Archive for category Climate Change

Hydrological Cycle and Climate Change

Posted by on Thursday, 24 March, 2011

Hydrological cycle refers to the movement of water in various forms within different spheres of the earth surface. It plays an important role in determining the climate through its influence on vegetation, types of soil formed, soil moisture, clouds, snow and ice. The hydrological cycle is also responsible for transport of heat from lower latitudes to mid latitudes.

The most important natural phenomenon on earth, the water cycle also known as the hydrological cycle – describes constant movement and endless recycling water between the atmosphere, land surface, and belowground. The hydrological cycle involves exchange of heat energy, which leads to temperature changes.

H20 Molecule:

H20 consists of one atom of oxygen of hydrogen. The water molecule has a positive charge on the side of hydrogen atoms and negative charge on the other side. Water molecules tend to attract each other because the positive ends attracts to the negative ends.

In reality water molecules are three dimensional, and water follows the VSEPR rules- VSEPR, or Valence Shell Electron Pair Repulsion, is a theory that allows us to build accurate 3 dimensional models of atoms and molecules.

The bonds between oxygen and the hydrogen in the H2O molecule are not even, the oxygen has a larger share of the electrons due to its nucleus containing more protons, also called as its electro negativity. This leads each of those bonds to be a polar covalent bond, resulting in water having a slight positive charge on its Hydrogen atoms, as seen to the right.

This then makes water a polar molecule, as it has two negatively charged parts [the electron pairs that are unbound] and two positive parts [the Hydrogen atoms]. These opposite charges are attracted to each other. This holds water molecules together which explains why water is a liquid at room temperature while almost all other similar sized molecules are gases. This also accounts for water’s excellent dissolving capacity for other charged substances such as salt, and why uncharged substances [non polar] such as oil do not mix readily with water.

 

Hydrological Process:

The primary step of the water cycle starts with the evaporation- The primary source of energy for evaporation is the solar radiation. The sun, which drives the water cycle, heats water in oceans and seas. Rising air currents take the water, as vapour, up into the atmosphere, along with water from “evapotranspiration”- which is water transpired or “breathed out” from plants and evaporated from the soil.

 

 

Air currents move water vapour around the globe; the cooler temperatures in the atmosphere cause it to condense into clouds. The cloud particles collide, grow, and float around until they fall from the sky as precipitation. Some precipitation falls as snow and can accumulate as ice caps and glaciers, where it can stay, as frozen water, for thousands of years. In warmer climates, snow melts during the warmer spring and summer months, and that water flows into streams and rivers, which eventually return it to the ocean, or into the groundwater, which eventually reach underground aquifers.  Then again the initial process continues to roll. This is a big cycle and a never ending process.

There are four basic steps that tie this all together

Evaporation,

Transportation,

Condensation,

Precipitation and run off.

 

 

Evaporation:

The transformation of water from liquid to gas phases as it moves from the ground or bodies of water into the overlying atmosphere. The primary source of energy for evaporation is the solar radiation. Evaporation often implicitly includes transpiration from plants, though together they are specifically referred to as evapotranspiration. Total annual evapotranspiration amounts to approximately 505,000 km3 [121,000 cu mi] of water, 434,000 km3 [104,000 cu mi] of which evaporates from the oceans.

Evaporation should not be confused with boiling because when water undergoes evaporation, only water molecules that are on the surface of the water are actually turning into water vapour. In the boiling process, existing water reaches a complete phase change and therefore, the water is being turned into gas at a much faster rate. For e.g. the steam that is rising off of a pot of boiling water is water vapour evaporating.

Transport

The movement of water through the atmosphere, specifically from over the oceans to over land, is called transport. Some of the earth’s moisture transport is visible as clouds, which themselves consist of ice crystals and/or tiny water droplets.

Condensation:

Condensation is the change of physical state of matter from gaseous phase into liquid phase. In the water cycle process, the change is from water to water vapour.

Precipitation:

Precipitation is any product of the condensation of atmospheric water vapour that falls under gravity. Precipitation is a main component of water cycle. Precipitation occurs as rain and also as snow, hail, fog drip, and sleet. Approximately 505,000 km3 (121,000 cu mi) of water falls as precipitation each year, 398,000 km3 (95,000 cu mi) of it over the oceans.

Precipitation can be divided into 3 categories, based on whether it falls as liquid water that freezes on contact with the surface, liquid water or ice.

