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Showing posts with label Carbon emission. Show all posts
Showing posts with label Carbon emission. Show all posts

Sunday, December 15, 2019

Can Hydrogen substitute Carbon and avoid catastrophic climate change?

 The answer is most likely NO for the following reasons.
It has been established that man-made GHG emissions mainly by CO2 is causing the globe to warm by a phenomenon known as “Greenhouse gas effect” triggering change in climate. Therefore, many are suggesting Hydrogen as an alternative clean fuel to reduce or eliminate CO2 emission. But replacing Carbon with Hydrogen we will only substitute Oxides of Carbon (CO2) with Oxides of Hydrogen (H2O). But water vapor too is a potent greenhouse gas GHG and it may enhance the warming of the globe by a phenomenon known as Feedback effect as explained by NASA and American chemical society (ACS) by the following references:

 Moreover, Renewable Hydrogen is still very expensive compared to Hydrogen derived from fossil fuel such as coal and gas even though cost of renewable energy has reduced substantially in recent past. By injecting valuable renewable Hydrogen into existing pipeline carrying natural gas one will generate additional issues because of varying physical and chemical properties of Hydrogen and its flammability and explosive nature compared to natural gas. Hydrogen is an unstable atom and readily forms a bond with Oxygen and Carbon and that is why Nature does not produce free Hydrogen. It requires a Carbon backbone. Only an emission free power generation technology can solve the problem of global warming. It is only possible by recycling Carbon (Carbon recycling technology) with the help of renewable Hydrogen and to achieve a circular economy. There is no shortcut.

