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Sunday, September 23, 2018

Small-scale gasifiers for solar hybrid gensets

So-called "intermittent" renewable energy can be used in two or more ways to make synthetic methane from any material (straw, waste plastic, coal, etc) containing carbon.

One way is to use renewable energy when supply exceeds demand to power a plasma gasifier.

Another way is to use renewable energy to produce hydrogen by electrolysis of water - and combine that hydrogen with carbon from one or more sources.

Each kilogram of wheat straw with about 7% moisture content is made of 48% cellulose by weight (of which carbon is 44%) and 25% is lignin by weight (of which carbon is 65%) ... (((1000 x (48 / 100) x (44 / 100)) + (1000 x (25 / 100) x (65 / 100))) = 374.

That is 374 grams of carbon in each kilogram - sufficient to manufacture about 500 grams of synthetic methane which has a heating value of 50-55.5 megajoules per kilogram (MJ/kg).

The carbon in 2 tonnes of wheat straw would be sufficient to manufacture 1 tonne of methane with a heating value of 50-55.5 gigajoules (GJ). Natural gas has a wholesale price of $10-$12 per gigajoule in Australia. 

Over 500 million tonnes of wheat straw are produced annually world, the majority of which are burnt in the field. See "Physical Properties of Wheat Straw Varieties", American Journal of Engineering and Applied Sciences, 2012, 5 (2), 98-106.

Small-scale biomass gasifiers are one more renewable energy generation option for Australian farms that need affordable, reliable 24 hour a day electricity supplies.

For example, a seller on Alibaba in China has a biomass gasifier offered for $500 - $1,000 per unit.
Environment Friendly Biomass Gasifier
Environment-Friendly Biomass Gasifier

Another offers gas-fueled electric generators for $550 - $1,250 per unit.

Teenwin biogas electric generator

Teenwin biogas electric generator


Thursday, September 20, 2018

Fossil fuel industry opposes innovation

The World Coal Association ignores innovations to reduce electricity prices, raise efficiency and reduce emissions.

Technology now available allows reliable electricity to be generated with just one-third of the coal burned in "High Efficiency, Low Emission" (HELE) coal-fired power plants.

The World Coal Association had called for investment in development of technology for cleaner coal in 2015. Now that technology is available, the World Coal Association has slammed a moratorium on its use.


The natural gas industry also opposes innovations to reduce energy bills and avoid the need for ever more costly drilling and fracking.
Beyond HELE - thermal power generation technology
Beyond HELE - thermal power generation technology
Carbon from many different substances can be combined with hydrogen to produce methane.
When methane is used to fuel an Ultrahigh Temperature Gas Turbine Combined Cycle power station, carbon dioxide emissions are 310 grams per kilowatt-hour.

The amount of carbon needed for each kilowatt-hour from any power station can be calculated if the carbon dioxide intensity is known. Each 44 grams of carbon dioxide contain 12 grams of carbon. The other 32 grams are oxygen.

The Ultrahigh Temperature Gas Turbine Combined Cycle power station needs methane made with 310 x (12 / 44) grams of carbon for each kilowatt-hour of electricity. That is 85 grams of carbon for each kilowatt-hour.

Some other power station technologies need a lot more carbon for each kilowatt-hour of electricity generated.

When coal is used to fuel a high-efficiency low-emission "HELE" ultra-supercritical coal-fired power station, carbon dioxide emissions are 900 grams per kilowatt-hour. The amount of carbon in the coal needed for each kilowatt-hour of electricity generated is 900 x (12 / 44) grams. That is 245 grams of carbon for each kilowatt-hour.

Some other common materials contain carbon that can be used to produce methane.

Each 28 grams of waste polyethylene plastic (C2H4)n contain 24 grams of carbon and 4 grams of hydrogen.

Each kilogram of wheat straw with about 7% moisture content is made of 48% cellulose by weight (of which carbon is 44%) and 25% is lignin by weight (of which carbon is 65%) ... (((1000 x (48 / 100) x (44 / 100)) + (1000 x (25 / 100) x (65 / 100))). That is 374 grams of carbon in each kilogram.

Choosing whether to burn 245 grams of carbon in coal or just 85 grams of carbon in methane to produce each kilowatt-hour of electricity seems to have only one obvious answer.

The World Coal Association simply refuses to answer this question.

Representatives of the gas industry also refuse to answer this question.

