Abstract
Introduction
The open burning of agricultural residues and lack of access to affordable energy remains a major challenge in the rural areas of the developing countries. One million tons of crop residue like rice husk, wheat straw and cotton stalks are wasted each year, contributing to excessive air pollution, greenhouse gases and wasted bioenergy. Briquetting of charcoal is a potential waste-to-energy conversion platform where low density agricultural byproducts can be converted into more clean and high energy density solid fuels to be used in decentralized rural energy use. This paper is aimed at analyzing the design, development and performance analysis of a low cost manually operated charcoal briquetting system, which is targeted towards the smallholder farmers with special attention being on the fuel quality, system productivity and its environmental performance.
Methods
The constructed system comprises of drum kiln to carbonize biomass, a size reduction unit to prepare charcoal and manually operated compaction press, which is made of locally available materials. Agricultural waste is burned in the presence of limited oxygen and reduced to fine charcoal dust and then mixed with other natural binders like starch and molasses. The briquettes obtained are tested in terms of bulk density, compressive strength, moisture content, calorific value, burning time and smoke emission. The controlled burning tests that are used to evaluate combustion performance and emission properties are conducted by use of the portable Testo-350 gas analyzer to compare between briquettes and the traditional biomass fuels.
Results
The system yields 25-35 kg/hr of charcoal briquettes with bulk densities of 650-820 kg /m3 and calorific values of 18-24 MJ/kg. The briquettes have a lifespan of 30-45 percent longer and much lower smoke emissions as compared to raw biomass fuels. According to the availability of crop residues in the region and the potential of their utilization as briquettes, the system suggests that 30-40 percent of agricultural residues can be diverted against open field burning. Moreover, the household fuel expenses will decrease by 25-35 percent. These findings demonstrate that biomass briquettes can be used as a dependable renewable solid fuel which can partially substitute the conventional fuels like firewood and coal in decentralized rural energy systems.
Conclusions
In general, the subject of manual charcoal briquetting has been demonstrated to be a technically and economically viable to rural energy solution. At the same time, it can serve to manage crop residues and domestic energy demands in households. The research shows the significance of emission controlled carbonization equipment and standardized production of briquette to enhance energy efficiency, minimize environmental pollution, and promote the use of briquette by rural populations.
