This blog has mentioned the subject of so-called ‘geoengineering’ before – a series of proposed technologies designed to work on a planetary scale to slow or mitigate the effect of global warming. The reason it remains a topic of relevance to readers of this magazine is that, of all of the techniques proposed, those involving burning large volumes of sulphur to create sulphur dioxide in order to reflect sunlight at high altitudes seem to be the most feasible.
The cooling effect of high-level SO2 has long been documented. In 1991-2 planetary temperatures were cooled by about 0.6C by the eruption of Mount Pinatubo in the Philippines, which put an estimated 15-30 million tonnes of SO2 into the atmosphere. Similar effects were observed after the Krakatoa eruption in 1883. The argument is that if the emissions were more targeted, both in terms of geographical location and atmospheric height level, even greater changes could be achieved by smaller amounts of SO2. A study published in April in Atmospheric, Chemistry and Physics Discussions reported that modelling had indicated continuous injection of 5 million t/a of SO2 into the upper atmosphere might be able to achieve a 0.7C global temperature reduction (taking us back to pre-industrial levels), albeit with considerable regional variation.
Ironically, our success in reducing SO2 emissions from burning sulphur-containing fuels may have actually exacerbated the problem, as we used to put several tens of million tonnes of SO2 into the lower atmosphere every year. While this low level SO2 caused great damage to human health and the environment and caused the ‘acid rain’ phenomenon, enough reached the upper atmosphere to lead to a mild cooling effect which we no longer enjoy. It has on the other hand also provided us with stockpiles of tens of millions of tonnes of sulphur around the world for which we are continually searching for a use. Producing five million t/a of SO2 would require 2.5 million t/a of elemental sulphur – a readily achievable total on current production/storage levels.
While geoengineering was once an area that brought together a handful of ‘lateral thinkers’ with some of the stranger fringes of the global warming debate, as a global deal on reducing carbon emissions post-Kyoto has continued to prove elusive, so the topic has steadily become more mainstream as an item for discussion. A number of prominent scientists now argue that – in the absence of a comprehensive climate change deal - humanity needs some sort of ‘Plan B’. It is a planetary-scale Pascal’s Wager – the theory is that the scale of the risks and potential benefits make it imperative to at least put some serious money into researching the area, whatever our beliefs or viewpoint might be. In September last year the Royal Society in London said almost exactly this in a report on global warming. Other supporters have included such disparate personalities as Nobel chemistry laureate Paul Crutzen, Edward Teller the so-called “father of the hydrogen bomb”, economists and ‘Freakanomics’ authors Steven Levett and Stephen Dubner, Bill Gates and Richard Branson. Now in a report published just a few weeks ago, Dr David Keith at the University of Calgary has chimed in with some ideas on mirrored nanoparticles and sulphuric acid aerosols.
However, environmentalists have been loudly critical of the idea, most notably because they argue it is a seductive illusion, treating the symptoms rather than the disease, and allowing us to think we can engineer our way out of climate change without having to change our lifestyles. The effect on the ozone layer would be predictably adverse, while the long-term effect of high levels of CO2 and SO2 remains difficult to predict and could have any number of unplanned and unpleasant side effects. Even the study referred to above predicted potentially catastrophic changes to regional rainfall patterns, for example. But more than that, it is argued, once we had embarked down the road of geoengineering, we would be unable to stop. The underlying concentration of carbon dioxide would continue to rise, and any halt in sulphur injections, even for a year or two, could cause warming to rebound at a rate 10 to 20 times that of the recent past - a phenomenon referred to as the "termination problem". Once we start engineering the atmosphere we could be trapped, forever dependent on sulphur injections.
Carbon dioxide sequestration is of course itself a form of geoengineering, albeit one with more predictable consequences, and for that there is considerable government support, at least in Europe and North America. At the moment the debate still rages over SO2 injection between those who say we cannot afford to take the risk, and those who say we cannot afford not to, but it remains an open question as to how long will it be before a government somewhere decides that SO2 injection is a cheaper option.