So-called "intermittent" renewable energy can be used in two or more ways to make synthetic methane from any material (straw, waste plastic, coal, etc) containing carbon.

One way is to use renewable energy when supply exceeds demand to power a plasma gasifier.

Another way is to use renewable energy to produce hydrogen by electrolysis of water - and combine that hydrogen with carbon from one or more sources.

As well as industry refusing to answer simple questions about innovation, the Australian Government tries to sell gas exploration rights to the gas industry even though this old method of obtaining natural gas - which is mostly methane - is no longer needed.



The Western Australian Government is also reviewing this obsolete method of obtaining methane in considering whether to sell "fracking" rights over large swathes of Western Australia.


Small-scale biomass gasifiers are one more renewable energy generation option for Australian farms that need affordable, reliable 24 hour a day electricity supplies. For example, a seller on Alibaba in China has a biomass gasifier offered for $500 - $1,000 per unit.

Monday, September 3, 2018

Saving $1 million allocated to reinvent the wheel

The Australian Government announced it was allocating another $1 million for research into ways to make something useful from brown coal reserves in Victoria.

Coal has a future in Victoria: Matt Canavan

Senator the Hon Matt Canavan
Minister for Resources and Northern Australia

Investing in brown coal research and development

31 August 2018

The Coalition Government continues to focus on harnessing the economic benefits that can come from the nation’s vast brown coal resources by making $1 million in funding available to Brown Coal Innovation Australia (BCIA).

BCIA will use the funding to focus on advancing Australia’s economic prosperity by researching low emissions technologies for both electricity generation and products derived from brown coal.

Minister for Resources and Northern Australia Matt Canavan said BCIA was at the forefront of research into low-emissions, low-cost, coal technologies and novel, high-value products derived from brown coal. Since 2009, the Government has provided more than $7 million to BCIA through the Commonwealth’s funding of the Australian National Low Emissions Coal Research and Development initiative.
...
This funding comes on top of the $620 million already being administered by the Australian Government to accelerate the deployment of low emission fossil fuel technologies.

Australian Governments have been "investing" in "harnessing the economic benefits that can come from the nation's vast brown coal resources" long before 2009.

For over thirty years no progress has been made.

Victoria's brown coal in the Latrobe Valley still has a moisture content of more than 50%:
Moisture content of raw coal Wt(%)

Research is still fixated with the presumption that before any value can be made of this vast resource that "coal drying is essential":
Coal drying is essential...

In 2012 the US granted a patent for converting 'wet carbonaceous material' (such as "brown coal") to methane:

Method and apparatus for steam hydro-gasification with increased conversion times

 Patent: US8143319B2

Abstract







A method and apparatus for converting carbonaceous material to a stream of carbon rich gas, comprising heating a slurry feed containing the carbonaceous material in a hydrogasification process using hydrogen and steam, at a temperature and pressure sufficient to generate a methane and carbon monoxide rich stream in which the conversion time in the process is between 5 and 45 seconds.

It could be applied in a plant with a design such as the following, or one that uses hydrogen produced by electrolysis from renewable energy in place of the steam reforming unit, or one that produces any combination of hydrogen and/or synthetic natural gas:
Converting brown coal - without drying - to methane (and/or hydrogen)
Converting brown coal - without drying - to methane (and/or hydrogen)

Saturday, September 1, 2018

Energy transition


Final Report Summary - HELMETH (Integrated High-Temperature Electrolysis and Methanation for Effective Power to Gas Conversion), 25 July 2018

A highly efficient Power-to-Gas process has been realized by the European research project HELMETH. It has the potential to be the most efficient storage solution for renewable energy utilizing the existing natural gas grid without capacity limitations and to be a source for “green” Substitute Natural Gas (SNG) to avoid fossil carbon dioxide emissions.

The objective of the HELMETH project is the proof of concept of a highly efficient Power-to-Gas process by realizing the first prototype that combines a pressurized high temperature steam electrolysis with a CO2-methanation module.

The demonstration plant was assembled at the sunfire facility in Dresden. The methanation unit, developed and built by KIT in Karlsruhe, was set up inside a container and transported to sunfire to perform combined operational tests.

The steam outlet from the methanation cooling circuit is fed to the electrolyser and the hydrogen output from the electrolyser is fed to the methanation unit. The steam is converted to hydrogen in the electrolyser.
Coupled Power-to-Gas plant (left container: methanation; right container: electrolyser)
Coupled Power-to-Gas plant (left container: methanation; right container: electrolyser)

The efficiency is significantly increased by using the heat of reaction from the exothermic methanation reaction to produce steam for the high temperature electrolysis.

