Using Building Air Conditioning Systems For Carbon Capture and Synthetic Fuels

Posted on May 18, 2019 by duanetilden

There have been many global developments on the science of CO2 recovery from the atmosphere. Existing and future buildings use A/C systems for temperature control of ventilation systems. Large buildings move massive amounts of air during the course of a day.

At design rates of 10 to 20 cfm (cubic feet/minute) per person large assemblies or office towers rates of ventilation can reach up to 100,000 cfm or more per building. This air is required to be temperature controlled, which is achieved by air conditioning units, which extract heat energy from the air stream and reject this heat to the outside (a heat pump can also operate in reverse mode, heating the inside air stream and absorbing heat from the outside air).

The fan motors used to move the conditioned air consumes considerable electricity to operate as do the outside air fans used to cool the A/C system. The outside cooling (heating) loop is operated by forcing air through fin-tube radiators which contain pressurized refrigerant circulating in a closed loop cycle.

Calgary-based Carbon Engineering’s first direct air capture plant in Squamish, B.C. David Keith, the founder of Carbon Engineering, thinks the idea of AC integrated carbon capture systems is attractive, but may not be practical because of economies of scale. (THE CANADIAN PRESS/Darryl Dyck) (1)

It has been proposed to incorporate carbon capture and sequestration in these systems and create a new, clean energy source which can be re-introduced to the economy as a fuel and material feed-stock for a variety of industries.

However, the process is not without certain drawbacks. One major hurdle is finding the additional energy required to further process the captured CO2 into a viable fuel. The process requires electrolysis of water and other energy inputs to refine the captured carbon. It is proposed that PV Cells would be a good energy source for the process.

“[…] In a new analysis, scientists argue for using air conditioning units to capture carbon dioxide straight from the atmosphere and transform it into fuel. The idea is that these renewable-energy powered devices would lower atmospheric CO2 and provide a scalable alternative to oil, natural gas and other fossil fuels.

The conversion tech would first take in CO2 and water from the air. Then, an electric current would split the water into hydrogen and oxygen. Finally, combining the hydrogen with the captured CO2 would produce hydrocarbon fuel.

It’s all theoretical for now, but the technology for each step of the process already exists. Companies like Climeworks in Switzerland, Siemens AG in Germany and Green Energy in the US, have commercialized technologies that separately capture CO2 directly from the air, isolate hydrogen from water and produce fuels. But a complete system that puts all of the pieces together, is lacking. The fact that the components are available, however, means “it would be not that difficult technically to add a CO2 capture functionality to an A/C system,” the authors write.

If air conditioners were equipped with the appropriate technologies, the researchers calculate Fair Tower, a landmark office building in downtown Frankfurt am Main in Germany, could produce 550 to 1,100 pounds of liquid hydrocarbon fuels every hour, or about 2,200 to 44,00 tons per year. When the researchers extrapolated on this calculation they found the five cities in Germany with the largest office space could together produce 2.6 to 5.3 million tons of fuel each year, the team reports Tuesday in the journal Nature Communications. […]” (2)

Rural Electrification with Renewable Energy Micro-Grids

Posted on March 2, 2019 by duanetilden

Pilot Programs to Provide Research of Renewable Energy Solutions for Improved Air Quality

New Delhi, India— November 19, 2018—ENTRADE and Tata Powered Delhi Distribution Limited (Tata Power-DDL) has commissioned a waste-to-energy testing pilot in conjunction with solar and battery storage research and development at its Rohin-Delhi grid station test facility in New Delhi. Please see video of the Tata Power-DDL pilot currently underway .

Speaking on the launch of the testing facility, Mr. Praveer Sinha CEO & MD Tata Power said “Rural Electrification is the catalyst to bring economic growth and meeting the socio-economic goals of people living in rural communities. TATA Power is implementing renewable microgrid solutions across rural India. These Microgrid solutions run using Solar systems, Battery storage and Biomass Generation as a novel concept to promote renewable energy. We look forward to this collaboration of Tata Power and ENTRADE in promoting green, affordable and sustainable rural micro-grid power Generation solutions in India.”