Tuesday 5 October 2010
Trying to please all and satisfying none
[By our guest columnist, ‘Thiophilos’]
PennWell’s third annual Oil Sands and Heavy Oils Technology (OSHOT) conference showed up on schedule in Calgary in July, in the midst of more media madness on the topic of the environmental impact resulting from society’s continuing love affair with energy from converting the energy which Mother Nature (over many millions of years) put in the carbon-hydrogen bond into the energy needed to drive its ever more luxurious life style – for some.
It is hardly surprising that the sulphur recovered from the world’s second largest hydrocarbon reserve - in Alberta - (notwithstanding Colonel Hugo’s recent claims for Orinoco) was again featured in a whole day session on the yellow element. It is recovered during the upgrading and refining of a present 1.5 million bbl/d of daily oil sands bitumen production that is predicted to reach 3.5 million bbl/d by 2025. At a near 5% sulphur content this could mean over 9 million t/a of the yellow element from Alberta’s oil sand production alone. And all of this in the face of rising world wide production from sourer conventional hydrocarbon production and possible competition for its use in fertilizer manufacture. All of these factors popped up somewhere, somehow in the presentations and active and full discussion session that followed.
If there was one message that emerged from the day long dialogue on dirty sulphur from dirty oilsand it was the harder sulphur tries the more bad press it attracts. We try to please all and end up satisfying none. With sea floor oil gushing into the Gulf of Mexico, and US congressmen calling for Americans (the world’s most extravagant users of the stuff) to strike Alberta off its “to visit” list until the oil sands production (which goes mostly to them!!) is stopped, it is indeed a hard task to respond responsibly to the demands for less emissions and more production. But, notwithstanding the mood of the media and by extension the people their readers, the industry keeps on trying, regretfully without too much public relations success.
The rigor of regulation, and the resulting hoops that must be jumped through in the process of design and operation of facilities to handle the recovered sulphur, was reviewed and commented on by Rob Mann of Alberta Sulphur Terminals (Hazco). The harder you try, the longer it takes, and it is not for the faint of heart was the message. While doing all of this handling, storage and transportation, Glenn Weagle of IPAC Chemicals of Vancouver (where millions of tons of the stuff gets stored and handled), detailed just how complex a challenge reducing the environmental impact of fugitive sulphur fines can be. The stuff even volatilises from the surface of the stockpile when the sun shines on it. Tariq Cheema of Syncrude and Paul Davis of Alberta Sulphur Research Ltd. reported on recent very detailed studies of just how unsold and stockpiled elemental sulphur behaves as it sits waiting for end users to show up and haul it away. How does it shrink, crack and fail structurally? Does it acidify, and how fast under what conditions? How important is aerobic oxygen access and what role does moisture play? What role does percolation play and can cover affect this? Does burial help and what are the results of real life, full-sized tests of surface and buried block storage? And what about the hydrogen sulphide that it can evolve in storage, asked Mike Shields of ASRL, when it wasn’t “de-gassed” up front? Who said sulphur was just another bulk solid product to handle? That attitude is probably one of the main reasons for its current bad reputation.
The solution to much of the foregoing challenge is to find new markets for the old yellow element. It is not that the ideas and even the basic R&D has not been done; Shell Canada’s extensive and ongoing work on their Thiopave formulation for roadway surfacing was described by Timo Makinen. Gerry D’Aquin of Con-Sul reviewed and commented on some earlier ASRL work on a very convenient local use of both oil sands tailings and elemental sulphur for temporary mine site paving: An environmentally beneficial improvement to mining operations and an opportunity to save on haulage truck fuel costs due to reduction in frictional drag losses in the wet/mud seasons.
The essence of a good, productive day-long session on a focused topic is the discussion that it generates. Larry Marks, previously of Shell, joined Jim Hyne, Paul Davis and Gerry D’Aquin as the “provocateurs” in an hour long discussion of both the ideas from the papers and additional matters relevant to the future of recovered elemental sulphur. It was perhaps a pity that the audience did not include many of those in the Heavy Oil Patch that produce the stuff in the first place so that they can make money from the ‘in demand’ desulphurised fuel. We continue to try, but the way is long and the hill is steep!
