Biomass is long known as a viable source of fuel. However, the industrial revolution has changed mankind's dependence on fossil fuels until today. The depletion of the fossil fuel sources and it is escalating price encouraged many research works since two decades agoin the bid to replace fossil fuel with biomass. Biomass has now became an importantenergy source because of its extensive spread availability and promising potential to reduce global warming. Thermo-chemical conversion of biomass yield variety of solid, liquid and gaseousfuels and have equal importance both at industrial and environmental conservation aspects. This paper provides a review on several thermo-chemical conversion routes of biomass. The technologies of combustion, gasification, pyrolysis, liquefaction and carbonization is reviewed in this paper and highlighting each of their unique advantages. The benefits of biomass cofiring with fossil fuels were also highlighted in this paper.

Fluidized bed drying has become one of the preferred techniques in drying of agricultural products due to its thorough mixing ability and almost uniform moisture transfer from the product. This paper reports experimental studies on drying characteristics of chopped oil palm frond (OPF) when dried in a swirling fluidized bed dryer (SFBD). Unlike conventional fluidized beds, the SFBD is capable of fluidizing agricultural products which are fibrous and irregular in size and geometry, such as chopped OPF. Experiments were conducted to study the effect of hot air temperature ranging from 50°C to 80°C at a flowrate of 450 m 3 /hour, for two bed loadings. The OPF which consists of leaves and petiole (petiole) has different initial moisture contents of 57% and 70% respectively and dried to a final moisture content of 15%. Although higher temperatures of hot air result in rapid initial migration of moisture from the chopped OPF, the surface hardening due to shrinkage also becomes faster and hence limits further moisture removal prom the product. The OPF leaves and petiole exhibited different drying curves, suggesting the need for drying them separately unlike the current industrial practice for optimizing the drying process.

The demand for food has been ever increasing in proportion with the growing human population. This includes agricultural products including fruits. Hence, food preservation for extended usage through drying is gaining importance. This study reports the drying behavior of several agricultural products, namely sweet potato, carrot, ginger, turmeric, passion fruit and its rind. Focus has been given to the effect of relative humidity on drying for these products at room temperature. Experiments were carried out at 27°C by varying relative humidity at 40%, 60% and 80%. It was found that the relative humidity has a strong effect on drying, with lower relative humidity providing higher drying rates. In humid surrounding like Malaysia which has an average humidity more than 70%, controlling humidity of drying air may result in an energy efficient process in comparison to raising the drying air temperature

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Abstract.One of the viable techniques to reduce land filling of automotive shredder residue is by co-incinerating them with biomass. This study focuses on characterization of bottom and fly ashes produced from the coincineration of the automotive shredded residue with oil palm biomass. The co-incineration was carried out in a pilot-scale fluidized bed incinerator. The oil palm biomass used was oil palm shell while the automotive shredded residue was obtained from a local recycling company. The characterization was done based on particle size distribution, morphology (SEM analysis) and chemical composition (EDS analysis). In term of chemical composition the ashes contain C (Carbon), O (Oxygen), Si (Silicon), K (Potassium), Ca (Calcium) and Fe (Ferum.

Abstract. With the increasing demand for new and energy efficient drying methods of agricultural products, various techniques were deviced by researchers around the world. This techniques usually developed in laboratory scale prior to scale-up for actual industrial application. During this stage, modeling usually involved to aid scaling up process. This paper presents the modeling of drying kinetics of grated coconut using three semi emperical thin layer model. These models were Logarithmic, Modified Handerson and Pabis, and Verma et al models. Moisture ratio predicted by these models were compared against experimental drying carried out at four temperatures: 50°C, 60°C, 70°C and 80°C. The performance of these models were analyzed statistically using non-linear regression using LabFit software. The statistical parameters analyzed were coefficient of determination (R 2 ), reduced Chi-square (X 2 ), Root Mean Square Error (RMSE) and Residuals. Higher R 2 with lower X 2 , RMSE and Residuals implies good predictability of the models. From the analysis, it was found that Logarithmic model yields the best predictive capability of grated coconut drying kinetics with R 2 = 0.9996387, X 2 =0.505535x10 -3 , RMSE = 0.00623597 and Residuals = 0.0703607. IntroductionCoconut is believed to have its origins in the Indo-Malayan region, from where it spreaded throughout the tropics. Coconut palm is botanically referred to as the Cocos nucifera. It is known with high quality nutricious content and also rich in fiber, vitamins, and minerals. Today, the coconut is a domesticated plant and has become an essential resource for food, shelter, fuel and even medicine [1].Dried coconut is one of the coconut-derived products, and is used in the preparation of various desserts, e.g., donuts and ice cream. Traditionally, a tray dryer is used to produce dried coconut from the wet finely chopped coconut pieces. The process, however, takes very long time and yields a product that is not consistent, both in terms of colour and moisture content. This leads to a high rate of rejection of the dried product by the consumer. The need for an alternative drying technique that can produce a product faster and with higher quality therefore exists [2]. Rotary dryers and fluidized bed dryers are some of the examples of widely used drying techniques [3]. However, these techniques which were usually devided in laboratory scale requires scaling up to meet actual industrial demands, and hence mathematical modeling plays important role. Among these models were thin layer models which were widely used to predict drying kinetics of agricultural products.A comparison of green bell peppers drying and rehydration behaviours were studied on control samples and pre-heated samples with ethyl oleate solution by [4]. It was found that, samples drying time were inversely proportional with drying rate. While, rehydration ratio and drying rate of pre-heated samples was greater than control samples. The effective moisture diffusivity, D eff , were verified and moisture tran...

Drying is essentially a process of simultaneous heat and mass transfer, in general, to remove moisture from a wet material to give a long shelf-life or to facilitate further processing. The drying medium flowing around the material serves to remove the moisture. In most drying operations, water is the liquid evaporated using air as the drying medium [. For each individual particle, the drying process involves moisture migration from the inner core regions to the particle surface. The surface moisture is then vaporized or evaporated into the drying medium.

Abstract. Work piece surfaces produced by wire EDM can exhibit surface alterations resulting from rapid heating and quenching during machining. The thermally altered layers have tremendous impacts on mechanical properties of machined product. Multi-cutting passes of brass wire into stainless steel sheet SS304 has been suggested in this paper. Three holes was machined at one cutting passes, two cutting passes and three cutting passes respectively and the effect on surface roughness of machined steel was investigated. Visual micro-structure study has been done to explore the existence of white layer and Heat Affected Zone (HAZ) layer. Based upon experimental result, the surface roughness is decreased with the increment of cutting passes. The white layer only formed at first cutting part and did not appear at two and three cutting passes.