Pyrolysis Plant Research Articles

Effect of Temperature on Pyrolysis Oil Using High-Density Polyethylene and Polyethylene Terephthalate Sources From Mobile Pyrolysis Plant

This research aims to study the effect of temperature, collecting time, and condensers on properties of pyrolysis oil. The research was done be analyzing viscosity, density, proportion of pyrolysis products and performance of each condenser towers for the pyrolysis of high-density polyethylene (HDPE) and polyethylene terephthalate (PET) in the mobile pyrolysis plant. Results showed that the main product of HDPE resin was liquid, and the main product of PET resin was solid. Since the pyrolysis of PET results in mostly solid which blocked up the pipe, the analysis of pyrolysis oil would be from the use of HDPE as a raw material. The pyrolysis of HDPE resin in the amount of 100 kg at 400, 425, and 450°C produced the amount of oil 22.5, 27, and 40.5 L, respectively. The study found that 450°C was the temperature that gives the highest amount of pyrolysis oil in the experiment. The viscosity was in the range of 3.287–4.850 cSt. The density was in the range of 0.668–0.740 kg/L. The viscosity and density were increased according to three factors: high pyrolysis temperature, number of condensers and longer sampling time. From the distillation at temperatures below 65, 65–170, 170–250, and above 250°C, all refined products in each temperature range had the carbon number according to their boiling points. The distillation of pyrolysis oil in this experiment provided high amount of kerosene, followed by gasoline and diesel.

CFD-based coupled multiphase modeling of biochar production using a large-scale pyrolysis plant

This paper presents a combined CFD simulation of the thermal conversion of biomass to biochar and the co-combustion of air and biomass volatiles with non-premixed swirl air and volatiles in an industrial pyrolysis plant. The main objective of this study is to investigate thermal conversion process in indirect biochar plants taking into accounts the main challenges associated with biochar production. The model is based on the implementation of calculations on the thermal conversion of biomass in a computational fluid dynamics (CFD) environment. Several sub-models have been introduced to simulate the thermal conversion of biomass to biochar, taking into consideration heat and mass transfer, drying, pyrolysis and volume shrinkage. A non-uniform heat flux obtained by simulating the non-premixed co-combustion of the swirl propane burner and the wood volatile gas has been implemented as an inlet boundary condition in the pyrolysis section. The feasibility of the self-ignition of wood volatiles has been investigated. Uniformity of heat transfer rate between thermal oxidizer and pyrolysis section and lower moisture content in the feedstocks play a remarkable role in producing higher quality of biochar and minimizing residence time in indirect slow pyrolysis plants.

Economic assessment of a 40,000 t/y mixed plastic waste pyrolysis plant using direct heat treatment with molten metal: A case study of a plant located in Belgium

Pyrolysis has been identified as an ideal process to recycle mixed plastic waste (MPW). This study investigates the economics of a 40,000 t/y MPW pyrolysis process, called PlastPyro, located in Belgium, to an accuracy of ±15% i.e. “Definite Estimate”. The process uses molten metal in a direct heat treatment process to pyrolyse the waste. An internal rate of return (IRR) of 20% strongly indicates that a 40,000 t/y PlastPyro plant is financially attractive for private investors. The capital expenditure (CAPEX) is estimated to be €20.1 m or €26.1 m if the cost of capital is included. The operating expenditures (OPEX) of the plant are estimated €3.4 m per year. The sensitivity analysis shows six main variables having major impacts on the financial returns of a PlastPyro plant: (1) the addressable volume and quality of plastic waste, (2) the feedstock costs, (3) the capital and operating expenditures, (4) the revenues from the sale of the produced pyrolysis oil (P-oil), (5) the tipping fees and (6) the potential to co-locate a PlastPyro plant with a waste plastic sorting facility. For example, the 15-year low P-oil revenue price of €210/t results in an IRR of 20%; but on the 6th of March 2020 the P-oil price may have achieved €227/t, resulting in an IRR of 37%. The paper also shows that a reliable supply of MPW is available, and that reliable, accessible markets for the P-oil are available. Finally, cost estimates should state their accuracy and usually factorial cost estimates are not accurate enough to state the IRR.

