The world is debating on how to cut carbon emission and avert the disastrous consequences of global warming. But the emissions from fossil fuels continue unabated while the impact of global warming is being felt all over the world by changing weathers such as flood and draught. It is very clear that the current rate of carbon emission cannot be contained by merely promoting renewable energy at the current rate. Solar, wind, geothermal, ocean wave and OTEC (ocean thermal energy conversion) offer clean alternative energy but now their total combined percentage of energy generation is only less than 20% of the total power generation. The rate of Carbon reduction by renewable energy do not match the rate of Carbon emission increase by existing and newly built fossil power generation and transportation, to keep up the current level of Carbon in the atmosphere. The crux of the problem is the rate of speed with which we can cut the Carbon emission in the stipulated time frame. It is unlikely to happen without active participation of industrialized countries such as US, China, India, Japan, EU and Australia by signing a legally binding agreement in reducing their Carbon emissions to an accepted level. However, they can cut their emissions by increasing the efficiency of their existing power generation and consumption by innovative means.
One potential method of carbon reduction is by substituting fossil fuels with biomass in power generation and transportation. By using this method the energy efficiency is increased from current level of 33% to 50-60% in power generation by using gasification technologies and using Hydrogen for transportation. The Fixed carbon in coal is about 70% while the Carbon content in a biomass is only 0.475 X B (B-mass of oven-dry biomass). For example, the moisture content of a dry wood is about 19%,which means the Carbon mass is only 38% in the biomass. To substitute fossil fuels, the world will need massive amounts of biomass. The current consumption of coal worldwide is 6.647 billion tons/yr (Source:charts bin.com)and the world will need at least 13 billion tons/yr of biomass to substitute coal .The total biomass available in the world in the form of forest is 420 billion tons which means about 3% of the forest in the world will be required to substitute current level of coal consumption. This is based on the assumption that all bioenergy is based on gasification of wood mass. But in reality there are several other methods of bioenergy such as biogas, biofuels such as alcohol and bio-diesel from vegetable oils etc, which will complement biogasification to cut Carbon emission.
Another potential method is to capture and recover Carbon from existing fossil fuel power plants. The recovered Carbon dioxide has wider industrial applications such as industrial refrigeration and in chemical process industries such as Urea plant. Absorption of Carbon dioxide from flue gas using solvents such as MEA (mono ethanolamine) is a well established technology. The solvent MEA will dissolve Carbon dioxide from the flue gas and the absorbed carbon dioxide will be stripped in a distillation column to separate absorbed carbon dioxide and the solvent. The recovered solvent will be reused.
The carbon emission can be reduced by employing various combinations of methods such as anaerobic digestion of organic matters, generation of syngas by gasification of biomass, production of biofuels, along with other forms of renewable energy sources mentioned above. As I have discussed in my previous articles, Hydrogen is the main source of energy in all forms of Carbon based fuels and generating Hydrogen from water using renewable energy source is one of the most potential and expeditious option to reduce Carbon emission.
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.
It is clear substituting fossil fuels with Hydrogen is not only efficient but also sustainable in the long run. While efforts are on to produce Hydrogen at a cost in par with Gasoline or less using various methods, sustainability is equally important. We have necessary technology to convert piped natural gas to Hydrogen to generate electricity on site to power our homes and fuel our cars using Fuelcell.But this will not be a sustainable solution because we can no longer depend on piped natural gas because its availability is limited; and it is also a potent greenhouse gas. The biogas or land fill gas has the same composition as that of a natural gas except the Methane content is lower than piped natural gas. The natural gas is produced by Nature and comes out along with number of impurities such as Carbon dioxide, moisture and Hydrogen sulfide etc.The impure natural gas is cleaned and purified to increase the Methane content up to 90%, before it is compressed and supplied to the customers. The gas is further purified so that it can be liquefied into LNF (liquefied natural gas) to be transported to long distances or exported to overseas.
When the natural gas is liquefied, the volume of gas is reduced about 600 times to its original volume, so that the energy density is increased substantially, to cut the cost of transportation. The LNG can be readily vaporized and used at any remote location, where there is no natural gas pipelines are in existence or in operation. Similarly Hydrogen too can be liquefied into liquid Hydrogen. Our current focus is to cut the cost of Hydrogen to the level of Gasoline or even less. Biogas and bio-organic materials are potential sources of Hydrogen and also they are sustianable.Our current production of wastes from industries business and domestic have increased substantially creating sustainability isues.These wastes are also major sources of greenhouse gases and also sources of many airborne diseses.They also cause depletion of valuable resources without a credible recycling mechanisms. For example, number of valuable materials including Gold, silver, platinum, Lead, Cadmium, Mercury and Lithium are thrown into municipal solid waste (MSW) and sewage. Major domestic wastes include food, paper, plastics and wood materials. Industrial wastes include many toxic chemicals including Mercury, Arsenic, tanning chemicals, photographic chemicals, toxic solvents and gases. The domestic and industrial effluents contain valuable materials such as potassium, Phosphorous and Nitrates. We get these valuable resources from Nature, convert them into useful products and then throw them away as a waste. These valuable materials remain as elements without any change irrespective of type of usages.Recyling waste materials and treatment of waste water and effluent is a very big business. Waste to wealth is a hot topic.
