Wastes are not really wastes.

They are raw materials useful in other areas.

We see this by the way we use kitchen waste to produce compost…

Or when plastics are recycled back to industry…

Or when cow dung is used to make biogas.

Now think about that mound of rubbish in your neighborhood.

It’s possible to derive value from it only when we refuse to see it as trash but as an asset.

Now that we have that paradigm, let’s keenly look at one of the most abundant waste material from farming.

RICE HUSKS

Arguably, rice is only rivalled by maize, potatoes and wheat when it comes to global consumption.

In nations like Kenya, rice growing areas such as the Mwea and Ahero schemes have been touted as potential food baskets for the present and the future.

But rice production comes with its fair share of by-products such as rice husks.

Rice husks – or rice hulls – are the outer covering which is removed during processing and before sale.

The mounds of rice husks near rice milling plants are a testament to the solid waste problem this waste creates.

However, some rice millers still use them as fuel to run factory boilers etc.

With time, rice husks are gaining prominence as a valuable resource and so fetch some reasonable price – I remember buying a 70kg sack at about 5 USD (if memory serves me right).

Such a valuable waste material must attract more uses apart from fueling boilers.

How can an aspiring business man (or woman) use rice husks profitably?

Remember that doing so will not only generate employment but also solve the solid waste problem farmlands are grappling with.

So let’s dive into some possible applications of rice husks.

SILICON

Silicon is extremely useful especially when you’re talking about green energy.

In it’s pure form, it’s the basic building block for solar cells – which are used to make solar panels.

But what relationship does rice husks have with silicon?

You see, rice husks are about 50% silica by weight.

Silica is the oxide of silicon.

Which means that if you can recover silicon in it’s pure form from rice husks, you just might stumble upon the raw material for manufacture of solar cells.

But this is a tall order in many ways.

First, removing the oxygen from silica requires very high temperatures under low oxygen conditions.

But there are possibilities such as using high pressure reactors which some

reduces the temperature needed for this reaction.

But why use silicon from rice husk yet silica is all around us in the form of sand?

Well, sand harvesting isn’t environmentally friendly.

But more importantly, silica from rice husks is extracted in a form that could be easier to work with.

It’s size is in micro or nano form.

Besides energy, rice husks are also important in another area all together.

WATER TREATMENT

When rice husks are ashed – burnt to form an ash – a very interesting trait emerges.

They suddenly acquires the ability to attract many substances dissolved in water.

This attribute makes them very good water filters.

Simple rice husk ash has the ability to remove some metals, pesticides and other pollutants in our drinking water.

Now that it has such characteristics when in raw form, imagine how much value it could have when processed as a sophisticated water filter?

But rice husks possess more than just filter capabilities.

FERTILIZER

When the husks are burnt under low oxygen, a substance called biochar is the produced.

Now biochar is a well known soil amendment which helps some crops to grow in very poor soils.

Introducing biochar to soils also helps reverse the impacts of climate change.

This is because carbon is put back into the soil as opposed to into our air.

Biochar is also highly porous making it helpful as a home for microorganisms.

It is also known to detoxify soils from toxic metals, pesticides etc.

Last but not least, rice husks could prove useful in the area of construction.

POZZOLANA CEMENT

It’s high silica content means that it can be considered as an additive to construction cement.

Several trials of rice husk-based cement have been done showing promising results.

However, because of their light weight nature, to generate a sizeable amount of cement requires quite a large amount of rice husks.

So this is a venture worth exploiting at industrial scale given the opportunities for construction around us.

IN CONCLUSION

Rice husks could be used to manufacture other products such as rubber fillers, thermal insulators, silica, paint pigments, materials such as silicon carbide – used in industrial cutting equipment – all which could generate an income and put money in people’s pockets.

So the next time you eat rice, think about the opportunities that could be created by it’s waste material – rice husks.