“We started it as an R&D project and soon found that it has a big potential in the rural market particularly for offering inexpensive and sustainable rural micro-grid solutions. The combination of organic waste coupled with solar and battery storage to generate clean energy offers excellent choice to the consumers at a much reasonable price. ” said Mr. Sanjay Banga, CEO, Tata Power-DDL.

Utilizing the ENTRADE E4 mobile power system, Tata Power-DDL and ENTRADE have built India’s first biomass-to-energy testing facility, showcasing the ability to produce electricity using organic waste as feedstock. Solar panel and battery storage testing will also be conducted at the site. The pilot programs will provide R&D data on clean energy solutions while exploring options for electrification of rural India. The E4 system will be replaced with an EX system in the first quarter of 2019.

A major source of air pollution in the region comes from coal-fired power plants and the testing of renewable energy sources is detrimental to improving air quality. Plans for sourcing local biomass fuels to be converted to clean energy are being considered with the most technologically advanced and fasted growing biomass systems on the market. Long term studies will potentially include waste from agricultural crops. Implications of post pilot opportunities with the abundance of agricultural crops typically burned in the open could provide dramatic air quality improvements for industrial and rural regions.

“Through our R&D work with Tata Power-DDL, we can help alleviate environmental issues and provide massive new opportunities through this truly groundbreaking technology bringing access to clean energy,” stated Julien Uhlig, CEO of ENTRADE X. “Our decentralized energy systems are not only more cost effective but also provide a fast deployment solution for rural electrification anywhere in the world.”

https://www.linkedin.com/pulse/tata-power-ddl-entrade-launch-waste-energy-solar-power-julien-uhlig/

Is the Automobile Industry the Next Bubble?

Posted on December 20, 2018 by duanetilden

Over the past year and recently there have been significant changes happening in the North American automotive sector. Other parts of the world have been ramping up the development of the Electric Vehicle, with a number of countries and cities proposing banning or limiting sales of fossil fueled powered vehicles to meet future Climate Accord CO2 emission reductions.

World wide we see that auto manufacturers are making the switch over to the development of the EV which will eventually replace the ICE (Internal Combustion Engine).

Industry involvement in promoting electric vehicles

“To meet future demand for EVs, auto manufacturers need to plan and gear up for the relevant changes to design and manufacturing processes. Normally, government calls for reduced vehicle emissions are met with resistance from the private sector. According to Winfried Hermann, transport minister for Stuttgart, “We say, clean up your technology, they say it is impossible.”^[5] Nevertheless, many automakers are now planning to sell most of their vehicle fleet in electric versions. According to Volvo’s CEO, the manufacturer aims for 50 percent of sales to be fully electric by 2025.^[6]

Other companies including BMW and Renault have committed to significant increases in EV production in the next two years and plan on a full transition in the near future. The PSA Group, which owns Peugeot and Citroen, stated its intentions to electrify 80 percent of its fleet for production by 2023, and Toyota is manufacturing its first fully electrified Prius to meet California’s updated vehicle standards for 2020.^[7] Toyota also announced it will be adding more than 10 EV models by the early 2020s, and has partnered with Panasonic to develop a new EV battery.^[8] Companies that have already produced fully electrified cars, such as Nissan, are setting the pace by providing more variety to make EVs appealing to consumers with diverse needs. Aston Martin, Jaguar, and Land Rover, producers of luxury cars, have also spoken publicly about their company goals to move toward electrifying vehicles.^[9] German-owned makers of Rolls-Royce and Mini Cooper vehicles plan to bring 25 electric models to market by 2025, in line with the goals that several European countries have targeted for the end of new ICE vehicle sales.^[8] Additionally, they hope to stay ahead of shifting market demands and the impending European target goals by increasing research and development spending to 7 billion euros.^[8] The largest auto manufacturer in Europe, Volkswagen, has pledged 20 billion euros for its electric car program, and its luxury brand Porsche, in collaboration with Audi, will release 20 electrified models by 2025.^{[8] […]”}

One recent report details statistics provided by the US EPA, where 15% of man-made carbon emissions are produced by the transportation sector, and the US transportation represents 27% of national carbon emissions.

Technological developments in renewable energy, energy storage and batteries, autonomous vehicles, Internet of Things, materials, and many other nascent and emerging sectors. Changes in society as more people congregate in cities while the baby boomer generation are departing from the consumer sector, and emerging Millenials are making new choices in spending and interaction with the world.

