Posts Tagged ‘carbon dioxide’
Thursday, September 6, 2012 @ 07:09 PM gHale
Shell, Chevron and Marathon Oil will build a carbon capture and sequestration mechanism into their 225,000 barrels per day Athabasca Oil Sands Project, which they feel when the system is ready in 2015, it will be able to capture 1 million metric tons a year of carbon dioxide and inject it a mile underground.
The oil sands are more carbon intensive than other sources of oil because the sludge must undergo a partial refining process, or an upgrade, before it’s thin enough to flow through pipelines. That upgrading process requires a lot of heat, which comes from burning natural gas, which generates quite a bit of carbon dioxide.
The Quest CCS project will capture the carbon dioxide that comes out of the Scotford Upgrader near Edmonton, Alberta, then take it by pipe about 50 miles north where it will inject underground between impermeable layers of rock. Eliminating all that carbon dioxide will effectively reduce the emissions by 35%.
Quest will cost $1.4 billion, about half of which will be put up by the government of Alberta, paid out of a $2 billion fund specifically created to finance carbon capture technologies.
Chevron is no stranger to CCS; at its giant Barrow Island LNG project in Australia, the oil giant is building a system to inject 3.4 million tons of carbon dioxide a year into the earth. That CO2, however, separates out of the natural gas harvested from the Gorgon fields.
Tuesday, June 12, 2012 @ 04:06 PM gHale
A new property of flames allows for the ability to control reactions at a solid surface in a flame now opens up a whole new field of chemical innovation.
Chemists now say their previous understanding of how flames interact with a solid surface was incorrect, said researchers at the University College London (UCL). For the first time, they showed they can control a particular type of chemistry, called redox chemistry, at the surface.
This finding has wide implications for future technology, for example in detection of chemicals in the air, and in developing our understanding of the chemistry of lightning. It also opens up the possibility of being able to perform nitrogen oxide and carbon dioxide electrolysis at the source for the management of greenhouse gases.
Results of the study show that depending on the chemical make-up of the flame, scientists can record a distinctive electrical fingerprint. The fingerprint is a consequence of the behavior of specific chemical species at the surface of a solid conducting surface, where electrons can exchange at a very precise voltage.
“Flames can be modeled to allow us to construct efficient burners and combustion engines,” said Dr. Daren Caruana, from the UCL Department of Chemistry. “But the presence of charged species or ions and electrons in flames gives them a unique electrical property.”
“By considering the gaseous flame plasma as an electrolyte, we show that it is possible to control redox reactions at the solid/gas interface,” Caruana said.
The team developed an electrode system that can probe the chemical make-up of flames. By adding chemical species to the flame they were able to pick up current signals at specific voltages giving a unique electrochemical finger print, called a voltammogram.
The voltammograms for three different metal oxides — tungsten oxide, molybdenum oxide and vanadium oxide — are all unique. Furthermore, the team also demonstrated the size of the current signatures depend on the amount of the oxide in the flame. While this is possible and routinely done in liquids, this is the first time they saw it works in the gas phase.
UCL chemists showed there are significant differences between solid/gas reactions and their liquid phase equivalents. Liquid free electrochemistry presents access to a vast number of redox reactions, current voltage signatures that lie outside potential limits defined by the liquid.
The prospect of new redox chemistries will enable new technological applications such as electrodeposition, electroanalysis and electrolysis, which will have significant economic and environmental benefits.
“The mystique surrounding the properties of fire has always captivated our imagination,” Caruana said. “However, there are still some very significant technical and scientific questions that remain regarding fire and flame.”
Wednesday, May 16, 2012 @ 06:05 PM gHale
Fracking is undergoing more scrutiny in California as oil and gas regulators want to propose new regulations and re-examine existing rules for underground injection wells.
The Department of Conservation’s Division of Oil, Gas, and Geothermal Resources (DOGGR) released a “road map” earlier this month outlining its plan to revisit the state’s oversight of underground injection wells to better protect drinking water supplies and workers.
As part of the process, the division said it would look at the use of carbon dioxide as an enhanced oil recovery tool, the storing of carbon dioxide in injection wells, and the reinjection of waste gas.
“It’s a to-do list of Division priorities for the near-term, some of which involve hydraulic fracturing regulations,” said DOGGR spokesman Don Drysdale.
Hydraulic fracturing, or fracking, involves pumping water, chemicals, and other substances into shale formations at high pressure to enhance natural gas extraction. Injection wells are for deep-underground storage of wastewater, including “flowback” water from fracking.
