3.6 Environmental Implications
49
emission of 70% of its own weight. Further CO 2 emission occurs as a result of the
mineralization of the protein when it is used as fertilizer. Other emissions from this
process include ammonia, dinitrogen monoxide and nitrogen oxides.
For chitin production from crab shells, the CO 2 emission during the acid demineralization was estimated at 0.9 kg/kg of chitin produced. For both sources assessed,
crabs and shrimp, the chitin production process had more impact on acidification of
the environment and climate change than any other process in the supply chain from
transportation to chitosan production. However in terms of water use, the shrimp
shell supply had more impact on water use than chitin or chitosan production while
in crab shell supply chain, chitin production had more impact on water use. Likewise
in crab shell production, the chitosan production led to more toxins being released
into the environment while in shrimp shell production chitin production and chitosan
production had similar level of impact on Fr. Ecotox.
3.6.7 Energy and Electricity
The energy consumption starts from the fuel used in the transportation of raw materials to the factory. For Mahtani Chitosan, a reported 1.4 L of diesel is consumed
per tonne of shrimp transported using a tractor. A further 0.02 L of diesel is used
up per kg of chitin produced in bulldozer operations. The process is also reported
to consume 1.3 KWh of electricity per kg of chitin produced. Conversion of chitin
to chitosan through deacetylation consumes a further 1.06 KWh of electricity and
31 MJ of burning wood as fuel per kg of chitosan produced from shrimp shell.
For chitin production from crab waste, Company x reports an electricity consumption of 1.2 KWh and 6 kg of coal fuel for heating per kg of chitin produced. The
chitin is then transported to Europe from China, an estimated distance of 22,874 km
by sea, adding to the energy consumption.
In developing a greener supply chain for chitin and chitosan production, transportation systems such as bicycles could be considered to transport the aquatic waste
serving as the raw materials from the point of generation to the factory. Such is
being adopted in some recycle models in countries like Nigeria and India where
bicycles, rickshaws and pushcarts are used to transport used plastics from homes and
businesses where they are generated to recycle factories.
Therefore although chitin is a biopolymer, the process of extraction may not necessarily be biologically friendly. For this reason, researchers have explored green
chemistry for production processes which require the use of less resources and less
harmful chemicals in the production of chitin, chitosan and the chemicals used for
extraction. Other alternatives for extraction includes the use of enzymes and fermentation by microbes. Although these have been explored by researchers, the chemical process is still preferred in commercial production due to the high cost of the
biological extraction methods.
Chitin in its crude form without isolating it from the minerals and collagen has
also shown potential in applications such as agriculture and pharmaceuticals. Other
49
emission of 70% of its own weight. Further CO 2 emission occurs as a result of the
mineralization of the protein when it is used as fertilizer. Other emissions from this
process include ammonia, dinitrogen monoxide and nitrogen oxides.
For chitin production from crab shells, the CO 2 emission during the acid demineralization was estimated at 0.9 kg/kg of chitin produced. For both sources assessed,
crabs and shrimp, the chitin production process had more impact on acidification of
the environment and climate change than any other process in the supply chain from
transportation to chitosan production. However in terms of water use, the shrimp
shell supply had more impact on water use than chitin or chitosan production while
in crab shell supply chain, chitin production had more impact on water use. Likewise
in crab shell production, the chitosan production led to more toxins being released
into the environment while in shrimp shell production chitin production and chitosan
production had similar level of impact on Fr. Ecotox.
3.6.7 Energy and Electricity
The energy consumption starts from the fuel used in the transportation of raw materials to the factory. For Mahtani Chitosan, a reported 1.4 L of diesel is consumed
per tonne of shrimp transported using a tractor. A further 0.02 L of diesel is used
up per kg of chitin produced in bulldozer operations. The process is also reported
to consume 1.3 KWh of electricity per kg of chitin produced. Conversion of chitin
to chitosan through deacetylation consumes a further 1.06 KWh of electricity and
31 MJ of burning wood as fuel per kg of chitosan produced from shrimp shell.
For chitin production from crab waste, Company x reports an electricity consumption of 1.2 KWh and 6 kg of coal fuel for heating per kg of chitin produced. The
chitin is then transported to Europe from China, an estimated distance of 22,874 km
by sea, adding to the energy consumption.
In developing a greener supply chain for chitin and chitosan production, transportation systems such as bicycles could be considered to transport the aquatic waste
serving as the raw materials from the point of generation to the factory. Such is
being adopted in some recycle models in countries like Nigeria and India where
bicycles, rickshaws and pushcarts are used to transport used plastics from homes and
businesses where they are generated to recycle factories.
Therefore although chitin is a biopolymer, the process of extraction may not necessarily be biologically friendly. For this reason, researchers have explored green
chemistry for production processes which require the use of less resources and less
harmful chemicals in the production of chitin, chitosan and the chemicals used for
extraction. Other alternatives for extraction includes the use of enzymes and fermentation by microbes. Although these have been explored by researchers, the chemical process is still preferred in commercial production due to the high cost of the
biological extraction methods.
Chitin in its crude form without isolating it from the minerals and collagen has
also shown potential in applications such as agriculture and pharmaceuticals. Other