All states have laws regarding how scrap tires are to be documented, transported, stored and disposed of. This is all in an effort eliminate illegal tire dumps, environmental pollution save landfill space.
So how do I make money in the tire disposal / tire recycling industry?
The answer to this question can take many paths, and which path is right for you and your location may not be right for the next guy.
First the two main ways to make money from scrap tires is from the tipping fee and from culling resellable used tires.
As of the writing of this article I know of no recycling process for scrap tires that on it’s own produces a net profit on the back end. Count on your profit being produced from the tipping fees minus your processing costs. This is the fee charged for the transport or disposal of the scrap tires and is payed by the tire shop, government, or land owner looking to get rid of tires. This is similar to the fee’s charged to dispose of garbage. This fee varies greatly from one place to another and can be by the tire or by the ton. The fees range from $0.50 - $3.00 per tire for car and light truck tires, to $3.00 - $25.00 each for semi and off road tires. Most tire dump cleanups are charged by the ton and range from $75.00 - $200 per ton.
Tire culling involves picking up scrap tires from tire retailers, inspecting them for damage and tread depth, and reselling them. There are allot of good used tires with as much as 50% tread life left that make it into the waste tire stream. These are often from dealer take offs, people who get one flat tire and choose to replace all four, Ect. Most culled tires are bulk shipped to other countries to be grooved deeper and resold, some are also sold to used tire shops in the US. Depending on who your selling the tire to, used tire wholesale prices can range from $2.00 - $15.00 per tire, and $20.00 - $90.00 each retail. However if you plan to sell tires retail most customers will demand that they are pressure tested for leaks and ply separations, also for liability concerns selling tires that are over 6 years old is sketchy. Be aware though that some tire retailers will demand that their scrap tires be destroyed and not culled.
Tire disposal and processing business opportunities:
Become a Tire Jockey. No I don’t mean riding scrap tires for money. A tire jockey is a slang term for tire hauler. For many tire processors this is how they got started in the business. This involves getting a permit and bond if needed from your state or local municipality to transport scrap tires and get a truck to use on your tire pickups. Most small time tire haulers I have dealt with us a 14 - 25ft box truck. They are payed to pickup tires from local tire shops, then pay a local tire processor to get rid of the tires. Their profit is made from the spread between the two prices due mostly to volume. Say I take 20 tires to a processor they may raise the per tire price to say a $1.50 per tire, but if I take in a truckload of 1000 tires I can most likely negotiate a price down to say $1.00 per tire be able to get a per ton rate. Now the tire retailer pays you $1.50 or higher to pick up a low volume of tires and you make $.50 per tire. So on 1000 tires you grossed $500.00. Some tire haulers will also do some tire culling to increase there profits. Some even store and sell them directly on Craigslist and Ebay.
Become a scrap tire processor. To start with you need to find out what local markets are available for processed scrap tires, then how much you can spend on equipment and infrastructure to get going.
The most common methods and derived products from scrap tires are as follows:
These are tires that are simply packed together in a specialized tire baler and are used for bunker sides, fill, or are shipped outside the US. This method was a very popular for a while as other countries were taking the bales to chop them up and burn for fuel. However in recent years this has almost stopped completely and unless you are near a port or have a project requiring tire bales near by, the trucking and labor costs can be very prohibitive.
There are landfills that will accept tires if they are cut into quarters or smaller. This is usually done using a specialized piece of equipment called a tire shear. These range in price from as low as $9000.00 to as much as $500,000 it all depends on the tire size and volume you need to process. A good quality new shear for car and light truck tires is going to run about $9,000 to $20,000 one for doing semi truck and tractor tires is going to be between $20,000 to $50,000. This is by far the most labor intensive way to get rid of waste tires, but for many of the larger off road tires it is the only economical way.
This can take a few different paths and also depends on if you are processing car and light truck tires or semi truck tires. It starts by looking at how the tire is constructed. Modern radial car and light truck tires have steel wires in the tread section and bead seat section of the tire only.
Where modern radial semi truck tires have steel wire in all sections of the tire.
Radial tires only have wire in the bead seat.
“Semi tire sidewalls” are on their own a saute after commodity. They are used to weigh down highway construction barrels, signs, and silage tarps. The value of semi sidewalls is between $.90 - $2.00 each. Bias ply sidewalls are more valuable for use to hold down silage tarps because they have no chance of protruding wires to tear the tarp. However bias ply semi tires are becoming more and more rare. Many silage tarp applications have started to use light truck tire sidewalls. The small lightweight machines for cutting car and light truck tire sidewalls range from $4000 to $8000 and heavy duty machines for semi truck tires Range from $5000 to $35,000. Also add into this a tread cutter and you have a complete way to process and get rid of scrap tires.
The tread cutter simply cuts the tread across so it can be laid flat or cut into multiple strips. Bias ply treads are often used for manufacturing loading dock bumpers. Most landfills will also accept cut flattened tire treads. The treads can also be shredded into sized chips and sold as TDA (Tire Derived Aggregate) or TDF (Tire derived Fuel) I will cover the TDA and TDF in the shredding section. One other option for car and light truck tires is to also use a machine to cut out the bead seat and shred the remaining wire free sidewall to a 3/4” chip for play ground mulch. More on this in the Mulch section.
