Adsorbents markets

Zipax is a superficially porous adsorbent marketed by the E. I. du Pont de Nemours Co., Wilmington, Delaware. 

Considering these benefits, it is estimated that SILP materials will contribute a substantial part of the catalyst and adsorbent markets within the next 10 years. A... 

The commercialization by Kureha Chemical Co. of Japan of a new, highly attrition-resistant, activated-carbon adsorbent as Beaded Activated Carbon (BAC) allowed development of a process employing fluidized-bed adsorption and moving-bed desorption for removal of volatile organic carbon compounds from air. The process has been marketed as GASTAK in Japan and as PURASIV HR (91) in the United States, and is now marketed as SOLD ACS by Daikin Industries, Ltd. 

Market Data. The largest U.S. manufacturer of molecular sieves for adsorbent and desiccant use is UOP, which has a production capacity of 18—20 million kg/year. W.R. Grace and Zeochem have about 7 and 2 million kg/year capacity, respectively (55). W.R. Grace is the largest producer of siUca gel desiccants. Activated alumina for use as adsorbent and desiccant is produced by LaRoche Chemicals (formerly Kaiser) and by Aluminum Company of America. About one-third of the U.S. supply of activated alumina adsorbent and desiccant is imported by Rhc ne-Poulenc. 

Adsorbents Desiccants, Markets andTechnology, 1983—1990, Oxenham Technology Associates, Inc., New York, 1985. 

The best sub-atmospheric refrigerant is water. Unfortunately it is not strongly adsorbed by carbons, but refrigerators and heat pumps based on water - zeolite pairs have been built and tested in research laboratories. Methanol is adsorbed well by carbons and a solar refrigerator based on a carbon - methanol pair was marketed by Brissoneau et Lotz Marine in France. Methanol is environmentally friendly, but deeomposes at temperatures around 150°C and so camiot be used for very high temperature cycles. 

Other markets for charcoal are as a filtration medium, a horticultural soil improver, and an adsorbent. Its large surface area of hundreds of square meters per... 

Reinluft A flue-gas desulfurization process using coke. The carbon acts as a catalyst for the oxidation of the sulfur dioxide to sulfur trioxide in the presence of water, and the sulfur trioxide is retained on the coke. The coke is regenerated in another vessel by heating with a hot gas stream, which reduces the sulfur trioxide back to sulfur dioxide and expels it for use in sulfuric acid manufacture. The key to this process is the inexpensive adsorbent. Developed by Reinluft GmbH and Chemiebau Dr. A. Zieren GmbH, and marketed as the Reinluft (Clean Air) Process. Four plants had been built by 1985. 

During the last decade infrared spectroscopy has developed into a very important tool for studies of adsorbed molecules. Very rapid FTIR spectrometers, which are easily adapted to a reflection experiment, are commercially available. Recently a dispersive, modulation spectrometer dedicated for surface studies has also come on the market. In the same way as happened... 

ZeoHte adsorbents play a dominant role in purifications owing to their ability to both adsorb large quantities of material and to achieve extremely low mole fractions of these adsorbed these compounds in product gas. Zeolites are the preferred adsorbent types for dehydration to low levels, purification and in several bulk separations. Zeolites also are employed in a significant portion of the PSA hydrogen purification market segment where they add value to bulk separations by achieving particularly high purity specifications. 

Utilities using post-combustion SCR-supported ammonia injection for NOx control as well as those using ammonia conditioning to improve electrostatic precipitator performance will produce fly ash that contains ammonia compounds. The ammonia is primarily physically adsorbed onto the fly ash particles as sulphate and bisulphate species. In many cases, the residual ammonia levels are quite low (<50ppm) however, elevated concentrations can occur as the catalyst ages or due to mechanical problems with the ammonia injection system. While elevated ammonia concentrations in fly ash do not negatively impact pozzolanic properties, it can reduce ash marketability due to odour concerns. For this reason, several processes have been developed to remove or reduce the amount of ammonia in fly ash. 

Chitosan Chitosan has a molecular structure similar to cellulose. This material is produced from chitin, which is widely found in the exoskeleton of shellfish and crustaceans. Chitin is the second most abundant natural biopolymer after cellulose. Chitosan is a good adsorbent for all heavy metals. It has been estimated that chitosan can be produced from shellfish and crustaceans at a market price of 15.43 /kg. 

Separation of gas streams by adsorption is becoming increasingly popular as improved technology comes on the market. Some examples of commercially practiced adsorption processes are shown in Table 1. These processes take advantage of the selective adsorption properties of a number of microporous adsorbents, including activated carbon, silica, alumina, and various synthetic and natural zeolites. 

The quantitation of substances separated by TLC may be carried out in several ways. The most common method is to remove the spot from the plate, elute the compound from the adsorbent and measure the concentration of the compound in solution by spectrophotometry, fluorimetry, etc. The elution process has been significantly improved and facilitated with the Eluchrom instrument developed by Sandoz and marketed by Camag (see Fig.3.6). This instrument permits direct elution from the plates via small PTFE cups in a continuous flow-through mode without the necessity of removal of the adsorbent and with the minimum requirement of solvent (usually less than 1 ml). The measuring instruments used are those available for classical solution analysis. A discussion of these instruments is beyond the scope of this book. 

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