DOGGR said it will hold a series of public workshops to gather input for new fracking regulations, which it plans to propose by the end of the summer. Also, DOGGR said it will commission an independent study of the impact of fracking in California.
Monday, March 26, 2012 @ 02:03 PM gHale
The “hydrogen economy” is here and available and could begin commercial production in this decade, a scientist said.
Heat from existing nuclear plants could see use in the more economical production of hydrogen, with future plants custom-built for hydrogen production, said International Atomic Energy Agency’s (IAEA) Ibrahim Khamis, Ph.D., at the 243rd National Meeting & Exposition of the American Chemical Society (ACS).
“There is rapidly growing interest around the world in hydrogen production using nuclear power plants as heat sources,” Khamis said. “Hydrogen production using nuclear energy could reduce dependence on oil for fueling motor vehicles and the use of coal for generating electricity. In doing so, hydrogen could have a beneficial impact on global warming, since burning hydrogen releases only water vapor and no carbon dioxide, the main greenhouse gas. There is a dramatic reduction in pollution.”
Khamis said scientists and economists at IAEA and elsewhere are working intensively to determine how current nuclear power reactors — 435 are operational worldwide — and future nuclear power reactors could work in hydrogen production.
Most hydrogen production at present comes from natural gas or coal and results in releases of the greenhouse gas carbon dioxide. On a much smaller scale, some production comes from a cleaner process called electrolysis, in which an electric current flowing through water splits the H2O molecules into hydrogen and oxygen. This process, termed electrolysis, is more efficient and less expensive if water heats to form steam, with the electric current passed through the steam.
Khamis said nuclear power plants are ideal for hydrogen production because they already produce the heat for changing water into steam and the electricity for breaking the steam down into hydrogen and oxygen. Experts envision the current generation of nuclear power plants using a low-temperature electrolysis which can take advantage of low electricity prices during the plant’s off-peak hours to produce hydrogen. Future plants, designed specifically for hydrogen production, would use a more efficient high-temperature electrolysis process or couple with the thermochemical processes, which are currently under research and development.
“Nuclear hydrogen from electrolysis of water or steam is a reality now, yet the economics need to be improved,” Khamis said. He noted some countries are considering construction of new nuclear plants coupled with high-temperature steam electrolysis (HTSE) stations that would allow them to generate hydrogen gas on a large scale in anticipation of growing economic opportunities.
Khamis described how IAEA’s Hydrogen Economic Evaluation Programme (HEEP) is helping. IAEA has designed its HEEP software to help its member states take advantage of nuclear energy’s potential to generate hydrogen gas. The software assesses the technical and economic feasibility of hydrogen production under a wide variety of circumstances.
Wednesday, January 25, 2012 @ 03:01 PM gHale
A Hormel Foods subsidiary is facing “willful” safety law violations in connection with an accident last summer that severed a turkey plant worker’s arm, Occupational Safety and Health Administration (OSHA) officials said.
Shawn Redman, a 35-year-old veteran employee, was cleaning equipment July 20 at a Jennie-O Turkey Store processing plant in Barron, WI, when he caught his arm in a moving production line. Doctors were able to reattach the arm after emergency personnel flew him to a hospital.
Jennie-O should not allow cleaning of any sort while the production line is running, said Rhonda Burke, an OSHA spokeswoman. The agency has proposed fines of $318,000.
Austin. MN-based Hormel can contest OSHA’s findings and penalties; the company said in a statement that it’s reviewing the citations. Jennie-O employs 1,200 at its Barron plant and is one of the nation’s largest turkey processors.
OSHA issued 11 citations to Jennie-O, seven of them deemed “serious” and four “willful.” OSHA issues willful violations only when it believes employers have demonstrated “intentional, knowing or voluntary disregard” for safety rules, or “plain indifference” to worker safety and health.
The company is “committed to being a leader in our industry for employee safety. We have an extensive safety program designed to meet regulatory requirements, which includes ongoing employee training,” said Jennie-O’s human resources Vice President, Pat Solheid.
Redman was cleaning in a room in which the company uses carbon dioxide to kill the turkeys, which are shackled to a conveyor. OSHA cited Jennie-O for not cutting power to the line while Redman was cleaning, and for not adequately ensuring the room was free of carbon dioxide while he worked.
Also, the agency said Jennie-O didn’t have an attendant to oversee Redman when he entered and left the room. After the accident, Redman had to walk down a flight of 25 stairs and 200 feet across a production floor to flag down a co-worker, OSHA said.
