Bend Research

Kev>erse Osmosis (RO) Membranes A type of membrane system for treating oily wastewater is currently undergoing commercialization by Bend Research, Inc. The system uses a tube-side feed module that yields high fluxes while being able to handle high-sohds-content waste streams (Ref. 25). Another type of reverse osmosis technique is being designed to yield ultrapurified HF recovered from... 

FIGURE 19 Concept of membrane-assisted recompression for energy recovery from drying operations. (Bend Research, Inc.)... 

My knowledge grew at Bend Research, Inc. under Harry Lonsdale, another membrane pioneer who was involved in the theoretical and practical side of membranes since the early 1960 s at Gulf General Atomic (predecessor of Fluid Systems, now Koch Membrane Systems), Alza, and later Bend Research, which he co-founded with Richard Baker. At Bend Research, I had the opportunity to develop novel membranes and membrane-based separation processes, including leading several membrane-based projects for water recovery and reuse aboard the International Space Station. 

Silver membranes are permeable to oxygen. Metal membranes have been extensively studied in the countries of the former Soviet Union (Gryaznov and co-workers are world pioneers in the field of dense-membrane reactors), the United States, and Japan, but, except in the former Soviet countries, they have not been widely used in industry (although fine chemistry processes were reported). This is due to their low permeability, as compared to microporous metal or ceramic membranes, and their easy clogging. Bend Research, Inc. reported the use of Pd-composite membranes for the water-gas shift reaction. Those membranes are resistant to H2S poisoning. The properties and performance characteristics of metal membranes are presented in Chapter 16 of this book. 

T. Matsuura. Sourirajan s group at the Divison of Chemistry, National Research Council of Canada have published extensively on their studies with aromatic polyamide membranes (26-46), Others that the author wishes to acknowledge for their citations and discussions of material presented in this paper are V. T. Stannett and H. B. Hopfenberg at North Carolina State University W. J. Koros, D. R. Paul and D. R. Lloyd at the University of Texas at Austin J. M. S. Henis at Monsanto, and H. R. Lonsdale at Bend Research (47). 

Edlund, D., A Membrane Reactor for H2S Decomposition. In Advanced Coal-Fired Power Systems, Bend Research, Inc. Bend, 1996. 

Kajiwara M, Uemiya S, Kojima T. Stability and hydrogen permeation behavior of supported platinum membrtmes in presence of hydrogen sulfide. Int J Hydrogen Energy. 1999 24 839. Edlund D. A membrane reactor for H2S decomposition. Advanced coal-fired power systems. Bend Bend Research, Inc 1996. 

More recently, other carriers have been studied. An excellent review of this area was recently completed ( ). Bend Research Inc. has recently obtained a Japanese patent for oxygen separation from air using a cobalt-salen complex. They were able to obtain Oj/Nj selectivities in excess of 20 and an Oj permeability of 26 10" cm (STP)-cm/cm -s-cmHg. Using a ambient pressure feed and low pressure permeate, they measured Oj purity of 80-90 mole J (5). A major problem with synthetic carriers for oxygen at this time is that they will Irreversibly oxidize at ambient conditions and, therefore, require refrigeration to maintain their reversibility. Koval and Reyes (6) discuss the chemical problems encountered with facilitated transport of oxygen. 

W. K. Miller, S.B. McCray, D.T. Frie-SEN (Bend Research). Solvent resistant microporous polymide membranes. US Patent 5725769, March 1998. 

Apart from the work conducted by Li et al. at Exxon which is fully reported in the proceedings of a seminar on Liquid Membrane Applications in Waste Water Treatment and Metals Recovery held at UMIST in May 1980, investigations on applications of liquid membranes to metals recovery are conducted at a number of other places. Thus, extraction of copper is studied at UMIST (11, 12), Graz (13-15) and Bend Research (16). The last place is also active in the use of membranes for the extraction of uranium (17), whereas work on the extraction of copper, zinc, cadmium and lead is conducted by Boyadzhiev et al. (18). Extraction of different metals has also been studied by Stelmaszek (19) and Strzelbicki (20, 21) and of zinc alone at Imperial College (7). All the accumulated data point towards membrane extraction as a promising process for the solution of separation problems, particularly in dilute solutions. 

Bend Research, Inc., Bend, OR, USA Tel 541 382 4100 e-mail david.vodak BendResearch.com... 

The membrane permeation test is another bulk sparing in vitro dissolution technique. It was developed at Bend Research and has been used for more than a decade (Babcock et al. 2009). This biphasic dissolution test is designed to assess the ability of a formulation to rapidly establish a high free drug concentration and then sustain that concentration for a physiologically relevant time period. 

More than 500 different drugs have been formulated as SDDs at Bend Research and tested in various animal models. Absorption enhancement relative to crystalline drug ranges from around 1.5-fold to nearly 100-fold, but varies widely based on the dose and drug properties. Figure 9.12 shows representative preclinical in vivo data for BCS class II compounds. 

Fig. 9. 16 Histogram summarizing selected bend research experience in formulating stable SDDs after 6- to 13-week stability challenges for given Fg-Tltorage- Key bold numerals on the bars represent the number of formulations used to generate the percentages...

Graciela Terife Merck Co., Inc., Whitehouse Station, NJ, USA Gregory IVoup Merck Co., Inc., Whitehouse Station, NJ, USA Siva Ram Kiran Vaka Kashiv Pharma LLC, Bridgewater, NJ, USA Joao Vicente R D Drug Product Development, Hovione, Loures, Portugal David T. Vodak Bend Research, Inc., Bend, OR, USA... 

In answer to Mr Brueton I did not intend to give the impression that bone necrosis is less important than the bends. Research on bone necrosis is still going on. The Paper draws attention to the possibility of alternative means of tunnelling. 

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