**2. Method**

Within the methodology, the goal is to develop the energy model, which is mainly based on the use of renewable energy and the search for energy efficiency, with the purpose of ensuring sustainability in the proposal, satisfying economic, environmental, and social aspects.

The model begins with the search for alternatives for recycling biomass as an alternative resource to firewood, which is why briquettes emerge as the ideal

**113**

of briquettes and rice husks.

*Sustainable Energy Model for the Production of Biomass Briquettes Based on Rice Husks…*

biofuel in the environmental proposal development. Briquettes are formed from the conglomeration of various types of waste, may it be forestry, agricultural, or industrial [14], mixed with binders such as cassava starch or bentonite, in order to optimally compact the mixtures. The choice of agricultural waste or biomass as raw material for the briquette was rice husk, due to the high rate of charred husk on location, which will allow for a large supply of this waste, reducing the population's

Having selected the clean technology, it is necessary to perform a technical evaluation of the briquette based on energy efficiency, which includes calculations of heating capacity and efficiency during combustion. The rice husk briquette has 4040 kcal/ kg heating capacity, that is, the amount of heating capacity used per kilogram burnt [15]. Its combustion energy efficiency obtained a value of 80.39%; in comparison to firewood, fewer kilograms of briquettes are needed to heat or prepare food in a shorter time. Additionally, it is important to set out the development method within the technical product evaluation, in order to meet certain technical requirements, such as moisture measurement, through the drying method, which uses the "Colombian technical standard for domestic use briquettes," permitting a value between 9 and 10%. Furthermore, there are two important aspects that were investigated to obtain an optimal briquette, based on adequate biofuel combustion: granulometric analysis and agglomeration analysis. Granulometric analysis is used to achieve a resistant briquette with sound composition, analyzing different sizes of husk particles with metal sieves. On the other hand, agglomeration analysis, using cassava starch as a binder, will be important in balancing mixture resistance and moisture. Various forms have been used, the first of which compresses the briquette with a piston and the second by manual press compression. Thus, a briquette with high quality standards, based on the

percentage of moisture, ash, and volatile matter, was obtained.

scenarios of low, medium, and high demand for briquette sales.

To ensure the energy model—designed specifically for biomass briquette production proposals—is developed successfully, it is important to establish an integrated process system, starting from the supply and demand analysis process, to briquette commercialization and the opening of new markets. In this analysis, a market study is conducted to determine the population that uses firewood for cooking, as well as the supply of rice husk quantities in the mills. In addition, the sales price is determined, including the profit percentage that the company will earn and estimations of the final proposal budget. Then, it will be necessary to determine the logistics of the proposal's supply chain, beginning with alternatives for rice husk and cassava starch supply, to later produce various production programs based on

Once the production scenarios are determined, a processing plant must be designed, with enough physical capacity to store material for a high demand, considering probable openings to new markets or potential customers, including adequate distribution of machinery, materials, and other physical production resources. The supply chain culminates with the commercialization of briquettes in rural areas where the product will be consumed, considering the necessary resources and transport costs for correct development. For example, the company or mill should include the transport of cassava starch from agricultural areas to the processing plant or the most efficient form of transport for the commercialization

Finally, the energy model seeks to be sustainable by ensuring process operability,

so the economic, environmental, and social impacts of the briquette production proposal are analyzed. Regarding the economic impact, companies plan to economically value agricultural waste products, which will subsequently generate additional income, entering new briquette markets in both domestic and industrial sectors. Regarding the social impact, quality of life was improved, since inhabitants'

*DOI: http://dx.doi.org/10.5772/intechopen.81817*

social cost.

#### *Sustainable Energy Model for the Production of Biomass Briquettes Based on Rice Husks… DOI: http://dx.doi.org/10.5772/intechopen.81817*

biofuel in the environmental proposal development. Briquettes are formed from the conglomeration of various types of waste, may it be forestry, agricultural, or industrial [14], mixed with binders such as cassava starch or bentonite, in order to optimally compact the mixtures. The choice of agricultural waste or biomass as raw material for the briquette was rice husk, due to the high rate of charred husk on location, which will allow for a large supply of this waste, reducing the population's social cost.