Utility To Replace N-Gas Peaker Plants With Energy Storage

Posted on November 10, 2018 by duanetilden

Duane M. Tilden, P.Eng                          November 10, 2018

The main caveat of Energy Efficiency is to do more with less. Energy Efficiency is low-lying fruit, easy to harvest. For utilities and the grid there are many advancements coming that will allow us to enable a more resilient and sustainable electrical transmission system connecting providers, consumers, and prosumers.

Electricity Prosumers & Renewable Energy

“Active energy consumers, often called ‘prosumers’ because they both consume and produce electricity, could dramatically change the electricity system. Various types of prosumers exist: residential prosumers who produce electricity at home – mainly through solar photovoltaic panels on their rooftops, citizen-led energy cooperatives or housing associations, commercial prosumers whose main business activity is not electricity production, and public institutions like schools or hospitals. The rise in the number of prosumers has been facilitated by the fall in the cost of renewable energy technologies, especially solar panels, which in some Member States produce electricity at a cost that is the same or lower than retail prices.” (1)

What is a Peaker Plant?

“Peaking power plants, also known as peaker plants, and occasionally just “peakers”, are power plants that generally run only when there is a high demand, known as peak demand, for electricity.^[1]^[2] Because they supply power only occasionally, the power supplied commands a much higher price per kilowatt hour than base load power. Peak load power plants are dispatched in combination with base load power plants, which supply a dependable and consistent amount of electricity, to meet the minimum demand.” (2)

As more renewable energy projects are added to provided base load power, in an absence of electricity when renewable sources of electricity are inactive a greater reliance is put on peaker plants to make up energy shortfall . However, as improvements in energy storage solutions gain traction through capacity and competitive costing it is now possible to replace fossil fuel powered peaker plants with energy storage.

Public Utilities Commission of the State of California (CPUC)

In a recent decision the State of California has proceeded with plans to develop and procure electrical storage solutions for the Public Utility as an alternative to aging natural gas peaker plants. A net reduction in carbon emissions by eliminating fossil fuel consumption.

Energy Storage California 2018

Table 1 – Summary of Pacific Gas and Electric’s (PG&E’s) energy storage power purchase
agreements (PPAs)

“Approval of PG&E’s landmark energy storage solicitation is the most significant example to date of batteries taking the place of fossil fuel generation on the power grid.

Energy storage has helped decrease the California’s reliance on gas for years, particularly since 2016, when regulators ordered accelerated battery procurements to counteract the closure of a natural gas storage facility outside Los Angeles.

The PG&E projects, however, are the first time a utility and its regulators have sought to directly replace multiple major power plants with battery storage.

The projects would take the place of three plants owned by generator Calpine — the 580 MW Metcalf plant and the Feather River and Yuba City generators, both 48 MW.

Calpine and the California ISO last year asked the Federal Energy Regulatory Commission to approve reliability-must-run (RMR) contracts for the plants, arguing they are essential to maintain power reliability. The one-year contracts would see California ratepayers finance the continued operation of the generators, which are losing money in the ISO’s wholesale market.

FERC approved the request in April, but California regulators were already planning for when the plants retire. In January, they ordered PG&E to seek alternatives to the generators, writing that the lack of competition in RMR contracts could mean higher prices for customers. ” (4)

References:

Zip Code 00000

Quote

Posted on November 2, 2018 by duanetilden

via The 50 Year Underground Coal Mine Fire

“In this part of Pennsylvania, a mine town gone bust is hardly news. But there is none whose demise has been so spectacular and observable. Centralia has been on fire, literally, for the past four decades.

The Centralia mine fire began in 1962 when a pile of burning trash ignited an exposed seam of coal. The fire soon seeped down into the lattice of old mine tunnels beneath town. When it was founded in 1866, Centralia’s ocean of underground coal, aptly named the Mammoth Vein, meant limitless wealth. But once the fire began, it came to mean endless destruction.