Multivariate optimisation study and life cycle assessment of microwave-induced pyrolysis of horse manure for waste valorisation and management

The increasing amount of waste generated globally due to industrialisation and economic activities require a proper and efficient waste management route. Turning waste to energy via pyrolysis pathway is a promising solution to reduce the amount of waste while generating useful end products. In the present study, microwave pyrolysis of horse manure for the production of bio-fuels and bio-chemicals is conducted and optimised using a lab-scale reactor. Pyrolytic products derived from optimised parameters show that the energy density of bio-char increased by 38.7% with a surface area of 799.57 m2g-1. The bio-oil was found to be enriched with phenolic content while the gaseous product contained high syngas proportion (67.17 vol%). A life cycle assessment (LCA) on the microwave pyrolysis of horse manure for a modelled pyrolysis plant located in Peninsula Malaysia has been conducted to evaluate the energy consumption, operation cost and environmental impact of each unit processes involved. Processing of horse manure via microwave-induced pyrolysis is demonstrated to be more advantageous as compared to the conventional pyrolysis of swine manure from the aspects of higher conversion efficiency, lower energy consumption and reduced environmental risk. Overall, the LCA of horse manure on microwave pyrolysis shows positive environmental impact as compared to other biowaste treatment methods such as composting and incineration.

Small-scale biochar production on Swedish farms: A model for estimating potential, variability, and environmental performance

Several small-scale pyrolysis plants have been installed on Swedish farms and uptake is increasing in the Nordic countries. Pyrolysis plants convert biomass to biochar for agricultural applications and syngas for heating applications. These projects are driven by ambitions of achieving carbon dioxide removal, reducing environmental impacts, and improving farm finances and resilience. Before policy support for on-farm pyrolysis projects is implemented, a comprehensive environmental evaluation of these systems is needed. Here, a model was developed to jointly: (i) simulate operation of on-farm energy systems equipped with pyrolysis units; (ii) estimate biochar production potential and its variability under different energy demand situations and designs; and (iii) calculate life cycle environmental impacts. The model was applied to a case study farm in Sweden. The farm’s heating system achieved net carbon dioxide removal through biochar carbon sequestration, but increased its impact in several other environmental categories, mainly due to increased biomass throughput. Proper dimensioning of heat-constrained systems is key to ensure optimal biochar production, as biochar production potential of the case farm was reduced under expected climate change in Sweden. To improve the environmental footprint of future biochar systems, it is crucial that expected co-benefits from biochar use in agriculture are realised. The model developed here is available for application to other cases.

Application of Hydroprocessing, Fermentation, and Anaerobic Digestion in a Carbon-Negative Pyrolysis Refinery

This study investigates the economic and environmental benefits of integrating hydroprocessing, fermentation, and anaerobic digestion into a pyrolysis refinery. Two scenarios were developed for upgrading and/or utilizing the primary products of pyrolysis (bio-oil, gas, and char). The first (hydroprocessing) scenario hydroprocesses whole bio-oil into gasoline and diesel. The second (fractionation) scenario fractionates bio-oil into sugars for fermentation to cellulosic ethanol and residual phenolic oil as the primary product. Both scenarios use the gaseous product of pyrolysis for process heat in the plant and employ biochar to enhance anaerobic digestion of manure for power generation. The fast pyrolysis plant processes 2000 ton/day of corn stover while the anaerobic digester employs 430 ton/day of manure to generate power. The hydroprocessing scenario produces gasoline at a minimum fuel-selling price (MFSP) of $2.77 per gallons of gasoline while the fractionation scenario produces ethanol and phenolic oils (diesel) as a transportation fuel for $1.2 per gallon ($1.41 per GGE). Sensitivity analysis indicates that the MFSP for both scenarios is highly sensitive to the fixed capital cost. Fixed capital costs for the hydroprocessing and fractionation scenarios were estimated to be $643 and $288 million, respectively. Fuel production rates for the hydroprocessing and fractionation scenarios are 60.5 and 16 million GGE per year, respectively. Life cycle greenhouse gas emissions were calculated as −9.6 and −16.6 g CO2,eq per MJ for the hydroprocessing and fractionation scenarios, respectively. LCA emissions are sensitive to byproduct credits derived from biochar sequestration and power generation. This study shows that both systems produce transportation fuels at competitive market prices with an additional reduction in atmospheric CO2 levels compared to fossil fuel sources.

