Natural Gas Reformation

Let’s continue on our journey to discovering alternative energy processes that can be utilized to replace fossil fuels.  As many of you know by now, this blog has specifically been delving into types of alternative energies.  This week’s blog discusses and illustrates the natural gas reformation process of producing hydrogen.

hydrogen_energy_cycleWe are currently standing in an economic and political standstill because we keep producing the necessary hydrogen that we need from fossil fuels and other crude materials.  For example, many of you would know that this typically occurs at an oil refinery.  Nevertheless, there must be ways of producing hydrogen from renewable resources so that the United States can cut down on the amount of greenhouse gas emissions and pollution into the environment.  How does it work?

Hydrogen is a versatile energy carrier in today’s transportation sector and in industry.  For example, many of you may realize that hydrogen could be a viable energy carrier in hydrogen fuel cell electric vehicles, as illustrated by the very first blog post.   Now, where can the United States efficiently make enough hydrogen for today’s demand?

Steam-Methane Reformation

About 95% of today’s hydrogen is produced in a process known as steam-methane reformation (U.S. Department of Energy, 2012).  This is a process that utilizes high-temperature steam around 700 degrees Celsius to 1000 degrees Celsius.  The overall mechanism of natural gas reformation undergoes three steps:  the steam-methane reformation (or other natural gas reformations), water-gas shift reactions, and pressure-swing absorption.

Steam Methane Reformer_a1_img1Hydrogen can be produced from natural gas, such as methane, in the steam-methane reformation process.  This process utilizes a catalyst that allows methane and other natural gases to react with steam in order to produce hydrogen, carbon monoxide, and a small byproduct of carbon dioxide.  Comparatively, a small byproduct means that the substance makes a minor contribution to the total amount of product formed.  As a result of forming vast amounts of hydrogen in stream-methane reforming, the stream of carbon dioxide produced is very significant!

Overall, the steam-reforming process is endothermic.  An endothermic process is a particular reaction or mechanism that requires heat to be supplied in order for the reaction to move forward, that is, from reactants to products.

Water-Gas Shift Reaction

Here is where the overall reformation process can get interesting.  The water-gas shift reaction reacts the carbon monoxide and steam left over from the preceding the steam-methane reformation process using a catalyst in order to produce carbon dioxide and more hydrogen.  This cuts down on wasting the unnecessary byproducts of the previous reaction.  This essentially extends and increases the amount of hydrogen that can be produced in order to optimize the amount of desired product.

b916035c-ga

Pressure-Swing Absorption

At this point, the amount of hydrogen is maximized in the product streams of the two steps in the natural gas reformation process shown above.  You may be wondering about what engineers and scientists have done about the undesired products, and this subject is worthy of discussion.  In a process known as pressure-swing absorption, carbon dioxide and other impurities are removed from the gas stream (U.S. Department of Energy, 2012).  Essentially, all you have left is hydrogen, which is the only desired product in this overall process.

Steam-Reforming Reactions

Not only methane is used in steam-reforming processes.  Fuels, such as ethanol, propane, and gasoline, are utilized to their fullest extent to produce massive amounts of hydrogen.  Here are several of them illustrated below, along with the water-gas shift reaction:

Methane:  CH4 + H2O (+ heat) –> CO + H2

Propane:  C3H8 + 3H2O (+ heat) –> 3CO + 7H2

Gasoline:  C8H18 + 8H2O (+ heat) –> 8CO + 17H2

Water-Gas Shift:  CO + H2O –> CO2 + H2 (+ small amount of heat)

Why Does This Technology Matter?

PetroleumRefiningAs illustrated above, 95% of today’s hydrogen in the United States comes from natural gas reforming technology.  This hydrogen is utilized in the petroleum refining and ammonia production for fertilizer (U.S. Department of Energy, 2012).

This amount of hydrogen could help stimulate the hydrogen economy that could drive our nation from our economic dependence on foreign oils.  The hydrogen economy generally illustrates how hydrogen could be the major energy carrier in today’s society if it can be mass-produced on a nationwide scale.  Hydrogen fuel could be utilized in revolutionizing hydrogen fuel-cell electric vehicles that use hydrogen as their primary carrier of energy to produce the necessary amount of electricity from electrochemical reactions to power the vehicle.

