Saturday, 3 October 2015

Night visit to Bois Rouge sugar factory

One wet and windy evening recently I found myself on a night visit to the Bois Rouge sugar factory in Saint André, one of only two sugar factories that still operate on Reunion Island.

While the adjacent rum distillery can be visited all year round, the sugar factory can only be visited during the cane harvest season, which runs from June to December.

Bois Rouge receives sugar cane from the island's whole east coast, from Sainte Rose to Saint Denis.

As soon as the sugar cane is delivered, the loads are weighed and sampled by an independent technical centre to assess the sugar content of each load.

Weight and richness in sugar are determining factors in fixing the sugar cane buying price.

The unloaded sugar cane then goes into a shredder, a machine composed of 144 hammers mounted on a shaft. The hammers pulverise the cane onto a huge anvil in order to ensure clear passage for the cane fibre into the other machines.

One the sugar cane juice has been extracted, it is clarified and decanted by being preheated to 105°C and lime is added to stabilise its pH at 7.5. During the decantation process a flocculant polymer is added to obtain clear juice.

The leftover filtration residues following decantation are known as filter cakes. These cakes are rich in phosphates and are given back to the cane planters who use them as fertiliser.

The clear juice is preheated to 120°C and enters a 6-effect evaporation station. Output steam from the power station is introduced into the first evaporator body. As it passes through the evaporators the clear juice is concentrated into a syrup known locally as Sirop La Cuite.

The syrup is the crystallised in a cooking vacuum pan. The operators feed in a certain quantity of syrup and then add a few sugar grains in order to set off the crystallisation process. At the end of this process a crystallised mass is obtained, which is continuously mixed enabling the sugar contained in the original liquid to settle on the crystals and ensure greater crystal growth.

The centrifugal process separates the original liquid from the sugar crystals. In order to obtain high-quality crystals superheated water is used to dissolve the envelope of the original liquid surrounding the crystals. Finally, following the centrifugal process the original liquid undergoes tow other crystallisation cycles in order to extract as much sucrose as possible.

At the end of the three successive crystallisation, mixing and centrifugation cycles, a liquid called molasses is obtained, which is low in sucrose content. Molasses are transferred to the distillery for rum and alcohol production.

one of the workers

in the control room

Since 1992 in addition to its basic manufacturing process, the Bois Rouge sugar plant has been developing consumer sugar units for brown and refined white sugar.

sugar sample for laboratory testing 

These high added-value products require specific manufacturing processes all the way through the different production stages.

some different types of sugar
- the finished product !

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Saturday, 25 July 2015

Slacklining in Reunion Island

I've previously posted an incredible video about slacklining across the 3 Salazes, here are more videos of slacklining in Reunion, including a world record!

The first shows Swiss Raphael Bacot and his Reunionnese counterpart Kevin Borg of Slackline 974 crossing a suspended midline against a background of exploding waves on the south coast, at Cap Mechant.

© Dronecopters

© Dronecopters

The second takes place in the isolated mountain cirque of Mafate and shows Kevin crossing a 40-metre high gorge at Trois Roches. Both these exploits were filmed using a mixture of images from a Gopro (from the slack liners' point of view) and aerial shots by drones.

The third video shows Nathan Paulin setting a world record on 9th June 2015 by crossing the longest slackline in the world, 403m long and 250 metres above ground at the Cassé de la Rivière de l'Est. It took him 23 minutes to walk the 403m and he was filmed by Les six patates. (A few weeks later he set a new world record highline at the Natural Games in Millau, France – 469m).

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Sunday, 12 July 2015

Mauritius seen from Reunion and vice versa

Well-known local photographer Luc Perrot published a photo this week of Mauritius seen from Piton de la Fournaise, Reunion Island. He explained that winter brings clear night skies, which make this sort of photo possible.

Mauritius as seen from Piton de la Fournaise,
Reunion Island © Luc Perrot

cropped version of the above photo © Luc Perrot

Panoramic view, with the volcano clearly visible
to the right © Luc Perrot

As some people seemed to think it wasn't possible to see Mauritius from Reunion, Mauritian photographer Burty Makoona sent the photo below, which Perrot annotated.

