Dow Water & Process Solutions

Catalysis of Organic Reactions

Phenol Alkylation
Bisphenol A Catalyst
MTBE / TAME Catalysis
Esterification / De-esterification
Silane Inter-conversion and Processing

When catalizing organic reactions your primary concern is to produce the highest quality product, economically. Many factors, however, can interfere in your ability to do that - limitations in throughput, limitations of reactants into the catalyst sites, diffusion of product into the bulk solution, long diffusion paths, and dead zones and pressure drop due to bead size.

DOWEX™ heterogeneous catalysts are high capacity, immobilized acids and bases that can help eliminate many of these concerns. DOWEX heterogenous catalysts have many advantages over homogeneous processes offering:

• Excellent capacity equivalent to 3M acid, catalyzing more reaction in a given time.
• Ease of separation of catalyst from product by simple filtration.
• Elimination of acid neutralization saves time and money.
• Fixed bed reactors under better temperature and contact time control making reactions easier and more cost effective with less by-product and fewer side reactions.
• Polymer matrix excluding larger molecules (>1500-2000 MW) from further reaction improving selectivity and limiting by-product production.

The uniform bead size of DOWEX MONOSPHERE™ catalysts provide further advantage by preventing resin "dead zones," improving diffusion kinetics and limiting pressure drop due to varying bead size found in some resin beds. DOWEX MONOSPHERE catalysts are made by a patented process resulting in excellent uniformity of bead size. Many customers have experienced as much as 15% increase in productivity when switching from a standard bead size to uniform particles like DOWEX MONOSPHERE catalyst.

Dow offers a wide range of catalyst products from acid to base type catalysts to catalysts for immobilized metals applications. Catalysts are available with macroporous and gel type morphologies. Dow catalysts span a wide range of particle sizes from fine mesh resins (as small as 35 microns) to special products that are 1mm in size.

DOWEX Catalyst Resins

Product	Description	Type	Matrix	Total Exchange Capacity* eq/l (kgr/ft3)	Available Forms
DOWEX G-26 (H)	Uniform particle size strong acid cation exchange resin for specialty demineralization and catalyst applications.	Strong Acid Cation	Styrene-DVB, Gel	2.0	H+
DOWEX MONOSPHERE M-31	A uniform bead size strong acid catalyst. This is our highest performance catalyst for MTBE/TAME.	Strong Acid Cation	Styrene-DVB, Macroporous	1.85	H+
DOWEX M-31	Standard grade product for general catalytic applications. This catalyst has unmatched durability and dependability within the MTBE/TAME industry.	Strong Acid Cation	Styrene-DVB, Macroporous	1.7	H+
DOWEX MONOSPHERE DR-2030	Dry acid catalysts for chemical processing.	Strong Acid Cation	Styrene-DVB, Macroporous	4.7 eq/kg	H+
DOWEX DR-2030	Dry acid catalysts for chemical processing.	Strong Acid Cation	Styrene-DVB, Macroporous	4.7 eq/kg	H+
DOWEX 50WX4	Fine mesh resin for fine chemical and pharmaceutical column separations.	Fine Mesh	Styrene-DVB, Gel	1.1 meq/ml	H+
DOWEX CM-4	A macroporous strong acid cation resin for catalyst applications.	Strong Acid Cation	Polystyrene-DVB, Macroporous	0.65 (14.2)	H+
DOWEX M-43	Corrosion control with DOWEX M-43 ion exchange resin.	Weak Base Anion	Styrene-DVB, Macroporous	1.55	FB (Free Base) form
DOWEX MONOSPHERE 550A (OH)	A uniform particle size strong base anion exchange resin for mixed bed demineralization and condensate polishing applications.	Type I Strong Base Anion	Styrene-DVB, Gel	1.1 (24.0)	OH-