Like most technological innovations, there are some drawbacks.  Many areas of improvement can be made into intensifying the process, developing better designs to lower equipment manufacturing and maintenance costs, and increasing efficiency by using better catalysts and heat processes (U.S. Department of Energy, 2012).  As these areas are being further developed through research and experimentation, the public must be informed about using hydrogen so that we can make the transition from fossil fuels to alternative energy sources.

Reference

U.S. Department of Energy.  (2012). Hydrogen Production.  Energy Efficiency & Renewable Energy.  Retrieved from http://www1.eere.energy.gov/hydrogenandfuelcells/production/natural_gas.html.

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Biofuel: Alternative Energy Source

Welcome back!  Recently, I have been posting about alternative energy sources, especially within the realm of hydrogen energy.  This week I will be promoting another alternative energy source that many of you are probably know more about:  biofuels.

biodiesel-bigThat being said, I am a very strong supporter of alternative energy, especially when it comes to fuels in transportation.  This week’s application of biofuels is primarily used in trucks and other vehicles which implement diesel-fuel engines.

Like most forms of alternative energy, there are many pros and cons that uniquely distinguish biofuels from, say, nuclear energy.  Biofuels is one of many alternative energy sources, including wind, water, geothermal, and solar power.

Biofuels

What do you think biofuels are?  If you were to break the word up into two parts, you would get the prefix bio- and the word fuel.  The prefix bio- means that something has originated or once belonged to a living material or biomass.  Some examples of these are sugar cane, corn, cellulose, and vegetable oils (Harrison, 2013).  According to Merriam Webster Dictionary, a fuel refers to any material that can be burned in order to produce heat or power.  With both of these ideas in mind, you can contextualize how biofuels may be a suitable alternative to traditional fossil fuels that are being used in traditional vehicles.

Why Biofuels Apply to You

Now that you know what biofuels are, why should you care about their use?  Some of you may not realize this, but you can actually put oil into your gas tank if you own a diesel vehicle.  You can retrieve used oil from restaurants and snack bars, purify it in your garage, and then directly fill your tanks with the filtered oil (Harrison, 2013).

sawdust (1)

Biofuels can also be implemented through the use of plants like hemp.  Many farmers have incorporated many of their crops after processing it into viable fuel.  How might biofuel energy be produced?

The Process of Retrieving Biofuel Energy

There is a three-step process that you may take in order to turn waste oil into biofuel.  They are as follows:

  • OLYMPUS DIGITAL CAMERACollect the biofuel from oils like vegetable oil found in sunflower plants.
  • Heat the oil.  This will allow for the oil to reduce its viscosity, which refers to a substance’s ability to resist motion.  For example, a substance with a large viscosity has a lot of internal friction, preventing it from movement.  Also, a fluid with a low viscosity flows more easily.
  • Filter the oil.  This will remove all of the unnecessary residues that were currently residing in your fuel.

If you think about it, you could possibly do this in your basement if you have the resources!

Pros of Biofuel Energy

biodiesel_beakerOne of the most significant advantages of using biofuels is their utilization in environmental protection.  Substitution of conventional gasoline with biodiesel in a vehicle can reduce the emissions of greenhouse gases up to nearly 100% (Harrison, 2013).  Because carbon dioxide and other harmful chemicals are still produced when biofuels are burned, there is some pollution. However, the amount of pollution is much lower in comparison with the emissions of burning fossil fuels (Harrison, 2013).

Other than being more environmentally-friendly, biofuels also provide better lubrication and leaves less deposits in the engines after it is consumed.  Moreover, biofuels are biodegradable, which makes them significantly safer to use.

Drawbacks of Biofuel Energy

Alternative energy sources always have a drawback.  Therefore, they must be evaluated to see if the benefits outweigh the potential risks.  Because the United States greatly depends on fossil fuels, there is going to be a massive demand for biofuels that may not be available.   As a result, farmers would require more land to grow the necessary plants to meet the projections of the demand for the product.  In order to substitute for all of the petroleum used in the United States, an algae-derived biofuel would require the growing area equal to the size of Maryland (Harrison, 2013).

