Featured Posts

Activated Carbon Turns Wine Into Water? Activated Carbon Filter Turning Wine Into Water. Below is a video of an activated carbon filter turning wine into water.

Read more

Natural Gas Sweetening and the Claus Process


Posted on : 25-10-2011 | By : Mr. Green | In : Activated Alumina, Industry Issues, Natural Gas Industry
1 Star2 Stars3 Stars4 Stars5 Stars (2 votes, average: 2.50 out of 5)

An Overview of How Desiccants Are Involved in Sulfur Removal

Sulfur Stinks…

Literally, in nature some naturally occurring sulfur and sulfur compound smells include skunk spray and rotting eggs.  Sulfur’s reputation as a horrible smelling element has led the natural gas industry to calling any natural gas with sulfur in it, sour gas.  In addition to its horrible smell sulfur can also be deadly to humans when it is potent enough, and it is also corrosive.  Thus the removal of it from natural gas streams is an essential process, which is called natural gas sweetening.

In order for natural gas to be considered sour, hydrogen sulfide must  exceed 5.7 milligrams per cubic meter of natural gas.  Natural gas sweetening usually uses a process called amine treatment in order to remove sulfur from gas streams.  Sulfur has an affinity for amine and when it passes through the tower that contains amine, the sulfur sticks to the amine and is removed from the stream.  Amine treatment works similarly to glycol treatment because both use a liquid solution to remove unwanted elements and compounds from natural gas streams.

Despite my sulfur bashing earlier, and yes it does smell, it can also be useful.  For example sulfur is frequently used in fertilizer, matches, and insecticides and it is used to make sulfuric acid which has many industrial applications.  The sulfur that is removed from natural gas streams can be recovered using the Claus Process and sold as a separate product from natural gas.

The Claus Process has two steps: the thermal step and the catalytic step.

The thermal step is designed to turn the majority of the hydrogen sulfide removed from the gas stream into regular sulfur.  This is done by oxidizing hydrogen sulfide with air at high temperatures.  Approximately 60-70% of the sulfur is produced during this step.

The catalytic step is designed to take the remaining hydrogen sulfide and the newly created sulfur to make even more sulfur by heating them together over a catalyst, usually activated alumina and a specialty titania.  Specialty titania helps to convert the remaining hydrogen sulfide into sulfur and activated alumina helps to protect the titania from sulfation poisoning due to oxygen breaking through.

Approximately 97% of sulfur that is removed from natural gas streams is recovered using the Claus Process.  In the United States approximately 15% of all produced sulfur is extracted from natural gas streams.





Desiccants at War!


Posted on : 30-09-2011 | By : Mr. Green | In : Activated Carbon, History, Silica Gel, Zeolites
1 Star2 Stars3 Stars4 Stars5 Stars (1 votes, average: 4.00 out of 5)

A Look Into How Military’s Use Desiccants in Gas Masks and Medical Equipment

Desiccants are used all over the world and military’s around the world are no exception.

The first widespread use of desiccants by any military occurred during the First World War.  This war is famous for the use of chemical gases as a weapon, and armies that were afflicted with a barrage of gas containing shells needed protection in order to avoid being poisoned.

This led to the first gas masks being mass produced.  The material in the gas mask canisters that absorbed potential toxins was silica gel, and this helped to reduce the effects of poisonous gas attacks that opposing armies faced throughout the remainder of the war.

During 1915 ,while World War I was on-going, Russian scientist Nikolay Zelinsky improved upon the gas mask by creating a filter that used activated carbon, another desiccant.  Today activated carbon is the standard desiccant used in most modern gas masks.

The activated carbon filters in gas masks didn’t start getting used until after World War II.  During this war silica gel was replaced as the primary adsorbing material in gas mask by asbestos… which the world learned after the war caused serious illnesses like mesothelioma and malignant lung cancer.

This paved the way for modern gas masks which use activated carbon filters in combination with aerosol filters to keep soldiers safe.  Activated carbon has a larger surface area than silica gel and can adsorb more potentially dangerous airborne chemicals, thus making it more effective filter.

Besides being used in gas masks, desiccants have recently found a new use in military medical technology.

Zeolites have been attached to gauze and recently been used by the U.S. military to help reduce the blood flow in wounded soldiers and civilians.  The pores in the zeolites are small enough to adsorb the water out of the bloodstream leaving only cells and platelets.

Platelets circulate throughout our blood stream looking to clot blood.  With all the water absorbed out of the bloodstream, thanks to the zeolites, the blood is allowed to clot a lot faster.  This has helped save many lives because it greatly speeds up the time for a wound to close and stop bleeding and it also reduces the chance of wound becoming infected.

The success of zeolites in gauze has allowed this product to be used in the commercial medical market and it is now being used by law enforcement and emergency response units.


4×8 or 8×12 Figuring Out the Right Mesh Size


Posted on : 27-07-2011 | By : Mr. Green | In : Molecular-Sieve-Mavens
1 Star2 Stars3 Stars4 Stars5 Stars (5 votes, average: 3.80 out of 5)

Don’t know what mesh size you need?  What benefits does a 4×8 mesh size have over an 8×12 and vice-versa?  If you have ever been involved in purchasing desiccants you probably have had to convert mm to mesh size, but how do you convert mm to mesh?

The Tyler Equivalent is one of the most common forms of mesh size measurement available, it measures the number of openings in mesh per linear inch of mesh.

See this Tyler Equivalent mesh size table for sieve designation showing the various mesh sizes to mm, inches, and micron sizes.

Here is how it works.  Converting mesh size to mm:  Using 4×8 mesh as an example you would find the numbers 4 and 8 in the Mesh column and then just look at the numbers in the mm column, you should get 4.76mm for 4 mesh and 2.38mm for 8 mesh, thus a 4.76mmx2.38mm is the correct mm size.  Converting mm to mesh size: Using 2-5mm as an example you would have to find the 2 and 5 in the mesh column. 2mm should come up with a 10mesh and the closest numbers to 5 that you get are 4.76mm-5.66mm, thus putting the mesh size between 3.5 and 4.  A 3.5 x10 mesh size is rare but the more common 4×8 mesh size should work.

4×8 and 8×12 mesh sizes are two of the most common mesh sizes especially when your involved with purchasing molecular sieve.  The 4×8 beads are usually used in gas phase applications and due to their larger size have a  greater resistance to break while the 8×12 beads are usually used for liquid phase applications and have a greater packaging density.  Depending on your application each mesh size has its advantages.