Carbon dioxide

CO2

Molar mass 44.01 g/mol
Lifetime in atmosphere No single lifetime can be given
Global Warming Potential over 100 years 1
Estimated emissions in 2008 51,762,916 Gg
Atmospheric concentration in September 2013 393,510,000 ppt

Nearly all of the carbon content in incinerated waste is emitted to the atmosphere as carbon dioxide. Municipal solid waste contains approximately the same mass fraction of carbon as does carbon dioxide itself (27%), so incineration of 1 tonne of waste is estimated to produce approximately 1 tonne of carbon dioxide.

Carbon dioxide emitted by human activity is of course the main cause of global warming leading to climate change. Under the Climate Change Act 2008, the UK is committed to reduce greenhouse gas emissions from 1990 levels by at least 80% by 2050. In 1990, emissions from energy consumption were 10.5 tonnes of carbon dioxide per capita, so the target is slightly over 2 tonnes per capita.

In 2011, UK emissions from energy consumption were 8 tonnes per capita, the reduction from 1990 largely due to the replacement of coal by gas in electricity generation. The Exeter Incinerator is designed to accept up to 60,000 tonnes per year of waste, from Exeter and the immediate surrounding area in Devon. With a population of about 120,000, that means 0.5 tonnes of carbon dioxide added to every person’s carbon budget. But suppose the Incinerator replaced some carbon emissions from other energy plant……

Incinerators have electricity generation efficiencies of 14-28%. The waste heat can be used in a district heating network, giving efficiencies higher than 80%. The Exeter Incinerator will initially provide electricity to the national grid, and has the potential to export heat but only if a district heating network is established on the Marsh Barton estate.

So the Incinerator will produce electricity at a substantially lower efficiency than the rest of the national grid, and displace lower carbon alternatives.

Pattern – Bonds

Bonds

Download this pattern as a pdf

See also the patterns for the atoms and the number and colours of atoms and bonds needed for each particle.

Wool
Needles
Double knit
3.75mm DPNS

Pattern – joining two atoms of the same colour

Cast on 4 sts, leaving a 20 cm tail
Knit i-cord for 16 rows
Cast off i-cord, leaving a 20 cm tail

Pattern – joining two different colour atoms

Cast on 4 sts, leaving a 20 cm tail
Knit i-cord for 8 rows
Knit 1 stitch i-cord, join the second colour and knit the rest of the row
Knit i-cord for 7 rows
Cast off i-cord, leaving a 20 cm tail

Knot the tails of the two colours at the join.
Thread each tail in turn onto a needle, pass through the cord of the same colour, cut so ends stay inside.
Work the knot inside the cord, and the stitches so they even out.

 

Thread each 20cm tail onto a needle and sew the bond onto the atom.
Pass remaining tail through atom, cut so ends stay inside.

Pattern – Atom

Atoms

Download this pattern as a pdf

See also the patterns for the bonds between atoms and the number and colours of atoms and bonds needed for each particle.

Our prototypes were made with bog-standard acrylic wool, and the atoms stuffed with a slightly shredded half of a plastic charity collection bag. These are the sorts of materials that will be burnt in the Incinerator. But really, anything that is weatherproof will be suitable.

If you are new to knitting, some of the codes below may be a mystery. But the internet is full of
marvels such as tutorials and knitting videos. It’s how we learnt i-cord.

kfb
*..*
k2tog
skpo
knit into the front an back of the stitch
repeat stitches in between
knit two together
slip stitch, knit next stitch, pass slip stitch over the knitted stitch
Wool
Needles
Tension
Double knit
3.75mm
26 stitches to 10cm

The atom will be approx 20 cm in circumference.

Pattern

Cast on 12 sts

r1
r2
r3
r4
r5
r6
r7-r18
r19
r20
r21
r22
knit
purl
kfb into each st (24 sts)
purl all
*k1, kfb* across row (36 sts)
cast on 1 st, purl across row, cast on 1 st at end (38 sts)
continue in stocking stitch for 12 rows starting with a knit row
k2tog, *k1, skpo* (25 sts)
purl
k2tog, *skpo* to last 3 sts, k1, k2tog (13 sts)
p1, *p3tog*

Cut yarn leaving a 20 cm tail.
Thread onto needle, thread through remaining stitches and pull tight.
Sew edges together, stuff atom, thread through casting on stitches and pull tight.
Knot tails together, thread onto needle and pass through atom, and cut so ends stay inside.