Refrigerants natural types

Lactic acid-producing bacteria associated with fermented dairy products have been found to produce antibiotic-like compounds caUed bacteriocins. Concentrations of these natural antibiotics can be added to refrigerated foods in the form of an extract of the fermentation process to help prevent microbial spoilage. Other natural antibiotics are produced by Penicillium wqueforti the mold associated with Roquefort and blue cheese, and by Propionibacterium sp., which produce propionic acid and are associated with Swiss-type cheeses (3). 

The DirCon freeze crystallization process is a technology that can be used to purify aqueous waste streams and concentrate liquid waste by the freezing and subsequent melting of the liquid. This technology is a type of direct-contact secondary-refrigerant freeze crystallization and operates on the principle that when water freezes, the crystal structure that forms naturally exudes contaminants from its matrix. The terms freeze crystallization and freeze concentration are often used interchangeably. 

The physical processes by which natural gas liquids are recovered include phase separation, cooling, compression, absorption, adsorption, refrigeration, and any combination of these. Obviously the definition already stated excludes refinery light volatiles produced by the destructive decomposition of heavy petroleum fractions and it also excludes liquids that may be produced synthetically from natural gas. These distinctions are of economic importance in considering our basic energy reserves. Both the refinery volatiles and the synthetic liquids represent conversion products from other hydrocarbons and the conversion is usually attended by a considerable loss. Thus it has been stated that only about 47% (17) of the energy of natural gas is realized in the liquid hydrocarbon products of the Fischer-Tropsch type of synthesis. 

Dependable information has been developed for the heat rejector requirements of different types of power equipment air compressors, refrigeration equipment, steam condensers, diesel engines and natural gas engines. Table 5.1 gives information on the heat absorbed by cooling water for this type of power equipment. 

The foam sheet is clean, bright in appearance, has excellent cushioning properties, and is nonporous. The foam is extruded as a sheet and is subsequently vacuum thermoformed into the desired shapes for packaging, etc. (Chapters 5 and 7). Use includes low temperature insulation in freezers, coolers, and other types of refrigerated rooms auto, truck bodies, and railroad cars refrigerated pipelines and low-temperature storage tanks for liquefied natural gas. They find usage as a replacement for molded-paper-pulp board in meat and produce trays and egg cartons. 

Gas treatment also includes the recovery of various hydrocarbons associated with natural gas. There are several processes to achieve this goal lean gas absorption, various types of refrigeration, turboexpansion, and others. However, since there were certain disadvantages in these processes, there was need for a refined process which can eliminate some of these limitations to economically and efficiently recover the valuable hydrocarbons from natural gas. One of the major limitations of the conventional processes was the inflexibility to meet the market demand. A process called the Mehra Process has been patented to solve some of these problems [9], in which a physical solvent is used for the removal and recovery of only desirable hydrocarbons from the gas stream. Basically, this is an extraction process since the volatility of hydrocarbons is increased on contact with a physical solvent. The equipment used for this process are arranged in two different configurations extractive-flashing and extractive-stripping. 

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