Friday, June 6, 2014

The science and politics of carbon and climate change

President Obama seized his ‘moment of truth’ when he announced his decision to cut carbon emission by 30% by 2030 in USA. His decision may not be popular in USA and in many parts of the world but it is the right decision. He was able to address to some extent ‘ the √≠nconvenient truth’ that has been nagging him during his second term in office. He introduced his decision through EPA (Environmental protection authority) effectively bypassing congress. In fact the whole purpose of creating EPA was to address the environmental issues but it failed in many ways and rest of the world followed such failures time and again. This has resulted in an accumulated carbon both in the atmosphere and in the sea in an unprecedented scale causing disease and environmental degradation world-wide. Air pollution is costing the world's most advanced economies plus India and China $3.5 trillion per year in lives lost and ill health, with a significant amount of the burden stemming from vehicle tailpipes, according to a report by the Organisation for Economic Co-operation and Development (OECD). In the 34 OECD member states, the monetary impact of death and illness due to outdoor air pollution was $1.7 trillion in 2010. Research suggests that motorized on-road transport accounts for about 50 percent of that cost. In China, the total cost of outdoor air pollution was an estimated $1.4 trillion in 2010. In India, the OECD calculated the toll at $500 billion. The costs were calculated based on survey data of how much people are willing to pay in order to avoid premature death due to ailments caused by air pollution. The methodology assigns a cost to the risks of emissions that decision makers can use in weighing public policy decisions. In addition to the health cost the environmental degradation due to carbon pollution includes global warming resulting in mass extinction of species, causing mega bush fires that are wiping out forests including rain forests, creating new bugs that are resistant to antibiotics, increasing sea level that erodes coastal cities and submerge remote islands in pacific displacing millions of people as refugees, acidifies oceans with massive extinction of species including fish stock. Such degradation is nothing but suicidal. When a food or drug is introduced in the market it is subject to scrutiny by FDA (Food and drugs authority), but when it comes to environmental clearance to set up a coal-fired power plant or to set up a seawater desalination plant it is relatively easier to get such clearance from EPA. When power plants emitted gaseous emissions initially EPA was able to limit the emissions of oxides of nitrogen, sulphur, phosphorous, soot and particulate matter , other organics including mercury and arsenics except carbon dioxide. Carbon dioxide has been accepted as part of the air we breathe in; otherwise no power plant could have been approved because bulk of the emissions are only carbon dioxide. Had EPA acted timely in sixties or even in seventies to curb CO2 emissions an alternative energy would have emerged by this time. Industries and economics were high in the political agenda and the environment was overlooked. Many drugs were introduced during this period to cure diseases that were actually caused by environmental pollution such as carbon dioxide. Both power industries and drug industries grew side by side without realizing the fact that environment is degraded slowly which causes chronic diseases. Australia is the largest consumers of power in terms of per capita consumption in the world and yet the new Government in Australia is pushing a bill in the parliament to repel Carbon tax introduced by previous Government. They are also planning to raise revenue up to $ 26 billion for medical research over a period of time. On one hand politicians want to freely allow unabated carbon emissions into the atmosphere and on the other hand they want to introduce new drugs that can cure diseases actually caused by such pollutions. It is an anomalous situation created by politics of climate change. Unfortunately carbon pollution has turned into an energy related issue and attracted political attention world-wide. The high cost of cleaning carbon pollution has turned many politicians into skeptics of science on carbon pollution and climate change. “More than 170 nations have agreed on the need to limit fossil fuel emissions to avoid dangerous human-made climate change, as formalized in the 1992 Framework Convention on Climate Change .However, the stark reality is that global emissions have accelerated (Fig. 1) and new efforts are underway to massively expand fossil fuel extraction by drilling to increasing ocean depths and into the Arctic, squeezing oil from tar sands and tar shale, hydro-fracking to expand extraction of natural gas, developing exploitation of methane hydrates, and mining of coal via mountaintop removal and mechanized long wall mining. The growth rate of fossil fuel emissions increased from 1.5%/year during 1980–2000 to 3%/year in 2000–2012, mainly because of increased coal use.” (Ref : 1) The coal usage continues to grow especially in Asia due to expanding population and industrial growth and demand for low cost energy. USA is expected to achieve energy independence by 2015 which means more fossil fuels are in the pipeline. India and China are planning more coal fired power plants in the coming decade. Australia is planning for massive expansion of coal and LNG and Coal seam methane gas for exports. Fracturing and hydrocracking of shale deposits are adding to the fuel. Countries are more concerned with economic growth than the consequences of climate change. Despite recent warning from NASA that the depleting arctic glaciers have reached a ‘point of no return’ and the predicted sea level rise up to 10 feet is irreversible, there is a little reaction from countries across the globe. There is a clear evidence that shows GHG emission will continue to increase in the future in spite of growing renewable energy projects because renewable solar panels, wind turbines and batteries will require additional power from fossil fuels. It is critically important to reduce carbon emission with great urgency by substituting fossil energy with renewable energy. For example, concentrated solar power (CSP) can be used instead of large scale PV solar to reduce carbon footprint. Solar energy is the origin of all other energy sources on the planet earth and solar energy will be the solution for a clean energy of the future. But how fast solar energy can be deployed commercially in a short span of time is a big issue. The increasing growth of fossil fuel production dwarfs the growth of renewable energy exposing the planet to catastrophic climate change. The GHG emission can be contained only by an aggressive reduction of CO2 emission into the atmosphere as well as by drastic reduction of fossil fuel production. This is possible only by using renewable Hydrogen. The cost of renewable hydrogen is high but this is the price one has to pay to clean up the carbon pollution before the climate is changed irreversibly. The obvious method to reduce carbon emissions is to tax carbon in such a way that it will no longer be economically viable to emit carbon to generate power or to transport. Paying carbon tax will be cheaper than paying for diseases and environmental degradation and natural disasters. Clean environment is the key for the survival of our planet and life on earth and one cannot put a price on such a life. Ref 1: Citation: Hansen J, Kharecha P, Sato M, Masson-Delmotte V, Ackerman F,et al (2013) Assessing ‘‘Dangerous Climate Change’’: Required Reduction of Carbon Emissions to Protect Young People, Future Generations and Nature. PLoS ONE 8(12): e81648. doi:10.1371/journal.pone.0081648

Thursday, July 11, 2013

How to control Carbon emissions in coal-fired power plants?

