Practical Potential of Grain Impurities in the Processing of Sunflower Oil Raw Materials in the Oil and Fat Industry


 The analysis of statistical data showed that a large amount of plant waste is generated annually in oil and fat production plants, which must be processed and reused. The paper analyzes the problems of reusing sunflower oil production waste, which is characterized by a relatively high energy value: 1 ton of plant waste is equivalent to 0.625 tons of conventional fuel. According to the mathematical estimation, the actual total amount of impurities is 7.29%, in which major impurities constitute 25.7%. Studies have shown a high probability of oil – containing impurities – 37.25%. Therefore, it is recommended to process such impurities into fuel briquettes and technical oil to increase the profitability of sunflower oil production. For example, at the annual load of technological equipment of the Melitopol Oil Extraction Plant, in 250 days, at a daily processing capacity of 550 t˙day-1, an annual profit of 560,000 EUR is obtainable from the sunflower grain impurities processed into fuel and technical oil.


Introduction
The global lack of fossil energy resources in developed countries leads to the expansion of efficient use of alternative energy sources. Along with the use of solar and wind energy, biofuels, various solid organic materials, and biogas, the use of agricultural products is becoming more widespread (Tryhuba et al., 2020). Prospects for nonfood use of the latter also follows from the analysis of the dynamics of prices for energy, as well as industrial and agricultural products (Tryhuba et al., 2021, Korys et al., 2019. Agricultural production turns from a consumer of traditional energy sources into a producer with significant potential for the future. Currently, three main global trends can be observed in the development of rural bioenergy can be observed (Mikhailov et al., 2019): reduction of total energy consumption; increasing the use of renewable energy sources; predominant use of solid biofuels.
A promising direction is the use of biomass in heating technological units, especially in dryers. Using heat generators that run on organic waste shows high profitability of such technologies (Yermakov et al., 2021). On the other hand, efficient use of energy boilers requires the development of biofuel preparation technologies, automatic combustion process control systems and special materials of the combustion chamber (Sumets, 2016).
Particular attention should be paid to the choice of recycling technology and equipment, which determine the amount of capital expenditures. Minimization of these costs is possible due to modernization of existing power units at the plants, retrofitting the design of the combustion chamber and the corresponding gas purification constructions. Foreign experience in the use of plant waste as an energy raw material testifies to the effectiveness of the search for alternative fuels (Szufa et al., 2020). For this purpose, various types of fuel solutions for the incineration of plant waste have been developed, in briquetted, crumbly, or granular form (Dziedzic et al., 2021).
The analysis of statistical data showed that at the agro-processing Centers (APC) a large amount of plant waste is generated annually. his waste type is characterized by relatively high energy value, as 1 ton of vegetable waste is equivalent to 0.625 t of conventional fuel. Therefore, plant waste can be considered an important potential fuel for the development of small power engineering in agricultural areas. Thus, compared to other types, the energy use of plant waste is the most accessible, economically effective, and also has ecological and social and economic advantages (Mykhailov, 2020).
Among all waste types generated during the processing of agricultural raw materials, sunflower husk poses a special problem. It requires large storage areas due to its low bulk density and special storage conditions due to its fire-hazardous properties. Processing sunflower husk to fuel is quite a new task for Ukrainian producers and in this work is the object of study. Some practical experience has already been obtained in the production of fuel pellets and briquettes from sunflower husk has already been obtained, however, not without challenges. On the other hand, comparison of the composition of sunflower husk combustion products against traditional coal have shown that the sulfur content in the ash residue of the husk is 0.1 -0.2%, which is 10-20 times less compared to coal. Therefore, from the point of view of environmental protection, sunflower husk is a more environmentally friendly fuel than coal.
Ukraine has the most favorable conditions in terms of oilseed production; it is one of the country's main areas of agricultural production. Last year, oilseeds occupied almost 30% of 26.7 million hectares of arable land, and the share of oilseeds in the structure of crops remained unchanged (Kharchenko et al., 2019).
The foundation of Ukrainian production of oilseeds is sunflower. Its share in the total production of this group of crops is almost two thirds and has been steadily increasing in recent years , Mykhailov, 2020. This requires an objective assessment of industry development and increasing its efficiency in the new economic environment. Therefore, the main purpose of the article is to determine the economic potential of the use of sunflower seed processing waste from sunflower oil production in a oil and fat processing plant.

Materials and Methods
Previous studies have shown that over the past five years, i.e., from 2015 to 2019, Ukrainian companies have significantly increased the processing of sunflower oil raw material. This has led to a proportional increase in the generation of industrial waste, especially sunflower seed husk. The volume of sunflower oil processing in the oil and fat industry (OFI) is summarized in Table 1 (Mikhailov and Zadosna, 2015;Mikhailov et al., 2016).
Previous studies of OFI enterprises revealed that the greatest attention was paid to the processing of industrial waste into fuel materials (granulated husk, husk pellets and fuel briquettes) at Zaporizhzhya Oil and Fat Plant (OFP), Vinnytsia OFP, Vovchansky Oil Extraction Plant (OEP). In 2015, these plants significantly increased the production of fuels compared to 2019. The results of the analysis of the sunflower oil production process in specialized Ukrainian enterprises show that the share of husk in the processing of relevant raw materials is quite significant. According to sources (Mikhailov and Zadosna, 2015;Mikhailov et al., 2016) in the years 2015 -2019, husk waste averaged 14.5 -15.0% of the total sunflower seed processed in the studied companies (Table 2). However, please note that the disposal process at these enterprises needs to be urgently improved in order to reduce the cost of its implementation (Sumets, 2016). The above proves that such enterprises have vast opportunities for organization of efficient utilization of industrial waste, which will increase their efficiency and allow Ukraine to increase energy security.
Experimental studies of the fractional composition of sunflower oil raw materials allowed us to determine its statistical characteristics.
The source material quality coming to the enterprise from agricultural producers is determined by the analysis results of the samples (Chernyakov et al., 2021;Choszcz et al., 2020;Konopka et al., 2017).

