Rex B Demafelis

• Chemical Engineering
• University of the Philippines Los Baños

Rice straw is an agricultural waste produced abundantly every rice cropping cycle. Its disposal or removal from the field is a problem to rice farmers every start of the next cropping cycle due to its labor-intensive collection from the field. One traditional practice is soil incorporation; however, rice straw does not degrade easily, and this mana...

Traditionally, the transesterification reaction for biodiesel production takes place at elevated temperatures, around 60-65°C, for up to two hours of reaction time, entailing a high energy consumption. As the University of the Philippines Los Baños – Interdisciplinary Biofuels Research Studies Center (UPLB-IBRSC) continuously aims to conduct studie...

Large-scale cement production has led to serious environmental issues since the process is energy and resource intensive. Moreover, the cement industry is one of the sources of anthropogenic CO 2 emissions. As a matter of fact, in the Philippines, the CO 2 emission increased by 88.23% in over a decade. Hence, this research conducted a life cycle as...

As the Philippine bioethanol industry concluded its first decade, it is in due time to assess whether the objectives of the Biofuels Act of 2006 (Republic Act No. 9367) are being met. Specifically, the law aims to reduce the country’s dependence on oil importation, mitigate toxic and greenhouse gases (GHGs), and promote the use of biofuels from ind...

As biodiesel is continuously aimed to be a better alternative to petroleum-based diesel fuel, the University of the Philippines Los Baños – Interdisciplinary Biofuels Research Studies Center (UPLB-IBRSC) continues to explore process conversion techniques to improve efficiencies in biodiesel production. In this study, the catalytic activity of potas...

This study identified and evaluated conventional and low-carbon swine production systems through a review of literature and visits to commercial farrow-to-finish swine farms in the Philippines, aiming to recommend a swine production system that cost-effectively reduces GHG emissions. Parameters assessed were greenhouse gas (GHG) emission, carbon an...

This study investigates the water scarcity implications of bioethanol production in Negros Occidental, Philippines. The water footprint (WF) of three bioethanol production scenarios was assessed, revealing respective values of 3,574 L L-1, 3,935 L L-1, and 4,293 L L-1 for Case 2 (molasses bioethanol), Case 3 (50% sugarcane and 50% molasses bioethan...

In response to the worsening crisis on energy security and climate change, the Philippine Biofuels Law (Republic Act 9367) was enacted which mandates the blending of biodiesel to petroleum diesel sold in the country. Primarily, feedstock and pricing concerns led to stagnant growth of the Philippine biodiesel industry. Hence, viability of different...

This study quantifies the energy balance and water requirement for ethanol production from sweet sorghum. The energy balance assessment is important to verify if the system actually achieves a positive net energy balance, while inventory of water requirement provides primary approximation of the water economy of this alternative feedstock. The boun...

Biofuel feedstock development is in limelight because of its pronounced capability to reduce greenhouse gas emissions (GHG). The move towards renewable energy intensified researches to provide concrete attestations that could be benefited from the effort. This research assessed the GHG reduction potential of biodiesel produced from Jatropha curcas...

To pursue the continuous implementation of the bioethanol blending mandate by the Philippine Biofuels Law, part of the roadmap of the National Biofuels Board (NBB) through the Department of Energy (DOE) is to find a sustainable feedstock. This is due to the deficit in locally produced bioethanol as there is an insufficient supply of currently used...

To pursue the continuous implementation of the bioethanol blending mandate by the Philippine Biofuels Law, part of the roadmap of the National Biofuels Board (NBB) through the Department of Energy (DOE) is to find a sustainable feedstock. This is due to the deficit in locally produced bioethanol as there is an insufficient supply of currently used...

Biofuels production is intended to address shortage on fuel supply. This study assessed the energetics and water inventory of the Philippine bioethanol production from sugarcane, aiming to provide a definitive value from where studies for economic assessment for this system could pick up. A 30-million-liter-per-year (MLPY) processing facility was d...

Coco-biodiesel is the only type of biodiesel currently being produced in the country as a response to the biodiesel blending mandate under the Biofuels Law. The blending mandate was supposed to increase from 2% to 5% in 2015, however, due to feedstocks concern, the said increase has not yet been implemented to-date. Other than increasing the countr...

The use of OH-impregnated CaO as heterogeneous catalyst in the conversion of refined coconut oil into crude biodiesel was investigated in this study. Wet impregnation method was used to study the effects of NaOH concentration (10–20% (w/v) solution), calcination temperature (550 °C–700 °C), and calcination time (2–5.5 h). Characterization of the OH...

Pyrolysis of rice straw using a fixed bed-batch reactor was investigated to determine the effects of varying pyrolysis temperature (300ºC, 400ºC, and 500ºC) and heating rate (low (0.2-2.0ºC min-1), high (2.6-7.2 ºC min-1)) on pyrolysis products yield and composition. Bio-oil is a liquid fuel that may be refined or upgraded for advanced biofuels pro...

