MANAGEMENT OF RESIDUE CASHEW NUT SHELL USING GASIFICATION TECHNOLOGY : A CASE STUDY OF THA PLA DISTRICT, UTTARADIT PROVINCE

Abstract

The amount of residue from cashew nuts processing process which is eliminated by burning impacts health and the environment. For this reason, the research on management of residue cashew nut shell using gasification technology is conducted. The objective of this is to study the chemical elements of residue cashew nuts shell as fuel by using the survey regarding the types and quantity of cashew nuts shell in Tha Pla District, Uttaradit Province, to do the proximate analysis and ultimate analysis and study the environmental impacts (chemical indicators of air pollution) between residue cashew nut shell direct-burning which is emitted from stack and gasification technology burning by measuring the amount of Carbon Dioxide, Oxygen, Carbon Monoxide, Moisture Content, Total Suspended Particulate, Sulfur Dioxide and Oxide of Nitrogen.

The result has revealed that the chemical properties of residue cashew nut shell fuel “Sisaket 60-1” (Sor Kor 60-1) and “Sisaket 60-2” (Sor Kor 60-2) ecotypes have 9.09% of Moisture Content, 2.39% of Ash, 88.28% of Volatile Matter, 0.24% of Fixed Carbon, 54.09% of Carbon (C), 6.008% of Hydrogen (H), 38.45% of Oxygen (O), 1.38% of Nitrogen (N), and Heating value at 5,071.10 Kcal/Kg.  The result of measurement on the air pollution emitted from the stack caused by direct-burning of residue cashew nut shell has revealed that the content of Sulfur Dioxide (SO₂) is 1.0 ppm; the Oxide of Nitrogen (NO_x) is 103.9 ppm which meets the standard criteria. However, the content of Total Suspended Particulate (TSP) is 648.329 mg/m³ and that of Carbon Monoxide (CO) is 844.0 ppm, which are over the standard criteria. When we used cashew nut shell as fuel in a downdraft gasifier equipped with a gas cleaning producer system, the research results have found that the Total Suspended Particulate (TSP) is 2.532 mg/m³, the content of Sulfur Dioxide (SO₂) is 1.0 ppm, the Oxide of Nitrogen (NO_x) is 8.1 ppm, and Carbon Monoxide (CO) is 65.0 ppm. These meet the standard criteria in all parameters. Consequently, it is concluded that the residue cashew nut shell can be used as fuel in a downdraft gasifier equipped with a gas cleaning producer system in order to eliminate the air pollution as a result of burning. The amount of the cashew nut shell residue from the cashew nut processing process in Tha Pla District is 4,900 tons per year. This can be used as biomass fuel in the downdraft gasifier stove system in order to re-use this heat energy for cashew nut processing process.