Biodiesel-300x199

Algae-Derived Biofuel

What Does This Mean?

After analyzing the potential advantages and disadvantages of using biofuels as an energy source, could there be a possible solution?  My proposed solution is to use multiple modes of alternative energy together in an attempt to lessen the dependency of the demand for crude oil.  Many vehicles already utilize biofuels and use hydrogen fuel cells.  With growing research, multiple waves of alternative energy can be made more efficient for our use in the next couple decades.

Reference

Harrison, P. (2013).  What is Biofuel Energy.  Benefits-of-Recycling.  Retrieved from http://www.benefits-of-recycling.com/biofuelenergy/#wrap.

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Genetically-Modified Foods

What are your opinions about genetically-modified foods?  There is a long-lasting debate between farmers, environmentalists, health specialists, and many others about the possible advantages and disadvantages of using genetically-modified foods (GMF).  Little to people know that they have the capability to solve many of the major problems that we face.  Third-world countries could get the proper nutrition and healthy food that they need in order to survive.  The world could be a cleaner place without the vast amounts of pesticides used in plants.  All in all, is it worth the possible risks?  Let’s delve into the subject matter.

GMF: Genetically-Modified Food

crop-cornGenetically-modified foods are crops created for our consumption and even other organisms’ consumption due to advanced technology in the fields of molecular biology and genetic engineering.  What kinds of developments do ordinary crops receive?

Many of these plants are modified in the laboratory in order to enhance some type of desirable trait.  For example, some plants have been modified in the laboratory to increase their resistance to herbicides or to improve the nutritional content of the crops (Whitman, 2000).  Traditionally, the desired traits are obtained through the breeding of certain crops in order to optimize a particular trait.  On the other hand, a gene can specifically be isolated in order to get this desired trait.  Another example of genetically-modified plants allows scientists to isolate the gene responsible for drought tolerance, in which they are able to “insert” that gene into another plant (Whitman, 2000).

Hit-or-Miss Approach:  Using rDNA Techniques

recombinant DNA techChemical engineers are concerned with effectively transferring the genetic materials of one plant to another plant.  Through a team of chemical engineers, food scientists, and biotechnologists, they are able to cross-breed plants over multiple generations using a process known as the “hit-or-miss approach” (AIChE, 2009).  Through this trial-and-error approach, researchers are able to identify the genes responsible for creating the desired trait, which enables them to insert that gene into another microorganism.

By using rDNA techniques (or recombinant deoxyribonucleic acid techniques), engineers are able to make the desired changes in characteristics of plants, animals, and food-related organisms like yeast and enzymes (AIChE, 2009).  Through this process, these crops are able to provide resistance against toxins and pesticides, and prevents allows the fruit to become ripe as a faster rate.  This is significant because it allows for farmers to output more products because of the more efficient growing and processing process.

genetically_modified_foods

Advantages

The heart of the argument for using GMOs (genetically-modified organisms) is supported by all of the various advantages of using them.  Many of the advantages have been illustrated in examples above.  Many of the advantages can be supported by the fact that the population is predicted to double in the next 50 years from about 6 billion people to about 12 billion people (Whitman, 2000).  As a result, the United States has a challenge in feeding the vastly growing population.  Some of the advantages are listed below:

  • Pest resistance:  Because of the lack of food and resources in developing countries, many pests will eat the majority of the crops, resulting in an extreme famine.  However, pesticides that prevent these pests from eating the crops have significantly helped third-world countries’ economies using genetically-modified food.
  • Disease resistance:  Many viruses, fungi, and bacteria feed off the plants.  Genetic engineers have found a way to provide resistance against many different strains of diseases.
  • tips_3-787748Cold tolerance:  Engineers have used an antifreeze gene from cold water fish in tobacco and potato crops in order to be used in plants.  The plants are able to withstand cold temperatures that would normally kill unmodified seedlings (Whitman, 2000).
  • Nutrition:  Engineers and scientists are currently working on inputting a gene that will enable rice to contain additional vitamins and minerals.  Because impoverished countries generally rely on rice as a main source of food, this will enable them to receive a more balanced diet.

