The Extraction of Bioethanol from Cassava (Manihot esculenta) Peelings
Using Active Dry-Yeast (Saccharomyces cerevisiae)
An Investigative Study
Researchers:
Ina Louise B. Magno
Celine Yssabell C. Paragas
Chamagne Dane M. Valencia
Michelle Louisse R. San Diego
Jan Erika Shea B. Ramirez
Khrystyn S. Manuel
Research Adviser:
Mr. Marc Euclid Marquez
S.Y 2015 – 2016
Chapter I
The Problem and Its Background
Introduction
A long time ago until now, gasoline usages have a higher demand every year. In recently, the world face a crisis of diminishing fossil fuel reserves, thus an alternative energy sources need to be renewable, sustainable, efficient, cost-effective, convenient and safe.
The more the civilization develops, the higher living standards are and the higher demand for primary energy is. According to the forecast by 2030 the world's demand for energy will climb by 50%, and will double by 2050 (European Commission 2006). Bioethanol can be extracted from different organic sources like sugarcane, pineapple, cassava and a lot more.
In some parts of the world like here in the Philippines, it is easy grow cassava because of the good climate. Cassava is abundantly growing to different parts of the country, and is widely used on different native desserts like, pichi-pichi, cassava cake, bilo-bilo, nilupak and a lot more. When cooking this favorite Filipino delicacy, the peelings are just thrown away and are not used. This increase the percentage of pollution that's why researchers first thought about how to lessen the pollution and with that, the researchers come up of extracting bioethanol from cassava peelings for better and cleaner alternative fuel.
The twenty-first century witnessed man's constant search for renewable and non-renewable resources of energy. Solar panels had been invented to harness solar energy, running water had been discovered to produce electricity, and still countries continue to harvest fossil fuels from beneath the earth.
The main objective of this study is to successfully produce bioethanol from cassava peelings. Cassava peelings are an agricultural waste which used to produce bioethanol using fermentation process. This research will test the effectiveness of cassava peelings as a renewable source for ethanol through the process of fermentation. The ethanol produced may be used as an additive to unleaded gasoline, therefore producing an effective biofuel. It will be more convenient since cassava peeling is an agricultural waste that may be harvested and available in different areas.
The researchers have to determine the yield of bioethanol produced from cassava peelings. By determining the yield, study the effects of temperature and pH of fermentation process in bioethanol production.
With the bioethanol produced, following must be determined: the contents of cassava peelings that is compatible for making a fuel; compare the amount of extracted bioethanol from the bio waste produce from the samples, amount of the bioethanol produce from the samples and determine how the cassava peelings produce bioethanol that would be useful for the benefactor's environment.
Background of the Study
People nowadays are experiencing trouble because of weekly oil price hike. Not only those who have cars but also the commuters. Cassava peelings (Manihot esculenta) known as "kamoteng kahoy" has considerable potential as a raw material for bioethanol production. The researchers felt a need of country for other sources of fuel and thought of conducting a study and research about how can be the cassava peelings used together with yeast be made as bioethanol.
The world is currently undergoing an oil crisis. Due to continuous annual oil consumption, reserves are quickly being depleted, with scientists predicting that at current rate of consumption, in just 40 years, the entire fossil fuel supply will run completely out. However, oil consumption rates are increasing rather than decreasing, thereby using up even more of this finite resource.
Ethanol fuels have been powering cars since 1826. Samuel Morey developed an engine that ran on ethanol and turpentine. It has been used as Moonshine Whiskey since 15th Century Scotland. After almost 80 years, the Ford Motor Company's first car, The Model T, used ethanol corn alcohol gasoline as fuel energy.
Although agricultural products in the country specifically grown for use as biofuels include several crops, RA 9367 or the Biofuels Law is the response of Philippine Government to the quest of more renewable sources of diesel and fuel. With the recent enactment into law of the RA 9367 last January 12, 2007, the mandatory use of biofuels shall be enforced in support to the government's goal in reducing dependence on imported fuels with due regard to the protection of public health, the environment and natural resources. The law mandates only coconut for biodiesel; and sugarcane, sweet sorghum, cassava, and corn for bio-ethanol.