Results and discussion
As a result of field research to determine the statistical characteristics of sunflower oil raw materials at the Melitopol oil extraction plant (MOEZ), qualitative indicators of sunflower oil raw materials arriving from different regions of Ukraine were studied. The results are shown in Table 3 (Mikhailov et al., 2016).
According to the test results, the authors determined the mathematical estimation value-m, the maximum -(max) and the minimum -(min) of impurities, the standard deviation -σ and the coefficient of variation -υ. The analysis of full-fledged seeds in the source material (Table 3, Fig. 1), shows that their highest percentage was Mnp(max) − 96.8% with a mathematical estimation of Mnp(sr) − 88.5%, and the minimum value Mnp(min) − 68.7. In this case, the standard deviation σ was 5.07%, and coefficient of variation υ -5.73% (Mikhailov and Zadosna, 2015).
In terms of oil content impurity mod, further processing is required within first 24 hours. When used for long-term storage as a production reserve, this impurity must be removed from the sunflower heap.
According to the results of field tests, the oil content impurity mod in the raw material (Table 3, Fig. 2) was 4.35%, according to the mathematical estimation mod(sr), while the maximum value of mod(max) was 11.27%, the minimum value of mod(min) − 0.76%, the standard deviation σ -2.37% and a coefficient of variation υ -54.41%. The coefficient of variation has a fairly high value, indicating quite a broad range of oil impurities in the raw material. Agrotechnical requirements state that the impurity of the oil content in the input material should not exceed 3% for the south of Ukraine and 3.5% for all regions of the country. Results presented indicate that the content of oil content impurities significantly exceeds the agrotechnical requirements.

Figure 3. Statistical characteristics of major grain impurities
Major grain impurity mkd in the raw material (Table 3, Fig. 3) was 2.99%, as calculated from the mathematical estimation mkd(sr), the maximum value of mkd(max) was 6.0%, the minimum value of mkd(min) − 0.76%, at a standard deviation σ -1.75% and a coefficient of variation υ -58.49%.

Figure 7. Statistical characteristics of the purity of raw material.
When analyzing the fractions of the components of the sunflower oil raw material components, it can be concluded that purity of the source material is 92.8%, max − 97.1%, min − 84.6%, and impurity − 7.2%, with max − 22% , аnd min − 2.1%.
The analysis of impurities showed that content of major impurities in them was 2.9%, the fraction passing through a 3 mm sieve -4.23%, minor impurities -0.06%. The oil content impurity in the source material was 4.35%. On the other hand, analysis of the total amount of impurities in the sunflower heap: oil impurity in the source material -37.25%, major impurities -25.7%, fraction passing through a 3 mm sieve -36.5%, minor impurities 0.55%.
The oil content of the waste (impurities) after separation was 15 -18%., which allows for obtaining technical oil when such raw material is processed. The MP -68 No. 7 oil press operating in the Melitopol Oil Extraction Plant (Fig. 8) was used to process the impurities. As a result of processing of 1 ton of grain impurity, 10 liters of technical oil and 990 kg of fuel material were obtained. The practical efficiency of sunflower grain impurities processing is carried out according to the following input data (Table 4): For calculations of the economic efficiency of the sunflower grain impurity processing technology, DSTU 4397: 2005 «Methods of economic evaluation of equipment in the testing stage» was used. According to this standard, the annual economic effect (E) of the processing of impurities in sunflower raw materials can be determined by the following formula: Taking into account the annual load of technological equipment of the Melitopol oil extraction plant, in 250 days, at a daily processing capacity of sunflower oil raw material of 550 tday -1 , an annual profit of 560,000 EUR can be obtained from waste impurities processed into fuel materials and technical oil.

Conclusion
The problem of the depletion of natural energy resources requires the search for alternative fuels. Statistical data analysis showed that a large amount of plant waste is generated annually at the enterprises of agroindustrial complexes. A feature of this waste type is their relatively high energy value, as 1 ton of plant waste is equivalent to 0.625 tons of conventional fuel.
When sunflower oil raw materials get to oil extraction plants, its impurity content according to DSTU 4694: 2006 should not exceed 2%. According to the mathematical estimation, in fact, the total amount of impurities is 7.29%, in which there is major impurity -25.7%.
As a part of the total amount of impurity mathematical estimation of an oilcontent impurity is 37.25%. This requires further processing of these impurities into fuels and technical oil.
In conclusion, at the annual load of technological equipment of the Melitopol oil extraction plant, in 250 days, at a daily processing capacity of sunflower oil raw material of 550 tday -1 , an annual profit of 560,000 EUR can be obtained from waste impurities processed into fuel materials and technical oil.