There are so many advantages.  Now, why might someone argue against genetically-modified foods?

Disadvantages

Environmentalists are quite concerned with the fact that genetically-modified foods might harm other organisms around them.  For example, some pesticides include toxins to kill insects before they kill the crops.  Now what happens when a deer happens to get inside this farm that has revolutionized pesticides on the crops?  This could cause severe illness to the organism, hence the concern.  Another major issue is the gene transfer to a non-target species (Whitman, 2000).  This is prevented by creating a buffer zone around the field of the genetically-engineered food so that the non-genetically engineered food will not get contaminated.

GM_crop_field

Which Side Will You Take?

Ultimately, it is important to fund this technological development because it could revolutionize the way that developing countries can improve their wellbeing, both physically and economically.  With a vastly growing population, we are running out of a lot of options.  There are viable ways to prevent against the disadvantages presented above.  Genetically-modified foods have advantages that may overshadow the disadvantages.  What side are you on?

References

AIChE.  (2009). Chemical Engineering Innovation in Food Production.  American Institute of Chemical Engineers.  Retrieved from http://www.chemicalengineering.org/docs/ChemE-Food.pdf

Whitman, D. B. (2000).  Genetically Modified Foods:  Harmful or Helpful?  ProQuest.  Retrieved from http://www.csa.com/discoveryguides/gmfood/overview.php

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Hydrogen as an Energy Carrier

We are in a desperate need for an alternative form of fuel.  Many scientists and engineers have proposed multiple solutions to our energy crisis.  However, the primary problem is that people do not seem to care about our current energy crisis.  Can you come up with any solutions of your own?  All it takes is one brilliant idea to change the world.  Only we can make it happen during our generation.  We desperately need this new development.  By the year of 2080, our supply of oil and petroleum will be highly depleted, if not completely used up.

Inok

This post highly relates to my very first post.  Because of my passion for alternative fueling in the transportation sector, I chose to expand upon this post.  Alternative energy engineering is the reason why I chose Chemical Engineering as my major.

Hydrogen: The Perfect Fuel

hydrogencarThink about it.  Hydrogen could possibly be the “perfect fuel” (Air Products, 2013).  Why so?  Well, it is abundant in the atmosphere, it is arguably the most efficient energy source, and it does not produce harmful chemicals into the atmosphere when it is utilized in hydrogen fuel-celled vehicles.  The efficiency of hydrogen is based upon how the hydrogen is completely used up into a reaction for a specific purpose.  You can think of efficiency as how many products you get based upon what you put into the reaction.

Because of its efficiency, hydrogen is non-toxic, it can be produced from renewable resources, and it is a viable energy source (Air Products, 2013).  It is one of many proposals that is gaining attention because it can substantially reduce the country’s dependence on fossil fuels and reduce the amount of greenhouse gases into the atmosphere.

The next question is this: how can hydrogen be applied to various applications?

Material Handling

hydrogenfuelcellMany problems exist today because form of our technology is outdated or inefficient.  For example, there are a lot of applications that use batteries that are simply wasted and completely used up.  Furthermore, other batteries constantly need to be recharged after use.  This can be dramatically altered by using hydrogen fuel cells.  Many companies, including Air Products and Chemicals, Inc., use their hydrogen supply in fuel cell power packs, which are “direct replacements for industrial batteries used in forklifts” (Air Products, 2013).  This is efficient in three ways:

  • It eliminates the time required to recharge and exchange dead batteries.
  • Fuel cell stacks provide a constant voltage.  This allows for the vehicles to maintain a steady speed throughout the day (Air Products, 2013).
  • Water is the only byproduct from fuel cells.  Sometimes, heat is also transferred from the hydrogen fuel cell.