Cassava peelings are also one of the factors contributing to thousands of agricultural wastes generated every year that is normally dumped in different locations which not only pose environmental pollution but also becoming a source of dangerous disease to humans and animals. The agricultural wastes are organic in nature and consist of certain contents that cannot be directly used as food. After learning what it takes to produce bio-ethanol from cassava in terms of its viability, it is only sensible to take into consideration both its positive and negative impacts in pursuing such a large-scale project.
The research project is designed to determine the potential of cassava peelings for extraction of bioethanol using active dry-yeast and distillation process. This situation demands the managements of such waste of bioconversion. Converting of cassava peelings to bioethanol can make it more useful to human beings than being a waste material.
Bioethanol out of cassava peelings produces only carbon dioxide and water as the waste products on burning, and the carbon dioxide released during fermentation and combustion equals the amount removed from the atmosphere while the crop is growing.
The price of bioethanol / petrol fuels will be kept low due to government subsidies and lower rates in tax. This has shown to encourage the use of a cleaner fuel, assuming public interest is sufficient to create a significant market in alternatively fueled bioethanol and alcohol cars.
Statement of the Problem
From the past to the present, energy is very essential to life. Without it, people will die. The major sources of energy come from fossil fuel and the most consumed for energy are the oil, the coal and the natural gases. As the population grows, so is the need for higher production of energy, however, the world now faces a problem, as the limited amount of fossil fuels begin to diminish.
In response to this problem, the group wants to investigate whether waste materials from cassava peelings can be used to produce bioethanol. It is important to determine the process by which bioethanol can be extracted from cassava peelings. The researchers must determine the environmental benefits of using bioethanol and its safety. The chemical composition of cassava peelings has to be determined to know if it is a possible source of bioethanol. The researchers must be able to explain if this bioethanol is renewable, sustainable, efficient, cost-effective, convenient and safe.
Hypotheses
If the cassava (Manihot esculenta) peelings are subjected to fermentation process using the yeast (Saccharomyces cerevisiae), then a significant amount of bioethanol can be extracted.
There are no significant differences among the bioethanol obtained in terms of:
amount of biowaste and;
time of fermentation.
Significance of the Study
The study aims to determine if an agricultural waste such as cassava peelings and yeast can be made as the useful component of energy fuel.
The study will redound to the benefit of the economy considering every country doesn't have a large reserve of oil to sustain the needs of the people. Having to import the oil puts a huge dent in the economy. If more people start shifting towards biofuels, a country can reduce its dependence on fossil fuels.
For bioethanol production, it is important that the final bioethanol fuel possess more energy than it took in fossil fuels to create it. This ratio of net bioenergy outputs / net fossil fuel inputs is called the Renewability. More jobs will be created with a growing biofuel industry, which will keep our economy secure. Producing biofuel as an alternative source of fuel or gasoline reduces one country's dependence on foreign oil. The environment will also be benefited by this product, knowing that it is a renewable source of energy. Since the source of bioethanol is cassava peelings, it does not run out of supply any time soon cause cassava can be replanted again and again. This product also facilitates the reduction in greenhouse gases because unlike commercially sold fuels which produces a large amount of greenhouse gases when burnt.
The concern of this project is to bring Science and Technology to the quick service for the people by using renewable and recycled materials to conserve energy. The study will also show the creativity and resourcefulness of a man for welfare without harming the environment.
During the research, the researcher's analyzing and thinking skills are being enhanced, thus the researchers also benefited from the research. Cassava is better in terms of the environment with its advantages in nutrient enrichment and lowered photo-oxidation. As is the case with many sustainability issues, the method of weighting each of the dimensions of sustainability may determine which choice is ultimately judged as the better. It awakens the researchers' young minds to the future.
Scope and Delimitation
The study will be conducted for the sake of commuters, motorists and other vehicle owners. It must determine the feasibility of cassava peelings as bioethanol. The capability of cassava peelings may be used not only nationwide but also all over the world. The researchers conducted the study at school from July 2015 and still under process.