'Thiophilos'
PennWell’s third annual Oil Sands and Heavy Oils Technology (OSHOT) conference showed up on schedule in Calgary in July, in the midst of more media madness on the topic of the environmental impact resulting from society’s continuing love affair with energy from converting the energy which Mother Nature (over many millions of years) put in the carbon-hydrogen bond into the energy needed to drive its ever more luxurious life style – for some.
It is hardly surprising that the sulphur recovered from the world’s second largest hydrocarbon reserve - in Alberta - (notwithstanding Colonel Hugo’s recent claims for Orinoco) was again featured in a whole day session on the yellow element. It is recovered during the upgrading and refining of a present 1.5 million bbl/d of daily oil sands bitumen production that is predicted to reach 3.5 million bbl/d by 2025. At a near 5% sulphur content this could mean over 9 million t/a of the yellow element from Alberta’s oil sand production alone. And all of this in the face of rising world wide production from sourer conventional hydrocarbon production and possible competition for its use in fertilizer manufacture. All of these factors popped up somewhere, somehow in the presentations and active and full discussion session that followed.
If there was one message that emerged from the day long dialogue on dirty sulphur from dirty oilsand it was the harder sulphur tries the more bad press it attracts. We try to please all and end up satisfying none. With sea floor oil gushing into the Gulf of Mexico, and US congressmen calling for Americans (the world’s most extravagant users of the stuff) to strike Alberta off its “to visit” list until the oil sands production (which goes mostly to them!!) is stopped, it is indeed a hard task to respond responsibly to the demands for less emissions and more production. But, notwithstanding the mood of the media and by extension the people their readers, the industry keeps on trying, regretfully without too much public relations success.
The rigor of regulation, and the resulting hoops that must be jumped through in the process of design and operation of facilities to handle the recovered sulphur, was reviewed and commented on by Rob Mann of Alberta Sulphur Terminals (Hazco). The harder you try, the longer it takes, and it is not for the faint of heart was the message. While doing all of this handling, storage and transportation, Glenn Weagle of IPAC Chemicals of Vancouver (where millions of tons of the stuff gets stored and handled), detailed just how complex a challenge reducing the environmental impact of fugitive sulphur fines can be. The stuff even volatilises from the surface of the stockpile when the sun shines on it. Tariq Cheema of Syncrude and Paul Davis of Alberta Sulphur Research Ltd. reported on recent very detailed studies of just how unsold and stockpiled elemental sulphur behaves as it sits waiting for end users to show up and haul it away. How does it shrink, crack and fail structurally? Does it acidify, and how fast under what conditions? How important is aerobic oxygen access and what role does moisture play? What role does percolation play and can cover affect this? Does burial help and what are the results of real life, full-sized tests of surface and buried block storage? And what about the hydrogen sulphide that it can evolve in storage, asked Mike Shields of ASRL, when it wasn’t “de-gassed” up front? Who said sulphur was just another bulk solid product to handle? That attitude is probably one of the main reasons for its current bad reputation.
The solution to much of the foregoing challenge is to find new markets for the old yellow element. It is not that the ideas and even the basic R&D has not been done; Shell Canada’s extensive and ongoing work on their Thiopave formulation for roadway surfacing was described by Timo Makinen. Gerry D’Aquin of Con-Sul reviewed and commented on some earlier ASRL work on a very convenient local use of both oil sands tailings and elemental sulphur for temporary mine site paving: An environmentally beneficial improvement to mining operations and an opportunity to save on haulage truck fuel costs due to reduction in frictional drag losses in the wet/mud seasons.
The essence of a good, productive day-long session on a focused topic is the discussion that it generates. Larry Marks, previously of Shell, joined Jim Hyne, Paul Davis and Gerry D’Aquin as the “provocateurs” in an hour long discussion of both the ideas from the papers and additional matters relevant to the future of recovered elemental sulphur. It was perhaps a pity that the audience did not include many of those in the Heavy Oil Patch that produce the stuff in the first place so that they can make money from the ‘in demand’ desulphurised fuel. We continue to try, but the way is long and the hill is steep!
'Thiophilos'
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