Power Generation

Within the hydrogen fuel cell, hydrogen combines with the oxygen from the air in order to create an electric current.  The electricity can therefore be converted from energy to work in order to power a particular function (using the available work from the electric current).  In other words, fuel processors can produce hydrogen-gas from a hydrocarbon-based fuel, like propane and other natural gases, in order to distribute the hydrogen to the fuel cells to power a generator.  If you wish to get more information on hydrogen fuel cells, please visit the first blog!  One of the major advantages of using this process is that it produces highly-pure hydrogen to the fuel cell.

Hydrogen_Generator-1

Transportation Sector

bmwMost importantly, hydrogen can act as an energy carrier in trucks and smaller vehicles.  This is most practical to you because I am assuming that you are not going to drive your bike to work presently or in the future.  You might have to if we cannot find a solution to our fossil fuel crisis.  This is fundamental because hydrogen can be used in both fuel cells and in internal combustion engines.  Fuel celled vehicles that use electricity are often quieter and more environmentally-friendly, as opposed to conventional internal combustion engine vehicles.  The transportation sector depends on the hydrogen economy, which implements hydrogen-fueling stations that act like traditional gasoline stations.  The primary difference in the fuel-celled vehicles would be its larger hydrogen tank.

Why does this matter?

Many of you may not be interested in energy and the political and economic dilemma that the United States currently faces with our dependency on foreign oil.  However, it is better to fix the problem now than to face the problem later.  We have an entire generation to actually fix our energy crisis.  How will you make an impact?

Reference

Air Products.  (2013). Hydrogen Energy.  Air Products and Chemicals, Inc. Retrieved from http://www.airproducts.com/industries/Energy/Hydrogen-Energy.aspx.

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Chemical Engineering Lab: Working on a Small Scale Project

For this week’s blog post, I want to get more personal.  As a result, this blog post is about what I have been doing in my thermodynamics lab since the start of this spring semester.  I have been working with a team on an experiment called the Cooling Tower Experiment.  Throughout this semester, I have been getting more experience working with this technology in the lab.  In contrast to actual cooling towers in chemical processing plants, this cooling tower is a small-scale machine that is capable of representing actual cooling units that are crucial parts of most power and chemical plants.

cooling-towers-nice

Cooling Towers in Plants

Let’s get to know more about how cooling towers work in the industry.  One of the primary reasons why cooling towers are used currently is because of their ability to lower the temperature of process streams by using utility cooling water.  Process streams represent the many inputs and outputs of mass and energy that travel throughout multiple chemical units in a plant.  These cooling towers are used in refineries, steel mills, petrochemical manufacturing plants, and paper mills, which all require a process that needs temperature control (Baird et al., 2012).  One way of supplying some of this control is by implementing cooling towers.

3432927-cooling-towers-at-grangemouth-refineryEssentially, the cooling tower performs its function by passing cold water through a heat exchanger.  The heat evolving from the heat exchanger is absorbed by the cool water.  This aspect represents a classic example of equilibrium.  As the water absorbs the heat from the exchangers, it is able to cool the process stream to its desired temperature through latent heat.  This will be described more in context with my lab below.

Working in the Lab

In my lab, the cooling tower is operated by pumping heated water to the top of the cooling tower.  As a result, gravity causes the water to fall down the packing material of the column.  Simultaneously, air is being injected by a fan from the bottom of the column to the top, in which the packing material of the column allows for the greater surface area of contact between the water and the air.  Because air has a low density, it is able to rise up the column.

CoolingTowerLabManual

Cooling Tower Apparatus Used in the Lab

There are specific processes that both the air and the water undergo.  Once the air contacts the water as it is rising in the column (and while the water is falling in the column), the water begins to evaporate into the air.  The heat of vaporization, or latent heat, of the water when it evaporates into the air transfers the heat from the water to the air.  As a result, the goal of the lab is achieved; the water is cooled.  Also, it is good to note here that the humidity of the air increases as the air travels up the column due to the mass transfer of water vapor to the air.

