Flow improvers

One remaining possibility that is less costly from an energy point of view but needs to be carefully controlled is to incorporate additives called flow improvers. These materials favor the dispersion of the paraffin crystals and in doing so prevent them from forming the large networks which cause the filter plugging. The conventional flow improvers essentially change the CFPP and pour point, but not the cloud point. They are usually copolymers, produced, for example, from ethylene and vinyl acetate monomers ... 

Figure 5.9 shows an example of the efficiency of these products. The reductions of CFPP and pour point can easily attain 6 to 12°C for concentrations between 200 and 600 ppm by weight. The treatment cost is relatively low, on the order of a few hundredths of a Franc per liter of diesel fuel. In practice, a diesel fuel containing a flow improver is recognized by the large difference (more than 10°C) between the cloud point and the CFPP. 

Flowers of zinc Flow improvers Flow injection analysis Flow measurement... 

Retrofitting features of the more efficient reactor types have been the principal thmst of older methanol plant modernization (17). Conversion of quench converters to radial flow improves mixing and distribution, while reducing pressure drop. Installing an additional converter on the synthesis loop purge or before the final stage of the synthesis gas compressor has been proposed as a debotdenecking measure. 

Fillers may be broadly defined as solid particulates or fibrous materials, substantially inert chemically, incorporated in polymer compositions to modify the properties and/or to reduce cost. Cost reduction is not the primary reason to incorporate fillers in adhesives but they are used to impart specific properties such as flow, improved adhesion, mechanical, thermal, electrical and optical properties, chemical and weather resistance, and rheological behaviour. 

MODELING THE EMISSIONS IMPACTS OF TRAFFIC FLOW IMPROVEMENTS... 

These problems can be minimized by the use of polymeric flow improvers and freeze-point depressants, similar to those employed in fuel oils. 

Cold flow improvers (pour point depressants) These viscosity improvers are often specified in cold climates for unheated gas oil or where existing residual oil heaters are inadequate. The use of these paraffin crystal modifiers permits fuel to continue to flow at temperatures of 30 to 40 °F lower than the point at which wax crystallization would normally occur. 

Holman BL, Mendelson J, Garada B, er al Regional cerebral blood flow improves wirh treatment in chronic cocaine polydrug users. J Nucl Med 34 723—727, 1993... 

Effect of Flow Improver Additives on Paraffin Deposition... 

N. E. Almond. Pipeline flow improvers. In Proceedings Volume, pages 307-311. API Pipeline Conf (Dallas, TX, 4/17-4/18), 1989. 

J. Balzer, M. Feustel, M. Krull, and W. Reimann. Graft polymers, their preparation and use as pour point depressants and flow improvers for crude oils, residual oils and middle distillates. Patent US 5439981, 1995. 

M. Brod, P. Venables, and G. S. Lota. Crude and heavy fuel flow improvers. Patent AU 603180,1990. 

I. M. El-Gamal and E. A. M. Gad. Low temperature rheological behavior of umbarka waxy crude and influence of flow improver. Rev Inst Franc Petrol, 52(3) 369-379, May-June 1997. 

C. F. L. Goudy. How flow improvers can reduce liquid line operating costs. Pipe Line Ind, 74(6) 49-51, June 1991. 

M. Krull, S. P. von Halasz, W. Reimann, J. Balzer, and H. Geiss. Copolymers of ethylenically unsaturated carboxylic acid esters with polyoxyalkylene ethers of lower, unsaturated alcohols as flow-improving agents for paraffin containing oils. Patent US 5718821, 1998. 

C. L. Muth and S. M. Kolby. Cost saving by use of flow improver. In Proceedings Volume, pages 353-357. 13th Int Pipeline Technol Conf (Houston, TX, 2/5-2Z7), 1985. 

W. Ritter, C. Meyer, W. Zollner, C. P. Herold, and S. von Tapavicza. Copolymers of acrylic acid and/or methacrylic acid esters as flow improvers. Patent AU 611265, 1991. 

Flame retardants - Fire retardants - Smoulder retardants -Smoke-suppressants Flexibilisers Flow improvers... 

Continuous flow analysis (CFA) (Skeggs), since 1960 Segmented flow Improved ISEs Tubular electrodes (Blaedel) Adapted ISFETs Special sampling requirements in plant and environment control (Sections 5.5 and 5.6)... 

MAK fining A petroleum refining process which combines MAK hydrocracking with a cold-flow improvement process. Developed by Nippon Ketjen and first licensed in 1998. 

Excellent turndown up to the maximum design flow lower vapor flow improves separation effectiveness. 

Cold composite curve, 23 191 Cold-ethanol precipitation, 22 135-136 Cold exhaust dyeing, 9 176-177 Cold flow improvers, for diesel fuel, 22 427-428... 

In addition to refining techniques, compounds identified as wax crystal modifiers are available for use in contending with the effects of wax in fuels. Wax crystal modifiers, also called pour point depressants or cold flow improvers, are typically polymeric compounds which have the ability to crystallize with fuel wax as it forms. By co-crystallizing with wax, the modifiers typically effect a change in the size, shape, and conformation of wax crystals. Other wax crystal modifiers function by dispersing or inhibiting the nucleation or growth of wax crystals within a fuel or oil. 

Test method IP 309 is used to determine the low-temperature filterability of distillate fuels including those treated with a cold flow improver. The cold filter plugging point (CFPP) is defined as the highest temperature at which the fuel, when cooled under the prescribed conditions, will not flow through the filter or requires more than 60 seconds for 20 mL to pass through or fails to return completely to the test jar. This method is part of a series of standardized tests developed by the Institute of Petroleum. Test method IP 309 is summarized as follows ... 

Pour point reversion can occur in oils treated with a pour point improver. Often, pour point reversion can be overcome by increasing the cold flow improver treat rate by about 25% to 50%. 

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