Since the produced SNG is fully compatible with the existing natural gas grid and storage infrastructure, practically no capacity limitations apply to store energy from fluctuating renewable energy sources.


Steam Hydrogasification

By replacing the CO2 methanation module in the Power-to-Gas process realized by the HELMETH research project with a lignite methanation module, Australia can manufacture 50% renewable methane. That is, synthetic natural gas containing 50% renewable energy (as hydrogen) and 50% fossil fuel (from low-cost wet lignite).

This can fuel dispatchable generators in conjunction with renewable intermittent generators to provide 100% reliable electricity generation: the intermittent renewable generators supplying 50% of electricity and dispatchable generators powered by 50% renewable methane providing the other 50%.

The lignite methanation module has been developed in the U.S.

Steam Hydrogasification in a hydrogen environment

Making synthetic natural gas from hydrogen and a variety of waste streams and coal has been researched for some time.

For example:

UC Riverside researchers receive two grants to advance steam hydrogasification reaction for waste-to-fuels, 15 September 2011

Researchers at the University of California, Riverside’s Center for Environmental Research and Technology (CERT) at the Bourns College of Engineering have received two grants to further explore a steam hydrogasification process they developed...

A $650,000 grant from the California Energy Commission (CEC) extends its commitment to $2 million to CERT for the patented steam hydrogasification reaction (SHR), which can turn any carbonaceous material into transportation fuels or natural gas. The CEC grant will allow for the completion of a process demonstration unit at CERT that will provide data needed before a proposed pilot plant is built at the city of Riverside’s waste water treatment facility.

Synthetic natural gas made from wet carbonaceous feedstock such as lignite
Synthetic natural gas made from wet carbonaceous feedstock such as lignite

Wednesday, August 22, 2018

A carbon policy thread


Cr Philip Penfold blocks advisor - too much advice
Cr Philip Penfold blocks advisor - too much advice


Maitland City Council

ORDINARY MEETING AGENDA 10 JULY 2012


17.2 REDUCTION OF METHANE GAS AT MT VINCENT WASTE SITE

NOTICE OF MOTION SUBMITTED BY CLR RAY FAIRWEATHER
File No: P44197
Attachments: Nil
Responsible Officer: David Evans - General Manager

Bernie Mortomore - Executive Manager Planning, Environment and Lifestyle


Clr Ray Fairweather has indicated his intention to move the following Notice of Motion at the next Council Meeting being held on Tuesday 10 July 2012:

THAT

  1. The General Manager provide a report to council on all possible options available to council for the reduction of methane gas at the Mt Vincent Waste Site;
  2. What are those options and if council can implement any of those options to reduce the huge carbon tax cost impost on our ratepayers ($2.2 million dollars in 2012/2013 budget);
  3. The report expand on the possible sale of methane gas to generate power for electricity grid and if such a venture would benefit council financially;
  4. The opportunity if one exists for the calling of tenders for the extraction of methane gas for commercial uses; and
  5. What is involved in the 'burning option' of reducing methane gas and carbon tax payments.

NOTES BY CLR RAY FAIRWEATHER

The $2.2 million cost of the carbon tax is a huge impost on ratepayers (though it is yet to be properly costed) that needs urgent investigation on all options available to reduce those costs and if economically beneficial should be given urgent priority.

RESPONSE BY EXECUTIVE MANAGER PLANNING, ENVIRONMENT AND LIFESTYLE

A reduction of methane gas emissions from any landfill can be made by reducing the quantity of organic matter buried at the site as methane gas generation is a product of decomposition of organic materials that are subject to anaerobic conditions. These conditions are found in a landfill.
In the landfill context if methane is being generated then a landfill gas extraction system can be installed to capture the gas, pass it through a flare to convert it to carbon dioxide and hence reduce the carbon footprint of the site. If there is sufficient and constant gas production the gas can be used to power a generator which will create electricity that can be either exported to the grid or used sacrificially on site.
Alternatively organic waste can be processed in aerobic conditions so that it does not convert the waste to methane. It will generate other gases but because methane is said to be more than 21 times more problematic than carbon dioxide the greenhouse gas outputs are reduced. Aerobic waste processing of total organic waste streams utilises some form of technology to control and manage the processes. Council will recall that a waste technology solution was explored through the HIR partnership prior to the project being abandoned.
Council has a contract in place to install a gas extraction system at the Mt Vincent Rd Waste Facility. This contract with LMS Energy was entered into on the basis that infrastructure costs and ongoing management of the system was borne by LMS Energy in return for the carbon credits generated minus a royalty payment to Council. The contract remains in place and commercial in confidence. The system is to be installed within the next 3 months and gas capture should commence towards the end of the year. At this stage the reduction effect on Council's carbon liability remains unknown. It will however reduce the gas emissions from the site.
Whether there will be sufficient gas generation from the site to generate power will be known once the system is commissioned. Given the system is being retrofitted the efficiencies of the gas capture are difficult to model.
A further detailed report can be provided to Council as required.

