Environmental Waste International

EWI Systems

The Problem

Scrap tires continue to be a significant waste management issue worldwide. Current estimates of the number of scrap tires or scrap tire equivalents (such as shredded tires) stockpiled in North America alone range from 550 to 800 million.

The Solution

The Hybrid Microwave Process and Reverse Polymerization™ by EWI offer profitable and environmentally friendly methods to address the growing scrap tire problem. The processes completely reuse or recycle 100% of the scrap tire feed and allow the recovery of the following valuable by-products:

Reclaimed Carbon Black (rCB),
Steel,
Hydrocarbon Oil and Gases.

How it Works

The process is a continuous feed system. Tires enter a nitrogen-filled chamber on a moving conveyor. The nitrogen prevents the formation of hazardous by-products (e.g. dioxins and furans) through oxidation. The tires pass through a patented microwave delivery system that reduces the tires to their base components. Hydrocarbons are extracted as vapours and separated into gaseous and liquid fractions. The carbon and steel remain on the conveyor and are separated at the discharge. This system allows us to constantly control and monitor the energy delivered at all times and make adjustments as needed.

Models and Efficiency

The tire system is extremely flexible and the commercial facilities have been designed based on the TR25 as the base model. The TR25 processes 25 tonnes of tires per day or 8,250 tonnes of tires per year. Each subsequent model is made up of multiple TR25 processors with the associated economy of scale. Hence the TR50 is two lines and the TR100 is four lines with appropriately sized ancillary equipment.

How the TR Series Operates:

Step 1 – Scrap tires enter the processing area. They are moved up an inclined tire feed (see diagram) into the dry-feed tower.
Step 2 – Each tire passes through a series of shutters before entering the microwave reduction chambers.
Step 3 – Tires move through the tunnel of microwave reduction chambers. The wave field causes reverse polymerization to occur. The tires break down.
Step 4 – Gases produced by this process are drawn off, collected, and passed through a condenser to form the hydrocarbon oil.
Step 5 – Leftover gaseous hydrocarbons continue to a scrubber, where sulphur is removed. The gas and oil can then be used either to a) generate electricity for the RP process, or b) be sold as feedstock in other industrial processes.
Step 6 – Carbon and steel remain on the feed belt. They exit the microwave reduction tunnel. The materials are separated in a water separator tank. Carbon is collected and sent to storage containers.
Step 7 – The steel is collected and washed. It is placed in storage bins.

Statistical Data

The reclaimed carbon black can be used in new rubber or plastic production or other feedstock. The steel is sold for recycling. From a 20 lb (9.1 kg) tire, 7 lbs (3.18 kg) of carbon black and 2.0 lbs (0.91 kg) of steel are recovered. The remainder of the tire (oil and hydrocarbon gases) can be reused in the production of electricity or sold for use in other applications. The process has almost 0% waste produced.

EWI’s tire reduction system is designed around the TR25 model. The TR25 processes 25 tonnes of tires per day (8,250 tonnes annually). The model TR50 (two TR25 modules) processes 50 tonnes of tires daily (16,500 tonnes annually). It produces over 14 million lbs of carbon black, 4 million lbs of steel and almost 1.7 million gallons of oil per year. Alternatively, the oil and gas hydrocarbons can be combined to produce up to 6 MW of power, netting almost 3 MW for use by local industries or homes.

Recycling more than 16,500 tonnes of tires annually with the TR50 reclaims over 6,600 tonnes of rCB. When compared to utilizing the tires as a tire derived fuel (TDF) savings of up to 27,500 tons (25,000 tonnes) of carbon dioxide are the result. There is a further decrease in carbon emissions as the use of reclaimed carbon black reduces the need for production of new material. In addition, the hydrocarbons produced from the Reverse Polymerization process are much lower in sulfur than the scrap tire rubber; therefore, there is a significant reduction (88%) in the sulfur released to the atmosphere by generating power from Reverse Polymerization compared to burning of TDF.

How Much Does It Cost?

The cost to construct a tire facility varies from $8MM to $20MM USD, depending on location, the number of tires processed and the equipment included. The larger commercial system, the TR100, yields attractive annual returns based on the quality of the by-products produced and their marketable value. We believe that the growing environmental concerns and rising oil and electrical prices, will establish the EWI TR systems as the preferred method of recycling used tires worldwide.

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