Two pilot-scale open raceway pond systems were designed and fabricated in the University of the Philippines Los Baños (UPLB) for the cultivation of Chlorella vulgaris Beijerinck to observe the biomass productivity of the alga in an open condition in the Philippines. One design was an oval track with a middle island, while the other was a multi-stag...

To meet the need for biodiesel blending in the country, exploration of alternative feedstock such as oil palm is significant. Like coconut oil, palm oil is composed of highly saturated vegetable fats. Compared to other biodiesel feedstocks such as microalgae, soybean and rapeseed oil, palm oil has high oxidative stability and low production cost. B...

Clarification is defecating the organic acids in the juice by means of the addition of lime saccharate. Organic acids hasten the deterioration of the juice, and these acids tend to form salts which maximize the inversion of sucrose into glucose and fructose. Clarification is an important step prior to the production of quality syrup for better ferm...

ABE (acetone butanol ethanol) production was important for some petrochemical industries during the early 20th century, except in areas of South Africa, the Soviet Union and China. It was only during the 1950s that the decline of its production and use was observed due to substrate cost. Since the Philippines has a fairly stable sugar industry and...

The IPCC warns that the window to keep global temperatures down to less than 2°C is rapidly closing. Can the Philippines help reduce greenhouse gases (GHGs) in the atmosphere, even as it seeks to accelerate national development? The Oscar M. Lopez Center, in partnership with the Climate Change Commission, recently released the Philippine Climate C...

The Philippine sugar industry aims to increase its productivity and efficiency as well as maximize the utilization of sugarcane resources. Aside from sugar, bioethanol, having a captive market as mandated under Biofuels Act of 2006, is another product that can be processed from sugarcane. This paper examined the effects of increasing sugarcane yiel...

The conversion of sweet sorghum to ethanol undergoes major processes, namely clarification and fermentation. Clarification is the removal of suspended and turbid particles of the raw juice to make it quality-ready for concentration and/or fermentation. Fermentation is a biological process that releases energy when a particular organic molecule, in...

The technical viability of soybean biodiesel production was evaluated to meet the Philippines' increasing demand for diesel blending as mandated by The Biofuels Act of 2006. Multistage base-catalyzed transesterification reaction of soybean oil using methanol and sodium hydroxide at ambient temperature was performed to reduce the biodiesel productio...

This study details the energetics and environmental analysis of a commercial plant capable of producing 30 million liters of ethanol per year using seaweed Sargassum spp. as feedstock. Two scenarios were considered depending on the substrates used for ethanol production. Scenario 1 utilized the alginic acid, mannitol and the cellulose contents of t...

The global movement to curb carbon dioxide emissions to mitigate climate change has led to the development of several technologies and researches that use renewable energy to reduce fossil fuel consumption and consequently, reduce harmful emissions. This paper aims to share information that will help develop a carbon tax policy in the Philippines....

In light of heightened discussions regarding food vs. fuel issue, different feedstocks have emerged to compromise in meeting the desired volumetric requirement of bioethanol in the country. Sweet sorghum is considered as one of the promising feedstocks taking into account its remarkable characteristics such as shorter crop duration, less water and...

Carbon footprint calculations for raw sugar manufacture was conducted with the aim of determining if the industry is carbon neutral or net contributory to carbon emission. A detailed procedure for the production of raw sugar from sugarcane was designed to account all the sources of carbon emission. The factory design was based on a capacity of 4000...

Carbon footprint calculations for raw sugar manufacture was conducted with the aim of determining if the industry is carbon neutral or net contributory to carbon emission. A detailed procedure for the production of raw sugar from sugarcane was designed to account all the sources of carbon emission. The factory design was based on a capacity of 4000...

Proper feedstock selection is one of the most significant elements in evaluating the feasibility of an ethanol production process. An ideal fuel crop must be inexpensive to cultivate, contains sufficient amount of fermentable carbohydrates to be converted into the desired product, ethanol and can adapt to the chosen technology for processing. The p...

Macroalgae, commonly known as seaweed, as source of bioethanol poses several advantages over other types of feedstocks. Aside from the bases that its cultivation overcomes land use and its composition is abundant in fermentable carbohydrates, seaweed like Sargassum spp. does not have lignin. In biochemical processing such as fermentation, the organ...

One of the parameters to assess the environmental sustainability of the bioethanol industry is to conduct carbon analysis and determine its effectiveness in terms of mitigating climate change. By comparing the carbon savings and carbon debt payback periods of two bioethanol feedstocks (sugarcane and sweet sorghum), not only the more environmentally...

Healthcare waste must be managed properly due to the hazards they impose on public health and the environment. In this study, an alternative method of treating infectious waste via thermal treatment using coconut oil was investigated in a laboratory-scale setup. The effects of oil temperature (121°C, 145°C and 170°C) and treatment time (10, 20 and...

Ninety bacterial isolates from copper-contaminated wastewater from a local semiconductor company were screened for resistance to varying concentrations of copper. Of the copper-resistant isolates, 49 produced biofilm at varying thickness on microtiter plate using Tryptic Soy Broth as substrate. Isolate T21 could tolerate up to 125 ppm copper and wa...