The coverage of the study will be the area of the researchers' knowledge about bioethanol and the benefits it can offer and promote once used and/or marketed and sold to the public. The research will focus only on the possible benefits the product can promote. The extraction of bioethanol from cassava peelings will be conducted not only to produce an alternative fuel better and more eco-friendly than the commercial product but also to determine the peelings' potential as a bioethanol source and whether bioethanol can be extracted through the fermentation and the distillation process.
Using it in an actual vehicle is not covered by the study. The attempt to use the peelings to conduct bio-ethanol production experiments for a larger net bio-ethanol yield, as well as the feasibility analyses and studies about the economic technicalities of the research project were not included because of the unavailability of needed protocols for fermentation methodologies for the said samples, as well as the insufficiency of time, finances and technical expertise of the researchers.
Definition of Terms
For the purpose of clarification and better understanding of this study, the following terms are operationally defined.
Bioethanol – clear, colorless liquid, also a biodegradable substance, causes low toxicity and if split, little environmental pollution is produced. It is also the principal fuel used by vehicles for transportation. Bioethanol is an energy derived from biomass. This is a generic terms for fuels that are derived from recently grown biological materials.
Cassava – scientifically known as "Manihot esculenta". In the Philippines, it is known as "kamoteng kahoy". It is a tropical plant with thick root which yield nutritious starch.
Distillation – is the process of purifying liquid by evaporation and condensation. It is also the process of separating component of mixtures base on two materials.
Fermentation – breaking down of energy-rich compound. It is the use of yeast to convert sugar into alcohol or the use of bacteria to create lactic acid in certain food.
Yeast – scientifically known as "Saccharomyces cerevisiae". It is used in making alcoholic liquors and a leaven in baking.
Chapter II
Review of Related Literature
Related Literature
History of Cassava
Cassava (Manihot esculenta), well known as "kamoteng kahoy", is the third largest source of carbohydrates for human consumption in the world, with an estimated annual world production of 208 million tonnes. In Africa, which is the largest centre of cassava production, it is grown on 7.5 million hectare and produces about 60 million tonnes per year. It is a major source of low cost carbohydrates and a staple food for 500 million people in the humid tropics (Leen et al., 2007). Wild cassava sub-species were cultivated and domesticated in west-central Brazil about 10,000 BC. Around 6,000 BC, cassava pollen spread to the Gulf of Mexico as was proved by finds at the San Andrés archaelogical site. Although cassava probably originated in Brazil and Paraguay, the first evidence of cassava cultivation was found at a 1,400-year-old Maya site in El Salvador. Thanks to its ability to grow in nutrient-poor soils and hot climates, it soon became a staple food of native South American people and the Caribbean. Cassava is also often portrayed in indigenous art, for example of the Moche people.
Today, cassava is amongst the most important crops in the tropical world, from Latin America to Asia, although it is only little known or used in western countries.
Characterization of Cassava
The "food of the poor" has become a multipurpose crop that responds to the priorities of developing countries, to trends in the global economy, and to the challenge of climate change. Manihot esculenta has characteristics that make it highly attractive to smallholder farmers in isolated areas where soils are poor and rainfall is low or unpredictable. Since it is propagated from stem cuttings, planting material is low-cost and readily available. The plant is highly tolerant to acid soils, and has formed a symbiotic association with soil fungi that help its roots absorb phosphorus and micronutrients.
Table 1. Proximate Composition and Mineral Content (% of matter) of Several Cassava Varieties with Different Treatments
Cassava roots are more than 60 percent water. However, their dry matter is very rich in carbohydrates, amounting to about 250 to 300 kg for every ton of fresh roots. When the root is used as food, the best time to harvest is at about 8 to 10 months after planting; a longer growing period generally produces a higher starch yield. However, harvesting of some varieties can be "as needed", at any time between six months and two years. Those attributes have made cassava one of the world's most reliable food security crops. Thanks to its roots' high starch content, cassava is a rich source of dietary energy. Its energy yield per hectare is often very high, and potentially much higher than that of cereals. In many countries of sub-Saharan Africa, it is the cheapest source of calories available. In addition, the roots contain significant amounts of vitamin C, thiamine, riboflavin and niacin6.
