Energy Potential of Agri Residual Biomass in Southeast Asia with the Focus on Vietnam
Figure 4. Impact of pretreatment on bagasse yearly energy potential
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- Figure 4. Impact of pretreatment on bagasse yearly energy potential. 4. Conclusions
| Figure 4. Impact of pretreatment on bagasse yearly energy potential.
0 5 10 15 20 25 Red River Delta Northern middlands Northern Central Central Highlands Southeast Mekong River Delta Vietnam Energy potencial of sugarcane bagasse (TWh) Dry biomass (Q = 16.47 MJ kg‐1) Wet biomass (Q = 10.40 MJ kg‐1) Figure 4. Impact of pretreatment on bagasse yearly energy potential. 4. Conclusions The most important agricultural crops in Vietnam are paddy rice and sugarcane, with an annual production of more than 44 million tons and nearly 18 million tons, respectively. The production of these crops has been increasing in recent years, which was indisputably associated with the growing amounts of residues that are unused and contributes adversely to the environment and sustainable farming in general. Rice residues, especially rice straw, offer an alternative material for energy use, which meets the requirements of minimizing CO 2 emissions, i.e., renewable energy source and fulfils the main preconditions, i.e., material in vast concentrations, readily available and on Agronomy 2021, 11, 169 15 of 18 a dry basis. From the point of view of logistics and energy density improvement, the most appropriate option is the production of briquettes or pellets. The unfavorable property for pellets is the relatively high ash content (>10 wt.% dry in rice straw and >13 wt.% dry in husks); therefore, combustion in boilers with structurally adapted ash removal mechanisms is to be considered. Nevertheless, thanks to its composition, rice ash could be used for soil amendment. Similarly, rice husks are a suitable source of energy; furthermore, in a state that allows pressing into briquettes or pellets directly, i.e., without mechanical disintegration. On the other hand, husks may find another usage such as poultry litter. This implies a certain price of the material and economic calculations must be performed. The energy use of sugarcane residues again meets the requirement of significant amounts in large concentrations in one place. Furthermore, also partly, relatively low moisture content; thus, it can be burned directly, which is typically done. However, for enhancing the energy potential and more efficient application and through briquetting or pelleting, it is necessary to dry the material up to 15% moisture. This biomass is also characterized by high ash content (nearly 12 wt.% dry for bagasse), so that solution could be the same as in the case of rice residues. The present research revealed the potential and abundancy of leftover biomass and mapped in detail the situation throughout the whole country. It was calculated that the total annual energy yield of rice and sugarcane residues is about 443 TWh (416 TWh and 27 TWh accordingly), which is equal to the energy consumption of approximately 92 million average Vietnamese households in the form of electricity and energy for cooking per year. Finally, the maximization of energy production from biomass sources and the number of households or small local industries that will benefit from biomass-based energy is directly proportional to the selected pretreatment and technologies for biomass processing and/or biofuels production. tải về 1.15 Mb. Chia sẻ với bạn bè của bạn:
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