Petroleum-based fuel performs a crucial function in the energy sector. Petroleum is used principally in the transport sector, specifically in motor engines to run vehicles and power plants. This resource is however, running out (Othman et al., 2017; Fadhil et al., 2019). Global warming is also becoming a concern as a result of anthropogenic activities such as burning of fossil fuels. There are however, significant efforts and interest to explore for renewable, sustainable and energy-friendly fuel sources (Unglert et al., 2020; Yu et al., 2020). There is no doubt that renewable energy sources could provide the much-needed reprieve from the over utilisation of petroleum products.
Research has been extensively carried out on new, renewable energy sources in the quest of fulfilling the world's ravenous energy demand. The new substitute sources of energy include solar, wind, biomass among others. Biodiesel has become one of the most preferred forms of liquid fuel. Biodiesel can however, be compared in terms of characteristic to conventional petroleum diesel. It is renewable and produces minimal emissions after combustion as compared to petroleum diesel. It could revolutionise into a sustainable fuel source (Demirbas, 2009b; Fadhil et al., 2020).
Biodiesel is produced through chemical processes such as transesterification with alcohol that are short-chain including methanol, butanol and ethanol (Takase et al., 2014; Takase et al., 2015).
The choice of an alcohol takes into consideration of many factors including performance and cost-effectiveness. Ethanol and methanol are however, primarily used as alcohol. Methanol is cheap and has desirable physical and chemical properties. On the other hand, ethanol is friendly to the environment since it is obtained from renewable source such as corn making the process entirely independent of petroleum-based alcohol (Mujeeb et al., 2016; Fadhil et al., 2020).
Kinematic Viscosity of the oil from plants is supposed to be lowered to enhance its utilisation in diesel engine. Various methods have been developed to reduce oil's viscosity. The methods are blending with diesel, transesterification, pyrolysis and micro emulsification (Axelsson et al., 2012; Borugadda & Goud, 2012). Blending and transesterification however, remain the most popular methods. Meanwhile, among the two, transesterification remains a more superior and efficient method of reducing vegetable oil’s viscosity and yielding fuel with similar diesel properties (Refaat & Refaat, 2010; Hassan, 2021).
Transesterification entail the use of catalysts such as alkali, acids, or enzymes for biodiesel. Homogenous catalyst exists in the same phase (either gas or liquid) as the reactants. Typical case of homogenous include sulphuric acid, sodium hydroxide and many others. Alkali catalysts are mostly preferred due to its practical and industrial feasibility. They are also less costly, unlike enzymes. Glycerol as the backbone of the reaction process is essential component in soap-making and cosmetic industries (Altikriti et al., 2015).
In this study Parkia biglobosa is been used. In Ghana, biodiesel is being produced from edible oils such as rape seed, soybean oil and castor. However, recent studies by Takase et al. (2015) revealed that there are a lot of alternative non-edible high oil yielding crops that can be considered as resources. One of the new and promising non-edibles is Parkia biglobosa oil, which is gaining popularity in medicinal and pharmaceutical studies but very scanty in terms of a resource for biodiesel (Janick & Paull, 2008; Abioye et al., 2013; Kipkoech 2021).
Parkia biglobosa, a member of the Fabaceae family is widely grown in Ghana. The key Regions that grow the plant are Northern, Oti and Volta (Kipkoech, 2021). The active components of the plant have been exploited for medicinal and pharmaceutical purposes (Janick & Paull, 2008; Abioye et al., 2013). Typically, the extract obtained from the leaves and seeds can be used to treat liver diseases (Ojewumi, 2016). Current studies have shown that the seeds from the plant contain a lot of oil (Olowokere et al., 2018). According to studies by Olowokere et al. (2018), the amount of oil per seed could be more than 11.4%. In addition, at Parkia industrial oil production in Volta Region Ghana, the oil is seen by-product and goes waste with little used. The purpose of this study was henceforth to investigate biodiesel production from Parkia biglobosa seed oil using efficient and economical sulfuric acid catalyst.