Cultivation of Cassava
Major farming activities including land preparing, planting, fertilizing, weeding, and harvesting were covered in this stage (Nguyen et al., 2007). Detailed information on fuel, fertilizers, and herbicides inputs was verified by field survey in the north eastern cultivation area of the country. The total cassava planting area in 2007 was 1.2 million hectare and production yield was 22.9 ton fresh roots per hectare (Pimentel, 1992). When comparing to India which had 0.24 million hectare of cassava planting areas, the production yield was 31.4 ton fresh roots per hectare which was 37% higher than production yield of Thailand (Office of Agricultural Economics, 2008). In traditional agriculture, the most common form of seedbed preparation for cassava planting is on mounts or on unploughed land (Ecoivent, 2006).
In improved agriculture, the land is first ploughed and then harrowed. Thereafter cassava may be planted on the flat, on ridges or in furrows. Flat plantings of cassava seem to produce higher yields of tuber than ridge or furrow plantings. However, flat planting is unsuitable on heavy clay soils, because the tubers tend to rot. Cassava is propagated vegetatively as clones. Generally, cuttings are taken from the mature parts of the stems, which give a better yield than those taken from the younger portion of the stems (Leen et al., 2007).
History of Bioethanol
Ethanol can be used as fuel substitute and its potential was known since World War II when the Armed Forces of the Philippines were in search for a viable substitute. Later, in the 1980s when there was oil crisis and oil price hike, ethanol as an alternative substitute for conventional fuel was considered. Ethanol was also taken into consideration to replace tetraethyl lead as an octane enhancer as a solution for high levels of lead in air pollution. Nowadays, the use of ethanol-blended gasoline was mandated in the Biofuels Law. The enacted Biofuels Act of 2006, RA 9367, mandates the use of Bioethanol as fuel to reduce the country's dependence on imported oil and to improve the environmental condition of the country. The provisions include the mandatory blending of at least 5% by volume ethanol, E5, two years from the implementation of this act and a minimum of 10% ethanol blend, E10, within four years of its implementation. There are a lot of studies done in the Philippines with the use of ethanol as fuel. In this chapter past studies on ethanol were reviewed which covers the following topics: raw materials available for ethanol production; pre-treatment process; fermentation processes, which includes the microorganism used, the assessment of engine performance and air emissions, and the utilization of production byproducts.
Sources of Bioethanol
Ethanol is a light alcohol that can be produced from the fermentation of carbohydrates in plant. Ethanol derived from plants is regarded as Bioethanol. The three main types of biomass raw materials for ethanol production: a) sugar bearing materials or saccharine plants (such as sugarcane, molasses, sorghum, etc.) which contain carbohydrates in sugar form; b) starches (such as cassava, corn, sweet potatoes, etc.); and c) cellulose (such as wood, agricultural residues, etc.) for which the carbohydrates molecular form is more complex (DENR, 1990-1993). In addition, Del Rosario (1982) also identified hemicellulosic materials, which include pentosans and hexans, as potential source of ethanol. Hexans are polymers of hexoses other than glucose and are major constituents of 'sapal', which is the fibrous residue obtained after extracting 'gata' in coconut meat. Zayco and Rosario (1980), has listed major potential biomass materials for ethanol production in the Philippines and their expected yield. The list is presented in Table 2.
Table 2. Yields of Biomass and Ethanol for Some Agricultural Crops
Related Studies
Bioethanol from Tundan Peelings
The present increase of oil price has led to an intensified search for other source of energy. One alternative source of biomass, particularly the abundant but wasted fruit peelings. Tundan peelings were collected, sliced and grounded. The extracted juice from the measured mass of ground peelings were distilled after being fermented for seven days. One group without yeast and other with minimum mass of yeasts. The ethanol contents were compared and analyzed. The minimum mass of yeast needed in the fermentation was determined by adding a varying mass of yeast to equal volume of extracted juices of tundan. Based on the findings of the study, the ripe peelings are potential sources of ethanol of domestic energy consumption.
Bioethanol from Sargassum spp.
Bioethanol from Sweet Sorghum
Bioethanol from Corn
Bioethanol from Sugarcane
