Final Report: The Manufacture of Carbon Black From Oils Derived From Scrap Tires

EPA Contract Number: 68D99080
Title: The Manufacture of Carbon Black From Oils Derived From Scrap Tires
Investigators: Wojtowicz, Marek
Small Business: Advanced Fuel Research Inc.
EPA Contact: Richards, April
Phase: II
Project Period: September 1, 1999 through September 1, 2001
Project Amount: $224,966
RFA: Small Business Innovation Research (SBIR) - Phase II (1999) Recipients Lists
Research Category: Hazardous Waste/Remediation , SBIR - Waste , Small Business Innovation Research (SBIR)

Summary/Accomplishments (Outputs/Outcomes):

Problem Significance and Opportunity - The disposal of 280 million tires generated each year in the U.S. by landfill is becoming an increasingly unacceptable solution. The estimates of the number of tires already stored in tire piles in the U.S. are in the range of 2-3 billion. The tires take up large amounts of valuable landfill space and also present fire and health hazards. Tire-pyrolysis plants have been in operation for years, but the economics are poor. This is due to the low value of the end products, which are usually fuels (oil, pyrolysis gas, char). Reprocessing of waste tires into value-added products would improve the economic leverage.

Innovation - The main innovations are the substitution of tire pyrolysis oil for traditional petroleum feedstocks and the processing of the oils to produce high value carbon black products. AFR has also proposed a scheme for a "tire pyrolysis refinery" which produces a range of products from used tires. This SBIR project is one of the two components of this "tire refinery" scheme, the other on being the development of sulfur-rich activated carbons for mercury emission control. The commercialization of the latter project is pursued with operators of solid waste incinerators.

Summary of Phase I Work - The project addresses reprocessing of oils derived from waste-tire pyrolysis into carbon black - a valuable feedstock for the manufacture of tires, other rubber products, paints, pigments, ink, powder coating, toner, etc. Such a process would form a recycling loop for the carbon black recovered from waste tires. The overall objective of the project is to develop a process for producing carbon black from tire pyrolysis oil. The Phase I objective was to demonstrate the feasibility of making carbon black of acceptable quality. This was successfully accomplished, and ASTM grade carbon blacks were produced. The following tasks were performed as part of the Phase I research: (1) preparation of tire-pyrolysis oils; (2) synthesis of carbon black; and (3) product analysis and process assessment. The Phase II objective is to optimize product quality, as a function of process conditions and reactor design, and to advance the process to a pilot scale (Ph. II option).

Phase I Results - The main Phase I conclusions are:

  • Despite the limitations of the AFR reactor (low temperature and laminar flow), the data generally fall into the range of values characteristic of ASTM materials.
  • For the carbon blacks produced from tire oils, TEM micrographs reveal the well-defined grape-like structures that are so characteristic of carbon black. No contamination from char residue is observed. This demonstrates the advantage of AFR's approach as compared with the usually unsuccessful attempts to separate the carbon black originally present in tires from the char residue. The latter methods are usually expensive and have problems with product purity. Our method produces virgin carbon black.
  • The behavior of the reference carbon-black sample produced from the Exxon oil is identical to the behavior of samples derived from tire-pyrolysis oils. This constitutes a direct feasibility proof for Phase I: tire oils are as good a feedstock for carbon-black manufacturing as the traditional petroleum feedstock (Exxon oil). Any slight deviations from the typical product characteristics are artifacts associated with non-standard and non-optimum reactor design (laminar flow) and process conditions (low temperature).
  • The yields of carbon black produced from tire oils are essentially the same as yields of the product obtained from the Exxon oil. This should translate to good process economics.
  • It was also found that all tire-derived oils used in the Phase I project had similar elemental composition, and remarkably high stability. This makes them a convenient feedstock for industrial storage and handling.

Anticipated Benefits - The proposed research, if successful, should result in a process allowing to recycle a huge stream of solid waste, the majority of which currently ends up in a landfill. The recovered carbon black would be reused mainly in tire manufacturing, which is a large-volume industry. Other potential applications are: rubber products (hose, gaskets, etc.), paints, pigments, ink, powder coating, toner. The proposed technology should provide a strong boost for the tire-pyrolysis plants which have suffered from poor process economics.

Production, Marketing, and Financing Plans - Commercialization of the new process is pursued with a company involved in the large-scale pyrolysis of scrap tires, and with a manufacturer of pyrolysis equipment (see the report for details regarding these two partners). We have received a Phase III agreement in the amount of $600,000. The Phase III effort will include pilot-scale testing, scale-up, technology-transfer, and marketing issues, all of which will be done by the commercial partner with assistance from AFR. AFR's strategic partner has also agreed to make in-kind contributions to the Phase II effort for a total cost of at least $100,000. Details of this latter arrangement are currently under negotiation.

Markets - The markets for carbon black are huge (over seven million tons per annum worldwide), both internationally and domestically, and they are primarily driven by the sheer size of the automobile industry. These markets are projected to rapidly grow as the demand for automobiles increases, especially among the developing nations.

Competitive Advantages - While other players could enter the competition to produce carbon black from tire pyrolysis oils, AFR would have the following advantages: 1) many years of experience working in the tire pyrolysis field; 2) international recognition as a leading pyrolysis technology development laboratory (Dr. Wojtowicz and Dr. Serio recently authored a chapter entitled "Pyrolysis" for Wiley's Encyclopedia of Energy Technology and the Environment, and AFR's FG-DVC pyrolysis model has been licensed by over 50 fuels research laboratories worldwide); 3) the expertise acquired under the Phase I program and the patented process knowledge that will be gained under the Phase II program; 4) the experience of AFR and its spin-off company, On-Line Technologies, Inc., in the area of process monitoring and control using advanced FT-IR-based equipment for measurement of process gas compositions.

Supplemental Keywords:

RFA, Scientific Discipline, Waste, Sustainable Industry/Business, Chemical Engineering, Sustainable Environment, Municipal, Environmental Chemistry, Chemistry, Technology for Sustainable Environment, Environmental Engineering, rubber tire pyrolysis, tire recycling, scrap tires, pyrolysis, municipal waste, rubber tire, carbon black, activated carbon, marketable products, reusable oil

SBIR Phase I:

The Manufacture of Carbon Black from Oils Derived from Scrap Tires  | 1999 Progress Report  | Final Report