Page (270)

Friday, August 3, 2018

Transition from thermal coal exports

Australia exports 200 million tonnes of thermal coal each year.

Japan is the largest importer, importing 80 million tonnes per year. In planning to eliminate its reliance on fossil fuel imports, Japan is looking to CO2-free hydrogen to replace its imports of coal and LNG, used primarily for electricity generation, and oil, used primarily for road transport.

One step in the 20-year transition timetable is to invest in large solar PV installations in Saudi Arabia and construction of a 'hydrogen pipeline" to deliver hydrogen produced by electrolysis to Japan.

Another step is the construction of combined-cycle gas turbine power stations that have integrated gasification plants to convert imported coal to gas to fuel them. These plants can later run on hydrogen when sufficient supply is available.

Australia and Japan could co-ordinate projects in this transition of Japan's energy systems.
One of the benefits of co-ordination is that Australia's industry and workforce has a planned transition in how it prepares energy for export, adapting employment skills and infrastructure as the plan progresses.

Another of the benefits is that part of the infrastructure development is undertaken by Australia, sharing the effort so that Japan can focus its investments on the most efficient technology to use the energy it imports.

The long-term transition would see Australia's coal export terminals replaced with hydrogen export facilities and the fleet of bulk ore carriers replaced with specialised hydrogen shipping vessels. The coal mining workforce would gradually be replaced with a workforce that constructs and operates hydrogen production plants.

During the early years of the transition it may be beneficial to convert hydrogen and coal to methane and make use of existing natural gas pipelines, LNG export terminals and LNG tankers to transport the hydrogen to Japan's existing LNG import facilities.

One benefit for Japan would be to avoid the time and cost of building integrated coal-gasifiers with new combined-cycle gas turbine power stations and fuel cell generators. The gasification can be carried out in Australia before exporting the coal with hydrogen as LNG.

Large-scale solar farms are currently built with inverters that are a significant part of the cost.
The inverters change direct-current electricity produced by the solar panels into alternating-current electricity for distribution on the electricity grid.

Inverters aren't needed when the goal is to produce hydrogen by electrolysis with the electricity generated.

A second income-stream from renewable electricity production will assist farmers struggling with drought near coal-mining regions. Solar PV installations could be designed to be "stock-friendly" for Australian livestock producers, and not copies of European installations where fields are covered with closely-spaced solar panels just above ground level.

Cattle and solar PV systems
Cattle and solar PV systems


The renewable energy generated would be fed to electrolysis units creating hydrogen.
The hydrogen is to be transferred into methanation units that have pulverised coal handling equipment where the hydrogen and coal is transformed into methane, ready for transfer to LNG export terminals.

Thyssenkrupp coal handling system
Thyssenkrupp coal handling system
Gasification technologies
Gasification technologies


See Thyssenkrupp Australia - "Power-to-gas: Storing wind and sun [energy] in natural gas"

Power-to-gas: storing wind and sun renewable energy in natural gas

The 2015 Japanese government report "Overview of Assessment by Power Generation Cost Verification Working Group", Institute of Energy Economics, Japan (IEEJ) explained that renewable energy costs are higher in Japan than in other countries, and showed Australia has a comparative advantage in large-scale wind and solar installations.
"Unit construction costs for solar PV and wind power generation systems in Japan are higher than in other countries. ...Apparent factors behind the cost gap include higher personnel costs, complex topography and FIT scheme introduction backgrounds in Japan." (at pages 8-9)

International comparison of unit construction costs for solar PV generation systems

Related posts:

Australian energy exports

Keeping waste plastic out of landfill

 


Thursday, July 26, 2018

Consumerism in an ecosystem

Rain forests are centres of great activity that depend on quite small reserves of nutrients.

