Gasification of post-consumer tires and solid fossil fuels to produce organic compounds

Abstract

Tires are co-fed into a solid fossil fuel such as coal and fed into an entrained flow partial oxidation gasifier. High concentrations of solids and tires in the solids stream can be stably obtained without significant impact on the feedstock stream stability and pumpability. A consistent quality of syngas can be continuously produced while stably operating the gasifier and avoiding the high tar generation of waste gasifiers and without impacting the operations of the gasifier. The subsequent syngas produced from this material can be used to produce a wide range of chemicals.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Provisional Application Ser. No. 62 / 800,745 filed on Feb. 4, 2019, the disclosures of which is herein incorporated by reference in its entirety.BACKGROUND OF THE INVENTION[0002]There is a well-known global issue with waste disposal, particularly of large volume consumer products such as plastics, tires, textiles and other polymers that are not considered biodegradable within acceptable temporal limits. There is a public desire to incorporate these types of wastes into new products through recycling, reuse, or otherwise reducing the amount of waste in circulation or in landfills.[0003]A variety of means for the recycle, reuse, or reduction of waste stocks such as biomass, solid municipal waste, plastics, and paper have been articulated, among which is the gasification of such waste stocks. In such proposals, waste gasifiers, which typically air supplied fluidized bed gasifiers that can readily accep...

AI Technical Summary

Benefits of technology

This patent describes a process for producing syngas from post-consumer recycled materials and a solid fossil fuel. The recycled materials may include post-consumer tires. The process involves gasifying the feedstock in a gasifier with an oxidant to produce the syngas composition. The syngas composition can then be used to produce organic compounds. The technical effect of this patent is a more sustainable and efficient way to produce chemicals from recycled materials.

Problems solved by technology

There is a well-known global issue with waste disposal, particularly of large volume consumer products such as plastics, tires, textiles and other polymers that are not considered biodegradable within acceptable temporal limits.

Further, while waste gasifiers have the advantage of accepting a highly variable sizes and compositions of feedstocks, the resulting syngas compositions are also widely variable over time rendering them unusable for making chemicals without installation of expensive post treatments systems to clean up and purify the syngas streams existing the gasifier vessel.

In many instances, the gasifier is a fluidized or fixed bed type, and the processes described generate high amounts of tar, which renders the syngas stream unsuited for chemical synthesis, or are operated in a manner that generate undesirable amount of unconverted carbon products such as char, or do not efficiently generate a large output of reliable syngas composition relative to the carbon energy input, or have high energy requirements.

A small amount of water introduced to the gasification process is helpful and needed (e.g. 5-20%) but more than 30% begins to be detrimental to the performance of the gasifier as the water must be heated and vaporized, using energy, and takes up space in the processing equipment.

Introducing a co-feed to the gasifier can be problematic in that the co-feed has to be mixed with the coal / water slurry feed.

Since the coal / water slurry is concentrated as much as possible to the edge of pumpability for economic reasons, any introduction of a co-feed can disrupt the delicate balance and cause the slurry to be unstable (solids settle out), too viscous, two-phase, or otherwise unsuitable for feeding to the gasifier safely, reliably, and economically.

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