Introduction Steel and its alloys are widely used

Introduction Steel and its alloys are widely used in industrial applications, and may be subjected to different acidic environments. Acids attack metal surface and lead to severe corrosion problems. Corrosion can be controlled by using inhibitors. Most of the well-known cyp3a inhibitors inhibitors used in industry are organic compounds having multiple bonds in their structure and contain mainly nitrogen, sulphur and oxygen atoms through which they adsorbed on the metal surface (Yaro et al., 2013a,b). Corrosion inhibitors generally control corrosion by forming various types of films in several ways: by adsorption, by the formation of bulky precipitates, and/or by the formation of a passive layer on the metal surface. Most of organic inhibitors retard corrosion by adsorption and forming a thin, invisible film with only a few molecules thick (Yaro et al., 2011, 2014; Lagrenee et al., 2001). Industrial synthesis of organic inhibitors may cause a great destructive effect on the environment. The organic inhibitors separated from the organic extraction of plants and vegetable extracts, these extract are effective, economical and eco-friendly (Singh et al., 2010). The known hazardous effects of most synthetic corrosion inhibitors are the motivation for the use of some natural products. Most of the natural products are non-toxic, biodegradable and readily available in plenty. Several investigations have been reported using such naturally occurring substances as corrosion inhibitor for several metals in different media (Adardour et al., 2016; Chaieb et al., 2005; Chauhan and Gunasekaran, 2007; El-Etre et al., 2005). Citrus aurantium leaves (CAL) are very common, available and cheap plants in Diyala governorate/Iraq. In present work, the naturally corrosion inhibitor (CAL) was extracted and tested to control the corrosion of mild steel in 1 M H2SO4 at different operating condition.
Experimental
Results and discussion
Conclusion The acid extract of Citrus aurantium acts as good and efficient inhibitor for the corrosion of steel in sulphuric acid medium. Inhibition efficiency increases with inhibitor concentration and maximum inhibition efficiency for the extract was found to be 89% at the optimum concentration of 10 ml/l at 40 °C. The adsorption of different concentrations of the plant extract on the surface followed Langmuir adsorption isotherm. The negative value of the free energy of adsorption indicates that the adsorption of the CAL on the steel surface was a spontaneous process and be of physisorption one.
Introduction The high costs, the environmental impact, and the decrease in fossil resources are the main reasons behind attracting a great deal of attention of the research community towards searching for alternative raw materials in different industrial fields. Now, with the increase in world demand for oil and the challenges to expand the existing oil supply for human consumption and industrial utilization (Basumatary et al., 2012), there is need to utilised less expensive and non-edible product (oil) in the synthesis of the resins or biodiesel and other products in order to meet up with the competitive environment of such industries. One of such product which can be utilised to yield a desirable result both in terms of cost, renewability, biodegradability and non-edibility is gmelina seed oil (GSO). Gmelina seed oil have been found to be a sustainable material for biodiesel and alkyd resin synthesis in terms of its availability and renewability. Gmelina seed oil based biodiesel have been produced keeping two criteria in mind; the biodiesel met all the technical and industrial standards of ASTM D6751 and EN 14214, and, met all the ecologically relevant standards (Basumatary et al., 2012; Sangay et al., 2014). However, there has been doubt over sustained use of gmelina seed oil for large scale production of biodiesel and alkyd resin due to low yields. Most methods of oil extraction seem to be very costly due to inability to control some inherent factors. A lot of researches has been carried out to find alternative ways of producing oil for process industries and for food industry. It has been found that almost all the seeds contain oil, hence, these gives ground for other researchers to consider studies on the possible uses of other oil producing substances found in people\'s everyday lives. There are various ways of extracting oil from oilseeds but solvent extraction has been reported to be most efficient techniques (Topallar and Gecgel, 2000). There is need therefore, for process industries to optimize current methods of extraction, thereby improving the profitability of production and ensuring a sufficient supply of oil.