This abandoned section of Route 61 runs smack through one of Centralia’s so-called hot zones. In these areas the underground fire directly affects the surface landscape. The traffic that used to flow over this section of road has been permanently detoured several hundred yards to the east. Thanks to a recent snowfall, the tracks of other visitors are obvious — that is until the snow cover abruptly ends. It’s as if someone has drawn a line across the road. On one side there’s snow. On the opposite side there’s bone-dry asphalt. The road’s surface is not exactly warm. But the asphalt is definitely not as cold as it should be on a chilly day in the Appalachian Mountains. In the roadside woods, all the trees are dead, baked to death by the subterranean smolder. Even their bark has peeled away.

Further in, a crack 50 feet in length has ripped through the highway. Puffs of white gas steadily float out. I step to the edge of the crack. It’s about two feet wide and two feet deep, filled with garbage and chunks of broken pavement. Then the wind shifts slightly, and a gas cloud bends in my direction. I cover my nose and mouth with the collar of my jacket. Standing on the roof of this inferno has suddenly lost its appeal. I turn and walk back to my car.”

http://wapo.st/1eMhdGq

Related image

Heating Efficiency and Proper Sizing

Posted on October 27, 2018 by duanetilden

An excellent piece on sizing heating equipment for the home. Check out this blog, many years of experience shared… a tribute to a life’s work.

York Central Tech Talk

This weekend I got an email from my nephew who lives in New Hampshire. He recently moved into a home and they finished the basement and attic. Now, he had a contractor come in and he was telling him that he needed an additional 50,000 BTU larger boiler to heat the house. Since he knew I retired from heating and air conditioning, he wanted my opinion. My first question to him was, ” How did the contractor determine that he needed an additional 50,000 BTU’s to heat the new areas?” Then I asked, ” Did he do a load calculation? Was he basing it on how many feet of new baseboard radiators he was installing? What water temperature is the existing boiler operating at?” The existing boiler may be large enough to handle additional baseboard radiators. I told him that basements usually are not included in load calculations so that…

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Supercritical Carbon Dioxide – A Plan to Eliminate 25% of Existing Power Plants

Posted on October 27, 2018 by duanetilden

Duane M. Tilden, P.Eng                           October 26, 2018

Is it possible that we can drastically reduce the existing fleet of power plants by 25% or more? Yes, this does seem to be a rather extravagant claim considering how many power providers or utilities such an increase in energy efficiency in output will impact. Examining the United States as our example:

As of December 31, 2017, there were about 8,652 power plants in the United States that have operational generators with a combined nameplate electricity generation capacity of at least 1 megawatt (MW). A power plant may have one or more generators, and some generators may use more than one type of fuel. (1)

So, reducing the existing fleet by 25% would enable us to decommission approximately 2,163 of these plants. This plan would require the examination of the total supply chain to optimize these reductions whilst maintaining the integrity of the existing distribution network. A significant project having enormous impact on the economy and meeting carbon reduction strategies on a global scale.

Supercritical Carbon Dioxide (SCCD) Turbines

In previous posts I have discussed the technology of SCCD turbines for power production and how this system can be used for a wide variety of power production and energy extraction methods. A recent article published by Euan Mearns with commentary delves even deeper into this technology to discuss the global impacts of increased power production efficiency on reducing carbon emissions.

GHG’s, carbon, NOx, pollution, waste heat, entropy effects, and consumption of resources are all commensurately reduced when we systematically increase power production energy efficiency at the plant level. An improvement of energy efficiency at the system level has a profound impact in output capacity or input reduction. For example, if we can increase the efficiency by 10% from 30% to 40% in conversion, the output of the plant is improved by 4/3 or 33% or inversely, the input requirement will reduce by 3/4 or 25%.

Power Plant Energy Efficiency

To measure the energy efficiency of a thermo-electric power plant we use the heat rate. Depending on the quality of the fuel and the systems installed we convert heat energy into electrical energy using steam generators or boilers. We convert water into steam to drive turbines which are coupled to generators which convert mechanical motion into electricity.

Examination of data provided will be simplified using statistical averages. In 2017 the average heat rates and conversion efficiencies for thermal-electric power plants in the US (2) are given as follows:

Coal: 10465 Btu/Kw – 32.6%
Petroleum: 10834 Btu/Kw – 31.5%
Natural Gas: 7812 Btu/Kw – 43.7%
Nuclear: 10459 Btu/Kw – 32.6%

Examination of the US EIA data for 2017 shows us that currently Natural gas is 11.1% more efficient than Coal in producing electricity while consuming 25.4% less fuel for the same energy output.

