**1. Introduction**

The largest component of biomass available on the world is lignocellulosic material. Oil palm is one of the most important sources of lignocellulosic biomass in Asia, especially in Malaysia and Indonesia. Malaysia, after Indonesia, is the world's second-largest producer of palm oil, with a capacity of 17.32 million tonnes and a cultivated area of 5.74 million ha [1]. According to the Malaysian Palm Oil Board (MPOB) statistics from 2016, the total volume of oil palm products was 25.64 million tonnes [2]. Oil palm biomass accounts for the remaining 90% of total dry matter palms, with oil accounting for just about 10% of total dry matter palms [3]. Oil palm empty fruit bunches (OPEFB), oil palm fronds (OPF), and oil palm trunks (OPT) make up the majority of oil palm biomass in Malaysia.

Malaysia's annual production of OPEFB, OPT, and OPF is approximately 84.23 million tonnes (dry basis) (**Table 1**) [4]. This massive amount (i.e. 7 million tonnes of OPEFB, 21.4 million tonnes of OPT, and 55.8 million tonnes of OPF) suggests that oil palm biomass is a readily available feedstock for chemical products, particularly through the biological fermentation process.

Nowadays, fermentation processes are the most commonly used method of utilizing biomass because they are non-toxic, environmentally friendly, and have

