ABSTRACT. The reserves of non-renewable energy sources such as coal, crude oil and natural gas are not limitless, they gradually get exhausted and their price continually increases. In the last four decades, researchers have been focusing on alternate fuel resources to meet the ever increasing energy demand and to avoid dependence on crude oil (Karunanithy et al. 2012). Amongst different sources of renewable energy, biomass residues hold special promise due to their inherent capability to store solar energy and amenability to subsequent conversion to convenient solid, liquid and gaseous fuels. At present, among the coconut farm wastes such as husks, shell, coir dust and coconut leaves, the latter is considered the most grossly under-utilized by in situ burning in the coconut farm as means of disposal. In order to utilize dried coconut leaves and to improve its biomass properties, this research attempts to produce solid fuel by torrefaction using dried coconut leaves for use as alternative source of energy that can be utilized in the indirect drying of coconut meat in the farm-level to produce copra. Torrefaction is a thermal method for the conversion of biomass operating in the low temperature range of 200 o C-300 o C under atmospheric conditions in absence of oxygen. Dried coconut leaves were torrefied at different feedstock conditions. The key torrefaction products were collected and analyzed. Physical and combustion characteristics of both torrefied and untorrefied biomass were investigated. Torrefaction of dried coconut leaves significantly improved the heating value compared to that of the untreated biomass. Proximate compositions of the torrefied biomass also improved and were comparable to coal. The distribution of the products of torrefaction depends highly on the process conditions such as torrefaction temperature and residence time. Physical and combustion characteristics of torrefied biomass were superior making it more suitable for fuel applications.

Virgin coconut oil (VCO) has become one of the most prominent high-value coconut product in coconut producing countries because of its versatility. This research attempts to design a fresh-dry process based on the Low-Pressure Oil Extraction Method for the production of VCO to reduce the settling time of the oil after extraction, that usually takes 1-2 weeks. Different parameters, such as drying temperature, centrifuge speed, and centrifugation time were varied and analysed. Three mathematical models were examined to describe the drying behaviour of the grated coconut meat at 65, 70, and 75°C using a tray dryer. A VCO production fresh-dry process based on the Low-Pressure Oil Extraction Method was developed through the employment of a centrifuge. The modified method lessens the settling time while still producing standard quality VCO. As predicted by the Laplace Transform Model, the shortest time for the comminuted coconut meat to reach a moisture content of 11% at which oil from nuts can be extracted using low pressure is at 29.07 minutes using a tray dryer. The best setting of VCO production using the modified method is at a drying temperature of 70°C and at 2700 RPM and 60 minutes of centrifugation as it produced the clearest oil with a yield of 92.84 % v/v and a recovery of 18.43%. The produced VCO was tested for free fatty acid (FFA), moisture and volatile matter, colour, peroxide value, and iodine value, and the results are 0.03%, 0.11%, 0R/0.3Y, 0, and 5.77, respectively, which all passed the Philippine National Standards for VCO.

The traditional methods of copra processing such as sun-drying and smoke-drying are still generally implemented in the Philippines by coconut manufacturers. These methods produce aflatoxin and polycyclic aromatic hydrocarbon (PAH) in copra and crude coconut oil (CNO) that resulted to very low prices of copra-related products in the world market. This research aims to improve the quality of the products of the Philippine coconut manufacturing industries by employing modern design engineering and technology to coconut processing that would develop highvalue exportable coconut products. The Wijose Process of coconut processing developed for the production of copra, milk and dietary flour resulted to 94.7% recovery of the coconut fruit parts and waste materials. Seven mathematical models were examined to describe the drying behavior of coconut meat slices at 60, 70 and 80 o C. The modified combined decomposition model (MCDM) gave the best fit with high coefficient of determination value. Solid fuel was produced by torrefaction from dried coconut leaves that significantly improved its heating value compared to that of the untreated biomass. A coconut processing plant was developed based on the conceptual design of the Wijose Process.

Sweet potatoes are prone to fungi Rhizopus oryzae that results in fast spoilage upon delivery due to its moisture content which can develop fungi that can give foul odor and color. The decrease in moisture content can prolong the shelf-life of the sweet potato. This problem can be addressed by a drying process where a hot tray air dryer was used. Sweet potatoes were cut to 5x5x30 mm uniformly and dried it at 40°C, 50°C, 60°C until the constant weight of the batch was obtained. Laplace Transform Model, Non-Linear Decomposition Model, and Page Model are the three mathematical model that were compared to determine what is the best fit for the drying of the sweet potato. Based on data gathered, Page Model is the best fit at 60˚C. Page Model fitted best from the other two models with an average drying time of 115 minutes and 46 mins to obtain the desired moisture content of 10%.

No abstract