“Over two-thirds of today’s proven reserves of fossil fuels need to still be in the ground in 2050 in order to prevent catastrophic levels of climate change” – a warning by scientists. There is a great deal of debate on climate change due to man-made Carbon emissions and how to control it without any further escalation. The first obvious option will be to completely stop the usage of fossil fuel with immediate effect. But it is practically not feasible unless there is an alternative Non-Carbon fuel readily available to substitute fossil fuels. The second option will be to capture carbon emission and bury them under ground by CCS (Carbon capture and sequestration) method. But this concept is still not proven commercially and there are still currently many uncertainties with this technology, the cost involved and environmental implications etc.The third option will be not to use fresh fossil fuel for combustion or capture and bury the Carbon emissions but convert the Carbon emissions into a synthetic hydrocarbon fuel such as synthetic natural gas (SNG) and recycle them. By this way the level of existing Carbon emission can be maintained at current levels without any further escalation. At least the Carbon emission levels can be reduced substantially and maintained at lower levels to mitigate climate changes. It is technically feasible to implement the third option but it has to be implemented with great urgency. One way of converting Carbon emission is to capture and purify them using conventional methods and then react with Hydrogen to produce synthetic natural gas (SNG) CO2 + 4 H2 ----------> CH4 + 2 H2O The same process will be used by NASA to eliminate carbon built-up in the flights by crew members during their long voyage into the space and also to survive in places like Mars where the atmosphere is predominantly carbon dioxide. But we need Hydrogen which is renewable so that the above process can be sustained in the future .Currently the cost of Hydrogen production using renewal energy sources are expensive due to high initial investment and the large energy consumption. We have now developed a new process to generate syngas using simple coal, which is predominantly Hydrogen to be used as a Carbon sink to convert Carbon emissions into synthetic natural gas (SNG). The same Hydrogen rich syngas can be directly used to generate power using gas turbine in a simple or combined cycle mode. The Carbon emission from the gas turbine can be converted into SNG (synthetic natural gas) using surplus Hydrogen-rich syngas. The SNG thus produced can be distributed for CHP (combined heat and power) applications so that the Carbon emission can be controlled or distributed. By implementing the above process one should be able to maintain Carbon at specific level in the atmosphere. Existing coal fired power plants can retrofit this technology so that they will be able to reduce their Carbon emissions substantially; they can also produce SNG as a by-product using their Carbon emissions and achieve zero Carbon emission at their site while generating revenue by sale of SNG. Coal is the cheapest and widely used fossil fuel for power generation all over the world. Therefore it will be a win situation for everyone to use coal and also to reduce Carbon emissions that can address the problems of climate change. Meanwhile research is going on to generate renewable Hydrogen cheaply directly from water using various technologies. But we believe we are still far away from achieving this goal and we require immediate solution to address our climate change problems. Recently BASF made a press release‎ claiming a break-through technology to generate Hydrogen from natural gas without any CO2 emissions.

Saturday, July 28, 2012

Can alternative energy combat global warming?

The world is debating on how to reduce 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 currently 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 maintain the current level of Carbon in the atmosphere. The crux of the problem is the rate of speed with which we can reduce 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 reduce 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 require massive amounts of biomass. The current consumption of coal worldwide is 6.647 billion tons/yr (Source:charts the world will require 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 reduce 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 absorb 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.