Reunion, seen from Mauritius © Burty Makoona

Annotated version:

Reunion, seen from Mauritius (annotated) © Burty Makoona

Another photo by Perrot was recently Photo of the Day on the Earth Science Picture of the Day (EPOD) website (EPOD is a service of the Universities Space Research Association).

Piton de la Fournaise © Luc Perrot

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Wednesday, 8 July 2015

Advance warning: solar eclipse on 1st September 2016

On Thursday 1st September 2016 an annular solar eclipse will be visible from Réunion Island.

example of an annular solar eclipse

A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light (in this case 97%) and causing the Sun to look like an annulus (ring).

path of the eclipse

While the whole eclipse will last from 06:13–12:00 UT, the point of maximum eclipse will last 186 seconds (3 minutes 6 seconds), and the maximum width of the band will be 100km (62 miles). It will be seen across central Africa southwards to Madagascar and into the Indian Ocean. The partial eclipse will be visible across most of Africa and parts of the Middle East. The points of Greatest Eclipse and Greatest Duration will be in southern Tanzania.

path of the eclipse

Most of Réunion will see the annular eclipse at about 10:09 UT. Although the island is not on the centreline, the duration in the south-west (near St Pierre) should be quite good, as the centreline duration is still over 3 minutes.

map showing path of eclipse over Reunion

The last solar eclipse visible on Réunion was on 21st June 2001.

For more information:

Sunday, 31 May 2015

May 2015 volcano eruption

Réunion's volcano, Piton de la Fournaise, erupted for the second time this year on May 17th and continued erupting for two weeks until yesterday, May 30th. During the 13 days the eruption lasted at least 8 million cubic metres of lava were ejected, which corresponds to the volume normally ejected over a period of 20 days. The volcanic cone which has formed has a volume of 400,000 cubic metres, or 13 Olympic swimming pools!

Here are some photos and videos of the eruption. 

This AFP photo by Richard Bouhet was widely distributed
by the international media

© Drone copters

© Lionel Ghighi

© Sebastien Conejero

© Sebastien Conejero

Note that one of Reunion's Volcano Observatory four webcams was directed towards the eruption (bottom right hand corner).

screenshot of the Volcano observatory webcam (source)

Update: the photo below, by Pierre Choukroun, was photo of the day  for June 16th on the website Volcano Discovery.

Sunday, 29 March 2015

Scuba Diving in Rodrigues

The island of  Rodrigues, about 600 km ENE of Mauritius, is probably one of the remotest places I've dived after Saipan in the Pacific. The island covers only 108 sq. km, but the lagoon covers 230 sq. km! Its coral reefs are very rich, and we saw many species of reef fish while there, including some enormous porcupinefish, as well as some green turtles and lots of trevallies.

Rodrigues and its lagoon

We did 11 dives on ten different sites while in Rodrigues, all from the Cotton Dive Center in the east. The two most memorable were the St François Pass (which we dived twice), and Canyon where we had to used ropes! Below are a few photos.

Phyllidia varicosa nudibranch

Sea cucumber

this type of angelfish is only found in the waters around Rodrigues 

Yellow teardrop butterflyfish (Chaetodon interrupts), only found in the Indian Ocean

Blackspotted pufferfish (Arothron nigropunctatus)

Black-saddled leopard grouper (Plectropomus laevis)

Scorpion fish, possibly a humpback scorpionfish

Blue triggerfish (Pseudobalistes fuscus)

Moray eel

Pipefish (Corythoichthys)

Great barracuda (sphyraena barracuda)


Me (holding a Gopro) at Karlanne dive site

Bigeye trevallies (Caranx sexfasciatus)

Leaf fish (Taenianotus triacanthus)

Spiny lobster (Panulirus versicolor)

Giant clam (tridacna maxima)

Other articles about diving in Rodrigues:

me, watching a shoal of fish go by

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