Rain is a type of precipitation during warmer weather, occurs mainly when the clouds are saturated. Snow is a type of precipitation like rain but at cooler temperatures eventually melts and becomes runoff in stream Mechanisms of producing precipitation include convective, stratiform, and orographic rainfall.

Stratiform processes involve weaker upward motions and less intense precipitation.

Convective processes involve strong vertical motions that can cause the overturning of the atmosphere in that location within an hour and cause heavy precipitation.

Groundwater:

Some of the precipitation soaks into the ground and this is the main source of the formation of the waters found on land – rivers, lakes, groundwater and glaciers.

Runoff:

There are different ways by which water moves across the land; they are surface runoff and channel runoff.

Surface runoff is when the precipitation rate exceeds infiltration rate, or when the soil is saturated, water begins to move down slope on ground surface. As it flows, the water may seep into the ground, evaporate into the air, become stored in lakes or reservoirs, or be extracted for agricultural or other human uses.

Other Process involved:

Infiltration:

Infiltration is the process by which surface water enters into the soil ground.  Once infiltrated, the water becomes soil moisture or groundwater. It is related to the saturated hydraulic conductivity of the near soil. Infiltration is governed by two forces, gravity and capillary action. Capillary action is when the water gets absorbed to the soil under the force of gravity. The process of infiltration can continue only if there is room available for additional water at the top of the soil surface.

This is a general hydrological budget formula, when all the components except “infiltration component “are known.

F = BI + P E T ET S R IA BO

“E” is for evaporation, “ET” is evapotranspiration, “P” is precipitation, “B0” is the boundary out, “Bi” is boundary input, “R” is run off and “Ia” is the initial abstraction

Sublimation:

Sublimation is when a solid turns directly into a gas, instead of first becoming a liquid. In the water cycle, this is seen when ice or snow is heated up enough to turn directly into water vapour.

Advection:

The movement of water in solid, liquid or vapour states through the atmosphere. Advection is a lateral or horizontal transfer of mass, heat, or other property. Accordingly, winds that blow across Earth’s surface represent advection movements of air. Advection is important for the formation of orographic cloud and the precipitation of water from clouds, as part of the hydrological cycle. Advection also takes place in the ocean in the form of currents.  Without advection, water that evaporated over the oceans could not precipitate over land.

Transpiration:

Transpiration is the process where water contained in the liquid form in plants is converted to vapour and released to the atmosphere.

 

Water Vapour escapes through open stomata, mainly on the undersides of leaves. Water enters the stomata from the inner cell; the guard cells open creating pores through which water vapour escapes, this process is called Transpiration.

Canopy interception

The precipitation that is intercepted by plant foliage and eventually evaporates back to the atmosphere rather than falling to the ground

Effects of Climate change on hydrological cycle:

Greenhouse gases and global warming are the major players that are seriously disrupting the world’s water cycle. It has been estimated that global warming by 4°C (7.2°F) is expected to increase global precipitation by about 10 percent. Increasing atmospheric concentrations of greenhouse gases, mainly carbon dioxide, have led to a warming at the surface, by nearly 0.6°C (1.0°F) during the twentieth century, and it is widely believed that this trend will continue in the twenty-first century, leading to a higher sea-surface temperature and several other natural calamities.

 

Reference:

Picture:

http://dardel.info/images/hydrologic_cycle.gif

http://schoolworkhelper.net/wp-content/uploads/2010/07/3D_model_hydrogen_bonds_in_water.jpg

http://www.green-planet-solar-energy.com/images/h2o-molecule.gif

Condensation:

http://4.bp.blogspot.com/_e3fbY8dy2kY/SuwKzRgo74I/AAAAAAAAADk/0EhLakolSKw/s320/condensation2.jpg

Evaporation:

http://www.tech-faq.com/wp-content/uploads/images/Evaporation.jpg

Transpiration:

http://t1.gstatic.com/images?q=tbn:ANd9GcTCSMFRFPH-fQSp9AJ_6y_-OMvzEdGuBj2QpJPS0Z049h3tab06MQ&t=1

http://1.bp.blogspot.com/__iMtPpHiaxo/Ry878TJS_cI/AAAAAAAAAhc/Ukd0GHhnYxM/s320/transpiration.gif