Thursday, January 12, 2012 @ 06:01 PM gHale
By Nicholas Sheble
For the first time, comprehensive greenhouse gas (GHG) data reported directly from large facilities and suppliers across the U.S. are easily accessible to the public via the Environmental Protection Agency’s (EPA) GHG Reporting Program.
The 2010 GHG data released Wednesday includes public information from facilities in nine industry groups that directly emit large quantities of GHGs.
A greenhouse gas is a gas in the atmosphere that absorbs and emits radiation in the thermal infrared range. This process is the cause of global warming. GHGs include water vapor, carbon dioxide, methane, nitrous oxide, and ozone.
Three coal-fired power plants owned by Southern Company led the emitter hit parade and each released more than 20 million metric tons of carbon dioxide equivalent in 2010.
Two of the plants, Scherer and Bowen, are in Georgia. The third, James H. Miller Jr., is in Alabama.
The fourth-largest emitter was the Martin Lake, TX power plant of Energy Future Holdings Corporation subsidiary, Luminant.
Duke Energy Corp.’s largest plant, the Gibson plant in Indiana, came in fifth.
“Thanks to strong collaboration and feedback from industry, states and other organizations, today we have a transparent, powerful data resource available to the public,” said Gina McCarthy, assistant administrator for EPA’s Office of Air and Radiation.
“The GHG Reporting Program data provides a critical tool for businesses and other innovators to find cost- and fuel-saving efficiencies that reduce greenhouse gas emissions, and foster technologies to protect public health and the environment,” McCarthy said.
One can view and sort GHG data for calendar year 2010 from over 6,700 facilities by facility, location, industrial sector, and the type of GHG emitted. This information helps communities to identify nearby sources of GHGs, help businesses compare and track emissions, and provide information to state and local governments.
GHG data for direct emitters show that in 2010:
• Power plants were the largest stationary sources of direct emissions with 2,324 million metric tons of carbon dioxide equivalent (mmtCO2e), followed by petroleum refineries with emissions of 183 mmtCO2e.
• CO2 accounted for the largest share of direct GHG emissions with 95 percent, followed by methane with 4 percent, and nitrous oxide and fluorinated gases accounting for the remaining 1 percent.
• One hundred facilities each reported emissions over seven mmtCO2e, including 96 power plants, two iron and steel mills, and two refineries.
Click here to access EPA’s GHG Reporting Program Data and Data Publication Tool. On the right side of the page click on “View GHG data” and then play around with the interactive sorting functions to find facilities of interest.
Nicholas Sheble (email@example.com) is an engineering writer and technical editor in Raleigh, NC.
Tuesday, December 6, 2011 @ 03:12 PM gHale
Five oil refineries in Washington state are under pressure to clean up their airborne emissions as a result of a district court decision late last week.
The state and regional clean air agencies have been violating the Clean Air Act by not requiring the refineries to reduce pollution using what is termed “reasonably available technology,” said the Washington Environmental Council and the Sierra Club.
Attorney Janette Brimmer with Earthjustice argued the case for the plaintiffs and summarizes the main question.
“What was the state’s obligation, or the regional clean air agencies, to set basic minimum standards for this kind of pollution — like methane and nitrous oxide and carbon dioxide — from refineries? And the state was saying, ‘We don’t think we have to do this, at least not under our federally-enforceable plan.’ And we said, ‘Well, we think you do have to do it.’ ”
The state and regional clean air agencies said they’ve been waiting for more guidance from the U.S. Environmental Protection Agency (EPA), but U.S. District Court Judge Marsha Pechman said the agencies have a responsibility to enforce the state clean air plan that’s already in place, ruling in favor of the plaintiffs.
One issue raised in court is Washington’s State Implementation Plan for regulating air pollution is tougher in some ways than federal greenhouse gas standards, and the agencies weren’t sure they could enforce it. However, the judge pointed out the EPA has “repeatedly approved” the state plan.
“The reality is that, despite a lot of good policy statements about greenhouse gases and climate change in Washington, we really have not regulated greenhouse gas pollution very much, particularly from existing sources like these big refineries,” Brimmer said.
Thursday, October 28, 2010 @ 09:10 AM gHale
Biochar, a charcoal-like substance made from plants and other organic materials, could cut as much as 12 percent of the world’s human-caused greenhouse gas emissions.
“These calculations show that biochar can play a significant role in the solution for the planet’s climate change challenge,” said Jim Amonette, a soil chemist at the Department of Energy’s Pacific Northwest National Laboratory and a co-author of a study on the subject. “Biochar offers one of the few ways we can create power while decreasing carbon dioxide levels in the atmosphere. And it improves food production in the world’s poorest regions by increasing soil fertility. It’s an amazing tool.”