Sargassum spp., a brown macroalgae, is one of the promising feedstocks for bioethanol production. It consists of polysaccharides such as alginic acid, laminarin and fucoidan, and a sugar alcohol, mannitol. This study dealt with the evaluation of the potential of mannitol from seaweed as a substrate for batch ethanol fermentation under varying ferme...

The Philippines, being an agricultural country, can offer substantial amount of biomass resources that can serve as feedstock for bioethanol production or as fuel for power generation. The main target of the study is to identify the location of existing agricultural residues and evaluate their potential for power/bioethanol. The study was conducted...

Macroalgae has a number of potential advantages as a source of bioethanol principally due to its fermentable carbohydrates, such as laminarin, mannitol and cellulose. However, limited studies have been published detailing algae-derived bioethanol. This study aimed to maximize the use of macroalgae as a substrate by providing summarized ideal result...

The sweet sorghum has been proven to be technically and economically viable alternative feedstock for bioethanol production in the Philippine setting. The plantation, agronomic performance and actual bioethanol production of sweet sorghum was evaluated on different plantation sites nationwide. A hectare of sweet sorghum plantation can potentially p...

The growth kinetics of Rhizopus chinensis BIOTECH 3273 using coconut paring cake for the production of microbial rennet was evaluated. Flasks containing 4%, 6%, 8% and 10% by wt. concentrations of coconut paring cake (CPC) were placed in a rotary shaker set at 33 °C and 100 rpm for 3 d. The amount of microbial rennet produced for each concentration...

The effects of the antioxidant extract from "banaba" (Lagerstroemia speciosa L.), mangosteen (Garcinia mangostana L.) and "tsaang gubat" (Ehretia microphylla L.) on the oxidation stability of biodiesel from Jatropha curcas L. were determined based on the induction period (IP) of the samples using the Rancimat method of oil stability index. The most...

Bani (Pongamia pinnata (L.) Pierre) seeds were extracted using Soxhlet apparatus to determine which among hexane, cyclohexane, and petroleum ether would be a more suitable solvent for extraction of bani oil. Seed moisture content, the presence of seed coat, and grinding of the seeds affected oil yield by solvent extraction. Hexane, which is relativ...

The use of petroleum ether as a possible dispersal medium for the transesterification of J. curcas oil was investigated. Initial results have shown that at 1:5 (v/v) petroleum ether:methanol ratio, the reaction time can be reduced to 10 min which is a significant improvement compared to the 60-min reaction time required in a typical transesterifica...

This paper summarizes the major results of the study to determine the feasibility of establishing a cassava plantation to supply feedstock for bioethanol processing. Crop characteristics, soil and climatic requirements, and potential of cassava as feedstock for bioethanol production are discussed. Target production areas identified by potential inv...

Enzymatic extraction process was utilized to recover oil from the seeds of vutalao (Calophyllum inophyllum L.). Optimum enzyme mix of three crude enzymes (xylanase, a-amylase and cellulase) was used to determine the optimum conditions in terms of temperature (40, 50 and 60 degrees C), incubation time (1, 3, and 5 h), and enzyme concentration (1.5,...

This paper presents the opportunities and challenges offered by the Biofuels Program to the sugarcane industry, as well as answer some common queries of potential investors. The Biofuels Act of 2006 mandates 5 and 10% bioethanol blending on February 6, 2009 and for 2011, respectively. This corresponds to 222.89 M L and 482.30 M L ethanol for 2009 a...

Development of nickel mining operation poses negative impacts on the bio-physical environment as well as on human health. The preparation, development, mining and loading stages generate solid waste materials which if not properly managed are detrimental to the environment. In addition, the use of chemicals and reagents in nickel analysis are gener...

As an alternative method, enzymatic extraction was applied to recover oil from the seeds of Alexandrian laurel or vutalao (Calophyllum inophyllum). Three crude enzymes (xylanase, a-amylase and cellulase) were used singly and in combination for the extraction process. The enzyme mixture for maximum oil recovery was determined by Response Surface Met...

Three major energy- and monetary-using stages in ethanol production from sugarcane were analyzed: cane production, cane processing and distillery operation, and distillery slop disposal. Storing, hauling, storage and distributing ethanol to gasoline stations and mixing also consume energy, but they were not included in this case study. Of the 3 mai...

Organic matter (chemical oxygen demand, COD) removal with decolorization in waste distillery slops and copper removal in a semiconductor industry wastewater were achieved in a single step mixing and precipitation/coagulation treatment system. The process utilized the complementary properties of the positively charged copper ions in semiconductor wa...

Coconut shell (containing 11.05% water, 63.20% volatile combustible matter, 1% ash, and 24.75% fixed carbon) was chemically activated with NH4Cl for 1 h at different temperature settings (400, 600, and 800 C) and at different NH4Cl-shell ratios (1:4, 1:6, 1:8). A laboratory-scale locally manufactured pyrolyzer was used in the chemical activation pr...