Hydrological cycle:

http://www.isws.illinois.edu/docs/watercycle/images/hcycle.jpg

Precipitation:

http://water.nationalacademies.org/images/water_cycle.jpg

Website and PDF:

http://www.green-planet-solar-energy.com/h2o-molecule.html

http://bit.ly/hDn0XU

http://bit.ly/gVhxZm

http://www.authorstream.com/Presentation/Samuel-32361-5-WATER-CYCLE-Molecule-Condensation-Convection-Cloud-Formation-Precipitation-Snow-Rain-Freshwater-as-Entertainment-ppt-powerpoint/

http://www.eolss.net/ebooks/Sample%20Chapters/C07/E2-16-10-01.pdf

http://web.aces.uiuc.edu/vista/pdf_pubs/WATRQUAL.PDF

http://www.aces.edu/crd/publications/wtrqlty/wq1.pdf

http://water.nationalacademies.org/basics_figures.shtml

http://www.treehugger.com/files/2008/03/green-basics-explanation-water-cycle-pictures-diagrams.php?page=3

 

 

 

 

 

 

 

 

 

 


Carbon capture technologies should move faster now !

Posted by on Saturday, 19 March, 2011

The nuke disaster in Japan is going to change the energy mix of the world soon.

The emphasize on renewables like solar, wind, geo thermal, tidal, wave, hydro etc will now become more.

For the earth quake and the tsunami that hit Japan climate change is probably not the reason. Nor the green house gasses. Probably not even the enhanced ppm of co2 in the atmosphere.

The need for speeding up the carbon capture from coal powered plants is now even more than ever before, now that nuke is going to take the back seat. Atleast for a while.
The CCS technology has to be perfected and implemented as soon as one can.

Carbon capture and sequestration technology for retro fitting of existing power plants also need to be hastened.

Nuclear  power provides about 6% of the world’s energy and 13–14% of the world’s electricity.

The Office of Fossil Energy’s National Energy Technology Laboratory (NETL) of USA has begun research under the Carbon Capture Simulation Initiative (CCSI), partnering with other national laboratories, universities, and industry to develop state-of-the-art computational modeling and simulation tools to accelerate commercialization of carbon capture and storage (CCS) technologies.

CCSI is one of three areas of research under the Carbon Capture and Storage Simulation Initiative announced late last year by Energy Secretary Steven Chu. The others involve developing validation data and experimental work, and developing methodology and simulation tools to assess risk.

Both the above are good news for the CCS industry. The need for them to move fast  is very high.

Certainly extensions of old nuclear plants will get delayed or more likely, get terminated. All the new plants will also get delayed and many will get cancelled.
Newer and stricter regulations and laws will ensure that many nuclear projects may get put off or not permitted.
Many under developed and less developed countries may go for coal based power plants.
This is not going to help CO2 emission reduction.

CCS will have to come to the rescue immediately. CCS is not going to generate new electricity.

It can help new coal plants fitted with CCS get operational as coal still remains cheap.

To do carbon capture and storage on a temporary basis is expensive .  At present NETL, CCSI and several private players as well as government bodies are planning to capture carbon and store it as geological sequestration or as ocean sequestration. Technology is being perfected for carbon capture, liquefaction, transportation and storage.

 

Many stringent stipulations that will come into being for nuclear power plants will also apply for coal powered plants.

Therefore CCS will gain importance and hence the need to reduce the time to market of CCS technologies.

Objections  to Carbon capture and sequestration may be a little less than for a new nuclear plant.

If the concept is to store Co2,  temporarily till such time such time new processes for products from co2 are conceived, then it will be a great idea.

However, there is a great need to capture co2 and store it quickly.

CCSI will utilize a software infrastructure to accelerate the development and deployment cycle for bringing new, cost-effective CCS technologies to market in several important ways. The operative term is quick.

Promising concepts will be more quickly identified through rapid computational screening of devices and processes.

The time and expense to design and troubleshoot new devices and processes will be reduced through science-based optimal designs.

The technical risk in taking technology from laboratory-scale to commercial-scale will be more accurately quantified.

Deployment costs will be quantified more quickly by replacing some of the physical operational tests with virtual power plant simulations.

CCS is critical to curb climate change. Capture co2 from power plants and industrial facilities, and store it to prevent the greenhouse gas from entering the atmosphere.DOE has started a number of programs to promote CCS, including the Carbon Capture and Storage Simulation Initiative.

CCSI will develop a set of tools that can simulate scale-up of a broad suite of new carbon capture technologies, from laboratory to commercial scale.  In its first 5 years CCSI will focus on oxy-combustion and post-combustion capture.

