*Article* **Production, Characterization, and Evaluation of Pellets from Rice Harvest Residues** †

### **Cristina Moliner \*, Alberto Lagazzo, Barbara Bosio, Rodolfo Botter and Elisabetta Arato**

Dipartimento di Ingegneria Civile, Chimica e Ambientale (DICCA), Università degli Studi di Genova, Via Opera Pia 15A, 16145 Genova, Italy; alberto.lagazzo@unige.it (A.L.); Barbara.bosio@unige.it (B.B.); Rodolfo.botter@unige.it (R.B.); elisabetta.arato@unige.it (E.A.)

**\*** Correspondence: cristina.moliner@edu.unige.it

† This paper is an extended version of our paper published in 27th European Biomass Conference & Exhibition (EUBCE 2019), Lisbon, Portugal, 27–30 May 2019; pp. 1023–1028.

Received: 20 December 2019; Accepted: 14 January 2020; Published: 18 January 2020

**Abstract:** Pellets from residues from rice harvest (i.e., straw and husk) were produced and their main properties were evaluated. Firstly, rice straw pellets were produced at lab scale at varying operational conditions (i.e., load compression and wt % of feeding moisture content) to evaluate their suitability for palletization. Successively, rice straw and husk pellets were commercially produced. All the samples were characterized in terms of their main physical, chemical, and physico-chemical properties. In addition, axial/diametral compression and durability tests were performed to assess their mechanical performance. All the analyzed properties were compared with the established quality standards for non-woody pellets. In general, rice straw pellets presented suitable properties for their use as pelletized fuels. Rice husk pellets fell out of the standards in recommended size or durability and thus preliminary treatments might be required prior their use as fuels.

**Keywords:** rice harvest pellets; palletization; combustion; ash recovery; normative
