Archive for category ENERGY

BENCHMARKS IN SOLAR VIZ A VIZ NUCLEAR

A company in Spain celebrated an historic moment for the solar industry: Torresol’s 19.9 MW concentrating solar power plant became the first ever to generate uninterrupted electricity for 24 hours straight.

The plant uses a Power Tower design which features a field of 2,650 mirrors that concentrate sunlight onto a boiler in a central receiver tower. The plant also utilizes molten salt as a heat-transfer fluid that allows the plant to generate electricity when there’s no sunlight. After commissioning in May 2011, the plant was finally ready to operate at full-blast in late June and benefited from a particularly sunny stretch of weather, according to Diego Ramirez, director of production at Torresol.

“The high performance of the installations coincided with several days of excellent solar radiation, which made it possible for the hot-salt storage tank to reach full capacity,” Ramirez explains.

Big milestones for Power Tower technology, which is still a very nascent technology compared to the more-mature parabolic troughs. There are only a few operating commercial-scale plants around the world, and Torresol’s is the only one with a 15-hour molten salt storage capability.

 

In the lead up to another 15% reduction in Germany’s feed-in tariff (the price paid for solar electricity fed into the grid), the German solar industry finished 2011 off with a bang — installing 3,000 megawatts of solar photovoltaic systems in December.

Let’s put those figures in perspective: In just one month, Germany installed almost twice as many megawatts of solar than the entire U.S. developed during all of 2011. Preliminary figures show Germany ended the year with roughly 7,500 MW of installations; the U.S. ended up with about 1,700 megawatts, according to GTM Research.

Oh, and I should probably mention that the Germans installed all of that solar at almost half the price. The average price of an installed solar system in Germany came to $2.80 in the third quarter of 2011. In the U.S., it was about $5.20 in the third quarter.

Why the disparity? The Germans have a much more mature solar market. The country’s simple, long-term feed-in tariff makes financing projects less expensive, and has created a sophisticated supply chain that allows companies to source product, generate leads and get systems on rooftops efficiently.

Some criticize feed-in tariffs for not creating a “market” like we imagine in the U.S. The activity we saw at the end of 2011 is representative of what happens every year in Germany: because the incentives are dropped down to meet market pricing, there is always a rush in December to install systems quickly. But isn’t that what we do in the U.S. when tax credits and rebates are about to expire?

It’s fair to criticize feed-in tariffs like those in Spain and the Czech Republic which caused an unsustainable boom before crashing down. But when looking at the numbers and pricing that the German solar market continues to post, there’s still a very compelling argument for states and municipalities to consider moderate, long-term pricing mechanisms like feed-in tariffs

Us peak demand is probably up around 850 GW summer. Installed at optimal locations solar PV is 20% of nameplate. Solar Thermal can as high as 60. If that number I said seems ridiculously high – remember in 20 years that would only be 400 Gw or around 100 GW of power tops with today’s tech – at which point (20 year mark) a good deal of it would be needed to replace existing systems too.

Feed in tariffs can fail badly, as you note about Spain and the Czech Republic.

The price tells the story: $2.80 per Watt. Wow! Imagine how fast our desert Southwest would fill with PV at that price!

 

With the kind of sustained and predictable insolation that most of the US Southwest gets, it would be a tremendous benefit to focus on solar PV and thermal, cut back on new wind farms, and aggressively shut down the worst coal plants in the area.
Five years of concerted effort towards those goals should pay a great many local dividends including jobs

Actually, there is a world price (range) for installed solar PV. One has to properly account for all the various incentives + tax breaks. In Germany the taxpayers are subsidizing ratepayers. Even so only the fortunate (and rich) can afford a roof top sized solar PV installation. Many live in apartments (flats) without the opportunity for this investment.

Not clear that by anybody’s notion of economics this is equitable; it seems to me a quite expensive way to generate electricity. Germans already pay the second highest rates in Europe (but then Germans are, on average, quite prosperous so maybe it doesn’t matter).

It’s a great irony that it’s Germany who’s leading on solar when their average insolation is not all that good.>>>>
It should be the US with its large flat roofs, sprawling parking lots, vast sunny states and insatiable demand for power and cooling that should be the world’s Solar Champion. Perhaps laying back on the great potential that could be exponential.