CCSI will be using solid sorbents and advanced solvents. Pulverized coal power plants, which currently generate nearly half of USA’s electricity and are expected to emit 95percent of the United State’s coal-based CO2 emissionsbetween 2010 and 2030.

The CCSI is led by NETL.  CCSI thus leverages the core strengths of DOE’s national laboratories in modeling and simulation. The project brings together talent from several well known research centres like NETL, Los Alamos National Laboratory, Lawrence Berkeley National Laboratory, Lawrence Livermore National Laboratory, and Pacific Northwest National Laboratory.

The CCSI’s initial industrial partners are ADA Environmental Solutions, Alstom Power, Ameren, Babcock Power, Babcock & Wilcox, Chevron, EPRI, Eastman, Fluor, General Electric, Ramgen Power Systems, and Southern Company.

There is this globalccsinstitute in Australia. The Institute connects parties around the world to address issues and learn from each other to accelerate the deployment of CCS projects. The global ccs institute too should get more funding and should fund/ lend more projects to start CCS.

Now, all these Government organisations of CCS,  may have to hasten their plans to reach out.
Similarly RECS the organization that fosters and advances education, scientific research, professional training and career networks for graduate students and young professionals in the CCS field.

They may need to look at training more people quickly.

The CCSI’s academic participants—Carnegie Mellon University, the University of Pittsburgh, Virginia Tech, Penn State University, Princeton University, and West Virginia University—bring unparalleled expertise in multiphase flow reactors, combustion, process synthesis and optimization, planning and scheduling, and process control techniques for energy processes. CCSI’s academic  section is pretty wide and very impressive. But it needs to move truly fast .

No sequestered carbon dioxide has any guarantee against earth quakes and tsunamis. However if the storage is made in zones that are less prone to earthquakes, it will be a lot safer.

With such solid backing of well known participants with proven capabilities, it is hoped that the carbon capture and storage technologies are moved forward faster than ever before as the need is now more than ever before.

CSLF set up in South Africa. The Carbon Sequestration Leadership Forum (CSLF) is a Ministerial-level internationalclimate change initiative that is focused on the development of improved cost-effective technologies for theseparation and capture of carbon dioxide (CO2) for its transport and long-term safe storage. Organisations like CSLF in all countries should change their road map for ccs and speeden up. Time is of essence.
These organisations also need to invest on research in CO2 to products immediately.

CCS plus ‘ co2 to products ‘ is the  way to go !

http://www.netl.doe.gov/publications/press/2011/110216-RECS_2011_Carbon%20Capture.html

http://www.globalccsinstitute.com

http://www.co2captureandstorage.info

http://www.cslforum.org/

 

Related Terms in the Glossary:

Carbon Capture and Storage

Greenhouse Gas

Climate Change

Carbon Sequestration

 



Global Climate and Energy Project at Stanford University

Posted by on Saturday, 5 March, 2011
The Global Climate and Energy Project (GCEP) at Stanford University seeks new solutions to one of the grand challenges of this century: supplying energy to meet the changing needs of a growing world population in a way that protects the environment.
Their  mission is to conduct fundamental research on technologies that will permit the development of global energy systems with significantly lower greenhouse gas emissions.
With the support and participation of four international companies—ExxonMobil, General Electric, Schlumberger, and Toyota—GCEP is a unique collaboration of the world’s energy experts from research institutions and private industry. The Project’s sponsors will invest a total of $225 million over a decade or more as GCEP explores energy technologies that are efficient, environmentally benign, and cost-effective when deployed on a large scale.
GCEP which was launched in December 2002, is well on its way to developing and managing a portfolio of innovative energy research programs. They currently have a number of exciting research projects taking place across disciplines throughout the Stanford campus and have started collaborating with leading institutions around the world.

 

GCEP’s primary objective is to build a diverse portfolio of research on technologies that will reduce greenhouse gas emissions, if successful in the marketplace.

 

Among GCEP’s specific goals:

 

1. Identify promising research opportunities for low-emissions, high-efficiency energy technologies.

 

2. Identify barriers to the large-scale application of these new technologies.

 

3. Conduct fundamental research into technologies that will help to overcome these barriers and provide the basis for large-scale applications.

 

4. Share research results with a wide audience, including the science and engineering community, media, business, governments, and potential end-users.