Two key differences in some cases are the equipment and materials used to generate the ultrasonic energy required for the process, and the positioning of the transducer s relative to the extruder.
The dry process digester has the advantage of generating less pollution than the wet process. However, estimating reduction in unit cost is difficult because of the lack of data relating to production costs to different levels of throughput capacity for particular devulcanization technologies.
Scrap rubber containing natural and synthetic rubbers can be reclaimed by the steam digestion process. Therefore, downstream of the baghouse, a scrubber is required to remove sulfur dioxide SO2as shown in Figure G. The crumb rubber is mixed with one or more devulcanization agents.
See Reference 1 Additionally, recycling rubber reduces demand for new natural rubber, which may keep rubber tree plantations from expanding into sensitive tropical ecosystems. A common method of reducing the rubber temperature is a cooling bath.
Aliphatic oil Tetraisobutylene Polymers: The data for the capital cost analysis include an allowance for engineering services for the construction of the facility.
Then, to remove any metals or other particulate, the vent gases are piped to a baghouse. This is especially true if the spent carbon requires disposal at a hazardous waste disposal site. The gel portion is typically soft and has significantly lower crosslink density than that of the original vulcanizate.
Another mechanical reclaiming process is the De-Link process. Scrubbed vent gases are then released to the atmosphere.
The fibers of the rubber scrap, remnants of the tire carcass, were first removed by mixing it with alkali, water, plasticizing oils and, if needed, chemical peptizers.
The difficulty of permitting—and the cost—would be a function of the type of devulcanization technology, the processing rates, and other factors.
All circumstances considered, any estimates of commercial production costs for devulcanization of waste tire rubber are highly speculative at best. Typical bond energies 1.
A second method to treat the vent gases exiting the ultrasonic devulcanization reactor would be use of vapor phase carbon. The vent gases are treated prior to release to the atmosphere. Devulcanization lacks adequate test data and data interpretation, and it has poorly defined end product specifications without adequately justified and defined applications and uses.
Naphthemic oil 1-isopropylmethylcyclohexane cis Plasticizers: The production of devulcanized rubber from home manufacturing scrap in the U. Aromatic oil Di-iso-butyl phthalate Plasticizers: In this process finely ground rubber powder is mixed with the De-Link masterbatch DeVulc: Aromatic oil Dimethylstyrene Polymers: The short extrusion times make this method suitable for SBR, that tends to harden when longer recycling times are applied.
This mechanical action serves to heat the rubber particles and softens the rubber. The operating cost estimates include the cost of crumb rubber feedstock for each of the processes. One continuous process for devulcanization of rubbers is based on the use of high-power ultrasound electromagnetic radiation.Devulcanization is a potential method of recycling waste tire rubber.
As its name implies, in the process of devulcanization, the structure of the vulcanized waste rubber is modified.
The resulting material can be revulcanized or transformed into useful products.5/5(1). Devulcanization of specific types of rubber and/or waste tire rubber has a long history. However, only recently have limited technical data been reported in the available literature.
Usually when reported, the tested properties of devulcanized rubber compose an incomplete list. Stanford Libraries' official online search tool for books, media, journals, databases, government documents and more.
This report presents the results of the evaluation of waste tire devulcanization technologies performed by CalRecovery, Inc.
under contract with the California Integrated Waste Management Board.
Devulcanization is a potential method of recycling waste tire rubber. Contractor’s Report to the Board Evaluation of Waste Tire Devulcanization Technologies December Produced under contract by: CalRecovery, Inc.
Zero Waste—You Make It Happen! This preview has intentionally blurred sections. Stanford Libraries' official online search tool for books, media, journals, databases, government documents and more.Download