Rough shredding tires:
Rough shred is simply tires that have been run through one maybe two passes through a tire shredder. This cuts the tire into large strips. Rough shred is often just disposed of in a land filled. However some land fills will take it at a reduced rate if they are approved to use it for daily ground cover it is also sometimes used as fill in leach beds and road beds.
TDA and TDF:
Tire Derived Fuel (TDF) and Tire Derived Aggregate (TDA) are essentially tires that have been shredded into sized chips.
TDA is typically chips in the 2 - 1” range with protruding wire no more then 1/4” long. It is used as fill in road beds, septic tank bottoms, leach beds, Ect.
The use of this product is just in it’s infancy and many municipalities do not approve of it’s use. However as many more and more gravel pits are being shut down to to urban sprawl it is gaining in popularity.
Tire Derived Fuel (TDF) this product varies greatly from one customer to another. It can be sized chip ranging from 2” - 3/4”, with 1/4” long or shorter wires protruding and some customers require it to also be wire free. This product is used to supplement coal In power plants, cement kilns, paper mills, Ect.
Both products TDA and TDF require a shredder or multiple shredders with some kind of screening system. If you you choose to produce wire free product then a Rasper and other material separation equipment such as self cleaning magnets and fluff separators will also be required. Tropically TDA and TDF are sold by the ton. The price paid will vary greatly depending on location. Most TDF sells for somewhere between $20 - $60 per ton and TDA is usually around $10 - $20 per ton.
System for Semi truck tires
Rubber mulch is used as a replacement for traditional wood mulch in applications around landscaping and is very popular for it’s shock absorbency around playground equipment. It is also often colored similar to wood mulch. There are four main types of rubber mulch.
The first type introduced was made from tire tread buffings. When a truck tire is retreaded a machine is used to shave off whats left of the old tread to prepare it for the new tread. The chips this machine makes are called buffings and there texture and shape look very similar to wood mulch.
The second type is whole tire mulch. This is just as it sounds the whole tire is shredded and the steel rasped out. It looks like a slightly fuzzy chip between 3/4” and 1/2” across. (see stage 1-2 off crumb rubber machinery for explanation of equipment)
The third type is sidewall mulch. This is a sized chip cut from car and light truck tire sidewalls only. The side wall I first cut from the tire then the bead ring is cut out, and lastly the leftover rubber sidewall is chipped into 3/4” - 1/2” particles.
The last type of rubber mulch in non tire rubber such as used conveyor belts and post consumer scrap rubber that is chipped into 3/4- 1/2” particles.
Good quality 99% wire free plain black rubber mulch sells for wholesale around $250 per ton colored $350 per ton or more. If you can warehouse and sell it retail you can easily get another 30% or more for the product. Sidewall only and non tire rubber mulch can often be marked up even higher because there is no chance of stray steel wires in it.
Crumb Rubber and Rubber Powder:
Crumb rubber is wire free, fiber free rubber granules in the 3/8” to .022” or 30 mesh.
Rubber powder is wire free, fiber free rubber particles smaller then 30 mesh.
Crumb rubber sells for $0.07 - $0.20 per pound. Rubber powder can sell for as much as $.40 per pound.
Crumb rubber is used in many different products, here are just a few: base filler in artificial turf fields, additive in rubberized asphalt, filler material for rubber pavers and bonded rubber products.
The manufacturing of crumb rubber requires a substantial investment in processing equipment and is done mostly in two different ways, knife type processing and cryo processing.
Cryo processing crumb rubber basically involves shredding the tires to a manageable size. Then running it through a system that freezes the rubber with liquid nitrogen to an extremely low temperature and pulverizing it into crumb and powder. Then the steel, fiber, and rubber are separated and screened. This is a simplified explanation of the process. The equipment and facilities involved in cryo-processing are proprietary and expensive. Also they consume massive amounts of liquid nitrogen. However the material produced has a consistent shape that is desirable for some industries.
Knife type machine crumb rubber processing involves multiple reduction and separation stages. The complexity and expense of the system and maintenance tends to grow as the desired material size gets smaller. Here is a list of the stages and machines in a typical crumb rubber plant.
1: Pre-Shredding: Take the whole tires down to a sized chip 4” or smaller. This is usually done with a dual shaft shredder or multiple dual shaft shredders and a screening system.
2: Rasping: The tire chips are taken down to a 3/4” - 1/2” chip and at the same time the steel wire is torn or rasped out of the chip. This is done in a machine called a Rasper. A rasper is a single shaft shredder similar in design to a granulator. It uses a heavy solid rotor with multiple knives to cut the material against a set of stationary bed knives. There is a screen mounted under the rotor that typically has 3/4” - 1/2” holes. The knife gap is set so that the material is torn instead of clean cut, this way the steel wires and some of the fiber is ripped out of the chips.