Plants continuously absorbing sunlight transform water and carbon dioxide into polymers, mainly cellulose, and release oxygen.

On the rain forest floor, a myriad of animals and insect munch their way through fallen leaves and branches, breaking the polymers into water and carbon dioxide. Their waste releases the very small nutrient reserves back into the thin soil layer where they are once again available to the plant community.

Caterpillar eating a leaf
Caterpillar eating a leaf

A productive rain forest ecosystem harboring a great variety of living organisms is a stark contrast to a desert landscape in which far fewer living things eek out a sparse existence.

Human activity might be viewed as damaging and harmful to the environment, and though this is sometime a reasonable observation, it does not have to be.

Consumers supporting producers and discarding obsolete items provide a level of economic activity to engage people and allow their participation in economic and social life.

That discarded items accumulate and are not reprocessed is a problem that can be solved.

Steel and aluminium can be reprocessed more or less indefinitely. Demand for new steel and aluminium eventually declines in economies as the accumulated volume being recycled meets more and more of demand.


Collecting municipal waste, then sorting, recycling and reprocessing at large central plants has been a fairly universal approach for some time. New technology may allow for some waste material to be reprocessed at or near the point of origin, reducing the cost and complexity of large-scale collection and sorting.


Many waste items that are compounds of only carbon, hydrogen and oxygen can be completely decomposed into a gaseous fuel and may be substituted for natural gas in space heaters and hot water systems.

There is no need for waste materials to accumulate and degrade the environment. Creative solutions can be found. Many creative solution exist but simply aren't well known, hence the word "found" rather than "developed".

Energy in the Future


One creative solution that does not exist but may be developed is a business model and technology for virtually unlimited energy at little or no cost.

One possibility is a process to transform materials from one nuclear structure to another that is commercially viable and that generates energy as a byproduct. The energy byproduct can be distributed for a nominal charge.Transforming nuclear waste into safe, naturally occurring and valuable isotopes is a possible additional benefit.

Wednesday, July 18, 2018

Australian energy exports

Japan intends to establish a "hydrogen pipeline" to replace its existing imports of energy from Australia and elsewhere.
Hydrogen is the key to energy security and the fight against global warming

To speed up the development of a "hydrogen pipeline" for Japan, Australia may be able to adapt existing energy infrastructure for the purpose.

Hydrogen produced by renewable energy creates a number of challenges for special-purpose overland transport and shipping. An interim processing strategy can skip over these challenges and re-use existing infrastructure, saving time and money. A little chemistry explains how this can work...

When hydrogen is combined with carbon dioxide to form methane and water, the energy content in the methane is about the same as the energy that was present in just the hydrogen:

CO2 + 4H2 → CH4 + 2H2O

In the above reaction half of the hydrogen combines with oxygen from the carbon dioxide to form water. The other half of the hydrogen combines with the carbon from the carbon dioxide to form methane. This is known as the "Sabatier reaction". It is used commercially by Audi to create "e-gas" for its Compressed Natural Gas vehicles.



Natural gas is essentially methane with smaller amounts of other gases such as carbon monoxide and ethane. Methane made from hydrogen can be transported through natural gas pipelines and shipped as LNG - liquefied natural gas - from Australia to Japan using existing LNG terminals and LNG tankers.

When methane is combined with water to form hydrogen and carbon dioxide, the energy content in the hydrogen is about the same as the energy that was present in just the methane:

CH4 + 2H2O → 4H2 + CO2

In the above reaction oxygen from the water combines with carbon from the methane to form carbon dioxide. All the hydrogen that was part of both the methane and water is separated. This is known as "Steam Methane Reforming". It is widely used in industry to manufacture hydrogen from natural gas.


The carbon dioxide produced in the above reaction may be liquefied in Japan and returned to Australia on the empty LNG ships that delivered the methane.

This allows the carbon dioxide to be re-used indefinitely in Australia to convert hydrogen to methane for shipping to Japan using existing natural gas pipelines, LNG terminals and tankers.



Thursday, July 12, 2018

Coal burns up research millions

If an industry needs to separate CO2 from different sources the first place to look is existing suppliers and projects that use their technology.

Reinventing the Wheel

Reinventing the wheel
"...the investment in research programs will yield industry
applicable technologies and methodologies in the near term."

Australian governments are spending millions to find out how to separate CO2 from different sources. This process is commonly referred to as "reinventing the wheel".