Operating Conditions

The model of the cooling tower used in the lab provides a great example of the efficiency of typical cooling towers in industry.  There are many thermometers and thermocouples that measured the temperature of water throughout the height of the column.  Without going into much detail, it is praiseworthy to note that the temperature of the water at each thermometer and thermocouple must remain constant in order for proper calculations to be made about the efficiency of the cooling tower experiment.  This is because most cooling towers do operate under steady-state conditions.

Throughout the three runs of the experiment that was performed in a two-hour period, one of the many calculations that my team made can be used to assess the efficiency of the cooling tower.  The three operating conditions we used were as follows:

  • Run 1:  1.0 kW and no heated air
  • Run 2:  1.5 kW and no heated air
  • Run 3:  1.5 kW and heated air

BOpEqSysCoolingTower_1WTo summarize the operating conditions, we altered both the power (wattage) of the cooling tower and we used either heated air or no heated air.  The power is the amount of heat that is used to heat up the water before it is reintroduced to the top of the column.  All of the heated air did in this experiment was allow for an increased transfer of heat between the air and the water.

My team performed a calculation on the energy lost (measured in kJ/s) by water during the three runs.  They are summarized below:

  • Run 1:  1.19 kJ/s
  • Run 2:  1.43 kJ/s
  • Run 3:  1.49 kJ/s

This calculation was crucial to the experiment because it illustrates how increasingly more energy can be extracted by the gradually cooling tower as it travels down the column.  As a result of the heated air condition with the highest wattage given above, the heat transferred between the water and the air was at a maximum, allowing for the maximum efficiency of the experiment.

Applying the Lab to Real-World Applications

CoolingtowersActual cooling towers operate under the same principles.  If they need a temperature control on a particular unit, they can transfer the heat from the water to heat up certain types of a process.  However, if the goal is to cool a liquid like water, it is most applicable to “dump” this heat into the atmosphere.  In general, many of these heat rejection methods are used in common applications like “air conditioning, manufacturing, and electric power generation” (Manser, 2012).

If you have any further questions about any more of the calculations performed in this experiment or if anything was not described in detail enough, feel free to comment below!

References

Baird, M. J., & Shannon, S.  Cooling Tower: Laboratory Manual.  Rev. #7. 2012. Print.

Manser, V. (2012).  Engineering the wise use of our water resources. Cooling Technology Institute.  Retrieved from http://www.cti.org/whatis/coolingtowerdetail.shtml

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Water Desalination

Water-In-Human-Body-169x300Everyone knows that water is one of the most essential things that you need in order to survive.  What happens to your body if it does not have water?  Without water, your immune system would be disabled, which may cause severe illness.  Since water is a necessary substance that transports biological and pathogenic materials throughout your body, the lack of water would poison certain parts of your body.  Even spending a few hours outside in 80 degrees Fahrenheit without water could degrade your body due to its lack of cooling.  Water is a basic necessity of life.  Without it, living things would not survive.

There are many places throughout the world that lack a clean water supply.  For example, there was an extreme drought in California in July 14, 2009 that posed a tremendous issue for the wellbeing of its residents (University of California – Los Angeles, 2009).  Increasingly, our nation’s major reservoirs and groundwater basins are subpar in being able to supply clean drinking water.  We must face the facts that our increased population growth is causing a critical water shortage. Nevertheless, there is a solution, one of which is water desalination plants.

Desalination: Two Methods

desalination_nicolas_metzl_2Desalination is the general process of removing salt and other minerals from water so that we can drink it.  Salt is the primary byproduct of this process.  There are generally two processes that engineers have innovated in order to produce clean water:  distillation and membrane processes.

MSF Distillation

The commercial process of desalination primarily uses multi-stage flash evaporation, or MSF evaporation.  Plants that use this process are close to large bodies of water in order to obtain the necessary amount of water demanded by the consumer.  Throughout this process, saltwater is heated under pressure; however, this process does not allow for the water to evaporate or boil in its heaters (Deliyannis et al., 1978).  The warm water is flashed in a chamber, where there is a significant reduction in the quantity of pressure. The saltwater will be flashed multiple times, allowing for the formation of a liquid and a vapor state due to successively smaller changes in pressures being used in each flash drum.  Here, the clean vapor state can be separated from the saltwater using gravity, as the clean water vapor will rise and channel out of the system.  During this process, brine, or the liquid saltwater byproduct, is reintroduced to the beginning of the process.

