Skip navigation

Tag Archives: Biofuel

The science and technology of Bioethanol production from starch or sugar is  well-established. Brazil leads the world in Bioethanol production with a capacity of 16,500 million liters/yr followed by US with a capacity of 16,230 million liters/yr.India produces merely 300 million liters/yr as the fifth largest producer in the world.US consumes about 873 MM gallons of oil/day of which about 58% is imported. The US forecast for 2025 import of oil is 870MMgal/day and the President wants to replace imported oil from the Middle East by 75% -100MMgal/day. (Ref: Environmental Protection Agency,Cincinnati,Ohio).

Currently bulk of the Bioethanol is produced in centralized plants. This is because an economical plant requires a production rate of 40-55 MMgal /day. Transportation of raw materials to long distance is uneconomical. Countries like India can substantially increase their sugar production and encourage small-scale distilleries for the sole purpose of replacing imported oil. Large scale Bioetehanol production involves fermentation of molasses; a byproduct of sugar industry.Bioethanol can also be produced directly from cane sugar juice or from starch such as Corn or Tapioca.

Molasses is diluted with water and inoculated by addition of yeast and other nutrients. The fermentation takes about 24 to 30 hours till the fermented broth has an alcohol content of 7.5 to 9.5% by volume. The fermented wash is then distilled in a separate distillation column. This alcohol which is 95-96% is known as rectified spirit. The rectified spirit is further passed though a Molecular sieve to remove moisture and to concentrate alcohol to 99.8% by volume. A spent wash of about 8 lits are generated per liters of Bioethanol.The spent wash will have a BOD (biological oxygen demand) value of  45,000ppm.This can be subject to Anaerobic digestion to generate ‘Bio  gas’ with about 55% Methane value and the liquid BOD will be reduced to less than 5000ppm. This Biogas can be used to generate power for the process. This process is economical for a production of Bioethanol 40-55MMgal/day.

But in countries like India the sugar cane molasses are available in smaller quantities and the sugar plants are scattered. Small scale distillery can adopt ‘Per-evaporation’ method to concentrate ‘Bioethanol’.The advantage with ‘Perevaporation’ is the process is not limited by thermodynamic vapor-liquid equilibrium. The distilled alcohol with 96% alcohol can be separated by Perevaportion into streams containing Bioethanol 99+% and alcohol depleted water.Perevaporation is a membrane separation process and it serves as an alternative to distillation and molecular sieve and saves energy. The membrane process can be suitably designed for alcohol enrichment as well as dehydration and easily adoptable for smaller production of Bioethanol.

Such process allows production of dehydrated Bioethanol which are suitable to use as a fuel in cars as a Gasoline blend without any engine modification. Production of Bioethanol from cane sugar molasses is cheaper than from corn starch. Countries like India should promote Bioethanol as an alternative fuel to gasoline and cut their oil imports.


World is busy developing alternative to Fossil fuel to cut anthropic Greenhouse gas  to avoid global warming. In fact all forms of alternative energy sources except nuclear energy are ‘solar energy’ from the sun, in one form or another. Sun has supplied energy from the time earth was born. It has conducted   ‘photosynthesis’ by supplying light energy and converting atmospheric carbon dioxide and water into glucose for plants, animals and human beings. The excess carbon from the ‘Carbon cycle’ has become fossil fuels under the earth over a time. The fossil fuel is the result of sun’s energy or solar energy. We unearthed fossil fuels and burnt them to extract energy to run our power plants or run our cars. In fact fossil fuel is also a form of  ‘Biofuel’ and technically there is no difference between them except fossil fuel formation takes millions of years.Fossil fuel is nothing but a source of Hydrogen with carbon backbone.

All forms of alternative energy sources we are currently trying to develop such as PV solar, solar concentrators, solar thermal, geothermal energy, wind energy and bioenergy etc, originate from solar energy. The word alternative energy is a misnomer because all these energy are fundamentally solar energy in one form or another.

Solar energy is a radiation of Nuclear fusion  of Hydrogen taking place in the sun. Two Isotopes of Hydrogen called Deuterium (with one proton and one neutron) combine to form a Helium 3 atom and Neutron with release of large energy. Deuterium is non-radioactive and can be extracted from seawater. But this process could not be duplicated commercially for Electricity generation. It is the safest and cleanest form of energy.

In other words, all forms of energy including solar energy come from Hydrogen. That is why Hydrogen has become a potential fuel source in the future. However, developing a commercial technology for the production and usage of hydrogen at a rate cheaper than fossil fuels with zero greenhouse emission has been elusive so far. Generation of Hydrogen from water by Photo electrolysis using a direct sunlight using a Photo catalyst is a promising technology. But duplicating Nature to generate large amount of energy using tiny amount of Hydrogen atom seems to be a distance dream. Nature knows the best. We human beings can use small energy generation technologies such as solar and wind to meet our small energy needs. “There is enough to meets everybody’s need but not everybody’s greed”,Gandhi said.

Exponential growth of population and industries has forced us to look for large power generation and fuel usage at the cost of serious environmental degradation and future generations. Only smarter and cleaner technologies will help sustain the future. Politicians and policy makers  should understand various technologies and their implications than advocating short-sighted and popular energy policies.

Bioethanol has successfully substituted Gasoline as a fuel for cars both in the form of blends with Gasoline or individually as an Anhydrous Ethanol. This  successful demonstration by Brazil opens up new generation of cars called flex-fuel cars that allow usage of various blends of Ethanol and Gasoline.Bioethanol can also be used to generate Hydrogen on site by steam reformation so that even Fuel cell cars such as Honda FCX can be felled by Bioethanol.This makes Bioethanol unique as an alternative fuel for transportation. It also facilitates on site electricity generation using Fuel cell, replacing diesel engines.