The waste materials both organic and inorganic are too valuable to be wasted for two simple reasons. First of all it pollutes our land, water and air; secondly we need fresh resources and these resources are limited while our needs are expanding exponentially. It is not an option but an absolute necessity to recycle them to support sustainability. For example, most of the countries do not have Phosphorous, a vital ingredient for plant growth and food production. Bulk of the Phosphorus and Nitrates are not recovered from municipal waste water and sewage plants. We simply discharge them into sea at far away distance while the public is in dark and EPA shows a blind eye to such activities. Toxic Methane gases are leaking from many land fill sites and some of these sites were even sold to gullible customers as potential housing sites. Many new residents in these locations find later that their houses have been built on abandoned landfill sites. They knew only when the tap water becomes highly inflammable when lighting with a match stick. The levels of Methane were above the threshold limit and these houses were not fit for living. We have to treat wastes because we can recover valuable nutrients and also generate energy without using fresh fossil fuels. It is a win situation for everybody involved in the business of ‘waste to wealth’.
These wastes have a potential to guarantee cheap and sustainable Hydrogen for the future. Biogas is a known technology that is generated from various municipal solid wastes and effluents. But current methods of biogas generation are not efficient and further cleaning and purifications are necessary. The low-grade methane 40-55% is not suitable for many industrial applications except for domestic heating. The biogas generated by anaerobic digestion has to be scrubbed free of Carbon dioxide and Hydrogen sulfide to get more than 90% Methane gas so that it can be used for power generation and even for steam reforming to Hydrogen generation. Fuel cell used for on site power generation and Fuel cell cars need high purity Hydrogen. Such Hydrogen is not possible without cleaning and purifying ‘ biogas’ much. Hydrogen generation from Biogas or from Bioethanol is a potential source of Hydrogen in the future.
Many universities, research and development institutions and industries are studying various biological processes to produce Hydrogen using different sources of organic materials such as Starch, Glucose, Bioethanol and cellulosic materials. However many of these technologies are at an early “proof of concept’ stages. Moreover these processes depend upon site and availability of specific raw materials in these locations. For example, Brazil has been very successful in the production of Bioethanol from sugar cane molasses and using it as the fuel for cars. Brazil has also successfully used Bioethanol as a substitute for Naphtha as a feedstock for the production of ethylene, a precursor for a several plastics such as PVC and Polyethylene and Glycols. Bioethanol is a classic example of biological process than can successfully substitute Gasoline .Many industrial raw materials are also derived from Sugar cane and Corn Starch. The main issue in substituting Gasoline with bio-chemicals is political, in many countries. India has produced industrial alcohol from sugarcane molasses for number of years but they were not be able successfully substitute Gasoline with Alcohol. They have to fix the price of Alcohol in relation to the price of Gasoline or Naptha.This pricing mechanism is critical.
We have been using coal as the raw material for several decades not only to generate power but also to produce host of organic chemicals and fertilizers such as Urea, coal-tar chemicals such as dyes and pharmaceuticals. These industries later switched over to oil and Gas. Now the world is facing depletion of fossil fuels at a faster rate. Greenhouse emission and global warming threats are looming large. There is a clear sign that the energy prices will sharply increase in the near future. Renewable energy projects are at early stages and their first costs and cost of productions are much higher compared to fossil fuel based power generation. However biological processes and biofuels offer a glimpse of hope to get over the energy crisis and also to mitigate greenhouse gas emissions.
Production of Biohydrogen using bio-organic organic materials such as starch, glucose and cellulosic materials are under development, but it may be a decade before they can be successfully commercialized. But production of Bioethanol and Biogas are well-known technologies. Generation of Biogas from agricultural waste, food waste and municipal solid waste and waste water are known technologies. However Methane the major constituents of biogas, is a potential greenhouse gas. The Biogas can be easily cleaned from other impurities such as Carbon dioxide and Hydrogen sulfide and can be readily converted in Hydrogen gas by steam reformation. This will substantially increase the energy efficiency of Biogas plants.
Many developing countries can adopt these technologies on a wider scale and promote Bioethenaol and Biogas generation to substitute petroleum oil and gas. They can convert Gasoline cars into 100% Bioethanol (anhydrous) or blended with gasoline fuels for cars. These technologies are commercially available. Some countries in Asia, Africa and South America produce various starches such as Tapioca starch for industrial applications. Vegetable oils such as Jatropha and Castor oils are excellent for bio-fuels and lubricants. Though it is theoretically possible to substitute most of the petrochemicals with bio- organic materials, it is important that food products such as corn should not be diverted for commercial applications such as fuel.
The coming decade will be a challenging one and Hydrogen generation from various biological organic materials can substitute fossil fuels at a much faster rate. A judicial mix of bio-energy and renewable energy such as solar and wind should help the world to overcome the challenges.