MSF

Reverse Osmosis

The reverse osmosis system generally works under four processes: pretreatment, pressurization, separation, and stabilization.

  1. The seawater is pretreated by removing suspended solids and by adjusting the pH.  The water is then biocompatible with the membranes and is suitable for use (Organization of American States, 2013).
  2. The operating pressure is raised by a pump.
  3. The primary separation allows the desalinated water to pass through the membrane, while the salts and other minerals are unable to do so due to their chemical and physical interactions with the membrane.  This desalinated water might not be completely pure.  As a result, it is reintroduced into the separation process until it meets the required purity.
  4. The drinking water is distributed to the public after it is adjusted for its proper acidity and chemical state.  The water may undergo vapor-liquid equilibrium passing through the membrane and through its final product stream.  Consequently, it is condensed so it is viable for drinking.

reverse_osmosis

Disadvantages of Desalination Plants

One of the primary disadvantages of using desalination plants is the tremendous quantity of energy that each plant must undergo on a daily basis.  It costs a lot of power and money in order to heat water.  Because of water’s high heat capacity, it is more resistant to the transfer of heat.  As a result, it takes more heat in order to put the water at the temperature at which it can be properly flashed.

Increasingly, it is difficult and costly to build the infrastructure required to desalinate water.  The pumps must be capable of compressing water in its saturated, liquid, and vapor phases.  Liquids cost an extreme amount of energy to compress, thus running up the energy costs of running the plant.saudi-arabia-desalination-jubail-500x352

One of the primary environmental concerns of desalination is the production of greenhouse gas emissions.  Because massive amounts of energy are required for the process, nuclear power and fossil fuels have been the primary energy sources.

Increasingly, marine biologists have been concerned with the impact that these desalination plants have on the marine life.  Some of the fish, invertebrates, birds, and other smaller mammals have passed through the intake screens of the input streams of the plant (Nellen, 2011).

Moreover, the most significant environmental damage from the plant is the byproduct stream of saltwater that is not properly treated.  This causes thermal pollution and contamination to our local sea water as a result of the dumping of the brine back into the ocean (Nellen, 2011).

Should You Support Desalination?

Like most sustainable technological innovations, the benefits outweigh the risks.  Energy generation is moving towards a more green movement, as more renewable energy sources like solar and wind generated energy are being used rather than crude oil and coal.  Even though there are environmental drawbacks, desalination plants have been established worldwide in order to improve the economies and standard of living in poorer countries.  While we await the arrival of a sustainable and clean energy source that can be used on the global scale effectively, desalination plants are going to continue to provide the necessary amounts of water for places like the Middle East that could not survive without this technology.

References

Organization of American States. (2013). 2.1 Desalination by reverse osmosis. Organization of American States. Retrieved from http://www.oas.org/dsd/publications/Unit/oea59e/ch20.htm.

Deliyannis, E., & Deliyannis, A. (1978).  Water Desalination. Naturwissenschaften – The Science of Nature.  Retrieved from http://download.springer.com/static/pdf/296/art%253A10.1007%252FBF00702832.pdf?auth66=1362715242_9b9fadeccd018593abd6c9a359c56ce8&ext=.pdf.

University of California – Los Angeles. (2009, July 14).  Major breakthrough with water desalination system. ScienceDaily.  Retrieved from http://www.sciencedaily.com/releases/2009/07/090713144124.htm.

Nellen, A. (2011, July 28).  Desalination: A Viable Answer to Deal with Water Crises?  FutureDirections International.  Retrieved from http://www.futuredirections.org.au/publications/food-and-water-crises/166-desalination-a-viable-answer-to-deal-with-water-crises.html.

