liquefaction system is connected to the ventilation pipe and liquefied before being discharged, the oil vapor can be recycled as a valuable gasoline resource, and environmental pollution can be completely prevented.

Currently, about 3800 gas stations in Korea have stage II recovery facilities installed, and stage III liquefaction equipment is not provided, so only half the effect is exhibited. The gas miner we developed is an oil vapor liquefaction device that most reliably solves the problem of air pollution at gas stations, and it is the most economical stage III recovery system in the world.

It seems obvious, but let's think about why. Because if you know the reason, it is easy to empathize with the high incidence. If it is a very small amount, there is no need to worry. But if it's a lot, it's a serious problem.To help you understand, let's first consider the evaporation of water. Hang wet laundry to dry on its own. This is because water turns into steam and blows away. Isn't it strange? Water boils at 100 degrees and turns into steam, but it dries even if you leave the laundry unheated. As a result, water vaporized no matter what temperature it was, so it is correct that it has evaporated.

More precisely, it is called evaporation. When it becomes a gas at the boiling point, it is called vaporization, and when it becomes a gas at a lower temperature, it is called evaporation. Well, in the end it is vaporization, but...The important thing is why? no see. When a cup is full of water, the water molecules above the water level are affected by the air above it. One absorbs heat and another receives kinetic energy by the movement of air. To put it simply, the molecules on the top surface are heated and vibrated. Then it will be easier to escape.

The same goes for gasoline. The boiling point of gasoline starts at 30 degrees, so it evaporates much more easily. Gasoline runs for tens of km in a tank truck from a distant gas station, and kinetic energy is accumulated. And the heat from the sun increases the temperature. In Korea, tank trucks only run at dawn. However, tank trucks in Southeast Asia, which are hotter than Korea, deliver in the middle of the day. When the heated gasoline is sent to the gas station storage tank, the gasoline molecules filled with kinetic energy will join the escape procession.

In this situation where gasoline has to be moved every day using a transport vehicle, it is impossible to prevent huge oil vapors from being generated at gas stations.

At first glance, it seems that gas stations that make money by selling gasoline should be responsible, but structurally, this is not necessarily the case. Delivery is the responsibility of the refiner, and since the delivery process is a major factor in accelerating the generation of oil vapors, it is also seen as the responsibility of the refiner. It is also the responsibility of the state to collect huge taxes through the sale of gasoline.

From a money perspective, it will ultimately matter who makes the most money. Gas Station, Refinery, Country Who earns the most? In countries like Korea where the tax is 49%, the country earns the most. Therefore, it is the primary responsibility of the state. It is not the state's responsibility to make a law requiring the installation of various recovery facilities. It's just shifting responsibility to the gas station. If the state bears the cost, it is the state's responsibility. Even so, it is less than 1% of the total gasoline tax.

Among the substances contained in the oil vapor, benzene and toluene are particularly harmful to the human body.

Benzene: According to the data of the Food and Drug Administration published in 2007, “Benzene is a substance commonly used in industrial fields, and leukemia or prodromal symptoms of leukemia were observed in exposed workers, and the incidence rate also increased significantly. In a study on workers who worked for more than 6 months, the incidence rates of leukemia, lymph cancer, and blood cancer in proportion to the exposure dose were known to be carcinogenic to humans and animals, and the World Health Organization (WHO) International Agency for Research on Cancer (WHO) It is classified as a carcinogen (Group 1) by the IARC.”

Toluene: It is said to cause hallucinations. Long-term exposure to toluene is known to have harmful effects on the nervous system, such as twitching, headache, dizziness, memory impairment, motor dysfunction, central depression, and fatigue.

Gasoline is considered as Volatile Organic Compounds (VOCs). This is true whether in the liquid state (gasoline) or the gaseous state (gasoline vapor). And VOCs cause environmental pollution and are known to be very harmful to the human body. However, not all VOCs are bad. For example, essential oils produced from herbal plants are VOCs and have many benefits for the body.

What ingredients are contained in gasoline, which has a strong property of changing to gas at room temperature (between 0 and 40 degrees Celsius)?

Gasoline contains a mixture of methane, ethane, benzene, toluene, xylene, and isooctane, which plays a key role in automobile fuel. Among them, benzene, toluene, and xylene are problematic as they are first-class carcinogens.

Most people seldom deal directly with gasoline. That's why I think it's safe, but it's absolutely not. This is because VOCs cause photochemical reactions in the atmosphere to generate ozone and fine dust. There are no exceptions on days when there is a lot of fine dust, and even on days when the air is clear, if you are near a gas station, the efficiency will increase. Half of VOCs are emitted as oil vapors at gas stations. So, are the oil vapor recovery facilities installed at gas stations sufficiently suppressing the emission of VOCs?

Petroleum and gasoline are representative fossil fuels. Thanks to its abundant existence on Earth, mankind has made great strides. A lot of money has been paid for that process. In fact, it can be said that the cost is ultimately the money consumers pay for their purchase.

However, while there are good points, there are also many bad points about fossil fuels. Because it emits carbon dioxide, it has become the main culprit of global warming and climate change. In addition, VOCs contain a number of carcinogens that are very harmful to the human body. It should never be inhaled into the human body.

In 2020, the world's remaining petroleum consumption, which has been greatly affected by the corona virus, has decreased by nearly 9%. What is important is that demand rebounded right in 2021, when the corona was not overcome, and the rise in global commodity prices coexisted. In other words, since the price has continued to increase despite a significant increase, price and demand will rise simultaneously until 2026.

Although the supply of electric vehicles is increasing, it should also be taken into account that gasoline consumption will inevitably increase for a considerable period of time in the future due to new demand for automobiles and price resistance. Therefore, while the number of gas stations may decrease in a particular country within at least 30 years, it is highly likely to increase from a global perspective.

If you look at the wall at the gas station, you will see a very tall pipe. That's the oil vapor outlet. The reason it is installed high is that the oil vapor is heavier than air. This is because it needs to be as high as possible to be blown away by the wind and dispersed widely. Otherwise, it will come down and cause a fire, or people will inhale directly in high concentrations.

The important thing is that after all, it is heavier than air, so on days with fog or smog, it all comes down.

This means that the chances of inhalation into the human body are very high.

Oil vapors, also known as VOCs, are also produced when grilling mackerel. You've probably heard that people who work in the school cafeteria get cancer. It is also the reason why housewives who have never smoked in their life choose gas stoves as the cause of lung cancer.