Why this is so remains an unexplained mystery.

"...our capture research has also made progress on several fronts. CO2CRC won a competitive $1.2 million grant from the NSW government’s Coal Innovation Fund to develop cost-effective carbon capture technology at the Vales Point power station in NSW. The plant has been relocated from the closed Hazelwood power station in Victoria to Vales Point and is currently being modified to use both solvent and membrane technologies. The funding enables us to combine the advantages of both solvent absorption and membrane gas separation methods of capturing CO2, while overcoming the drawbacks of both technologies.

Capture projects were also significantly enhanced in October when we installed our proprietary capture skid at the Otway National Research Facility. The capture plant has been designed for use in offshore natural gas applications, with varying percentages of CO2 content. It has been made to be robust, small and efficient, and will also applicable to different capture requirements in the future.

These developments are the result of our deep commitment to cutting-edge research. In 2016-17 we extended our research base through the opening of several new Australian CCS Research Laboratories Network (CCSNet) facilities.

In September 2016, we opened new capture, CCS modelling, and storage laboratories at The University of Melbourne.

The $7.56 million facility was opened just 12 days after the Minister for Infrastructure and Transport, the Hon Darren Chester MP, opened CCSNet’s $2.3 million analytical laboratory at Federation University.

And, in November, the Minister for Education and Training, Senator the Hon Simon Birmingham, opened our $5.04 million storage research facilities at the Australian National University.

As CCS research gains momentum, we also remain focussed on ensuring government and key decision makers understand the value that CCS has to Australian emissions reduction and national energy security. Our detailed and costed retrofit studies, submissions to government and presentations to senior decision makers were well received by governments.

With the commitment from staff, the collaboration of our research partners and the support of our members and the community, CO2CRC has reached a pivotal point where the investment in research programs will yield industry applicable technologies and methodologies in the near term. Thank you for sharing our vision for CCS.

Tania Constable
Chief Executive Officer
CO2CRC Annual Report 2016/17

Monday, July 9, 2018

Keeping waste plastic out of landfill

The March 30, 2018 report by the Australian Packaging Covenant Organisation describes the fall in the price of waste plastic following Chinese import restrictions for packaging.

There is a relatively small drop in the price for Plastic - HDPE ($575/tonne during 2015-2017 to $500/tonne in 2018), a larger drop in price for Plastic - PET ($575/tonne during 2015-2017 to $375/tonne in 2018) and a substantial fall in price for Plastic - mixed ($325/tonne during 2015-2017 to $75/tonne in 2018).

One avenue that raises the value of waste plastic is to convert it to methane and use it with natural gas.

A number of projects are underway to convert renewable energy to hydrogen and inject that hydrogen into natural gas distribution pipelines.



The wholesale price of energy delivered via that method is about $10/GJ. The retail price is about $35/GJ.

One tonne of methane can be made from about 875 kilograms of plastic waste and 125 kilograms of hydrogen. The energy content of this methane is about 55 gigajoules. At $10/GJ its value is $550.
Steam Hydrogasification in a hydrogen environment

The 125 kilograms of hydrogen made with renewable energy has an energy content of about 15 gigajoules. It contributes about $150 to the $550 value of the tonne of methane.

Put another way, 875 kilograms of plastic waste adds $400 to the value of the hydrogen that is to be injected into natural gas pipelines. This lifts the value of plastic waste to about $455/tonne: more than the $325/tonne price for Plastic - mixed during 2015-2017 and substantially more than the $75/tonne in 2018.

Using hydrogen to produce of methane is the subject of a number of research papers and patents.

The availability of hydrogen that is intended to be injected into natural gas pipelines means that this established body of knowledge is increasingly likely to find commercially viable applications.

Some References

  1. Hydrogasifcation of biomass to produce high yields of methane, U.S. Patent 4,822,935 April 18, 1989
  2. Production of Substitute Natural Gas by Biomass Hydrogasification, M. Mozaffarian, R.W.R. Zwart, Netherlands Energy Research Foundation, ECN, April 7, 2008
  3. The steam hydrogasification reaction, which researchers at the University of California, Riverside’s Center for Environmental Research and Technology engineers began developing in 2005, has been found to be 12% more efficient, with 18% lower capital costs, compared to other mainstream gasification technologies, September 15, 2011.
A different process is helpful if, for instance, you want to upgrade biogas - a mixture of carbon dioxide and methane - to be suitable for injection into a natural gas pipeline. One method is to separate the carbon dioxide from the biogas.

