**1. Introduction**

Any arid region biomass-based renewable energy form has to confront a number of challenges, such as the unavailability of enough arable land and lack of fresh water [1]. The two biomasses considered in this study were halophyte *Salicornia bigelovii*, which can be grown in arid lands using saltwater [2] and date palms (*Phoenix dactylifera*), a native arid land biomass and one of the most abundant agricultural residues in arid regions. Pyrolysis of biomass was identified as an effective way of producing pre-cursors for jet-fuel production. Pyrolysis of biomass yields pyro-oils, pyro-char and gases in varying proportions depending on process parameters [3–5]. Pyro oil yields of up to 35% have been obtained by various authors [6] while fast pyrolysis yields have reached up to 75% [5]. Other authors have studied the effects of temperature on pyrolysis oil yields [7,8].

Arid-land lignocellulose biomass pyrolysis literature is scarce [9–11], and co-pyrolysis of these types of biomass have not been reported before. Both *S. bigelovii* and date palm have attracted attention in the biorefinery of arid-land biomass [1,12,13]. From the sustainability perspective, both plants are addapted to the harsh conditions of arid-land. *S. bigelovii* can grow in arid-land coastal areas using seawater, thereby reducing the stress on freshwater demand [12,13]. Date palm leaf residues', including leaflets and rachis, annual global production is estimated to be over 6 million tonnes [1]. Hence, the pyrolysis of this biomass is an opportunity to divert these residues from landfilling.

Understanding the kinetic parameters and effect of heating rates on reaction rate at different stages in the pyrolysis process is important in the design of pyrolysis reactors specifically for the investigated biomasses and in scaling up the process. It is also necessary in predicting the extent of reaction under different experimental conditions at different times. This work studies the pyrolysis reactions using thermogravimetric analysis for *S. bigelovii*, date palm, and co-pyrolysis of both at different mass ratios. The effects of the heating rate on the reaction rates were determined and key Arrhenius kinetic parameters, i.e., activation energy and pre-exponential factor, were determined. By obtaining thermal loss data from thermogravimetric analysis [14], these kinetic parameters were determined by using pre-determined non-isothermal models such as the Kissinger model, the Flynn-Wall-Ozawa model (FWO), and the improved Kissinger-Akahira-Sunose model (KAS) derived from the generalized Arrhenius model. Results from these methods are compared.