Well, since everybody who breathes is subsidizing fossil fuels by bearing the burden of pollution on their bodies and wallets, a feed-in tariff is the LEAST the government can do to try and level out the playing field. How about we put a price on each ton of mercury, soot, fly ash, NO2, SO2, particulate matter, ozone and CO2 emitted instead? It would be more difficult to manage, but it would correct the horrendous Market Failures that all the externalities of pollution present.

Really, an expensive way to generate electricity?

At $3 per watt, the cost of solar is now less than half and maybe only a fourth or fifth of the start-up costs of a nuclear power plant, and this does not even scratch the surface of the true cost of nuclear when upkeep, management, safety, and the long-term storage of wastes are added to the picture.

Put another way, at $3 per watt, the solar equivalent of a 2 giga watt nuclear plant (which is on the large side of such plants) would cost $6 billion. That means the Iraq war at $1 trillion could have purchased the SOLAR EQUIVALENT of 1 trillion/6 billion = 167 nuclear power plants (3 for each state). But the U.S got so much more for the money by going to war, didn’t it?

Keep in mind that PV has a 20% capacity factor at best, while nuclear routinely have >90%. With that in mind, a 3$/W PV installation effectively becomes 15$/W, while a 5$/W nuclear plant (in the ballpark of the much over budget Olkiluoto 3) becomes 5,56$/W.

This completely ignores the cost of storage and/or backup (usually dirty and dangerous gas) during night and cloudy days.

Keep in mind that coal, gas, and oil are causing the destruction of civilization and the possible extinction of most life on Earth and even the self-perpetuating cybernetic system of all life on Earth that we call Gaia. How do we factor the cost of that into the equation to compare to the cost of solar, wind and other renewable energies that don’t cause all those inconveniences?

Also consider the synergistic effect of combining different sources like wind and solar across broad geographic areas in a distributed system… and the existence of clean storage like pumped storage, solar thermal, etc. ?

Keep in mind the high capital costs and long lag time of nuclear–it’s long construction time, long time to pay back its carbon construction costs, less-incremental and thus less interest-compounding growth, its decreasing fuel reserves, toxic qualities and storage problems, etc. Compared to efficiency, organic carbon sequestration and renewable energy it makes very little sense unless the goal is to reduce economic and therefore political democracy.

We also need to keep in mind the undeniable link between the Light Water Reactor Fuel Cycle and weapons grade nuclear material. The LWR was selected PRECISELY because its fuel cycle was the most mature at the end of the Manhattan Project. If we had abandoned nuclear power as we should have in the 1970s, Iran would have ZERO ability to use its civilian nuclear power program as a blatant cover for its weapons program

Even if it seems not to be accounting for the fact that all these aging, dilapidated reactors are 70s technology. Reactors have come a long way since then, to the point of gen-3+ and gen-4 reactors costing a sixth in start-up capital & time and costing much less in management as the manner of handling and processing nuclear materials has completely departed from the old rod/pellet in a giant bucket of water model, such as thorium salt and breeder reactors. LFTR reactors can burn off what is called waste by other facilities. Breeders can burn most all of it.

Just remember that the failures of today are of corporate complacency and lack of innovation due to using market ideology to run a utility. Modern reactors and their designers’ being shunned are not nearly to blame.

Maybe you’re not accounting for the fact that commercial “next-gen” thorium and breeder reactors don’t exist, and projected costs of new nuclear are astronomical and growing, not shrinking. And thank Gaia they don’t exist; the last thing we need is an over militarized country like the US, obsessed and paranoid about terrorists and using every excuse to ramp up weapons and surveillance systems and disappear human rights, trucking plutonium back and forth all over.

All kinds of technologies look better before they actually exist. Too cheap to meter, safe as houses, blah blah…. And then they actually build some, and what we get is half a century of subsidies with no end in sight, TMI, Brown’s Ferry’s comedy of errors, Chernobyl’s pathetic tragedy, Fukushima’ horror. Thousands of incidents, near-misses, lies and cover ups… and construction times and costs way over the projections and estimates and the costs of the alternatives. OMB gave it a 50% chance that loan guarantees for reactors would be defaulted on, leaving the US public holding the bag…again. And what about the next accident? Where will it be—and how bad?

Expectations have been halved for reactors built by 2035, so nuclear has even less chance than it ever did (which was almost zero) of helping solve the climate crisis in time. In the end, probably the most pernicious effect of nuclear power is its concentration of profits compared to decentralized efficiency, solar and wind, and the resulting destruction of practical democracy.

