Feasibility study of biodiesel production from oilseeds in Tehran province

Biodiesel is one of the proposed sources to replace fossil fuels. This renewable biofuel is compatible with current infrastructure and internal combustion engine systems. Potential measurement is necessary before manufacturing and industrial projects, and this is even more critical for biodiesel-related projects due to raw material issues. In this research, the potential measurement for the cultivation of oilseeds for biodiesel production in Tehran province has been done with the help of GIS software. The results of this potential measurement show that parts of the western and central regions of Tehran province are suitable for cultivating oilseeds for use in biodiesel production. However, about 90% of the areas of Tehran province are unsuitable for cultivating oilseeds, and its most significant limiting factor is soil texture. More than 50% of the surfaces of Tehran province have an unsuitable soil texture for growing oilseeds. In order to identify the optimal areas for planting oilseeds, the average cost variable of (Cave) per liter of biodiesel is introduced. The results show that the cost of production, transportation, distribution, and supply of raw materials in these areas is cost-effective when the average variable cost is less than 92 thousand rials per liter of biodiesel produced.


INTRODUCTION
In recent years, many steps have been taken to eliminate fossil fuels and replace them with cleaner energy. A suitable and renewable alternative energy source for the transportation industry is biofuels obtained from biomass renewable sources [1,2]. Compared to fossil fuels, biofuels are low carbon and naturally degradable fuels [3,4]. Also, unlike other renewable technologies such as batteries and hydrogen cells, there is no need to redesign vehicles, and biofuels can be used directly inside the engines of internal combustion vehicles [5].
Biodiesel with its many advantages can be a good alternative to petroleum diesel, so it is important to do economic feasibility studies. In the production of biodiesel, one of the most important obstacles is the supply of raw materials, which accounts for a large share of production costs [6]. In this study, the aim is to evaluate the feasibility of native oil products in Tehran. Most of these products include oilseeds such as rapeseed, sesame and sunflower seeds. Animal fats or oils can also be good sources of biodiesel. In this study, a GIS-based method has been used to investigate the potential of biodiesel production based on Tehran's native oil plants.

Literature Review
Numerous studies and researches have been done on biodiesel production methods, suitable raw materials and economic feasibility studies. Ferkova et al. Investigated biodiesel production using greasy municipal effluents in European cities. In this study, the problems that fat-containing effluents create for water treatment plants, the appropriate process methods for converting these fats into biodiesel, as well as the economic opportunities and risks were investigated. According to this research, there is an annual production capacity of 3-414 x 10E4 biodiesel depending on the effluent treatment method from these fat-containing effluents [7].

Methodology
About 85% of the price of biodiesel is determined by the price of raw materials, and most of the raw materials used in the production of biodiesel are also used for food [8]. For this reason, it is vital to study the factors affecting the production of oily products for use as a primary feed. In this study, the aim is to find suitable geographical areas for planting primary feed used in biodiesel refineries and soil salinity, soil structure, ambient temperature and rainfall in the area have been selected as the main parameters. By calculating the tonnage values of each of the native oil products, provided that the cost price of each hand is less than the desired criteria, the total price of all native oil products in each part of Tehran province is calculated using the following equation: The flow diagram implemented in GIS software to map the optimal areas for the production of biodiesel raw materials is shown in Figure 1. According to this flow diagram, at first, the land use and climate map of Iran has been found in four sections: rainfall, suitable temperature, soil texture and soil salinity for Tehran province. Then, in these four sections, the layers are classified and the desired classes are identified, and then these maps are overlapped to find the desired and desired areas.