3: Rough separation: This process separates the steel wire, fiber, and rubber. The wire is pulled off the mix with magnets self cleaning over head magnets and self cleaning box magnets and conveyor head pulleys are used. The fiber is vacuumed off and sometimes operations will employ a screen at this point to pull out rubber particles already reduced to the proper size.
4: Further size reduction: The following stages will depend on the particle size and volume per hour that needs to be made. For crumb size ranging 1/4 inch to 1/8” this can be done easily with a open rotor granulator. For particles less then 1/8 inch most operations use a Crackermill. The granulator size will depend on the volume of material being made a 30” 100hp granulator will be good for about 1 ton per hour or 1/4” minus material. The smaller the screen size the less the throughput. For smaller material down to 30 mesh a crackermill works well. A 50hp crackermill can process about 1000lbs per hour of 10-20 mesh crumb from 1/4” feed stock. This process can be condensed into just feeding the cracker mill directly after the rough seperation stage, but will require a much larger crackermill.
5: Final separation: The material exiting either the granulator or crackermill needs to be fed across a set of magnets to remove any tramp metal fragments, and typically a zigzag air separator is used to remove the last remaining bits of fiber. This is also sometimes done using an up draft density separator or destoner.
6: Final screening: Screen out the materials of different sizes and return the overs to the further reduction stage. This is where your product is classified into different material sizes for final packaging or further processing.
7: Fine grinding: This stage is only necessary if you are manufacturing rubber powder. The 30 mesh material is fed into wet grinding machines that mix it with water to form a slurry then grind it to the final powder size required. It is then fed into a system to dry and package the material. Often the powder grinding stage on it’s own can coast as much as all of the previous steps equipment combined.
A crumb rubber system depending on throughput and partical size will cost between $600,000 - $1,500,000 for a system to make 1/4” to 30mesh and $2mil plus for rubber powder. It’s not a cheap date to get into. However many processors will start out just rough shredding and accumulate the equipment required to get into making smaller more valuable product.
Tire Pyrolysis: This is a process of thermally decomposing a tire down to it’s raw components steel, carbon, oil, and gas. It is not as complicated as it sounds. But the equipment needs to be designed correctly or serious fire and explosion hazards exist. There are two main types of tire pyrolysis systems a batch system and a continuous feed system.
A tire pyrolysis batch system consists of a large seal-able vessel that can be heated to at least 800 degrees Fahrenheit and has a condenser or fractioning tower piped into it. Essentially it is a large high temperature still. The tires are loaded into the main vessel either whole or shredded. The vessel door is closed and sealed. Then the vessel is heated to a temperature high enough for the tires to break down. The gas produced is vacuumed out of the vessel and fed into a condenser and cooled, a large percentage will condense into oil. The syn-gas leftover is either burned off or used to help heat the vessel. When the unit has fully decomposed the tires, it is allowed to cool. Once cooled down it is opened up and the leftover steel and carbon is removed and the process starts again.
Continuous Feed pyrolysis systems utilize a reactor vessel that has a mechanism inside that feeds the tires through it. At each end of the reactor there is a series of air locks this is to let material in but not allow addition oxygen in. Tire chips and in some cases crumb rubber is fed into the intake airlocks. It is then moved through the heated reactor at rate that will complete the tire rubber decomposition by the time it gets to the exit side. Then at the exit side the remaining carbon and steel are dropped out of the exit airlocks. The gas is vacuumed out and processed the same way as the batch system.
Unfortunately the pyrolysis portion is the easy part. We will start by explaining the products produced.
Tire Pyrolysis oil: This oil has a dark brown color, similar consistency to diesel fuel and a strong sulfur smell. It contains a large variety of aromatic oils, solvents and a high sulfur content. It is often mixed with diesel and sold as heating oil. It does not make very good engine fuel because of the high sulfur and low cetane ratings. Using a fractioning tower to distill the pyrogas yields better more sell-able products particularly in the lighter solvent fractions. The technology however is always changing and soon after someone my come up with a better way to process or a better product for the pyro oil.
Sin-gas: The syn-gas is a mix of gasses that condense bellow ambient temperature. I’m sure with enough investment into processing equipment the more valuable gasses could be separated. Some have used the Fischer-Tropsch process to convert the gas into usable fuels, lubricants and plastics. The Fischer-Tropsch process is a system that forces the syn-gas through a catalyst, different products are made depending on the temperature, pressure and type of catalyst used. However most simply choose to burn it to help heat the reactor.
Carbon: The carbon if made pure enough is a very valuable product as carbon black. The kicker though is that if whole tires are used as feed stock the contaminates in the carbon are not very consistent. This is due mostly to the types of fiber used when the tires are manufactured. There are some very successful carbon black producers that utilize crumb rubber and non tire rubber as feed stock. The carbon from whole tire pyrolysis is often land filled or mixed with coal and burned for boiler fuel.
Steel wire: The steel wire is simply sold for scrap.
As stated before the technology is changing everyday and new uses are found for the products produced from Tire pyrolysis.