The failures of today are exactly the same as the failures to come—caused by arrogance, corruption, and addiction to profits (among other things). To say that reactors are not to blame is like saying guns don’t kill people, etc. etc.. OK, true. But how many fatal drive-by spatula-slappings have you heard of? In any case, nobody’s blaming reactors, and “their designer’s being shunned”???

Blame is irrelevant. Preserving life on Earth is the issue, and nuclear is making it harder.

No matter how figured solar PV together with a low carbon backup costs more than NPPs until the fully internalized cost of solar PV (plus low carbon backup) is around US$0.08/kWh LESS than electrical energy from NPPs. That might seem strange, but both solar PV and NPPs have very low variable costs; essentially all costs are either capital costs or fixed O&M. So the way the economics works out isn’t a clear cut as one might initialy think nor as rosy as the solar PV promoters would have you think.

Continued use of fossil fuels will cost us the planet. So any costs of solar, wind, etc., no matter how they compare to the skewed, externalization-ridden and profit-oriented prices we have today are miniscule by comparison. Nuclear’s high capital costs, numerous externalities and continuing subsidies, long lag time for construction and payback for construction carbon and the need to solve the climate problem before even the first nuclear reactor started now would likely be online mean it can’t be the solution. And I would think that the lessons of TMI, Brown’s Ferry, Chernobyl and Fukushima as well as hundreds of other incidents of leaks, corruption, and the inevitably-accompanying lies and cover ups would be that nuclear is not the way to go.

It shouldn’t be an either/or between advanced nuclear and solar. Nuclear is base load; solar PV is typically well-matched to daytime peaks.

Nuke plants have long construction times – 4 Areva EPR are all behind schedule, especially Olkiluoto, 75% over budget (so far), 3 yrs behind schedule and MIGHT fire up 9 yrs after construction began.
Yes, it’ll produce plenty of power but that’s a long time to live off candles.
Solar (and wind),notwithstanding their lower capacity factors can be producing power within months, weeks, even days, if the transmission is in place.

I’ve looked into all those matters rather carefully. In comparison to other industries, NPPs are highly and well regulated and are much safer. Could do better, of course, but the LLE risk from NPPs is about the same as the LLE risk of eating peanut butter.

To replace coal burners with a low carbon source there is no alternative except at a cost too high to seriously consider. Learn to do the electrical energy economics yourself; don’t just take somebody’s word for it. >>>>

And to say that there is no alternative except at too high a cost just seems ludicrous. Since there is no evidence or support and cite no references it’s hard to even know how you arrived at that conclusion but clearly wind, solar and other renewables are being produced at a cost that is perfectly acceptable, and are growing at a phenomenal rate (though still not fast enough). The cost of efficiency is even less, and to change our lives to make our lives more rational, connected and ecological the net benefits are enormous.

One should cite sources. By following World Nuclear News it is quite evident that the capacity factor of NPPs has increased over time. It now stands at around 92%; the new Gen III designs under construction ought to do a bit better than that, but time will tell.

Also to say that the nuclear industry is well-regulated and safer than other industries suggests you haven’t looked into these matters carefully enough. Fukushima alone is enough evidence that that’s not true, and there’s a pile of other evidence. We’ve been lucky so far, but the several major and many minor accidents as well as continued crimes and cover ups, including the collusion of captured regulators make the nuclear industry an unacceptable burden to humanity.

 

The problem in the US is that Wall Street/old energy interests run the county and they are obstructing virtually every effort communities and states are making to progress with local, distributed renewable energy. Until there is a mass movement to overcome excessive utility/corporate powers, and wage a ground-up push for FIT’s, we will be stuck in the dirty dark ages. Solar Done Right just launched a Call to Action for Energy Democracy

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THE ART OF PLATFORMING.

WHAT IS PLATFORMING?

The first time I heard about this word I thought about a platform to sit on………

Never mind me.

Consider this one of the things that happens to your fuel and you will never get a chance of knowing it ever happens. Quite strange that our refinery here in Kenya is quite behind and has a lot of catching up to do.

An upgrade of the refinery is overdue and should have been done yesterday.