So we already have proof that at a plant level, energy efficiency gains in consumption are leveraged by smaller improvements in the thermodynamic cycle. For natural gas power plants the current state of the art is to use a combined cycle combustion process which is not employed in other thermo-electric power plants.

HOW A COMBINED-CYCLE POWER PLANT PRODUCES ELECTRICITY (3)

This is how a combined-cycle plant works to produce electricity and captures waste heat from the gas turbine to increase efficiency and electrical output.

Gas turbine burns fuel.
- The gas turbine compresses air and mixes it with fuel that is heated to a very high temperature. The hot air-fuel mixture moves through the gas turbine blades, making them spin.
- The fast-spinning turbine drives a generator that converts a portion of the spinning energy into electricity.
Heat recovery system captures exhaust.
- A Heat Recovery Steam Generator (HRSG) captures exhaust heat from the gas turbine that would otherwise escape through the exhaust stack.
- The HRSG creates steam from the gas turbine exhaust heat and delivers it to the steam turbine.
Steam turbine delivers additional electricity.
- The steam turbine sends its energy to the generator drive shaft, where it is converted into additional electricity.

Image result for combined cycle power plant

Figure 1. Schematic of Combined Cycle Gas/Steam Turbine Power Plant with Heat Recovery (4)

Comparing Combined Cycle Gas Turbines with SCCD Turbines

The study of thermodynamic cycles is generally a domain studied and designed by engineers and physicists who employ advanced math and physics skills. The turbine is based on the Brayton cycle, while steam turbines operate on the Rankine cycle. The Rankine cycle uses a working fluid such as water, which undergoes a phase change from water to steam. The Brayton cycle is based on a single phase working fluid, in this case combusted natural gas.

Both SCCD turbines and Gas Turbines operate on the Brayton cycle, however, they use different working fluids and requirements based on operating conditions. The gas fired turbine takes in air which is compressed by the inlet section of the turbine and natural gas is combined with the compressed air and ignited. The hot expanding gasses turn the turbine converting heat to mechanical energy. A jet engine operates on the Brayton cycle.

For a combined cycle gas turbine some of the waste heat is recovered by a heat exchange system in the flue stack, converted to steam to drive a second turbine to produce more electricity and increase the overall energy efficiency of the system.

In the case of an SCCD the turbines working fluid is maintained in a closed loop, continually being heated through a heat exchanger from a source and run in piping through the turbine and a compressor. Secondary heat exchangers for recuperation and cooling may be employed. These are all emerging technologies undergoing serious R&D by the US DOE in partnership with industry and others.

Closed Loop SCO2 Recompression Brayton Cycle Flow Diagram

Figure 2. Closed Loop SCO2 Recompression Brayton Cycle Flow Diagram (NETL)

Technology Development for Supercritical Carbon Dioxide (SCO2) Based Power Cycles

The Advanced Turbines Program at NETL will conduct R&D for directly and indirectly heated supercritical carbon dioxide (CO₂) based power cycles for fossil fuel applications. The focus will be on components for indirectly heated fossil fuel power cycles with turbine inlet temperature in the range of 1300 – 1400 ºF (700 – 760 ºC) and oxy-fuel combustion for directly heated supercritical CO₂ based power cycles.

The supercritical carbon dioxide power cycle operates in a manner similar to other turbine cycles, but it uses CO₂ as the working fluid in the turbomachinery. The cycle is operated above the critical point of CO₂so that it does not change phases (from liquid to gas), but rather undergoes drastic density changes over small ranges of temperature and pressure. This allows a large amount of energy to be extracted at high temperature from equipment that is relatively small in size. SCO2 turbines will have a nominal gas path diameter an order of magnitude smaller than utility scale combustion turbines or steam turbines.

