## 1 Introduction  
In the current era of fast and significant global transition in which prosperity and planetary health are both primary concerns, it is necessary for countries to secure, stabilize, and optimize their energy resources [1]. Stability in the energy market, however, remains difficult to ensure as the sector continues to be characterized by significant turbulence featuring recurrent booms and busts [2]. Fuel emissions are also a significant health risk, inducing, for example, an estimated 600,000 premature deaths in European Union countries in 2010 alone and a corresponding morbidity of $1.575 trillion [3]. These security and environmental challenges have been exacerbated by the steep rise in the demand for fossil liquid fuels. Some scenarios project an oil demand of up to 300 million barrels per day by 2100 [4]. This increase in use and the associated environmental deterioration have instigated global (public, academic, industrial, and governmental) demand for a partial to complete replacement of conventional fuels by more secure, renewable, and sustainable sources [5]. These concerns are also shared by engine and automotive manufacturers, who have been subjected to increasing pressure to meet increasingly stringent tailpipe emission regulations [6]. As a result, a wide variety of alternative fuels, of which biodiesel are the most prominent, have been proposed to address some of the concerns associated with fossil fuels. However, factors including the limited availability, lower energy content, and high production costs pose significant challenges to the large-scale uptake of biodiesel and other alternatives [7]. In the biodiesel fuel case in particular, it has become necessary to seek out and evaluate any potential feedstock that can boost availability. The attempts to identify appropriate feedstocks can be classified into a series of biodiesel generations. First-generation biodiesel are agrofuels extracted from crops that would otherwise be cultivated for the purpose of food production. First-generation biodiesel have a number of desirable attributes that make them excellent compression-ignition engine fuels, including renewability, compatibility with existing automotive engines and fuel handling infrastructure, and high energy densities of \(\sim\)90% of that of fossil diesel (39.8 MJ/kg for date seed oil (DSO) compared with 44.6 MJ/kg for fossil diesel fuel). It has also been shown that pure biodiesel can result in a reduction of \"cradle-to-grave\" CO\({}_{2}\) emissions of at least 50% relative to its fossil-based diesel counterpart [8]. However, other life cycle analyses have shown that only limited savings in greenhouse gas emissions can be attained using biodiesel [9]. Although such analyses use significantly varying methodologies and the data and differences in the results should be viewed from this perspective [10], it is true that first-generation biodiesel suffers from other problems, including the difficulty in sustaining feedstock, accelerated deforestation, biodiversity damage, and the effects of production on water scarcity, production costs, and food prices. To address these issues, biodiesel derived from non-edible feedstocks or waste streams (second-generation biodiesel) have emerged as a promising alternative [11; 12; 13; 14; 15]. These biodiesel can be produced from waste streams in the food supply chain, which are estimated to comprise \(>\)30% of the global food supply balance and are typically landfilled or incinerated [16]. To produce second-generation biofuels, a number of waste streams have been investigated and exploited, including used cooking oil [17], waste coffee [18], and the seeds of the date palm trees [19]. The seeds of the date fruit are a promising feedstock for biodiesel production in the Middle East and North Africa, which support the most appropriate habitats for the cultivation of the desert date palm. Almost 90% of the total global production (8.166 million t in 2017 [20], harvested from more than 100 million trees [21]) originates from this region.