History

In the 1940s, Vladimir Haensel,[1] a research chemist working for Universal Oil Products (UOP), developed a catalytic reforming process using a catalyst containing platinum. Haensel’s process was subsequently commercialized by UOP in 1949 for producing a high octane gasoline from low octane naphthas and the UOP process become known as the Platforming process.[2] The first Platforming unit was built in 1949 at the refinery of the Old Dutch Refining Company in Muskegon, Michigan.

In the years since then, many other versions of the process have been developed by some of the major oil companies and other organizations. Today, the large majority of gasoline produced worldwide is derived from the catalytic reforming process.

Very few, if any, catalytic reformers currently in operation are non-regenerative.

Catalytic reforming is a chemical process used to convert petroleum refinery naphthas, typically having low octane ratings, into high-octane liquid products called reformates which are components of high-octane gasoline (also known as petrol). Basically, the process re-arranges or re-structures the hydrocarbon molecules in the naphtha feedstocks as well as breaking some of the molecules into smaller molecules. The overall effect is that the product reformate contains hydrocarbons with more complex molecular shapes having higher octane values than the hydrocarbons in the naphtha feedstock. In so doing, the process separates hydrogen atoms from the hydrocarbon molecules and produces very significant amounts of byproduct hydrogen gas for use in a number of the other processes involved in a modern petroleum refinery. Other byproducts are small amounts of methane, ethane, propane, and butanes.

Motor gasoline (Mogas) or what we call petroleum production starts with the distillation of crude oil. One of the products out of that process is a fraction of low octane gasoline, normally referred to as naphtha, typically boiling in the range 100 – 160 0C. Other gasoline fractions are produced as a result of secondary processes like catalytic cracking, isomerisation, alkylation and platforming. Petrol is then produced by blending a variety of these gasoline components of different qualities to meet a series of product specifications.

One very important property of Mogas is the octane number, which influences “knocking” or “pinking” behavior in the engine of cars. Traditionally lead compounds have been added to petrol to improve the octane number. Over the past years, in many countries legislation has been implemented aimed at reducing the emission of lead from exhausts of motor vehicles and this, calls for other means of raising the octane number.

The role of a platformer is to pave the way for this by a process which reforms the molecules in low octane naphtha to produce a high octane gasoline component. This is achieved by employing a catalyst with platinum as its active compound; hence the name Platformer. For many refinery catalyst applications, a promoter is used, and in the platforming process, it is a chloride promoter which stimulates the ‘acidity’ of the catalyst and thereby the isomerisation reactions. Often, a bimetallic catalyst is used, i.e. in addition to the platinum, a second metal, for instance Rhenium is present on the catalyst. The main advantage is a higher stability under reforming conditions. The disadvantage is that the catalyst becomes more sensitive towards poisons, process upsets and more susceptible to non-optimum regenerations.

You can check,

http://en.wikipedia.org/wiki/File:CatReformer.png

 

Chemistry:

The main reactions of platforming process are as follows:

  • Dehydrogenation of naphthenes, yielding aromatics and hydrogen

The dehydrogenation of naphthenes to convert them into aromatics as exemplified in the conversion methylcyclohexane (a naphthene) to toluene (an aromatic), as shown below:

  • Dehydro-isomerisation of alkyl cyclopentanes to aromatic and hydrogen
  • Isomerisation of paraffins and aromatics

The isomerization of normal paraffins to isoparaffins as exemplified in the conversion of normal octane to 2,5-Dimethylhexane (an isoparaffin), as shown below:

  • Dehydrocyclisation of paraffins to aromatics and hydrogen
  • Hydrocracking of paraffins and naphthenes to ligher, saturated paraffins at the expense of hydrogen

The process literally re-shapes the molecules of the feed in a reaction in the presence of a platinum catalyst. Normally it is the hydrocarbon in the C6-C10 paraffin’s that get converted to aromatics.

The above reactions take place concurrently and to a large extent also sequentially. A majority of these reactions involve the conversion of paraffin’s and naphtenes and result in an increase in octane number and a nett production of hydrogen. Characteristic of the total effect of these reactions is the high endothermicity, which requires the continuous supply of process heat to maintain reaction temperature in the catalyst beds. That is why the process is typically done in four reactors in series with furnaces in between, in order to remain sufficiently high reactor temperatures.

