Conrad process

Conrad Industries (Chehahs, Washington) have demonstrated the pyrolysis of post-use plastics into petrochemical feedstocks. The plastic most studied was a mixture of 60% high-density polyethylene, 20% polypropylene, and 20% polystyrene. Yields of liquid products were in the range 65-75% at 482-510°C. Other studies examined the effects of PET and PVC on the liquid yields. The liquid products were determined to be suitable feedstocks for further refining, but the economics were not competitive with conventional petroleum refining in 1994 [36]. 

10 OTHER PROCESSES WITH SEPARATE CATALYST BEDS 

The Likun Process (China) uses a two-stage cracking process under normal pressures where the waste plastics are first pyrolyzed at 350-400°C in the pyrolysis reactor and then the hot pyrolytic gases flow to a catalyst tower where they undergo catalytic reforming over zeolite at 300-380°C. By having the catalyst in the second stage this overcomes the problems of rapid catalyst deactivation from coke deposits on the surface of the catalyst. 

Such two-step processes are also referred to as cracking-catalytic reforming (CCR) processes. The catalytic reforming stage of the primary oil product ensures high-quality diesel or gasoline products are obtained. The catalytic reforming step improves the RON and the contents of isomer, cycloparafflns and aromatics. 

Conrad Industries, Advanced Recycling of Plastics A Parametric Study of the Thermal Depolymerization of Plastics, final report with the American Plastics Council, June (1995). 

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Results obtained for two mixed plastics are summarized in Table 4. A balance exists between process temperature, plastics feed rate, and product yields (67). For example, lower temperatures increase wax formation due to incomplete depolymerization. Slower feed rates and increased residence times reduce wax formation and increase the yield of Hquids. The data summarized in Table 4 illustrate that the addition of PET to a HDPE PP PS mixture changes the performance of the Conrad process. Compared to the reference HDPE PP PS mixture, increased amounts of soHds ate formed. These are 95% terephthahc acid and 5% mono- and bis-hydroxyethyl esters. At higher temperatures, apparentiy enough water remains to promote decarboxylation. 

In contrast, the addition of LDPE or PS to the mixture had Httie effect on its behavior in the Conrad process. 

Any post-consumer plastic stream will contain some halogens in the form of polyvinyl chloride, polyvinylidene chloride, brominated flame retardants, halogenated additives, food waste, or salt. Therefore, two issues must be considered. First, the gas stream resulting from the depolymerization of plastics must be scrubbed to remove any halogenated gases to satisfy emissions controls. Second, halogens in the liquid product must be minimized to increase its value and marketability. Therefore the Conrad process has been developed. It is a robust process unit that can accommodate a variable feedstream and produce a consistent product, free of nonhydrocarbon impurities by low feed preparation costs. 

With the Conrad process [1-3] a set of experimental runs with a throughput of approximately 100-1000 kg/h with PVC contents of up to 3% in a 60 20 20 HDPE PP PS base mixture have been performed. Typically 70-80% of liquids and 1-3% of solids are obtained. In scavenging the chlorine from evolving gases by hot calcium oxide and before condensation of the liquid fraction with a content of about 25 ppm chlorine were possible. Similar results were obtained by treating the plastics in the kiln with calcium oxide during pyrolysis. A direct condensation without any calcium oxide treatment led to concentrations of up to 10000 ppm chlorine. 

Conrad process—American Plastics Council Variable residence time and pyrolysis temperatures, rotary kiln reactor, CaO for HCl capture Feedstock for steam crackers giving higher amount of monomers, 86% naphta grade products 381a... 

Conrad Industries, Inc. (CentraUa, Washington) and Clean Air Products Company (Pordand, Oregon) have jointiy built a tire pyrolysis demonstration machine which allows recovery of combustible gases, oils, and other by-products. The equipment can also handle other carbonaceous material. It is designed to process 0.9 t/h of tires the entire system is estimated to cost about 2.3 x 10 . The feedstock consists of 5-cm tires chips which produce pyrolytic filler, a vapor gas yielding 11.5 kj/m (1000 Btu/ft ), and medium and light oils yielding about 42 MJ/kg (18,000 Btu/lb) (32). 

Schutz H, Seiler W, Conrad R. Processes involved in formation and emission of methane in rice paddies. Biogeochemistry. 1989 7 33-53. 

Conrad-Limpach-Knorr synthesis, of quinolines, 21 189 Conrad recycling process, 21 455 Conradson carbon test method, 11 705, 721 Consensus materials standards, 15 743 Consent decree protocols, in the United States, 11 692-694 Consent decrees, 11 689-690 Consequence analysis, 21 860-861 Consequence modeling, 13 165-166 Conservation applications, high performance fibers in, 13 398 Conservation of energy, 21 290 Conservation of mass, 11 737, 738-739 Conservation, of resources, 24 164-167 Conservation scientists, 11 398-399 Consistent force field, 16 744 Consolidants, in fine art examination/ conservation, 11 410... 

Peters V, Conrad R. 1996. Sequential reduction processes and initiation of CH4 production upon flooding of oxic upland soils. Soil Biol Biochem 28 371-82. 

M. Conrad, Cross scale interactions in biomolecular information processing, BioSystems, 35, 157-160(1995). 

R. R. Kampfner andM. Conrad, Computational modeling of evolutionary learning processes in the brain, Bull. Math. Biol., 45, 931-968 (1983). 

M. Conrad, Biomolecular information processing, IEEE Potentials, 12-15 (1987). 

In this year is the earliest known reference to corned powder. It was in the Firebook of Conrad von Schongau and listed in Marshall 1 (Ref 11, p 25). Corning means that the BkPdr cake was broken into small grains instead of preparing it in fine powder, known as serpentine . The process was essentially the same as described in Vol 2 of Encycl, p B169-L... 

The only raw material required for most tire pyrolysis processes is scrap tires. Some processors purchase and use whole tires, while others chip whole tires into two inch pieces, or purchase the tires already chipped. Conrad uses a local tire chipper to shred whole tires to a 2-inch size, wire-in, for their use. The tire chipper, who works on Conrad property, receives a tipping fee for collecting the tires, and provides the TDF to Conrad free of charge. 

The routes of delivery of rAAV in animal models have been largely based upon the specific needs dictated by the disease process to be treated. For example, rAAV-cystic fibrosis transmembrane conductance regulator (CFTR) vectors that have been developed for treatment of cystic fibrosis (CF) were tested in New Zealand white rabbits and in rhesus macaques by the endobronchial route (Flotte et al., 1993 Afione et al., 1996 Conrad et al., 1996). In each instance aliquots of vector were instilled directly into the lumen of a bronchus through a fiberoptic bronchoscope. Vector DNA transfer and mRNA expression were detectable (albeit at low levels) for more than 6 months in each instance, without any indication of inflammation or any other toxicity. Studies in rhesus monkeys also indicated that the likelihood of rescue of rAAV by concomitant wild-type AAV and adenovirus infection was low. These studies... 

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