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CCS Opportunities in NSW

The impetus for Carbon Capture and Storage (CCS) technology is the observed impact of CO2 on climate change.

Implementing CCS represents a significant additional economic and social cost in terms of:

  • additional equipment maintenance and other running costs;

  • a significant drop in net fuel efficiency and consequent faster resource consumption;

  • a significant increase in transportation infrastructure and its environmental impacts; and

  • some very real additional dangers and safety issues. 

The climate gains made need to more than offset these costs.

In 2005-6 World fossil sourced CO2 production is estimated to have totalled around 28,431.7 million tonnes (from all sources including petroleum)[3].  That year NSW sourced coal released 384.3 million tonnes of CO2 worldwide[4]. NSW coal therefore contributed about 0.13% of the total CO2 released. Of this total, around 91 million tonnes of coal sourced CO2 was released in Australia, predominantly in NSW.

Capture

In 2005-6 around 72% of domestic coal consumption was by electricity generators (65.5 million tonnes); 24% by iron making (21.8 million tonnes); and most of the balance to cement manufacture and smaller furnaces.  Lime calcination, the conversion of limestone (CaCO3) to lime (CaO), for cement, releases significant additional quantities of CO2 (0.8 tonne per tonne of cement produced plus the energy used to heat the process and transport the materials). 

The main metallurgical consumer of coal in NSW is iron smelting at Port Kembla.  This initially produces coke oven and blast furnace gas that is distributed around the plant and used as a furnace fuel and for cogeneration of electricity.  Dissolved carbon in the iron is subsequently converted to COxin the steelmaking process.  While it is conceivable that the CO2 eventually released by various processes could be captured, the diversity of release points would make capture and subsequent separation very difficult and costly to implement within the present technological paradigm. 

The Aluminium industry also uses carbon to reduce the oxide but the energy required is provided by electricity (from coal fired stations) and the main source of carbon is from petroleum (as petroleum coke). The scale of CO2 release is an order of magnitude smaller than iron and steel making but capture may be as feasible if the flue gas was processed with that from a nearby a coal burning power station.  Both NSW based aluminium smelters are in the Hunter Valley, near the power generation.

Cement calcination plants are relatively smaller in scale again, and more geographically disperse. They would need additional equipment and energy to capture and process, then transport, the exhaust CO2 and the difficulties involved would probably preclude capture. 

The best prospects for CO2 capture in NSW are the coal fired power stations, predominantly in the Hunter Valley.  In theory the full CCS applied to the CO2 emissions from coal fired electricity generation could reduce overall fossil fuel based emissions from NSW (including those from petroleum and gas) by as much as 25%.  A CO2 reduction target on this scale requires that all of the CO2 from coal powered electricity generation (including that from existing power stations) is successfully captured and stored.

There are substantial technical problems (that translate into increased costs) in converting the existing Hunter Valley stations to capture the CO2.  These stations are air fired so that most of the input (and output) gas is nitrogen (78% of air).  Nitrogen is semi-inert so most passes through the furnace unchanged but it is heated and leaves the plant at above boiling point so energy is consumed.  Raising the combustion temperature by injecting oxygen increases the small proportion of nitrogen that is oxidised to produce troublesome NOx pollutants.  In addition to nitrogen, CO2, NOx, and water vapour; the oxides of sulphur SOx, ash particles and some other trace elements, including compounds of mercury, are present in the flue gas. If allowed to fall below boiling point before being released the oxides react with the water vapour to make liquid acids that can do serious damage to equipment. Under CCS the CO2 component needs to be flushed out of this gas mixture (captured) and compressed. Several separation technologies are being trialled with some success, including ammonia absorption, but the potential costs and unsolved difficulties remain daunting.

The capture stage can be facilitated if the nitrogen is not fed into the furnace in the first place.  This requires a tonnage oxygen plant (common in the steel industry) to feed the combustion. This together with preliminary coal gasification can provide other benefits including improved combustion and thermal efficiency (at the expense of additional energy, capital, maintenance and operating expenses expended in oxygen production) but an entirely different furnace technology is required (to that presently installed) to gain these benefits.

To date trials around retrofitting more advanced Chinese furnace technology have been directed towards less efficient brown coal based plant in Victoria.

 

 


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Travel

Southern England

 

 

 

In mid July 2016 Wendy and I took flight again to Europe.  Those who follow these travel diaries will note that part of out trip last year was cut when Wendy's mum took ill.  In particular we missed out on a planned trip to Romania and eastern Germany.  This time our British sojourn would be interrupted for a few days by a side-trip to Copenhagen and Roskilde in Denmark.

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Fiction, Recollections & News

More on 'herd immunity'

 

 

In my paper Love in the time of Coronavirus I suggested that an option for managing Covid-19 was to sequester the vulnerable in isolation and allow the remainder of the population to achieve 'Natural Herd Immunity'.

Both the UK and Sweden announced that this was the strategy they preferred although the UK was soon equivocal.

The other option I suggested was isolation of every case with comprehensive contact tracing and testing; supported by closed borders to all but essential travellers and strict quarantine.   

New Zealand; South Korea; Taiwan; Vietnam and, with reservations, Australia opted for this course - along with several other countries, including China - accepting the economic and social costs involved in saving tens of thousands of lives as the lesser of two evils.  

Yet this is a gamble as these populations will remain totally vulnerable until a vaccine is available and distributed to sufficient people to confer 'Herd Immunity'.

In the event, every country in which the virus has taken hold has been obliged to implement some degree of social distancing to manage the number of deaths and has thus suffered the corresponding economic costs of jobs lost or suspended; rents unpaid; incomes lost; and as yet unquantified psychological injury.

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Opinions and Philosophy

Holden - The Demise of an Iconic Brand

 

I drive a Holden. 

It’s my second. The first was a shiny black Commodore.  A V6 Lumina edition.

I have owned well over a dozen cars and driven a lot more, in numerous countries, but these are my first from General Motors.

The new one is a white Calais Sportswagon and it's the best car I've ever owned.

Based on the German Opel, it has traction control conferring impeccable braking and steering and ample power and acceleration even with four adults and luggage.  Add to that: leather seats; climate control; head-up display; voice commands for entertainment, phone and so on; and it's a luxurious ride.

Yet I’m starting to think that I can put an end to any car brand, just by buying one.

Holden finally ceased manufacturing in Australia just after my present model rolled off the production line.

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