Review
All attempts to use straw as animal feed or fertilizer have failed, but scientists
have experimented with rice straw and devised a mechanical way to treat it without
contaminating it in order to extract the fibers so that they could be formed into
cheap, formable materials into medium, light, and high-density wood panels
(Density fiberboard MDF) that are imported from abroad at over $2 billion a year -
the only wood in the world to be considered the first in the world.
Rice straw can be treated in order to improve its nutritive value. Those
treatments are designed to enhance feed intake and/or digestibility. Improving
digestibility may be achieved through mechanical, chemical, heat and pressure
treatments.
Mechanical treatments
Chopping and grinding rice straw may reduce the time of passage in the
rumen and improve feed intake (Doyle et al., 1986).
Chemical treatments
Chemical treatments (NaOH, ammonia, urea) may be hazardous to
humans (NaOH is a dangerous chemical if handled wrongly) and animals (heavy
urination, faster rumen washout).NaOH treatment consists in soaking the straw in
NaOH solutions,
draining it and sometimes washing it after treatment. This may cause water
pollution. It is also possible to spray NaOH onto the straw and then allowing it to
dry.Ammonia treatments are safer and provide nitrogen that is lacking in straw.
Ammonia reduces physical strength and disrupts silicified cuticles in leaves.
Ammonia treatments can increase digestibility by 31%.Urea treatment is the
easiest to apply. It can be done by smallholder farmers using plastic bags, with a
5% urea w/w solution. It can increase digestibility by 18% (Van Soest, 2006).
Heat and pressure treatments
Steam pressure: it releases acetyl groups from the hemi-cellulose, thus
increasing digestibility of the rice straw.Association of steam pressure and
ammonia: this treatment has been reported to induce severe hyper-excitability in
cattle (Van Soest, 2006).
Environmental impact
When rice straw is burned or ploughed under, it may cause air pollution or
generate leachates. Ploughing under may also propagate fungi (Kadam et al.,
2000). Feeding it to livestock reduces its environmental impact and makes the best
use of rice as both an energy source and a protein provider. Cattle dung can be
burned or composted to benefit from rice energy and to enrich the soil.
Method and Instrumentations
One of the properties of rice straw is that it has many valuable ingredients,
rice strew has 6 ingredients that can be chemically separated quickly and it is :
fats, waxes, hotoscellulose, lingen, cellulose and silica, in addition to producing
bio- ethanol by rice straw cellulose, cellulose and baker's yeast in one bowl, 6%
ethanol was obtained, solving the black liquid from cooking rice straw with
caustic soda to produce pulp by producing valuable materials such as silica and
hemicellulose, and producing cellulose enzymes and hemicellulose from fungal
strains.
Materials & tools and devices:
1. The Mold.
2. Wooden Chopsticks.
3. Epoxy resins.
4. Insulator material.
5. Measuring instruments.
6. Milling machine
7. Water jet machine.
1. The Mold:
The mold is a cavity in which a substance is shaped. It
is in shape of rectangle made from wood, which its total
dimensions are: 33 cm, 36 cm and 1.2 cm for length,
width and thickness respectively. Divided into three parts,
each is 10x30 cm.
