Gas absorption a process that is also called scrubbing, in this procedure, gas or mixture of gases is brought into contact with a liquid so that one or more compounds of the gas mixture are dissolved in that liquid, thus, changing the compound from gas phase to liquid phase.
On the other hand, gas desorption (also known as stripping), is the mass transfer is in the opposite direction, that means from a liquid state to the gas phase. The main concept behind the two is the same.
The process of gas absorption is based on diffusion, as the gas is passed through a stagnant liquid; some gas compounds mix with the solute turning into a liquid state.
There are many reasons why this method can be used in laboratories, labs, and large manufacturing plants. However, the use of this method has become more prevalent for combating industrial air pollution. Harmful gases from industries can be easily converted to liquid form before the rest of the gases are released into the atmosphere.
However, as with every process, gas absorption also has its positive as well as negative impacts. First of all, let’s take a look at the pros of this procedure.
Broad application spectrum
This process of gas absorption can be utilized in various industries for many reasons. There are many applications of this process today, such as during the manufacture of ammonia, oil desulfurization, manufacture of ethylene, manufacture of hydrogen, low Btu gas, high Btu gas, and coal gas to mention a few.
The process helps in the separation of unwanted gases to give only the required component. As mentioned previously, gas absorption plays a significant role in the removal of harmful gasses from industry emissions to reduce air pollution.
Very high removal yields
Unlike many gases to liquid processes, gas absorption has a very high removal yield, according to GustaWater. This means that the percentage of a gas compound that is converted to a liquid state is high. This makes this process effective and provides an efficient solution for the procedure of converting compounds from gas to liquid state.
Compact installation and easy to maintain
The chamber used for gas absorption is an immensely simple one which can be installed without much trouble. After the successful installation of the gas absorption chamber, its regular maintenance is also very easy on the budget as well as less time consuming than other alternatives.
Relatively simple technology
The concept of gas absorption is rather a simple one, hence so is the technology. The gas chamber can be operated by the workers without any hassle. Unlike many other industrial processes, this does not require expertise for handling the technology.
Can also be used to cool hot gas flows
Another use of this technology is more commonly known as the Quencher. In this procedure, the hot gases can be cooled down through passing hot gas emissions through a cold liquid. In this process heat is diffused from the gas to the liquid, hence lowering the temperature of the gas.
There are some loopholes that come along with any technological device. Now let’s talk about the cons of gas absorption.
Wastewater must be treated
Unfortunately, the problem does not end with the conversion of harmful gases to liquid, although this does prevent the harmful gases from being released in the atmosphere, the liquid form of the harmful substances is left behind. The industries must be careful to dispose of this water, otherwise, there is a risk of water or land pollution.
When dust is simultaneously collected, drainage is necessary;
Susceptible to frost
The process requires certain temperatures, but due to the cold weather conditions, the gas chamber can be affected by the frost. The frost and low temperatures can affect the rate of gas absorption and hinder the process. Hence, to tackle this issue, temperature regulators must be installed alongside the gas absorption equipment which often strains the budget.
Depending on the location, a support construction may be necessary
The equipment requires a proper installation venue, which may or may not be available in the factory. If not, support construction may be required, this further strains the budget. Temperature and other environmental factors must also be considered when installing the equipment so that any necessary measures can be taken to support the process.
Pilot tests are often required for odor problems in order to evaluate attainability
Another pitfall of the gas absorption process is that the gaseous mixtures can sometimes leave behind a foul-smelling gas. This needs to be checked by the industry to avoid expelling the foul-smelling gas into the atmosphere. Although this is a simple step, it can be a hurdle.
The gaseous mixtures often contain corrosive gases and elements that can damage the equipment over time, thus increasing the maintenance cost of the gas absorption process. Nonetheless, there are various techniques and neutralizers that can be used to counter this problem.
High power requirements
High collection efficiencies for particulate matter are attainable only at high-pressure drops, resulting in high operating cost. This makes it difficult to adjust the budget for this process. However, this problem is specific to some but not all industrial emissions.
As a conclusion, there are several advantages as well as disadvantages of the gas absorption process, however, most of the disadvantages are not a result of the process itself but the negligent use of the equipment and irresponsible budgeting hence they cannot be called consequences of the process itself but rather precautions that must be taken.
Keeping in mind the effectiveness and usefulness of this procedure in industries, particularly for the environment, gas absorption is an efficient procedure that must be used with precautions to make the most of this technology.
Another important factor to keep in mind is that since scrubbers vary greatly in complexity and method of operation, devising categories into which all of them neatly fit is extremely difficult. Hence, you may find the perfect one for your industry depending on your needs.