A new strategy for using lint-microfibers generated from clothes dryer as a sustainable source of renewable energy

Lint-microfibers (LMs) generated during clothes drying are classified as primary microplastics and consist mainly of cotton, polyester and lignin. This research aims to convert LMFs into energy products using a pyrolysis treatment. The pyrolysis experiments were performed using a pilot pyrolysis plant. SEM-EDS was used to observe the morphology and elemental composition of the feedstock and the obtained biochar, while a digital unit of Instantaneous Gas analyzer and Gas chromatography (GC) were used to observe the concentration of O2, N2, CO2, CO, H2, CH4 gases during the whole conversion process. Finally, a simple mathematical model was developed to evaluate the economic and environmental performance of the suggested strategy based on the LMFs generated by one million persons. Based on the results of the developed model and yield of pyrolysis process, around 45 tons of LMFs are generated by one million persons annually and this amount is enough to produce 13.8 tons of oil (~31%), 21.5 tons of gas (47.7%), and 9.7 ton of char (21.6%) with estimated profitability of 120,400$ and reduction in carbon footprint estimated at −42,039,000kg CO2-eq/t of LMFs.

A Critical Review on Advancement and Challenges of Biochar Application in Paddy Fields: Environmental and Life Cycle Cost Analysis

Paddy fields emit considerable amounts of methane (CH4), which is a potent greenhouse gas (GHG) and, thereby, causes significant environmental impacts, even as they generate wealth and jobs directly in the agricultural sector, and indirectly in the food-processing sector. Application of biochar in rice production systems will not just help to truncate their carbon footprints, but also add to the bottom-line. In this work, the authors have reviewed the literature on climate change, human health, and economic impacts of using organic residues to make biochar for the addition to croplands especially to rice paddy fields. Biochar-bioenergy systems range in scale from small household cook-stoves to large industrial pyrolysis plants. Biochar can be purveyed in different forms—raw, mineral-enriched, or blended with compost. The review of published environmental life cycle assessment (E-LCA) studies showed biochar has the potential to mitigate the carbon footprint of farming systems through a range of mechanisms. The most important factors are the stabilization of the carbon in the biochar and the generation of recoverable energy from pyrolysis gases produced as co-products with biochar as well as decreased fertiliser requirement and enhanced crop productivity. The quantitative review of E-LCA studies concluded that the carbon footprint of rice produced in biochar-treated soil was estimated to range from −1.43 to 2.79 kg CO2-eq per kg rice grain, implying a significant reduction relative to rice produced without a biochar soil amendment. The suppression of soil-methane emission due to the biochar addition is the dominant process with a negative contribution of 40–70% in the climate change mitigation of rice production. The review of the life cycle cost studies on biochar use as an additive in farmlands demonstrated that biochar application can be an economically-feasible approach in some conditions. Strategies like the subsidization of the initial biochar capital cost and assignment of a non-trivial price for carbon abatement in future pricing mechanisms will enhance the economic benefits for the rice farmers.

