**8.6 Particle/composite board making**

Rice husk and cereal straw are used for making of particle boards. Rice husk is cleaned and cereal straw thus defibred into particles is mixed with rice husk


**Table 4.** *Residues produced from major crops [67].* *Sustainable Biowaste Management in Cereal Systems: A Review DOI: http://dx.doi.org/10.5772/intechopen.97308*

at desired proportion and then blended with cashew nut shell liquid or cardanol phenol formaldehyde resin [68]. The mixture is spread into a mat or layer of uniform desired thickness and hot pressed like conventional method of particle board making [68]. Rice husk is 20 per cent of total rice produced which can be used as cheaper, lighter, denser, stronger, durable and more uniform substitute for conventional wooden and ply boards thereby protect against deforestation and environmental degradation. Because of high Si content rice husk is difficult to burn. Apart from rice husk, rice and wheat straw can also be used for making strawwood particle composite boards and insulation boards. However, use of rice husk in comparison to bamboo for particle board making resulted in poor quality due to higher Si content in rice husk and non-availability of suitable blender for effectively binding rice husk [69]. Advance researches are still continuing to develop an efficient and effective adhesive for rice husk boards.

#### **8.7 Paper making and packaging**

Rice straw can be used as raw material for making quality paper. It contains lesser lignin compared to conventional wood and thus requires milder chemical pre treatment. Cheaper soda and soda-AQ methods are used for making paper in many developing countries but blending pollutes water by releasing more than 500 chlorinated compounds that are highly toxic, bioaccumulative and carcinogenic [70]. The graduates of IIT, Delhi have developed a pulp making process in a start up called Kriya Labs [71] that can be used in making paper, plates and cups [72].

Bio-Lutions India in Bengaluru purchases crop wastes from farmers and transforms them into biodegradable packaging materials for fruits and vegetables which can be degraded completely within three months [72]. Bio-plastics, derived from rice straw by mixing with starch, cellulose, glycerol and protein are ready to substitute the conventional plastic very shortly as it is readily biodegradable within 180 days of use compared to 500 years required for plastics to degrade [72].

#### **8.8 Briquetting**

The straw functions very well as bedding for animals such as horses. When briquetted, straw absorbs 5 times more fluid than normal straw for bedding. This minimizes the cleaning work in the stable, and creates a better environment for the animals. Furthermore, briquetted straw is useful for burning, and it is an excellent source of energy through generating heat, steam and electricity in conventional boilers or gasification plants.

### **9. Conclusion and future outlook**

With the advent of modern scientific agricultural practices, the agriculture and agri-waste production have increased at exponential rates across the globe. Cereals, being the staple food for humans as well as feed for cattle, contribute the most to the pool of such agri-wastes. Sustainable management of crop residues, especially in cereal systems, has been the greatest challenge before us in this world with the ever burgeoning population, agricultural production and economic growth. Rice and wheat contribute the most to the agri bio-waste pool due to wider cultivation and large scale production. However, many countries in Asia, Africa and America, at present, have failed to cope up with the large volume of crop residues although a majority of these are used as fodder and fuel. In India, northern states such as Punjab, Haryana, and western Uttar Pradesh burn crop residues in the month of

October and November every year thereby releasing toxic fumes into the atmosphere that are very often drifted to the adjacent cities and states. Most of these residues are byproducts of wheat and rice. Small farmers usually resort to burning of crop residues as it is the inexpensive alternative in absence of technical knowhow on any other better profitable and sustainable residue management or disposal opportunities.

Large scale burnings of crop residues shockingly increase air pollution and serious health issues. In the past few decades, the authorities have relentlessly tried to explore multiple waste management options to cater such unequivocal but perilous agri-wastes from the cereal systems. The possibilities of waste incorporation and decomposition through soil addition and composting are few preferred acceptable alternatives. Penal actions have also been provisioned against the errant promoters of open burning. In this line, in India, the National Remote Sensing Agency (NRSA) and Central Pollution Control Board (CPCB) have come together to monitor open burning of crop residues through aerial surveillance and to penalize farmers for doing so. However, continued air pollution in the month of November and December in spite of much touted successful, sustainable and effective actions against open burning has raised many eyebrows. Hence, efforts are being made to explore farmers' friendly and financially viable options of residue management such as composting, biochar making, biofuel and biogas production, particle and composite board making, paper manufacturing, etc. In many developed countries, 1G and 2G ethanol production have now gained momentum that use waste biomass judiciously for generation of liquid and gaseous fuels. Corporate social responsibility (CSR) funds are being allocated in many countries for conducting research and development on large scale profitable biofuel production. It is high time to develop national gas-grid line with the support of remote sensing and GIS tools to monitor and regulate biomass production and utilization. Community biomass collection centres could facilitate easy and speedy collection and back up storage of biomass for further residue management strategies. And importantly, the residue management options should involve environment, education, social, and economic sectors holistically in addition to agriculture and energy sectors beyond the disciplinary boundaries.