The cycle envisioned for the first fossil-based indirectly heated application is a non-condensing closed-loop Brayton cycle with heat addition and rejection on either side of the expander, like that in Figure 1. In this cycle, the CO₂ is heated indirectly from a heat source through a heat exchanger, not unlike the way steam would be heated in a conventional boiler. Energy is extracted from the CO₂ as it is expanded in the turbine. Remaining heat is extracted in one or more highly efficient heat recuperators to preheat the CO₂ going back to the main heat source. These recuperators help increase the overall efficiency of the cycle by limiting heat rejection from the cycle. (4)

Commentary and Conclusion

We already are on the way to developing new systems that offer significant improvements to existing. Advancements in materials and technology, as well as other drivers including climate concerns and democratizing the energy supply. Every percentage of increase in performance reduces the consumption of fossil fuels, depletion of natural resources, generated waste products and potential impacts on climate.

SCCD systems offer a retrofit solution into existing power plants where these systems can be installed to replace existing steam turbines to reach energy efficiency levels of Combined Cycle Gas Turbines. This is a remarkable development in technology which can be enabled globally, in a very short time frame.

References:

Oldest Nuclear Power Plant in US to be Retired – The 60 Year Decommissioning Process

Posted on September 14, 2018 by duanetilden

When a nuclear plant retires, it stops producing electricity and enters into the decommissioning phase. Decommissioning involves removing and safely storing spent nuclear fuel, decontaminating the plant to reduce residual radioactivity, dismantling plant structures, removing contaminated materials to disposal facilities, and then releasing the property for other uses once the NRC has determined the site is safe.

According to Exelon, Oyster Creek will undergo a six-step decommissioning process. The typical decommissioning period for a nuclear power plant is about 60 years, so parts of the Oyster Creek plant structure could remain in place until 2075. (1.)

retired nuclear power plants and nuclear power plants that have announced retirement

Since 2013, six commercial nuclear reactors in the United States have shut down, and an additional eight reactors have announced plans to retire by 2025. The retirement process for nuclear power plants involves disposing of nuclear waste and decontaminating equipment and facilities to reduce residual radioactivity, making it much more expensive and time consuming than retiring other power plants. As of 2017, a total of 10 commercial nuclear reactors in the United States have been successfully decommissioned, and another 20 U.S. nuclear reactors are currently in different stages of the decommissioning process.

To fully decommission a power plant, the facility must be deconstructed and the site returned to greenfield status (meaning the site is safe for reuse for purposes such as housing, farming, or industrial use). Nuclear reactor operators must safely dispose of any onsite nuclear waste and remove or contain any radioactive material, including nuclear fuel as well as irradiated equipment and buildings. (2.)

References:

Energy Efficiency of Power Production: How Supercritical Carbon Dioxide Turbines Operate

Posted on September 1, 2018 by duanetilden

Duane M. Tilden, P.Eng.                                    Sept 1, 2018

Foreword:

This is another article in an ongoing series of reports on the technological development of supercritical carbon dioxide in the power production and energy efficiency sectors of industry, power plants and utilities.

dodge-sco23 supercritical CO2 turbine

Figure 1. Size comparison of Supercritical Power Turbine to Conventional Steam Turbine (1)

Abstract:

The ever increasing search for improving energy and power production efficiency is a natural quest as developments in technology seek to be utilized to improve operations and supply cost effectively. The technologies behind the utilization of supercritical carbon dioxide and other such fluids have long been established. We are furthering our exploration into this sector of power production developing new technologies along the way to a smarter economy and modernization of infrastructure.

The Principle of Operation

Supercritical fluids can play an important role in developing better electricity generators because of their liquid- and gas-like properties. A supercritical fluid is an optimal working fluid because it has a temperature and pressure above its critical point, meaning that it doesn’t have a definite liquid or gas phase. Consequently, the slightest changes in pressure or temperature cause huge changes in the material’s density.

With any supercritical fluid, the ease of compressibility goes up, explains Stapp, so it becomes something more like water. Because supercritical CO2 also compresses more easily than steam, the amount of work done during the compression phase—normally accounting for 25 percent of the work performed inside the system—is dramatically reduced; the energy saved there greatly contributes to the turbine’s overall efficiency.

“We expand it like a gas, and pressurize it like a liquid,” says James Pasch, principle investigator of the Supercritical Carbon Dioxide Brayton Cycle Research and Development Program. “You can do this with any fluid, but supercritical carbon dioxide matches really well with ambient temperatures.”

