Potential use of biomass bottom ash as alternative construction material: Conﬂictive chemical parameters according to technical regulations M.J.R. Hinojosa a , A.P. Galvín a , F. Agrela a,⇑ , M. Perianes b , A. Barbudo a a Area of Construction Engineering, University of Cordoba, Cordoba, Spain b Department of Production, Environmental Manager, Sacyr S.A.U., Spain highlights  The most conﬂictive chemical parameters were evaluated in BBA samples.  A high variety of samples from different combustion power plants were analysed.  The limiting chemical values of Spanish technical regulations were used as reference.  The results prove the feasible application of BBA as a ﬁller in road embankments.  Furthermore, its use as cement treatment material under certain conditions was proven. article info Article history: Received 27 January 2014 Received in revised form 7 March 2014 Accepted 11 March 2014 Available online 22 March 2014 Keywords: Chemical parameters Biomass fuel Biomass bottom ash Recycling Construction materials abstract The production of energy from renewable resources, such as biomass, is increasing rapidly. Therefore, environmentally friendly and economic solutions to recycle the resulting by-products are essential. The present study was performed to search for possible applications of the biomass bottom ashes that result from biomass combustion at three biomass combustion plants located in the Andalusia region of southern Spain. The analysis of chemical parameters indicated the applicability of biomass bottom ashes as an alternative material in civil construction. Thus, the limiting chemical parameters were analysed according to Spanish regulations. According to the results, biomass bottom ashes could be used as ﬁller in road embankments, cement-treated materials or non-structural concrete, depending on the replace- ment percentage. This study determined that a review of the chemical parameters speciﬁed by the lim- iting regulations is recommended to promote the use of biomass bottom ashes as a building material in applications that do not require high structural strength. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction The development of energy is essential from an economic and social point of view. The use of renewable resources as a source of energy and environmentally sound technologies are necessary to ensure a high quality of life and the well-being of future gener- ations [1]. The substitution of coal and petroleum products as en- ergy sources is being studied to reduce costs and decrease the emissions of harmful gases into the environment. Therefore, the study of various new and alternative sources of energy has inten- siﬁed [2]. In the coming years, biomass will play a fundamental role as a natural resource for renewable energy due to the rising costs of fossil fuels, the doubtful safety of nuclear energy and the need to reduce CO 2 emissions [3]. According to the Directive 2009/28/EC (2009) [4] on the promotion of the use of energy from renewable sources, biomass is deﬁned as the biodegradable fraction of prod- ucts, waste and residues from the biological origin of farming (including plant and animal substances), forestry and related industries, including ﬁsheries and aquaculture, as well as the bio- degradable fraction of industrial and municipal waste. Vassilev et al. [5] deﬁned biomass as a complex heterogeneous mixture of organic matter and, to a lesser extent, inorganic matter, containing various intimately associated solid and ﬂuid phases with different contents and origin. Biomass energy can be deﬁned as the solar en- ergy transformed to chemical energy through photosynthesis being stored in plant material [6]. http://dx.doi.org/10.1016/j.fuel.2014.03.017 0016-2361/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +34 685844859; fax: +34 957212239. E-mail address: fagrela@uco.es (F. Agrela). Fuel 128 (2014) 248–259 Contents lists available at ScienceDirect Fuel journal homepage: www.elsevier.com/locate/fuel