Results and Discussion
Using GIS software, four parameters of annual rainfall in terms of mm, annual temperature in terms of Celsius, soil texture and soil salinity in Tehran province were measured to measure the potential of biodiesel production from oilseeds and results are shown in 9 individual maps and sectors.
After specifying the ideal classes in the map of Tehran province, we will overlap these areas to determine the ideal locations for growing biodiesel raw materials. The result is shown in Figure 2. As can be seen from the map, the suitable locations are in the west and parts of the center. Most areas of Tehran province are not suitable for cultivation. Damavand and Firoozkooh cities, although they have suitable salinity and precipitation levels, they do not have suitable temperature and soil texture. Varamin city is not one of the desirable places due to excessive soil salinity and inappropriate rainfall.

Conclusions
This study investigates the potential of oilseed production in Tehran province for use in biodiesel. In this study, four factors of annual rainfall, annual temperature, soil salinity and soil texture were investigated. According to the results and maps, the biggest limiting factor in Tehran province is soil texture, so that over 50% of areas in Tehran province have hard soil texture, which is unsuitable for cultivating oilseeds. Another factor limiting soil salinity is Tehran province. Although about 50% of the province has a suitable salinity level, but the parts that have high salinity overlap with areas with suitable soil, which leads to a significant reduction in land suitable for growing oilseeds in Tehran province. The two factors of temperature and average annual rainfall in Tehran province were not in a favorable situation in general. However, these two factors met the minimum requirements in most areas of Tehran province and therefore did not restrict the selection of desirable areas for oilseeds. About 65 to 75% of the provinces have good temperatures and rainfall. According to the materials presented in the economic analysis section and according to the sources of native oilseeds in the province and the economic parameter of Cave, Tehran province with an annual production of more than 2 million tons of agricultural waste and an estimated 10% of this province as desirable areas for biodiesel production, it has a production capacity of 6000 liters of biodiesel per day.
The result of this research is shown in Figure 2 and as it is clear from the map, most areas of Tehran province are not suitable for cultivating oilseeds. According to the obtained map, only about 10% of the area of Tehran is suitable for cultivating oilseeds. The most suitable areas of Tehran province include Mallard city in the west and Pakdasht city and Robat Karim city in the center in a more limited way. Very small areas of Rey, Shahriyar and Tehran are also suitable for growing oilseeds. According to the obtained map, it can be concluded that Tehran province is not suitable for the production of biodiesel with the raw material of oilseeds on a large scale. Most areas of this province are unsuitable for oilseed cultivation; And some conditions in the favorable areas are also minimal. Also, the fact that Tehran province is an urban province and most of its agricultural lands are currently under cultivation should be taken into account. However, Tehran province has the ability to produce biodiesel in a limited way and in most small production units. These biodiesel production units should be built in the west of Tehran and in Mallard city to be close to suitable lands for growing oilseeds. It is also recommended that agricultural plants that can grow in hard or saline soils be examined for planting in unsuitable soils.

Abstract
Biodiesel derived from oilseeds is one of the proposed sources to replace fossil fuels, especially diesel. The production technologies of this model of biodiesel have reached a suitable level of maturity and have the ability of mass production. The biggest obstacle to biodiesel production is the high cost of production, which stems from the high cost of its raw materials, which are oilseeds. Potential measurement is necessary before manufacturing and industrial projects, and this is even more critical for biodiesel-related projects due to raw material issues. In this research, potential measurement for cultivation of oilseeds for biodiesel production in Tehran province has been done with the help of GIS software. The results of this potential measurement show that parts of the western and central regions of Tehran province are suitable for cultivating oilseeds for use in biodiesel production. However, about 90% of the areas of Tehran province are unsuitable for cultivating oilseeds and its biggest limiting factor is soil texture. More than 50% of the surfaces of Tehran province have unsuitable soil texture for growing oilseeds. In order to identify the optimal areas for planting oilseeds, the average cost variable of (Cave) per liter of biodiesel is introduced. The results show that according to the costs of 90 production, transportation, distribution and supply of raw materials, when producing biodiesel in these areas is costeffective when the average variable cost is less than 92 thousand rials per liter of biodiesel produced. Keywords: GIS, Biodiesel production potential, Native oil products, Tehran.