The carbon-packed substance first came to light as a way to counteract climate change in 1993.
Biochar consists of decomposing biomass like plants, wood and other organic materials at high temperature in a process called slow pyrolysis. Normally, biomass breaks down and releases its carbon into the atmosphere within a decade or two. But biochar is more stable and can hold onto its carbon for hundreds or even thousands of years, keeping greenhouse gases like carbon dioxide out of the air longer. Other biochar benefits include: improving soils by increasing their ability to retain water and nutrients; decreasing nitrous oxide and methane emissions from the soil, and, during the slow pyrolysis process, producing some bio-based gas and oil that can offset emissions from fossil fuels.
Making biochar sustainably requires heating mostly residual biomass with modern technologies that recover energy created during biochar’s production and eliminate the emissions of methane and nitrous oxide, the study also noted.
For their study, the researchers looked to the world’s sources of biomass not already used by humans as food. For example, they considered the world’s supply of corn leaves and stalks, rice husks, livestock manure and yard trimmings, to name a few. The researchers then calculated the carbon content of that biomass and how much of each source could realistically see use for biochar production.
With this information, they developed a mathematical model that could account for three possible scenarios. In one scenario they looked at the maximum possible amount of biochar made by using all sustainably available biomass. Another scenario involved a minimal amount of biomass converted into biochar, while the third offered a middle course. The maximum scenario required significant changes to the way the entire planet manages biomass, while the minimal scenario limited biochar production to using biomass residues and wastes readily available with few changes to current practices.
Amonette and his colleagues found the maximum scenario could offset up to the equivalent of 1.8 petagrams, or 1.8 billion metric tons, of carbon emissions annually and a total of 130 billion metric tons throughout in the first 100 years. Avoided emissions include the greenhouse gases carbon dioxide, methane and nitrous oxide. The estimated annual maximum offset is 12 percent of the 15.4 billion metric tons of greenhouse gas emissions that human activity adds to the atmosphere each year. Researchers also calculated that the minimal scenario could sequester just under 1 billion metric tons annually and 65 billion metric tons during the same period.
But to achieve any of these offsets is no small task, Amonette noted.
“This can’t be accomplished with half-hearted measures,” Amonette said. “Using biochar to reduce greenhouse gas emissions at these levels is an ambitious project that requires significant commitments from the general public and government. We will need to change the way we value the carbon in biomass.”
Experiencing the full benefits of biochar will take time. The researchers’ model shows it will take several decades to ramp up biochar production to its maximum possible level. Greenhouse gas offsets would continue past the century mark, but Amonette and colleagues just calculated for the first 100 years.
Instead of making biochar, biomass can also produce bioenergy from heat. Researchers found burning the same amount of biomass used in their maximum biochar scenario would offset 107 billion metric tons of carbon emissions during the first century. The bioenergy offset, while substantial, was 23 metric tons less than the offset from biochar. Researchers attributed this difference to a positive feedback from the addition of biochar to soils. By improving soil conditions, biochar increases plant growth and therefore creates more biomass for biochar productions. Adding biochar to soils can also decrease nitrous oxide and methane emissions naturally released from soil.
However, Amonette and his co-authors wrote a flexible approach including the production of biochar in some areas and bioenergy in others would create optimal greenhouse gas offsets. Their study showed biochar would be most beneficial if people could till it into the planet’s poorest soils, such as those in the tropics and the Southeastern United States.
Those soils, which have lost their ability to hold onto nutrients during thousands of years of weathering, would become more fertile with the extra water and nutrients the biochar would help retain. Richer soils would increase the crop and biomass growth – and future biochar sources – in those areas. Adding biochar to the most infertile cropland would offset greenhouse gases by 60 percent more than if bioenergy used the same amount of biomass from that location, the researchers found.
On the other hand, the authors wrote bioenergy production could be better suited for areas that already have rich soils, such as the Midwest, and that also rely on coal for energy. Their analysis showed bioenergy production on fertile soils would offset the greenhouse gas emissions of coal-fired power plants by 16 to 22 percent more than biochar in the same situation.
The study also shows how sustainable practices can make the biochar that creates these offsets.
“The scientific community has been split on biochar,” Amonette acknowledged. “Some think it’ll ruin biodiversity and require large biomass plantations. But our research shows that won’t be the case if the right approach is taken.”