Research and Development of Mathematical Models of Elements of a Gas-Air Flow for Improvement of Automatic Control System of Organic Waste Processing Plant

Recycling of organic wastes is an extremely important and challenging environmental task. One of the promising trends in this field is the creation of multi-mode (combustion, pyrolysis and gasification) plants for processing organic wastes with production of such useful products as thermal energy and energy carriers (biocoal, bio-oil, pyrolysis resins, synthesis gas, etc.) and fertilizers. When creating such plants, the main problems include instability of the properties of a source material, its high water and ash content. This drives the developers to use non-standard equipment and atypical control algorithms, the creating of which requires a lot of experimental work to be done. At the same time, conducting field experiments is an expensive, difficult and long process that highlights the need for extensive use of mathematical and computer modeling. In this paper, mathematical models of elements of the gas-air path of the organic waste processing plant are obtained. The characteristics of the gas-air path of the plant as of an object of regulation for pressure in the lower and vacuum in the upper part of the combustion chamber are determined. The gas-air flow consists of the flue and the air ducts and serves to remove flue gases from the combustion chamber and supply air needed to maintain fuel combustion. When developing new automation systems, modeling allows assessing the applied solutions accurately, simplifying and reducing the cost of their development, solving the problems of system stability, optimizing transient processes, etc. The nonlinearity of the obtained mathematical models on the "the pressure at the inlet to the n-th section air-gas flow path — the pressure at the outlet of the n-th section of the air-gas flow path" channels, the nonstationarity of objects of control and dependence of their dynamic characteristics on operating mode of the plant are determined. Due to developed models, the two-way relationship of the gas and air paths has been revealed. When modeling, the gas-air flow of the plant is divided into several sections for which the mathematical models are obtained. They are required to synthesize controllers of flue gases vacuum in the upper part and the air pressure in the lower part of the combustion chamber.

Tire pyrolysis plant set for the UK

The Norwegian tire-recycling start-up Wastefront has picked the UK as the site for its first plant. Formed in 2019, the firm says it recently received funding from the state-owned Innovation Norway...

Plastic pyrolysis plants planned

Two new plastic pyrolysis plants are in the works in the US that could add a new recycling option for plastic trash and increase the supply of some commodity chemicals. In pyrolysis, a feedstock su...

A feasibility assessment of the production of char using the slow pyrolysis process

There is a growing need for the production and use of sustainable biofuels worldwide. One noteworthy approach is the production of biofuels via the thermochemical conversion of lignocellulose biomass. This work studied the production of char via the slow pyrolysis of corn-stover as a suitable supplement or replacement of coal in industrial processes. The char quality was assessed according to the ASTM D388 (American Standard Testing Method), which ranks coals according to their higher heating value (HHV), volatile matter and fixed carbon. Furthermore, an evaluation of the techno-economic feasibility of an industrial scale 30 t/day slow pyrolysis plant was conducted. The techno-economic study was conducted at a char baseline price of $100/ton. A two-level three-factor central composite design (CCD), with response surface methodology (RSM) was used to study the slow-pyrolysis process conditions. Optimisation experiments were conducted at bench-scale gram-level to study the influences of the process condition of char higher heating value (HHV) and yield. Furthermore, this study assessed the techno-economic feasibility of a 30t/day processing plant. The results showed process temperature had the most significant influence on char HHV and yield. Optimal conditions for char production were at a reactor temperature of 453 °C, and 5 °C/min and 29 min for heating rate and holding time respectively. Under these conditions char with HHV of 26.25 ± 1.5 MJ/kg and yield of 34.5% were produced. These chars are comparable to sub-bituminous A coals. A high energy efficiency of ~82% was also associated with the process. The economic feasibility of the plant is highly sensitive to the cost of CS feedstock. The process had a net present value (NPV) of -$1.17 million at the $20/ton CS baseline assumption. A cost sensitivity analysis showed that when the cost of CS was lowered to $3/ton, the NPV was zero. Uncertainties in the price estimation of the volatile by-products remained a concern.

Prediction of Yields of Lower Olefins during Pyrolysis of Hydrocarbon Feedstock

A method for predicting the yield of unsaturated hydrocarbons during pyrolysis of individual alkane hydrocarbons and mixed hydrocarbons based on the conducted research and on literature data for pyrolysis of various hydrocarbon feedstocks was developed. The proposed method is universal for any type of feedstock and allows the maximum possible yield of target pyrolysis products to be pre-evaluated both before starting of experimental research and during industrial operation of pyrolysis plants.

