Development of an Integrated Rice Straw Pellet Machine Using the House of Quality Technique and Evaluation of Biomass Fuel Properties

Abstract

This research aimed to develop an integrated rice straw pellet machine using the House of Quality technique and to evaluate the properties of rice straw biomass pellets. User requirements were collected from five users and applied to construct the House of Quality (HOQ), which was then translated into engineering characteristics for prototype design using SolidWorks. The prototype was subsequently fabricated and tested for performance evaluation. Physical and fuel properties, including moisture content, ash content, volatile matter, heating value, and bulk density, were analyzed. The experiment was conducted in three experimental sets, with each set replicated three times, and the mean of each set was used to calculate the overall mean and standard deviation (n = 3). The heating value was determined using a Bomb Calorimeter, and the data were analyzed using mean and standard deviation. The results revealed that the key user requirements were continuous operation, reduction of processing steps and operating time, structural strength, ease of operation, and safety. The developed machine achieved an average production rate of 27 kg/h during the pelletizing stage and an overall production rate of 15 kg/h for the entire process and a mass efficiency of 64.29%. In addition, the integrated system reduced the production time from 50 min to 36 min, representing a 28.00% reduction. The biomass pellets produced had an average length of 18.28 mm, an average diameter of 7.77 mm, an average moisture content after drying of 7.07%, an average heating value of 3,043.33 cal/g, and an average bulk density of 854.02 kg/m³. The proposed machine provides an effective approach for converting rice straw into biomass pellets while supporting community-scale biomass energy production.