Tuesday, June 19, 2012

Lithium batteries and Electric cars

All forms of renewable energy sources are intermittent by nature and therefore storage becomes essential. Energy is used mainly for power generation and transportation and the growth of these two industries are closely linked with development of energy storage technologies and devices. Electrical energy is conventionally stored using storage batteries. Batteries are electrochemical devices in which electrical energy is stored in the form of chemical energy, which is then converted into electrical energy at the time of usage. Batteries are key components in cars such as Hybrid electric vehicles, Plug-in Hybrid electrical vehicles and Electrical vehicles - all store energy for vehicle propulsion. Hybrid vehicle rely on internal combustion engine as the primary source of energy and use a battery to store excess energy generated during vehicle braking or produced by engine. The stored energy provides power to an electric motor that provides acceleration or provides limited power to the propulsion. Plug-in hybrid incorporates higher capacity battery than Hybrid eclectic vehicles, which are charged externally and used as a primary source of power for longer duration and at higher speed than it is required for Hybrid electric vehicles. In Electric cars, battery is the sole power source. All electric vehicles require rechargeable batteries with capacity to quickly store and discharge electric energy over multiple cycles. There are wide range of batteries and chemistries available in the market. The most common NiMH (Nickel Metal Hydride) used Cathode materials called AB5; A is typically a rare earth material containing lanthanum, cerium, neodymium and praseodymium; while B is a combination of nickel, cobalt, manganese and/or aluminum. Current generation Hybrid vehicles use several Kg of rare earth materials. Lithium ion battery offers better energy density, cold weather performance, abuse tolerance and discharge rates compared to NiMH batteries. With increasing usage of electrical vehicles the demand for lithium ion batteries and Lithium is likely to go up substantially in the coming years. It is estimated that a battery capable of providing 100miles range will contain 3.4 to 12.7 Kgs of Lithium depending upon the lithium-ion chemistry and the battery range. Lithium -ion batteries are also used in renewable energy industries such as solar and wind but Lead-acid batteries are now used widely due to lower cost. The lithium for Cathode and electrolyte is produced from Lithium Carbonate which is now produced using naturally occurring brines by solar evaporation with subsequent chemical precipitation. The naturally occurring brine such as in Atacama in Chile is now the main source of commercial Lithium. The brine is a mixture of various chlorides including Lithium chloride, which is allowed to evaporate by solar heat over a period of 18-20 months. The concentrated lithium chloride is then transferred to a production unit where it is chemically reacted with Sodium carbonate to precipitate Lithium Carbonate. Chile is the largest producers of Lithium carbonate. Though Lithium ion batteries are likely to dominate electric vehicle markets in the future, the supply of Lithium remains limited. Alternative sources of Lithium are natural ores such as Spodumene.Many companies around the world, including couple of companies in Australia are in the process of extracting Lithium from such ores. Manufacturers produce battery cells from anode, cathode and electrolyte materials. All lithium-ion batteries use some form of lithium in the cathode and electrolyte materials, while anodes are generally graphite based and contain no lithium. These cells are connected in series inside a battery housing to form a complete battery pack. Despite lithium’s importance for batteries, it represents a relatively small fraction of the cost of both the battery cell and the final battery cost. “Various programs seek to recover and recycle lithium-ion batteries. These include prominently placed recycling drop-off locations in retail establishments for consumer electronics batteries, as well as recent efforts to promote recycling of EV and PHEV batteries as these vehicles enter the market in larger numbers (Hamilton 2009). Current recycling programs focus more on preventing improper disposal of hazardous battery materials and recovering battery materials that are more valuable than lithium. However, if lithium recovery becomes more cost effective, recycling programs and design features provide a mechanism to enable larger scale lithium recycling. Another potential application for lithium batteries that have reached the end of their useful life for vehicle applications is in stationery applications such as grid storage. The supply chain for many types of batteries involves multiple, geographically distributed steps and it overlaps with the production supply chains of other potential critical materials, such as cobalt, which are also used in battery production. Lithium titanate batteries use a lithium titanium oxide anode and have been mentioned as a potential candidate for automotive use (Gains 2010), despite being limited by a low cell voltage compared to other lithium-ion battery chemistries.” (Ref: Centre for Transportation, Argonne National Laboratory) Usage of power for extraction of Lithium from naturally occurring brines is lower compared to extraction from mineral sources because bulk of the heat for evaporation of brine is supplied by solar heat. However Lithium ion batteries can serve only as a storage medium and the real power has to be generated either by burning fossil fuel or from using renewable energy sources. Governments around the world should make usage of renewable power mandatory for users of Electrical vehicles. Otherwise introduction of Lithium ion battery without such regulation will only enhance carbon emission from fossil fuels.