Having selected the clean technology, it is necessary to perform a technical evaluation of the briquette based on energy efficiency, which includes calculations of heating capacity and efficiency during combustion. The rice husk briquette has 4040 kcal/ kg heating capacity, that is, the amount of heating capacity used per kilogram burnt [15]. Its combustion energy efficiency obtained a value of 80.39%; in comparison to firewood, fewer kilograms of briquettes are needed to heat or prepare food in a shorter time. Additionally, it is important to set out the development method within the technical product evaluation, in order to meet certain technical requirements, such as moisture measurement, through the drying method, which uses the "Colombian technical standard for domestic use briquettes," permitting a value between 9 and 10%. Furthermore, there are two important aspects that were investigated to obtain an optimal briquette, based on adequate biofuel combustion: granulometric analysis and agglomeration analysis. Granulometric analysis is used to achieve a resistant briquette with sound composition, analyzing different sizes of husk particles with metal sieves. On the other hand, agglomeration analysis, using cassava starch as a binder, will be important in balancing mixture resistance and moisture. Various forms have been used, the first of which compresses the briquette with a piston and the second by manual press compression. Thus, a briquette with high quality standards, based on the percentage of moisture, ash, and volatile matter, was obtained.

To ensure the energy model—designed specifically for biomass briquette production proposals—is developed successfully, it is important to establish an integrated process system, starting from the supply and demand analysis process, to briquette commercialization and the opening of new markets. In this analysis, a market study is conducted to determine the population that uses firewood for cooking, as well as the supply of rice husk quantities in the mills. In addition, the sales price is determined, including the profit percentage that the company will earn and estimations of the final proposal budget. Then, it will be necessary to determine the logistics of the proposal's supply chain, beginning with alternatives for rice husk and cassava starch supply, to later produce various production programs based on scenarios of low, medium, and high demand for briquette sales.

Once the production scenarios are determined, a processing plant must be designed, with enough physical capacity to store material for a high demand, considering probable openings to new markets or potential customers, including adequate distribution of machinery, materials, and other physical production resources. The supply chain culminates with the commercialization of briquettes in rural areas where the product will be consumed, considering the necessary resources and transport costs for correct development. For example, the company or mill should include the transport of cassava starch from agricultural areas to the processing plant or the most efficient form of transport for the commercialization of briquettes and rice husks.

Finally, the energy model seeks to be sustainable by ensuring process operability, so the economic, environmental, and social impacts of the briquette production proposal are analyzed. Regarding the economic impact, companies plan to economically value agricultural waste products, which will subsequently generate additional income, entering new briquette markets in both domestic and industrial sectors. Regarding the social impact, quality of life was improved, since inhabitants'

*Green Energy Advances*

**Figure 2.**

**Figure 3.**

briquettes for domestic use.

*Dimensions of rice husk briquettes.*

between 8 and 10% [13].

environmental, and social aspects.

**2. Method**

As mentioned above, the briquette is not a new technology, so determining briquette design will depend on product use and specifications of the briquette machine. For industrial processes or businesses, lengths vary between 300 and 1000 mm, for producers length varies between 100 and 500 mm, and for domestic sector, length varies between 30 and 80 mm. **Figure 3** shows the ideal prototype of

*Environmental pollution due to rice husk burning during 2013–2014 agricultural campaign in Peru.*

The inclusion of an interior hole will endow the briquette with greater oxygenation capacity but could increase volatile matter, so the shape of the product will depend directly on its use, be it industrial or domestic. Another variable is the market approach to briquette production, since it will not necessarily be used as fuel but can also act as a heating resource in locations with low temperatures or may be exported to the European market. Density is another main characteristic, since as it becomes denser; less volume will be occupied, which will mean easier handling, optimum storage, and easier transport, compared to firewood. Its weight should be 1000 kg/m3 [12], and this depends mainly on rice husk density and the pressure exerted by briquette machines. Finally, humidity directly influences heating capacity, for they contain a large percentage of moisture and the energy released is lower during combustion, causing evaporation to consume heat. Humidity should vary

Within the methodology, the goal is to develop the energy model, which is mainly based on the use of renewable energy and the search for energy efficiency, with the purpose of ensuring sustainability in the proposal, satisfying economic,

The model begins with the search for alternatives for recycling biomass as an alternative resource to firewood, which is why briquettes emerge as the ideal

**112**

respiratory and lung disease incidence rates decreased, from the reduction of CO2 produced by burning rice husks and firewood in the domestic sector. **Figure 4** shows the energy model proposed for rice husk briquette production.

Finally, environmental impact was measured by the reduction of CO2 produced by burning rice husk in paddy fields or around the city and by the minimization of greenhouse gases (GHGs) from substituting wood for briquettes in food preparation.
