Introduction
Castor-oil plant is a member of the Euphorbiaceae family which is a kind of
perennial woody herbaceous plant. It originated from Egypt, Ethiopia and India.
Subsequently it was spread to Brazil, Thailand, Argentina and United States of
America etc. The castor planted in China came from India and has a history of
more than 1400 years. At the beginning of 20th Century, the growing aviation
industry needs such lubricating oil that doesn¡¯t freeze , so castor was
extensively developed in a short time and as one of the world's top ten oil
crops, castor was widely cultivated as the field crop. At present, the largest
castor producer is India, followed by China, Brazil and Thailand.
Castor
leaves are nutritious which can feed eri silkworms; Castor stems are good raw
material to make paper, medium density board and active carbon; Castor meal is
high protein feed after detoxication, it also can be used as biological pest
control agents to control farmland underground pests after drying and crushing;
Castor roots contain ricinine and ricin which can be used as biological pest
control agents too.
The oil content of castor seeds reaches up to 46-56%,
generally 2.2-2.5 kg seeds can produce 1 kg oil, which is higher than that of other oil crops. Castor oil has many characteristics such as high viscosity,high
specific weight, low solidifying point (-18¡æ£©and high burning point
(500-600¡æ),so castor becomes the only raw material to produce ricinoleic
acid.Most products made from petroleum can be made through ricinoleic acid deep
processing, so castor is looked as the reproducible ¡°petroleum¡± resource. With
the rapid development of the aviation industry and the chemical industry, castor
oil has been widely used as advanced lubricants, brake oil and preservative oil
in aviation and precise instrument fields, it also has had more and more
application in defense, chemicals and pharmaceuticals industries etc. The
synthetical resin particle Nylon 11 is made from castor oil and has been widely used in such industries
as automobile, ships, machine tool, construction, war industry and medical
attendance etc. Industrial developed regions and countries such as USA and
Western Europe have produced up to 3000 derivatives from castor oil, Formic
ester and butyl ester made through esterification are the main material to
produce lubricating agent, plastics, cosmetics and cleaning solvent. Among
castor oil fatty acid component, 90% is ricinic acid, it can produce health
salad oil after detoxification treatment. Castor meal can be used as fertilizer,
after detoxification treatment it also can be used as feed.
Only by means of
estimating of the wide application trend of high strength insulating materials
Nylon, the world castor oil demand in 2010 will reach up to 800000-1000000 tons,
equivalent to castor beans 1900000-2400000 tons. There are hundreds of castor
oil factories in China among which 20 ones are big and middle sized, the annual
castor beans demand is more than 800000 tons, but the actual total castor
production is only about 250000 tons, there is a big difference of quantity
between supply and demand. The domestic castor oil demand increased greatly, 70%
need to be imported. Because of the acute shortage of castor beans, 70% of
castor oil factories in China had to shut down or partly shut down
In China,
the castor distribution has no obvious boundaries, castor is planted in wide
regions from southern Hainan island to northern Heilongjiang province. The most
widely planting areas are Yellow River Valley and Yangtze River valley. Castor
has many outstanding characteristics such as drought- enduring,
barrenness-enduring, saline-alkali-enduring, strong adaptability, simple
management, low investment and high economic benefits etc., so it becomes the
promising crop of dry land cultivation and barren dryland development.