## 1 Introduction  
The low availability and high demand of fossil fuel has led to an increase in its prices. Therefore, biomass can be used to solve this issue. It might replace the demand for electricity, especially in villages with limited access to power. It can also be used for other purposes, such as driving internal combustion or turbine engines. Gasification and combustion are a thermochemical conversion that uses pressure, steam, and high temperature to change biomass feedstock into gas called syngas/synthetic gas. The main components of syngas include CO, N\({}_{2}\), H\({}_{2}\), CO\({}_{2}\), and other hydrocarbons such as CH\({}_{4}\), C\({}_{2}\)H\({}_{6}\), and C\({}_{2}\)H\({}_{4}\), and tar compounds.  
Therochemical conversion such as biomass gasification has many advantages compared to the combustion and pyrolysis process. This is because it has a lower tar production. In this research the downdraft gasification system with 10 kW on a laboratory scale was used. The feedstock was divided into non-woody and woody feedstock. Non-woody feedstock has limitations such as producing higher ash, N\({}_{2}\), and sulfur content. Woody biomass is an organic material derived from a living organism that is used as fuel in energy generation. Therefore, wood pellet was chosen since it is readily available and cheap. The particle size of feedstock affects the gasification process. The proportional size particle of the wood pellet is below 6.3 mm and has a mass fraction lower than 25% [1,2]. According to [PERSON] et.al., 12% of steam can be easily generated if the moisture content is reduced from 35% to 20% on a wet basis (wb) [3]. For this reason, the experiment was carried out on a 6 mm diameter wood pellet feedstock with a bulk density of 790 kg/m\({}^{3}\) and moisture content variation of 2 wt. %, 4 wt. %, and 6 wt. % respectively.  
The composition of the syngas yielded from the gasification process depends on the contents of the oxidizer such as oxygen in the air. Additionally, the amount of tar composition in the syngas interferes with the effectiveness of the syngas [4,5]. [PERSON] et al. stated that various chemical compounds exist in tar formation and this is affected by moisture content of the feedstock [6,7]. Tar can be defined as oxygenated and hydrocarbon compounds in the combustible gas as good as polycyclic aromatic hydrocarbon (PAH) and higher than the molecular weight of benzene [8]. Three international organizations have agreed with this definition of tar, including the Energy Department of the United States, the International Energy Agency (IEA), and The Directorate-General for Energy European Commission (DG XVII) [9,10].  
Tar is an unnecessary product in biomass gasification since it makes the equipment challenging to operate during combustion. The catalyst cannot overcome the tar problem for a long operation in the biomass gasification [11]. For this reason, varying the moisture content of feedstock must be done [12]. This variable affects tar characteristics such as tar formation, classification, and density. Limited studies have examined the influence of moisture content on the tar characteristics. Accordingly, this study aims to verify the effect of moisture content on the tar characteristics of the wood pellet on the downdraft gasifier. The experiments were conducted with a variation of moisture content of 2 wt. %, 4 wt. %, and 6 wt. % with a fixed air-flow rate of 80 L/min. The process used a tar-sampling method with patent number JP 2009-40885 from the Japan Patent Office [13].