The Industrial Phase-Transfer Catalysis Experts

PTC Tip of the Month E-Newsletter

PTC Tip of the Month - September 2017

A Potential Mechanical Device for Solid-Liquid PTC

By Marc Halpern, the leading expert in industrial phase-transfer catalysis.

An exhibit at the 2017 Specialty & Agro Chemical trade show in Charleston, South Carolina (just before Hurricane Irma hit the city) displayed a continuous feeder-mixer by Readco-Kurimoto that, in our opinion, may be useful for certain types of solid-liquid phase-transfer catalysis reactions. We speculate that PTC I-Reactions (in which the rate determining step is NOT transfer) that use two different solids such as NaOH and potassium carbonate and do not require vigorous mixing between the solids and liquids, may benefit from this system.

The unit starts with a screw feeder that delivers solids into a series of rotating blades that can be made of a variety of materials of construction and in a variety of geometries. There are two sets of blades, each on a shaft, that rotate with little clearance between them. This results in mixing and even mild grinding if solids are present. Liquids can be introduced at various locations along the axes of rotation. The unit can be enclosed for temperature control. The speed of the blades can be controlled. The diameter of the blades can be up to 24 inches.


One can envision the use of this system for a continuous process for a solid-liquid PTC reaction. The solids are fed continuously and moved down the length of the unit first by the screw feeder then by the rotating blades where the liquid is introduced and mixed with the solids, all the while being moved forward.

The manufacturer of the unit is willing to test applications in their facility and apply their expertise to the selection of blade geometry and other operating parameters.

PTC Organics would be happy to explore working with your company and Readco-Kurimoto to evaluate the feasibility of this system by integrating PTC Organics’ highly specialized expertise in industrial phase-transfer catalysis with your company’s needs and the expertise of the manufacturer of the unit. Now contact Marc Halpern of PTC Organics to explore custom developing a solution for your solid-liquid PTC application.

About Marc Halpern

Marc Halpern

Dr. Halpern is founder and president of PTC Organics, Inc., the only company dedicated exclusively to developing low-cost high-performance green chemistry processes for the manufacture of organic chemicals using Phase Transfer Catalysis. Dr. Halpern has innovated PTC breakthroughs for pharmaceuticals, agrochemicals, petrochemicals, monomers, polymers, flavors & fragrances, dyes & pigments and solvents. Dr. Halpern has provided PTC services on-site at more than 260 industrial process R&D departments in 37 countries and has helped chemical companies save > $200 million. Dr. Halpern co-authored five books including the best-selling “Phase-Transfer Catalysis: Fundamentals, Applications and Industrial Perspectives” and has presented the 2-day course “Practical Phase-Transfer Catalysis” at 50 locations in the US, Europe and Asia.

Dr. Halpern founded the journal “Industrial Phase-Transfer Catalysis” and “The PTC Tip of the Month” enjoyed by 2,100 qualified subscribers, now beyond 130 issues. In 2014, Dr. Halpern is celebrating his 30th year in the chemical industry, including serving as a process chemist at Dow Chemical, a supervisor of process chemistry at ICI, Director of R&D at Sybron Chemicals and founder and president of PTC Organics Inc. (15 years) and PTC Communications Inc. (20 years). Dr. Halpern also co-founded PTC Interface Inc. in 1989 and PTC Value Recovery Inc. in 1999. His academic breakthroughs include the PTC pKa Guidelines, the q-value for quat accessibility and he has achieved industrial PTC breakthroughs for a dozen strong base reactions as well as esterifications, transesterifications, epoxidations and chloromethylations plus contributed to more than 100 other industrial PTC process development projects.

Dr. Halpern has dedicated his adult life to his family and to phase-transfer catalysis (in that order!).

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