Carbon dioxide is optimal for this application because it doesn’t go through a phase change at any point during the cycle. Its critical temperature, 88 degrees Fahrenheit, is very close to ambient temperature, which means the heat emitted by the turbine is the same temperature as the surrounding environment. Supercritical carbon dioxide is also very dense; at its critical point, the fluid is about half the density of water. So, in addition to being easier to compress, less work is required to cycle it back to the heat source for re-expansion.

The Brayton Cycle also offers direct environmental benefits. For one, it’s carbon neutral. The system takes carbon dioxide out of the air and puts it in the recompression cycle loop. Just as important is the fact that the system limits water usage by minimizing discharge, evaporation, and withdraw.

“That’s a big deal for the southwest,” says Gary Rochau, manager of Sandia’s Advanced Nuclear Concepts Department. Sandia’s generator can work in places where water is in limited supply. This puts it on par with the Palo Verde Nuclear Power Generating Station, a nuclear power plant in Arizona that uses recycled waste water as cooling water, saving groundwater and municipal water supplies for other uses. (2)

Figure 1. Illustration of a Supercritical CO2 Turbine [Peregrine Turbine Technologies] (2)

Advances in Materials and Technology

GE Reports first wrote about Hofer last year when he 3D printed a plastic prototype of the turbine. His team, partnered with Southwest Research Institute and Gas Technology Institute, has since submitted the design to the U.S. Department of Energy and won an $80 million award to build the 10 MW turbine. The turbine features a rotor that is 4.5 feet long, 7 inches in diameter, and only weighs 150 pounds. The engineers are now completing a scaled-down, 1 MW version of the machine and will test it in July at the Southwest Research Institute.

The idea of using CO2 to power a steam turbine has been around for a while. It first appeared in the late 1960s, and an MIT doctoral student resurrected it in 2004. “The industry has been really interested in the potential benefits of using CO2 in place of steam in advanced supercritical power plants,” Hofer says.

By “supercritical” Hofer means efficient power stations using CO2 squeezed and heated so much that it becomes a supercritical fluid, which behaves like a gas and a liquid at the same time. The world’s most efficient thermal power plant, RDK 8 in Germany, uses an “ultrasupercritical” steam turbine operating at 600 degrees Celsius and pressure of 4,000 pounds per square inch, more than what’s exerted when a bullet strikes a solid object.

Hofer says that the steam power plant technology “has been on a continuous march” to increase efficiency and steam temperature, but once it tops 700 degrees Celsius, “the CO2 cycle becomes more efficient than the steam cycle.” Hofer’s turbine and casing are made from a nickel-based superalloy because it can handle temperatures as high as 715 degrees Celsius and pressures approaching 3,600 pounds per square inch. “You need a high-strength material for a design like this,” he says.

Figure 2. GE Global Research engineer Doug Hofer is building a compact and highly efficient turbine that fits on a conference table but can generate 10 megawatts (MW), enough to power 10,000 U.S. homes. The turbine, made from a nickel-based superalloy that can handle temperatures up to 715 degrees Celsius and pressures approaching 3,600 pounds per square inch, replaces steam with ultrahot and superpressurized carbon dioxide, allowing for a smaller design.

The hellish heat and pressure turn CO2 into a hot, dense liquid, allowing Hofer to shrink the turbine’s size and potentially increase its efficiency a few percentage points above where state-of-the-art steam systems operate today. “The pressure and fluid density at the exit of our turbine is two orders of magnitude higher than in a steam turbine,” Hofer says. “Therefore, to push the same mass through, you can have a much smaller turbine because the flow at the exit end is much denser.”

Hofer’s design uses a small amount of CO2 in a closed loop. “It’s important to remember that this is not a CO2 capture or sequestration technology,” he says. Hofer says that the technology, which is being developed as part of GE’s Ecomagination program, could one day start replacing steam turbines. “It’s on the multigenerational roadmap for steam-powered systems,” he says.

