Plastic Feedstock Specification

Plastic feedstock specifications are extremely important in order to obtain satisfactory and consistent fuel quality (see Table 15.2). A rigid incoming feedstock specification (IFS) ensures that limits are placed on critical contaminants. The critical contamination is based around the so-called hetero-atoms . These are listed below in order of priority  

Periodic feedstock audits also need to be conducted to ensme the IFS are being adhered 

Typical input specifications for BP s Grangemouth pyrolysis plant are shown in Table 15.3. 

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Apart from MPW and PVC, several feedstock recycling processes have been developed for some specific plastics. In this respect, the most important plastics are ... 

The majority of chemical commodities (plastics, foams, pharmaceuticals, agrochemicals) are made from rapidly depleting petrochemical feedstocks. Consequently, there is a growing need to develop catalytic methods for the direct manufacture of chemical products from abundant renewable resources in the absence of stoichiometric byproducts [1], In the specific case of carbonyl and imine addition, a departure from the use of premetallated nucleophiles represents a particularly important focus. Progress in this area will depend largely upon the discovery of new chemical reactivity. 

The action that pushes solid particles forward in the feed section of a single screw extruder, blow, or injection machine has always been a potential for one of the weakest features of these machines. This forward feeding force near the feed hopper is often weak and erratic and is classified as non-positive. It can be so tenuous that a specific screw/barrel combination will feed virgin but little or no additions of regrind, or one feedstock shape but not another, and often one family of plastics but not another. This action results in non-uniform feed that will in turn result in poor production rates, non-uniform output (surging), and poor product quality.147... 

A major problem in pyrolysis is in the rather unpredictable specifications of both feedstock, if it is a mix of plastics, and products. Especially the presence of halogens has been considered problematic, both because of product quality and operating problems, such as ... 

The efficiency of collection and sorting structures is measured by collection costs, capture rate and purity of generated feedstock. Some current methods of collecting discarded plastic products are displayed in Table 3.1. In kerbside collection households are given directives on at what level they should sort their waste, whereas drop-off and buy-back centres have specifications on what waste types are accepted. 

The milestone in the obtaining biologically produced PHAs came from the single observation that by changing the carbon feedstock, one can tailor new PHA. Thus, the metabolic flexibihty of certain microbes and the non-specificity of the enzymes involved in the polymerization of PHA monomers have been exploited in attempts to obtain new plastics that cannot be found in nature. 

Plasticating capacity n. Of an extruder or injection molder, the maximum rate at which the machine can melt room-temperature feedstock and raise it to the temperature suitable for extrusion or molding. This rate is determined mainly by the quotient of the available screw power, divided by the means specific heat of the... 

Chemical plants use the raw materials produced in the refinery to make the chemicals that are the basis of products like plastics and synthetic rubber. Chemicals made by these processes are used In the clothing and textile industry, automobile industry, pharmaceutical and medical industry, computer and electronic appliance industry, and in paint, fertilizers, and so on. Chemical plants specialize in the large-scale production of chemical feedstocks and products made from the ever-versatile hydrocarbons. Technicians may work inside a chemical plant manufacturing a specific chemical and be totally unaware of how and where that chemical product is being used in our complex modern society. 

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