Substitution of Gasoline by  Bioethanol has several advantages over other alternative fuels. The biggest advantage with Bioethanol is, it is renewable and it allows reduction of greenhouse gases from the atmosphere and will be eligible for Carbon credit. It can be produced by both developing  as well as developed countries using  locally available agriculture produces such as cane sugar, corn, tapioca, sorghum etc. Hydrogen generated from Bioethanol is also free from Sulfur compounds normally associated with natural gas, making it an ideal fuel for Fuel cell application in cars, as well as for power generation using SOFC (solid oxide Fuel cell) or PAFC (Phosphoric acid Fuel cell).The resulting high purity Hydrogen 99.99% can be used as fuel for all type of transportation including Fuel cell Buses, scooters and even boats.

The stoichiometric reaction of steam reformation in presence of catalyst can be represented by the following chemical reaction:

C2H5OH + 3 H2O———- 6H2 + 2 CO2

The Ethanol and water mixture is preheated and the vaporized mixture is fed into a catalytic reactor. The resulting Hydrogen is contaminated with carbon monoxide. This gas mixture is separated using membrane such as Palladium to get Hydrogen with less than 50ppm CO as contaminant. Such purity is acceptable by Fuel cell such as SOFC as well as PAFC.In future a small micro-reactor for on-board reformation may be possible making Fuel cell cars with onboard liquid fuel storage.

Commercial reformers consumes about 0.88 lits of Biothanol of 96% purity to generate 1 Nm3 of Hydrogen with 60% conversion. This translates to $ 5.90 per Kg of Hydrogen. Fuel cell cars offer a mileage of 240 from 1 kg Hydrogen costing only $5.90. For on site power generation 1 kg Hydrogen generates as much as 15Kw electricity and 20Kw heat .Onsite Hydrogen generation with steam reformation also facilitates using SOFC and PAFC for high temperature power generation applications. They are ideal for CHP (combined heat and power) applications for 24×7 operations like hospitals, hotels and super markets. These fuel cells are silent in operation without any emissions except water vapor.

Governments should encourage Bioethanol production and distribution for both transportation and power generation. There is a fear that Ethanol could be diverted for potable purposes illegally depriving Governments of potential reveneues.But this can be solved by denaturing Bioethanol and making it unsuitable for potable purposes. Denaturants such Pyridine has no effect on steam reformation and number of denaturants are available. Such policies will allow the transition from fossil fuels to Hydrogen or Bioethanol.This is a simple and straight forward step any Government can take irrespective of the size or type of nation. But it requires political will, determination and leadership. Developing countries need not wait for big greenhouse emitters such as US, China and India to make a decision on their Carbon emissions but start introducing Bioethanol as fuel locally.

We live in a technological world where fuel and power play a critical role in shaping our lives and building our nations. The growth of a nation is measured in terms of fuel and power usage; yet there are many challenges and uncertainties in fuel supply and power generation technologies in recent past due to environmental implications. Fossil fuels accelerated our industrial growth and the civilization . But diminishing supply of oil and gas, global warming, nuclear disasters, social upheavals in the Arabian countries, financial problems, and high cost of renewable energy have created an uncertainty in the energy supply of the future. The future cost of energy is likely to increase many folds yet nobody knows for certain what will be the costs of energy for the next decade or what will be the fuel for our cars.  Renewable energy sources like solar and wind seem to be getting popular among people but lack of concrete Government plans and financial incentives for renewable, are sending mixed signals for investors. Recently number of solar industries in Germany are facing bankruptcy due to withdrawal of Government subsidies. Wind energy in India has got a setback due to withdrawal of Government financial support. Renewable industries are at their infant stages of  growth both technologically and financially. These industries will face a natural death in the absence of Government supports and incentives.

Individuals, small businesses and industries are unable to plan their future due to above uncertinities.In a globalised world such problem have to be tackled jointly and collectively. But that too looks unlikely due to ideological, political and social differences between countries. In the absence of any clear path forward, a common man is left with no alternative but find solutions for himself. Individuals can form small groups to produce their own fuel and generate their own power. There has never been a right moment in our history for such ventures. It can be easily done by people from rural areas especially in farming communities. They can set an example and rest of the country can follow. This will also help preventing mass migration from rural areas to cities, especially in China and India. They neglect their farms and migrate to cities to work in electronic industries for a better life.

The farming communities can form  groups and generate their own ‘Biogas’ or ‘Bioethanol’  from a common facility to fuel their cars and power their homes without any Government incentives and political interefernces.Making ‘Bioethanol’ from cane sugar molasses, beet sugar, corn, tapioca or sorghum on a small or medium scale is a  straight forward method. Fermentation and distillation is a well-known technology. It is controlled by Government excise departments for revenue purpose but Government can certainly allow farms or people to make their own ‘Bioethanol’ for their cars. Farms can generate their own Biogas’ from manure, agriculture wastes,  food waste, and waste water treatment facilities and generate their own power and supply biogas for heating and cooking for their communities.

Governments should allow people to make their own choices and decisions instead of controlling everything especially when they are unable to solve a problem. Countries like India should encourage farming communities in groups to set up their own ‘Bioethanol’ and ‘Biogas’ plants and allow import of  flex-fuel cars for Ethanol blends of various proportions. Alcohol has been a a’taboo’in many countries for several years but with current uncertainties with supply of  fuel and power, Government  can certainly remove such ‘taboo’ by highlighting the value of ‘Bioethanol as a source of fuel.Goevernments  can forgo their excise revenue by allowing people to make their own fuel. Alternatively they should offer incentives and subsidies for renewable energy developments. They cannot refuse both and still hope to continue in power because people will sooner or later  throw them out of power. After all Government are elected by people to address their problems.

%d bloggers like this: