Chemical Engineering Journal 162 (2010) 580–590 Contents lists available at ScienceDirect Chemical Engineering Journal journal homepage: www.elsevier.com/locate/cej A techno-economic comparison between two design configurations for a small scale, biomass-to-energy gasification based system U. Arena a,b,∗ , F. Di Gregorio a , M. Santonastasi b a Department of Environmental Sciences – Second University of Naples, Via Vivaldi, 43, 81100 Caserta, Italy b AMRA s.c.a r.l., Via Nuova Agnano, 11, 80125 Napoli, Italy article info Article history: Received 30 March 2010 Received in revised form 28 May 2010 Accepted 28 May 2010 Keywords: Biomass Biomass-to-energy Gasification Fluidization Technical and economic analysis abstract Biomass has great potential as a clean and renewable feedstock for producing modern energy carriers. This paper focuses on the process of biomass gasification, wherein the synthesis gas is subsequently used to produce electricity. A comparison between the most promising design configurations for the industrial application of gasification based, biomass-to-energy cogenerators in the 100–600 kWe range is presented. Mass and energy balances and material and substance flow analyses drawn for each design solutions are based on the experimental data obtained from a pilot scale bubbling fluidized bed air gasi- fier, having a feeding capacity of 100 kg/h and operated with a commercially available, natural biomass. Measurements taken during the experimental tests include the syngas complete composition as well as the characterization of the bed material, the entrained fines collected at the cyclone and the purge material from the scrubber. The techno-economic performances of two energy generation devices, a gas engine and an externally-fired gas turbine, have been estimated on the basis of the manufacturer’s spec- ifications. The study concludes that the internal combustion engine layout is the solution that currently offers the higher reliability and provides the higher internal rate of return for the investigated range of electrical energy production. © 2010 Elsevier B.V. All rights reserved. 1. Introduction and framework Biomass is the oldest known source of energy and it is a renew- able energy. The possible utilization of the biomass energy content gained a great interest in the last decade, because of its potential to displace a large part of conventional fossil fuel for electricity pro- duction. The main reasons lay in the large availability of biomass resources, the progressive depletion of conventional fossil fuels and the potential better air pollution control of the related power gener- ation processes [1–3]. A large amount of energy is in fact potentially available from biomass, since sources that can be used for energy production cover a wide range of materials (wood and wood waste, agricultural crops and their waste by-products, organic fraction of municipal solid waste, residues from agro-industrial and food pro- cesses, aquatic plants such as algae and waterweeds). Moreover, the limitate sulphur and greenhouse gas emissions associated with the use of biomass for energy production could respond to the growing pressure for the achievement of a better environmental sustainability of power generation processes. ∗ Corresponding author at: Department of Environmental Sciences – Second Uni- versity of Naples, Via Vivaldi, 43, 81100 Caserta, Italy. Tel.: +39 0823 274414; fax: +39 0823 274593/605. E-mail address: umberto.arena@unina2.it (U. Arena). Despite the widely agreed potential of bioenergy utilization, key problems regarding the use of biomass remain the unsteady availability, related to biomass seasonality and geographical distri- bution over the territory that often make the logistics (collection, transport and storage operations) complex and expensive [2], as well as the necessity of an energy production which should be not only environmental sustainable but also economic competi- tive. In other words, biomass has great potential as a renewable and relatively clean feedstock for producing energy carriers, such as electricity and transportation fuels, but in order to compete with fossil energy sources it needs to utilize efficient conversion tech- nologies [4,5]. Biomass can be converted to a wide variety of energy forms (electricity, process heat for industrial facilities, domestic heat- ing, vehicle fuels) by means of a number of thermochemical and biochemical processes [3]. With reference to low-value lignocellu- losic biomass, biological conversion processes still faces challenges in low ecomomy and efficiency, even though fermentation and anaerobic digestion are today commercially proven technologies, suitably used to produce ethanol from biomass containing sugar [6–8] and biogas from high-moisture content biomass, such as the organic fraction of MSW [9]. Combustion, pyrolysis and gasification are the three main ther- mochemical process solutions. Combustion is traditionally used to convert biomass energy into heat and power in the process indus- 1385-8947/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.cej.2010.05.067