By virtue of becoming more efficient, the technology could help power-plant operators reduce greenhouse gas emissions. “The efficiency of converting coal into electricity matters: more efficient power plants use less fuel and emit less climate-damaging carbon dioxide,” wrote the authors of the International Energy Agency report on measuring coal plant performance. (3)

Previous Blog Posts on Supercritical Carbon Dioxide:

References:

Study Finds BC Pension Fund Manager is Funding Climate Agreement Breach

Posted on July 6, 2018 by duanetilden

A study* released by the Corporate Mapping Project (CMP), a watchdog organization indicates that public pensions could be overly invested in the fossil fuel industry. This is a concern as international agreements signed by Canada are directed to reducing emissions, while public money is invested in an agenda that requires growth and production in a sector which is in decline.

Image result for kinder morgan pipeline

Figure 1. Map of proposed expansion current pipeline and tanker route – Kinder Morgan / Trans Mountain Pipeline. (1)

Figure 2. Map of impact of refinery facilities and proximity to conservation areas, a University, a Salmon spawning inlet, residential housing and major transport routes. (1)

The area that will be impacted by the growth of the facility are diverse and vulnerable. This is not a brownfield development, and in fact is on the side of a mountain and part of a larger watershed. Serious consideration should be given to relocating the facility or decommissioning.

There are alternate locations better suited for this type of high hazard industrial facility, away from sensitive areas and remote from populations and high traffic harbours. Why are these alternatives not being discussed?

Here’s a snippet taken from the introduction of the report and their findings. How can we stop carbon emissions when local investing strategies are in the opposite direction? Are public pension funds safely invested and competently managed? Likely not.

CMP researchers Zoë Yunker, Jessica Dempsey and James Rowe chose to look into BCI’s investment practices because it controls one of the province’s largest pools of wealth ($135.5 billion) — the pensions of over half-a-million British Columbians. Which means BCI’s decisions have a significant impact on capital markets and on our broader society.

Their research asked, “Is BCI is investing funds in ways that effectively respond to the climate change crisis?”

Unfortunately, the answer is “No.” BCI has invested billions of dollars in companies with large oil, gas and coal reserves — companies whose financial worth depends on overshooting their carbon budget — and is even increasing many investments in these companies.

As another recent CMP study clearly shows what’s at stake. Canada’s Energy Outlook, authored by veteran earth scientist David Hughes, reveals that the projected expansion of oil and gas production will make it all but impossible for Canada to meet our emissions-reduction targets. The study also shows that returns to the public from oil and gas production have gone down significantly. (2)

*This study is part of the Corporate Mapping Project (CMP), a research and public engagement initiative investigating the power of the fossil fuel industry. The CMP is jointly led by the University of Victoria, Canadian Centre for Policy Alternatives and the Parkland Institute. This research was supported by the Social Science and Humanities Research Council of Canada (SSHRC).

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Pilot Programs to Provide Research of Renewable Energy Solutions for Improved Air Quality

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Electricity Prosumers & Renewable Energy

What is a Peaker Plant?

Public Utilities Commission of the State of California (CPUC)

Table 1 – Summary of Pacific Gas and Electric’s (PG&E’s) energy storage power purchase agreements (PPAs)

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Supercritical Carbon Dioxide (SCCD) Turbines

Power Plant Energy Efficiency

HOW A COMBINED-CYCLE POWER PLANT PRODUCES ELECTRICITY (3)

Figure 1. Schematic of Combined Cycle Gas/Steam Turbine Power Plant with Heat Recovery (4)

Comparing Combined Cycle Gas Turbines with SCCD Turbines

Figure 2. Closed Loop SCO2 Recompression Brayton Cycle Flow Diagram (NETL)

Commentary and Conclusion

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Foreword:

Figure 1. Size comparison of Supercritical Power Turbine to Conventional Steam Turbine (1)

Abstract:

The Principle of Operation

Figure 1. Illustration of a Supercritical CO2 Turbine [Peregrine Turbine Technologies] (2)

Advances in Materials and Technology

Previous Blog Posts on Supercritical Carbon Dioxide:

References:

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Figure 1. Map of proposed expansion current pipeline and tanker route – Kinder Morgan / Trans Mountain Pipeline. (1)

Figure 2. Map of impact of refinery facilities and proximity to conservation areas, a University, a Salmon spawning inlet, residential housing and major transport routes. (1)

References:

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Table 1 – Summary of Pacific Gas and Electric’s (PG&E’s) energy storage power purchase
agreements (PPAs)