Another method available if you have a quantity of hydrogen that is to be injected into the same natural gas pipeline is to convert the carbon dioxide that it is in the biogas into methane with the hydrogen. This avoids both the overhead and cost of separating the carbon dioxide from the biogas. It also dodges the limitation that the quantity of hydrogen that can be safely mixed with natural gas should be no more than 10 percent: the hydrogen gets converted into methane.

Monday, June 25, 2018

Three-eighths of a coal power station

Some notable milestones to pass on the way to 100% renewable energy are one-quarter, one-half, and three-quarters renewable electricity generation.

The average CO2 emissions per kilowatt-hour for all electricity generated at each of these milestones might be 660 grams, 440 grams and 220 grams respectively.

But they could be much less.

We'll look at the halfway milestone to see why this is so:

At this milestone, one-half of all electricity is delivered from renewable energy sources with no fossil-fuel CO2 emissions - solar PV and solar thermal, wind farms, hydroelectric including pumped hydroelectric storage, and battery storage.

The other half of electricity is delivered from fossil fuel power generators. These power plants are only dispatched at times when total demand exceeds the total capacity of all the available renewable energy sources.

These fossil fuel power plants may have average CO2 emissions per kilowatt-hour of electricity of 880 grams.
Average CO2 emissions and efficiency of a coal-fired power plant
Average CO2 emissions and efficiency of a coal-fired power plant
In this case the average CO2 emissions per kilowatt-hour for all electricity generated at the halfway milestone will be 440 grams: (Zero for the half from renewable energy sources plus 880 grams for the half from fossil fuel power plants) divided by two.

It isn't necessary for the CO2 emissions from the electricity generated by fossil fuels to be nearly this high. They can be reduced to three-eighths of 880 grams per kilowatt-hour of electricity.

A way of doing this allows the use of power plants that are far more efficient than coal-fired power plants, are far cheaper to build, and are able to start more quickly in response to increases in demand.

A further advantage is that they use only three-eighths of the coal to generate each kilowatt-hour of electricity so the cost of mining and transporting coal for electricity generation is cut to just three-eighths of the cost with the less efficient, more expensive coal-fired power plants.

This way of supplying electricity at the halfway milestone reduces the average CO2 emissions for all electricity generated to just 165 grams: (Zero for the half from renewable energy sources plus 330 grams for the half from fossil fuel power plants) divided by two.
Average CO2 emissions and efficiency of a combined cycle power plant
Average CO2 emissions and efficiency of a combined cycle power plant
The reduced quantity of coal for fuel for the combined cycle power plants can converted to methane by a reaction with hydrogen. The hydrogen can be produced by electrolysis using excess renewable energy generated whenever total demand is less than the output of renewable energy sources.

A coal-fired power plant that is emitting 880 grams of CO2 per kilowatt-hour burns coal containing 240 grams of carbon for one kilowatt-hour of electricity. Coal containing just 90 grams of carbon (three-eighths of 240 grams) is all that's needed for a combined cycle power plant to generate a kilowatt-hour of electricity.

Coal may be converted directly to methane by reacting it with hydrogen:

Hydrogen - A Key to the Economics of Pipeline Gas from Coal, C. L. Tsaros, Institute of Gas Technology, Chicago, Illinois

The objective in manufacturing supplemental pipeline gas is to produce high- heating-value gas that is completely interchangeable with natural gas - essentially methane.

The basic problem in making methane from coal is to raise the H2/C ratio. A typical bituminous coal may contain 75% carbon and 5% hydrogen, a H2/C mole ratio of 0.4:1; the same ratio for methane is 2:1. To achieve this ratio it is necessary to either add hydrogen or reject carbon. The most efficient way is to add hydrogen. The hydrogen in the coal can supply about 25-30% of the required hydrogen, but the bulk must come by the decomposition of water, the only economical source of the huge quantities needed for supplemental gas.

In the second, or direct, method, methane is formed directly by the destructive hydrogenation of coal by the reaction:
C + 2H2 → CH4

There is a steadily growing list of commercially available systems to produce hydrogen using excess renewable energy:
Clean and Low-cost Hydrogen for Industry
The Sunfire steam electrolysis system, based on solid oxide cell (SOC) technology, promises lower onsite hydrogen production costs compared to legacy technologies. The ability to supply steam directly to the electrolysis module is unique and maximises efficiency.