The reactions takes place at the surface of the catalyst and are very much dependent, amongst other factors, on the right combination of interactions between platinum, its modifiers or activators, the halogen and the catalyst carrier. During operating life of the catalyst, the absolute and relative reaction rates are influenced negatively by disturbing factors like gradual coke deposition, poisons and deterioration of physical characteristic of the catalyst (surface area decline).

The process of platforming:

The feedstock of the platformer is drawn from the refinery’s distillation units. This is first treated by passing the feedstock together with hydrogen over a catayst, in a process called ‘hydrotreating, to convert the sulphur and nitrogen compunds to hydrogen sulphide and ammonia, in order to prevent poisoning of the expensive platformer catalyst. After hydrotreating, the reactor effluent moves on through a stabiliser column to remove the gases formed (hydrogen sulphide, ammonia and fuel gas). In a second column, the C5 and some of the C6 is removed in a separate fraction called ‘tops’. The reason to remove C5/C6 is that this component will crack in the platformer to produce fuel gas, while C6 gets converted into benzene, which can only be allowed in limited amount into the mogas because of its toxicity. From the bottom of the splitter column, the naphtha stream is produced, which is the feed for the Platforming section.

At the heart of the Platformer process are the four reactors, each linked to furnaces to sustain a suffiently high reaction temperature, about 500 0C at the inlet of the reactors.

Over time, coke will build up on the catalyst surface area, which reduces the catalyst activity. The catalyst can be easily regenerated however, by burning the coke off with air. After coke burning, the catalyst needs to be reconditioned by a combined treatment of air and HCl under high temperature. This regeneration step is called ‘oxy-chlorination’. After this step the catalyst is dried with hot nitrogen and subsequently brought in its active condition by reducing the surface with hot hydrogen. The refinery will therefore regularly have to take out one of the reactors to undergo this regeneration process. This type of process is therefore called semi-regen platforming.

During the regeneration process, the refinery will suffer production loss,. in a Continuous Catalytic Reformer, CCR. In the CCR unit, the reactors are cleverly stacked, so that the catalyst can flow under gravity. From the bottom of the reactor stack, the ‘spent’ catalyst is ‘lifted’ by nitrogen to the top of the regenerator stack. In the regenerator, the above mentioned different steps, coke burning, oxychlorination and drying are done in different sections, segregated via a complex system of valves, purge-flows and screens. From the bottom of the regenerator stack, catalyst is lifted by hydrogen to the top of the reactor stack, in a special area called the reduction zone. In the reduction zone, the catalyst passes a heat exchanger in which it is heated up against hot feed. Under hot conditions it is brought in contact with hydrogen, which performs a reduction of the catalyst surface, thereby restoring its activity. In such a continuous regeneration process, a constant catalyst activity can be maintained without unit shut down for a typical run length of 3 – 6 years. After 300 – 400 cycles of reaction/regeneration, the surface area of the catalyst will have dropped to a level (120 – 130 m2/g) that it becomes more difficult to maintain catalyst activity and at such a time normally the catalyst will be replaced by a fresh batch. The batch of ‘spent’ catalyst is then sent for platinum reclaim to recover the valuable precious metals.

Catalysts and mechanisms

Most catalytic reforming catalysts contain platinum or rhenium on a silica or silica-alumina support base, and some contain both platinum and rhenium. Fresh catalyst is chlorided (chlorinated) prior to use.

The noble metals (platinum and rhenium) are considered to be catalytic sites for the dehydrogenation reactions and the chlorinated alumina provides the acid sites needed for isomerization, cyclization and hydrocracking reactions.[11]

The activity (i.e., effectiveness) of the catalyst in a semi-regenerative catalytic reformer is reduced over time during operation by carbonaceous coke deposition and chloride loss. The activity of the catalyst can be periodically regenerated or restored by in situ high temperature oxidation of the coke followed by chlorination. As stated earlier herein, semi-regenerative catalytic reformers are regenerated about once per 6 to 24 months.

Normally, the catalyst can be regenerated perhaps 3 or 4 times before it must be returned to the manufacturer for reclamation of the valuable platinum and/or rhenium content

References

    1. ^ A Biographical Memoir of Vladimir Haensel written by Stanley Gembiki, published by the National Academy of Sciences in 2006.
    2. ^ Platforming described on UOP’s website
    3. ^ Canadian regulations on benzene in gasoline
    4. ^ United Kingdom regulations on benzene in gasoline
    5. ^ USA regulations on benzene in gasoline

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