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Carbon Dioxide: Capture and Sequestration

What are we doing in order to prevent the depletion of the ozone layer?  Many people are concerned with the fact that our ozone layer is being depleted because of the burning and combustion of fossil fuels.  Many question what “professionals” or what the United States government is doing about the mass production of carbon dioxide into the environment.  There may be a solution to this:  carbon sequestration.  This process is a fundamental subject that chemical engineers are working with because of society’s strong push for a more sustainable future.  What is carbon sequestration and does it work?

Capture and Storage

carbon-sequestrationCarbon dioxide is capable of being captured and stored.  This process is known as carbon dioxide capture and sequestration.  This technology has the capability of reducing the amount of carbon dioxide that is being emitted into the environment.  There is a three step process that engineers have developed in order to perform this engineering feat and they are as follows:

  1. Capture the carbon dioxide from the power plants and other major CO2-polluting industries.
  2. Compress the carbon dioxide
  3. Use a system of pipelines in order to transport the compressed carbon dioxide
  4. Inject the gas underground.

When carbon dioxide is stored into the ground, it is permanently stored within certain rock formations that have tiny openings to trap and hold the carbon dioxide (EPA).

carbon-diagram

Reducing Atmospheric CO2

There are three other methods that are performed in order to successfully reduce the amount of carbon dioxide that would otherwise be released into the atmosphere.

  1. ENVIRONMENT Emissions 1Plants trap the carbon dioxide that is produced from the environment.
  2. Crops and soil are managed in order to reduce the amount of organic matter that decomposes (Al-Kaisi et al.).  This allows that plant material to live longer and trap more carbon dioxide.
  3. If soil erosion is reduced, carbon can be increasingly trapped in the soil.  When soil erodes, the carbon dioxide becomes present into the air.

All of these methods are being put into improving the croplands so that the organic matter will be able to sequestrate the carbon better.  You have seen a multitude of ways that carbon dioxide can be stored.  Now, how do we know that this process is safe for the environment?

Safety

Carbon dioxide is a basic necessity of life on earth.  We breathe out carbon dioxide through a respiratory process of inhaling oxygen.  Carbon dioxide is a necessity for the natural cycle of the environment.  However, too much carbon dioxide is a negative thing.  If there is a large production of carbon dioxide around a particular industry, it can upset the natural balance of the atmosphere and lead to the depletion of the ozone layer.

carboncycle_sm

Carbon sequestration is an ongoing project that is currently being analyzed for its safety.  The EPA has recognized that carbon sequestration is a “well-selected” and “well-designed” process that can permanently store carbon dioxide (EPA).  However, the EPA strongly promotes the ongoing research going into reducing the potential leaks of carbon dioxide that could pollute vulnerable ecosystems.

EPA

cleanwaterThe EPA is protecting the underground sources of our drinking water.  They hope to convince the general public that they are not being negatively impacted by this technological process.  They have created specific requirements like the Safe Drinking Water Act’s Injection Control program in order to appropriate the site of carbon dioxide storage (EPA).

The EPA also has requested the specific growth and effectiveness recordings of the carbon sequestration system in order to monitor the capture of carbon dioxide over time.  Furthermore, the EPA has passed hazardous waste laws and has been examining present risks to ecosystem health in order to evaluate the effectiveness and sustainability of this process.

Why is this Important?

Carbon sequestration can be an effective process to capture and store large quantities of carbon dioxide produced from power plants and other industries.  The U.S. Department of Energy estimates that as much as 3,600 billion tons of CO2 can be stored underground in both the United States and Canada (EPA).  Billions of tons of carbon dioxide are produced around the world every year.  Until carbon dioxide levels are significantly reduced, engineers and scientists will focus on optimizing the implementation and efficiency of carbon sequestration.

What will you do to reduce your carbon footprint?

References

(2012, June 2012).  Carbon dioxide capture and sequestration.  United States Environmental Protection Agency.   Retrieved from http://www.epa.gov/climatechange/ccs/index.html

Al-Kaisi, M., Hanna, M., & Tidman, M. (2003, August 4).  Carbon sequestration.  Integrated Crop Management.  Retrieved from http://www.ipm.iastate.edu/ipm/icm/2003/8-4-2003/carbonseq.html.

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