with large internal cavities are converted to agarose, then chemically modified
and purified to make a major component of Nemidon gels. The choice of agar is
critical; it must be capable of being converted to an agarose with a particular
macro structure regarding cavity size. Upon application to the skin, the gel partially
dries and forms a very thin film. Reflection intensities of lightshow that over 90%
of the light remains reflected or back-scattered, which requires that the film
contraction has lifted the bulk of the film from the skin, but with the aid of
additional components in the gel, it still remains firmly attached to the
higher spots. As it dries, the film contracts, which pleasantly tautens the
skin. The film then becomes a moisture regulator, which maintains a useful
water vapour pressure above the skin that is required to maintain skin
plasticity. The gels are therefore useful for any application where moisture
control to the skin is required, including as a moisturizer and for healing
cracked skin, particularly for feet. The film is transparent, but when rubbed
gives a particularly pleasant feel to the skin. The gels are also effective at
delivering active ingredients to the skin because there is invariably little
affinity for the agarose, while they are also useful for holding suspended
solids above the skin, such as for preventing chafing. For more details, and a
list of available products, visit http://www.nemidon.com.
Biomass pyrolysis is one
of the oldest known technologies, and products include charcoal, activated
carbon, pyrolysis oils, pyrolysis gases, and more recently, carbohydrate-based
chemicals have been made. As with any chemical processing, the two basic
problems are heat transfer and matter transfer, and at Carbonscape Ltd microwave energy
removes most of the problems associated with low thermal conductivities and
permits much improved heating, which gives several options to vary the
chemistry of the process. The charcoal can be made sufficiently pure to be of
interest for steel-making, while biochar may be of particular interest for soil
conditioning and remediating the emission of greenhouse gases such as nitrous
oxide and methane. With suitable feedstock, essential oils can be obtained and
of particular interest are the bio-oils, where in some variations of the
process, a relatively high per centage of the yield can be obtained in a very
few, relatively easily purifiable products, thus opening the possibility of
chemical production. Finally, torrefaction of the biomass will make it more
suitable for further processing.
Carina Chemical Laboratories Ltd was set up in 1986 to provide research for two major projects involving joint ventures with ICINZ Ltd. The topics listed below are no longer active, however samples and information are available. Current projects are listed under Science or Commercial Activities.
The ZSM5 catalysts of
the Motunui Synfuels plant
produced a stream of "heavy gasoline" that contained approximately
35,000 t/a of durene, a
hydrocarbon otherwise having to be produced by chemical synthesis. In 1986, ICI
Synchem Ltd won the rights from the New Zealand Government (which owned the hydrocarbon stream) to purchase durene
to convert it to pyromellitic acid and to pyromellitic dianhydride, a raw material for a number of temperature resistant polymers,
Carina developed routes for manufacturing a number of durene-based chemicals and
investigated prospective uses for them, including a number of pentacene-5,7,12,14-tetrones
(mainly photochemical properties), duroquinone , pyromellitic diimide, to be used as a ruminant methane inhibitor) or for polymer curing, 1,4-di(aminomethyl)-2,3,5,6-tetramethylbenzene, and a
number of polymer intermediates. The pentacene tetrones make dyes analogous to
the anthraquinone dyes as well as acid-base indicator dyes, but they
can also be strong photodegradative agents. 1 kg of pyromellitic diimide was made and was used to inhibit
methane formation in a number of sheep over a year. The objective here was to
make food supplements last longer during droughts, and food uptake efficiency
was strongly enhanced. Initial targets for the venture included low mobility
plasticizers and polyimides. The original promotion included a TV appearance with
a demonstration of the fire-resistance of "home-made" polyimide foam,
and while the pictures of that are unavailable, the effectiveness is shown on http://www.youtube.com/watch?v=i4kCAP4sQU8
. The venture, which had a projected worst-case IRR of > 50%, terminated
when the New Zealand Government refused to complete
the supply contract and sold the Motunui plant.
Agar and Agarose production
In 1987, the joint
venture company ICI Biocol Ltd was formed to implement a technology I developed
to make agar from mixed
seaweed as washed up on the Wairarapa coast, without sorting and drying it. The project
terminated when the two parties could not agree on the way to proceed, followed
by difficulties arising from the share-market crash. Subsequently, a process to
make agarose was developed, and a small production plant constructed by the
company Vela Agarose Ltd, but this plant had to be dismantled when property
development was to lead to the demolition of the building in which it was
contained. (In the event, they changed their mind about demolishing the
building after the plant was dismantled.) At this point the venture collapsed
due to financial reasons.
Enhanced processing technologies for agar production were developed, and are available for implementation. Standard extraction of agar from Pterocladia lucida gives an agar in about 25% yield and with a gel strength of about 500 g/cm2 for a gel made from 1.5% agar concentration. The enhanced technology gives a yield approaching 35% and approaching 1500 g/cm2 for a 1% gel. Similar improvements are possible for a number of other agaroids, however there are some seaweeds for which no such performance is possible, usually because of a significant dispersion of L-galactose throughout the
polymer. With suitable seaweed samples, it is possible to make a moderate grade agarose directly without subsequent purification. It is well-known that substitution of agarose gives agaroses that remelt at lower temperatures, which is useful for certain applications in biotechnology. Usually, there is an associated problem that gel strength also falls dramatically with lower temperature. A process that significantly overcomes this difficulty is also available.
Chemicals and Fuels from
Considerable work has been undertaken throughout the world to devise routes for making fuels from microalgae, in part because they are amongst the fastest growing plants on earth. The major problem with microalgae is the difficulty in harvesting. Their tissue is soft and sticky and they are small, which makes filtration difficult as they block filters. Their density is essentially that of water, so they can remain suspended, hence centrifugation is difficult. When they are "isolated" the "product" is often only a few per cent of microalgae, the rest being water. Their components are mainly protein and lipid, together with some outer structural membrane that contains the photosynthesis systems. While microalgae are growing rapidly, the energy is devoted to reproduction, and the composition is mainly protein, with about 5% free lipids. This lipid content is actually over 20%, but most is locked into cell walls and is not easily extracted.
The usual process for making fuel is to extract the lipids. Extraction of the wet mass tends to make emulsions that are difficult to separate, while there is considerable expense in drying the mass. Furthermore, the phospholipids and lipoprotein represents lost resource.
My preferred approach involves hydrothermal treatment. This
reduces harvesting costs as an aqueous slurry is used, the whole organism
is used, and this leads to a mixture of chemicals, including pyrazines, lactams,
aromatic hydrocarbons, long chain alkanes and alkenes, a variety of ketones and
a range of other materials. An example of such products is given here.
superficially the lack of specific cultivation has reduced the levels of what
is usually considered desirable, the process becomes a biological source of
certain chemicals that are otherwise difficult to obtain, while at the same
time the feedstock grows in water that will always be produced, e.g. sewage, and when sewage is used, the process permits the generation of value while removing pollutants that have to be removed anyway.
Pyrolysis of Cellulose
A small-scale process
was developed to make levoglucosenone in approximately 10% yield from
the pyrolysis of cellulose. The process appeared successful, but the targeted
market did not eventuate. Levoglucosenone can be purchased here.
Photostability of dyes
From 1990-1992, besides
demonstrating the acute photodegrading activity of pentacenetetrone dyes, two
methods were developed to enhance the photostability of dyed wool. A project
was undertaken to develop dye auxiliaries and examine their photochemical
developed for larger-scale substitution of algal polysaccharides, and a large
number of methylated and sulphated galactans were prepared. A number of these
show biological activity, and samples remain.