Performance and emissions of an automotive diesel engine using a tire pyrolysis liquid blend Juan Daniel Martínez a,b , José Rodríguez-Fernández c,⇑ , Jesús Sánchez-Valdepeñas c , Ramón Murillo a , Tomás García a a Instituto de Carboquímica, ICB-CSIC, Miguel Luesma Castán 4, 50018 Zaragoza, Spain b Grupo de Investigaciones Ambientales, Instituto de Energía, Materiales y Medio Ambiente, Universidad Pontificia Bolivariana, Circular 1 No. 70-01, Bloque 11, Piso 2, Medellín, Colombia c Grupo de Combustibles y Motores, Escuela Técnica Superior de Ingenieros Industriales, Universidad de Castilla La-Mancha, Avda. Camilo José Cela s/n, 13071 Ciudad Real, Spain highlights  Tire pyrolysis liquid – TPL can be used in low content for diesel fuel blends.  We compare a TPL blend and a pure diesel fuel in an automotive engine.  Engine performance with TPL improves by increasing the engine load.  Emissions with TPL are higher, but may be reduced by refining the production process. article info Article history: Received 28 May 2013 Received in revised form 2 July 2013 Accepted 17 July 2013 Available online 1 August 2013 Keywords: Waste tire pyrolysis Tire pyrolysis liquid Tire fuel Diesel engine Emissions abstract A tire pyrolysis liquid (TPL) fuel produced in a continuous auger reactor on pilot scale was blended at 5 vol.% (5TPL) with commercial diesel fuel (100D) and tested in a 4-cylinder, 4-stroke, turbocharged, intercooled, 2.0 L Nissan diesel automotive engine (model M1D) with common-rail injection system. The engine performance and exhaust emissions were obtained for both the 5TPL blend and the commer- cial diesel fuel. Experiments were conducted in four operating modes that simulate the New European Driving Cycle (NEDC). Both brake specific fuel consumption and brake thermal efficiency seemed to be deteriorated by the composition and the properties of the TPL blend at low engine load, while at higher engine load the values of these parameters were almost equal for both fuels. Total hydrocarbon (THC) emissions followed the same pattern than that of the specific fuel consumption since they were higher for 5TPL at low engine load but similar for both fuels when the engine load increased. NO x emissions were higher for 5TPL than those for 100D in three operating modes (U10, EU8 and EU16), while no significant differences were found in the other mode (U9). In addition, 5TPL led to higher smoke opacity respect to those found for 100D in all operating modes. Combustion duration was slightly longer for 5TPL than 100D. This work could be considered as a contribution for strengthening and encouraging the waste tire pyrolysis for the production of liquid fuels which could be used in automotive engines in very limited concentrations. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction About 1.5 billion tires are sold worldwide each year giving as result around 20 million tons [1]. Besides this huge amount, waste tires are non-biodegradable materials and their thermo-mechani- cal properties make them difficult to be directly reused or recycled without mechanical or thermal pre-treatment. Therefore, waste tires represent a serious pollution problem in terms of waste dis- posal. Rubber from tire has a high heating value (35–40 MJ/kg) and this energy may be recovered by means of waste-to-energy processes which encompass thermo-chemical treatments such as combustion, gasification and pyrolysis for power and heat genera- tion and/or fuel production. In addition, waste tires are a valuable source of renewable energy (part of the rubber contained has a bio- genic origin) and therefore they are within the scope of the 2009/ 28/CE Directive on the promotion of renewable energy. Waste tire pyrolysis has been studied for several years and a notable number of projects with a broad range of technologies and scales can be found in literature [2]. However, due to the lack of product standardization and available markets, legislative barri- ers (pyrolysis is considered as incineration in the EU) and 0016-2361/$ - see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.fuel.2013.07.051 ⇑ Corresponding author. Tel.: +34 926 295 300x6472; fax: +34 926 295 361. E-mail address: Jose.RFernandez@uclm.es (J. Rodríguez-Fernández). Fuel 115 (2014) 490–499 Contents lists available at ScienceDirect Fuel journal homepage: www.elsevier.com/locate/fuel