## 1 Introduction
Pyrolysis oil, also called bio-oil, is a complex blend of numerous oxygenated compounds produced from lignocellulosic biomass through a thermochemical process (i.e., pyrolysis) in the intermediate temperature ranges from 400 \({}^{\circ}\)C to 600 \({}^{\circ}\)C in the absence of oxygen [17]. Pyrolysis oil contains organic compounds such as carboxylic acids, alcohols, aldehydes, ketones, esters, furans, and aromatics [18]. The water content of pyrolysis oil generally ranges from 15 wt.% to 25 wt.% [19; 20]. Up to 70 wt.% of the original dry biomass can be converted into pyrolysis oil [21]. The properties of pyrolysis oil depends on multiple factors such as the type of biomass feedstock, alkaline compounds content, reactor type, reaction temperature, residence time, char removal, etc. [22; 23; 24]. For example, the pyrolysis oil produced from pyrolysis of beech wood chips consists mainly of aldehydes, acids, esters, alcohols, ketones, benzene derivatives, phenol, and alkanes; due to the different reaction conditions, the product content varies considerably [25]. Compared to the primary biomass, pyrolysis oil presents several advantages. First, its volumetric energy density is increased about five times more than the \"bulk\" biomass, making transport economically more attractive, especially over long distances [26]. When large-scale remote biomass collection is considered, pyrolysis oil can firstly be produced locally and then transported to the central processing area [21]. Second, pyrolysis oil is a liquid, which makes storage, transport, processing, and pressurization easier. It can also be stored in tanks that resist well against biodegradation and cannot be ignited at ambient temperature [27]. Third, compared to conventional fossil fuels, pyrolysis oil contains small quantities of sulfur, nitrogen, and ash. As a result, its combustion releases less harmful gas emissions such as nitrogen oxides (NO\({}_{\text{x}}\)) and sulfur dioxide (SO\({}_{2}\)). [26]. Furthermore, as the pyrolysis oil is produced through a low temperature process, minerals and metals remain in the solid char residue. However, the drawbacks of pyrolysis oil should not be ignored, the pyrolysis oil properties limiting its applications. This phenomenon is caused by high oxygen content, volatility, high viscosity, acidity, low heating value, and incompatibility with petroleum and other bio-based fuels [28]. Despite these constraints, pyrolysis oil has plentiful advantages to be used to produce syngas by gasification. In this paper, a new model is dedicated to simulating the methanol production via a set of processes including pyrolysis oil gasification, Rectisol, and methanol synthesis. The model is then validated by experimental and industrial results and used in a sensitivity analysis to identify the effects of varying operating conditions on the methanol production yield. Firstly, the modeling methodology is discussed, i.e., assumptions, model's description, and its validation. Thereafter, the main results of the sensitivity analysis are presented and discussed, highlighting the impacts of various operating conditions on methanol yield, i.e., the gasifying temperature, pyrolysis oil moisture content, Rectisol temperature/pressure, and methanol synthesis reactor temperature/pressure.