Abstract—Biofuel is one of the renewable energy sources adapted by the Philippine government in order to lessen the dependency on foreign fuel and to reduce carbon dioxide emissions. Rain tree pods were seen to be a promising source of bioethanol since it contains significant amount of fermentable sugars. The study was conducted to establish the complete procedure in processing rain tree pods for village level hydrous bioethanol production. Production processes were done for village level hydrous bioethanol production from collection, drying, storage, shredding, dilution, extraction, fermentation, and distillation. The feedstock was sundried, and moisture content was determined at a range of 20% to 26% prior to storage. Dilution ratio was 1:1.25 (1 kg of pods = 1.25 L of water) and after extraction process yielded a sugar concentration of 22 0 Bx to 24 0 Bx. The dilution period was three hours. After three hours of diluting the samples, the juice was extracted using extractor with a capacity of 64.10 L/hour. 150 L of rain tree pods juice was extracted and subjected to fermentation process using a village level anaerobic bioreactor. Fermentation with yeast (Saccharomyces cerevisiae) can fasten up the process, thus producing more ethanol at a shorter period of time; however, without yeast fermentation, it also produces ethanol at lower volume with slower fermentation process. Distillation of 150 L of fermented broth was done for six hours at 85 °C to 95 °C temperature (feedstock) and 74 °C to 95 °C temperature of the column head (vapor state of ethanol). The highest volume of ethanol recovered was established at with yeast fermentation at five- day duration with a value of 14.89 L and lowest actual ethanol content was found at without yeast fermentation at three-day duration having a value of 11.63 L. In general, the results suggested that rain tree pods had a very good potential as feedstock for bioethanol production. Fermentation of rain tree pods juice can be done with yeast and without yeast. Keywords—Fermentation, hydrous bioethanol, rain tree pods, village level. I. INTRODUCTION RODUCTION of bioethanol in the Philippines was boosted by the implementation of Republic Act 9367 commonly known as Biofuel Act of 2006 that mandates a 5% to 10% blend to gasoline fuel in order to mitigate the adverse effects of greenhouse gas emission in the environment. To reduce the net greenhouse gas emissions to the atmosphere, bioethanol has been recognized as a potential alternative to Dharell B. Siano is with the Central Luzon State University, Science City of Munoz, Nueva Ecija, 3121, and Bataan Peninsula State University, Abucay, Bataan, Philippines (e-mail: dharellsiano@yahoo.com). Wendy C. Mateo, Victorino T. Taylan, and Francisco D. Cuaresma are with the Department of Agricultural and Biosystems Engineering, Faculty, Central Luzon State University, Science City of Munoz, Nueva Ecija, 3121, Philippines. petroleum derived transportation fuels [1]. According to the forecast of the Department of Energy, demands for the bioethanol in the Philippines shall drastically increase along with the steady growth in registration number of automobile and accelerating blending ratio of bioethanol to the gasoline [2]. Continuous production of bioethanol is mainly dependent on the availability and volume of feedstock in a certain location. Also, different feedstocks require different handling processes for the production of bioethanol. There is a lot of feedstock available in the country such as sugarcane, sweet sorghum, corn and others. Aside from being a seasonal crop, the cost of production and the food versus fuel debate are the main constraints on using those feedstocks for the production of bioethanol. Lignocellulosic feedstock is also considered as a promising source of bioethanol; however, it needs additional technology before the sugar can be fermented that in return leads to higher production cost. The simplest way to produce ethanol is the sugar to ethanol production. Thereby, biomass that contains six – carbon sugars is used which can be fermented directly to ethanol. Although fungi, bacteria, and yeast microorganisms can be used for fermentation, the specific yeast Baker’s yeast (Saccharomyces cerevisiae) is frequently used to ferment glucose to ethanol [3]. Baker’s yeast is widely used in ethanol production due to its high ethanol yield and productivity, no oxygen requirement, and high ethanol tolerance. Rain tree pods are a possible feedstock suitable for bioethanol production because it contains an appreciable amount of fermentable sugar and has a large volume of production during its fruiting season. Rain tree fruit is a promising source of bioethanol that does not compete on the food sector and on the space needed to plant cash crops. Rain tree pods are sessile indehiscent, six to eight inches long and half to one inch broad, flattened, containing 10 to 12 seeds embedded in a sugary edible pulp and yields up to 275 kilos of pods per year which can be obtained from 15 years old trees [4]. In the Philippines, rain tree pods have been commonly utilized as a feed for ruminant animals since they contain high amount of protein. However, it was observed that most of the pods are unutilized and remain to the ground until they are rotten. In places where rain tree pods are planted along roadside and school vicinities, the pods fallen on the ground were pounded, and as a result, become sticky and invite flies when rotting, and those make the rain tree pods completely a waste. Processing and Economic Analysis of Rain Tree (Samanea saman) Pods for Village Level Hydrous Bioethanol Production Dharell B. Siano, Wendy C. Mateo, Victorino T. Taylan, Francisco D. Cuaresma P World Academy of Science, Engineering and Technology International Journal of Biotechnology and Bioengineering Vol:11, No:2, 2017 168 International Scholarly and Scientific Research & Innovation 11(2) 2017 scholar.waset.org/1307-6892/10006391 International Science Index, Biotechnology and Bioengineering Vol:11, No:2, 2017 waset.org/Publication/10006391