Saturday, June 23, 2018

National Energy Guarantee and known pitfalls

A Japanese study released in October 2017 warns of costly European policy mistakes when investment in renewable energy is increasing.

Though details of the National Energy Guarantee policy are still under discussion, the Japanese study is worth checking so that Australia doesn't fall into any of the pitfalls it warns of.

This is an extract with some of the warnings in the Japanese study.


The Ways Forward for Japan EPCOs in the New Energy Paradigm
October 2017
Renewable Energy Institute, The Ways Forward for Japan EPCOs in the New Energy Paradigm (Tokyo: REI, 2017), 76 pp.
Executive Summary
Japan electric power companies(EPCOs) have essentially been focusing on their domestic market so far. Yet, business opportunities also exist overseas. ... Critical to successful internationalization of Japan EPCOs business will be their ability to deploy cost efficient Renewable Energy (RE).
To make their way through this new energy paradigm, Japan EPCOs have the chance to learn critical lessons from their European peers.
European EPCOs have already faced similar challenges to those Japan EPCOs are now confronted with. And European EPCOs have failed to adapt quickly. Japan is lagging behind, and that is not necessarily a bad thing. Indeed, it means that Japan EPCOs may benefit from their European peers painful experiences.
Struggling, several European EPCOs posted record losses and saw their market capitalization collapse in recent years. They were victims of low wholesale electricity prices resulting from sluggish electricity demand and dramatic expansion of wind and solar power with lower marginal cost, leading to overcapacity and pushing fossil power plants out in the competitive market merit order. (page 1)
Key Challenges Faced by Japan’s EPCOs
Global Annual Change in Electricity Generation 2010-2016
In the past two years RE accounted for the majority of new power capacity globally driven by dramatic cost reductions in wind and solar, and globally for the past three years the increase in RE electricity generation has been higher than the increase in fossil electricity generation. (Page 15)
European EPCOs Failed to Adapt Quickly
These overall negative performances result from the European EPCOs failure to quickly adapt to the energy transition, at the generation level especially. While electricity consumption stagnated, significant expansion of close to zero marginal cost wind and solar power, in which European EPCOs did not sufficiently invest, took place in Europe. The latter helped lowering wholesale electricity prices due to the merit order effect. At the same time, conventional power capacity did not significantly decrease which combined with stagnating electricity consumption and the expansion of RE resulted in overcapacity further reducing wholesale electricity prices (Chart 31). European EPCOs conventional power plants were thus outcompeted due to their higher marginal costs and suffered from low wholesale electricity prices, thus significantly affecting European EPCOs profitability. (page 26-27)
In Europe, several EU Member States including France, Germany, Italy, Spain, and the UK, notably, have introduced rewards for making capacity available, in the form of capacity mechanisms. However, capacity mechanisms are considered problematic because they risk distorting electricity markets. Inappropriate designs of mechanisms may for instance result in existing uneconomic power plants receiving financial support and disturbing the transition to a low-carbon economy – a failure. 31  The UK and Germany offer telling examples of far from perfect capacity mechanisms. (page 28)
In Germany, from this year 2.7GW of largely inflexible and high-emitting lignite capacity will be placed into an emergency stand-by reserve, only to be used as back-up when required for a period of four years, after which these plants will be permanently retired. 33  This comes at an estimated cost of €1.6 billion to the German government to compensate for lost revenues from the electricity market during these years of security stand-by. 34
These flawed designs are unsurprising insofar as it has been found that many of EU Member States did not adequately assess the need or cost-effectiveness before introducing such mechanisms. 35
In addition, it has also been recognized that capacity mechanisms implementation must be accompanied by appropriate market reforms. 36
Thus, before adding gigawatts of new conventional power plants and/or pushing for the implementation of a capacity mechanism in Japan, Japan EPCOs should thus be well aware of these painful lessons learnt in Europe (page 29)
ENDNOTES
31   European Parliament, “Capacity mechanisms for electricity – May 2017” (accessed 28 August 2017)  
33   The Economist Intelligence Unit, “Is Germany’s Energiewende cutting GHG emissions? – 20 March 2017” (accessed 31 August 2017)
34   Overseas Development Institute, Rethinking Power Markets: Capacity mechanisms and decarbonisation (London, United Kingdom: ODI, 2016), 46 pp
35   European Parliament, op. cit. note 31
36   Ibid.