Abstract
Palmyra palm is a significant economic crop in Kirimat District, Sukhothai Province, and
generates large quantities of husks, stalks and shells as by-products and wastes, which
impacts on the local environment. This study investigated (1) production of compressed
charcoal briquettes from Palmyra palm husks, fruit calyx and shells, whose physical
properties and thermal performance were tested and analyzed according to Thai Community
Product Standard (tcps 238/2004); (2) the economic return of the production process. The
results showed that 40% of shells of a mature palm fruit and 90% of the husk and fruit calyx
of young palm fruit are left over. Moreover, the thermal properties of the palm husks, fruit
calyx and shells were found to be similar to those of coconut shells and oil palms. In an
experiment to test the properties of blends of the two products (husks and fruit calyx: shells)
in 6 different mixing ratios using starch paste as binding agent, all 6 mixing ratios showed
thermal values ranging from 5,281.60–6,702.00 kcal/kg, which exceeded the Thai Community Product
Standard (tcps). During combustion, these briquettes produced low levels of crackling, odour
and smoke emissions, and drop shatter. These characteristics make the studied briquettes
appropriate for storage and transport. At a production cost of 4.83 baht/kg for a production
capacity of 400kg/day, the payback period was 1.3 years. Therefore, the palm briquettes
would make an alternative source of additional income and an alternative fuel substitute for
wood charcoal and LPG.
Keywords: Charcoal briquette production; Palmyra palm; palm fruit calyx; shells