## 1 Introduction
However, the utilization of acid (HCl) has harmful effects on health and the environment, which was not considered in the study. There is no other study reported in the literature that claims to have produced anodes using modified biocoke without deteriorating their properties, except the work of the authors of the present study. [PERSON] et al. [18] concluded that good-quality anodes can be produced using biocoke based on the average properties of a calcined mixture of non-modified biocoke and coke without producing any anodes. This is not reliable unless the effect of using this mixture on anode properties are tested. The research group of the authors (CHIMI) was the first to modify biocoke using environmentally friendly additives and produce anodes with properties similar to those of industrial anodes. They have published numerous articles on this subject; most other published studies obtained anodes with deteriorated properties as mentioned above. The first study carried out by the authors of the current article was on the wettability of non-modified biocoke by coal tar pitch. This study showed that biocoke is well-wetted by pitch. In addition, biocoke's anisotropic and lamellar structure is suitable for partially replacing the coke used in anode production [9]. Then, they studied the interaction mechanism of three different pitches with non-modified biocoke. The FTIR and XRD analyses of biocoke indicated that the surface functional groups can form covalent and hydrogen bonds with pitch, and the crystalline length of biocoke increases with increasing pyrolysis temperature [11]. In their next study, anodes were made using biocoke, and the particle size of the biocoke to be used in anode production was established as less than 45 \(\upmu\)m [13]. Biocoke is very porous, which decreases the anode density. Therefore, the particle size of biocoke should be small, and only the fine fraction of petroleum coke should be partially replaced by biocoke to eliminate the large pores and reduce the porosity effect. In the following study, the anodes were produced using a different coke than the one used in the previous study. However, the results were not as good. The only difference between this study and the previous one was the type of coke used, since the biocoke and the pitch were the same. This shows that not all cokes can be directly replaced with biocoke, because the surface chemical composition of biocoke and its compatibility with pitch are very important. Thus, biocoke was modified with an environmentally friendly additive, which significantly improved the anode's properties. They were similar to those of the anodes manufactured without biocoke [16]. This result showed that the utilization of chemically modified biocoke in anode production results in good-quality anodes. Subsequently, the effect of the coke type on the properties of anodes' containing biocoke was investigated in more detail. Anodes were produced with three different cokes. The pitch, biocoke, and the additive were the same as the ones used in previous studies. This study showed that any type of coke can be replaced with the modified biocoke, and good-quality anodes can be obtained. However, one type of additive was used in this study [19]. Finally, the effect of additive type was also investigated, which was the subject of the current paper. For this study, three environmentally friendly additives were identified, and the results are presented. There are no other studies that have investigated the effects of different parameters of biocoke utilization on anode production in such detail. Thus, the current paper constitutes the last part of a group of novel studies that the authors of this article have carried out.