The Development of a Waste Tyre Pyrolysis Production Plant Business Model for the Gauteng Region, South Africa

Some of today’s modern life challenges include addressing the increased waste generation and energy deficiencies. Waste tyres have been identified as one of the key environmental concerns due to their non-biodegradable nature and bulk storage space demand. Pyrolysis is a thermochemical process with the potential to address the growing waste tyre problem, energy deficits, and material recovery by converting waste tyres to pyrolysis oil that can be used as a fuel. This study seeks to critically evaluate the feasibility of constructing and operating a waste tyre processing facility and then subsequently marketing and selling the pyrolysis secondary end products by developing a financial business model. The model encompasses costing, procurement, installation, commissioning, and operating a batch pyrolysis plant in Gauteng, South Africa. To achieve the study objectives, an order of magnitude costing method was used for model construction. The results showed the feasibility and sustainability of operating a 3.5 tonne per day batch waste tyre pyrolysis plant in Gauteng Province, South Africa, with a 15-year life span and a projected payback period of approximately 5 years. It was concluded that for the pyrolysis plant to be successful, further treatment steps are required to improve the process economics; also, a stable and sustainable product market should exist and be regulated in South Africa.

A lab scale waste to energy conversion study for pyrolysis of plastic with and without catalyst: Engine emissions testing study

Plastics in many forms have been regarded as one of the most polluting material in the modern world. Therefore, a study has been conducted to check the effectiveness of catalyst-fly ash and zeolite on the production of biofuel from plastics as an attempt to contribute in the reduction of plastic waste pollution to the environment. A lab scale plastic pyrolysis plant has been constructed and feed particle size of 3 ± 1.5 cm2 were used as raw materials. The samples were tested in the pyrolysis plant at about 500 ± 30 °C with and without the presence of catalyst. The catalyst loading ratio of 1:10 catalyst to feed is applied. The result shows that plastic pyrolysis (bottle) without any catalysts have the highest liquid fraction yield with an average yield of 24% while those with catalyst has lower yield (16–22%). Carry bags with zeolite catalyst yield liquid fraction of 22% at a conversion rate of 47%. The inclusion of catalyst has lowered the yield but has produce oil yield of superior quality compared with the samples without catalyst. Engine characteristics study showed that blend fuel D80PO20 (80:20 diesel: plastic pyrolytic oil) have shown similar cylinder pressure during combustion with diesel. Higher brake thermal efficiency and lower brake specific energy consumption were also observed from the engine testing using the blend fuel. The blend fuel has lower hydrocarbon emissions while oxides of nitrogen reduces by 19% and 26% compared to pure diesel and PPO respectively.

Clariant's new ReforMax 330 LDP Plus catalyst increases significantly energy and production efficiency at OCI's ammonia plant

Plastics in many forms have been regarded as one of the most polluting material in the modern world. Therefore, a study has been conducted to check the effectiveness of catalyst-fly ash and zeolite on the production of biofuel from plastics as an attempt to contribute in the reduction of plastic waste pollution to the environment. A lab scale plastic pyrolysis plant has been constructed and feed particle size of 3 ± 1.5 cm2 were used as raw materials. The samples were tested in the pyrolysis plant at about 500 ± 30 °C with and without the presence of catalyst. The catalyst loading ratio of 1:10 catalyst to feed is applied. The result shows that plastic pyrolysis (bottle) without any catalysts have the highest liquid fraction yield with an average yield of 24% while those with catalyst has lower yield (16–22%). Carry bags with zeolite catalyst yield liquid fraction of 22% at a conversion rate of 47%. The inclusion of catalyst has lowered the yield but has produce oil yield of superior quality compared with the samples without catalyst. Engine characteristics study showed that blend fuel D80PO20 (80:20 diesel: plastic pyrolytic oil) have shown similar cylinder pressure during combustion with diesel. Higher brake thermal efficiency and lower brake specific energy consumption were also observed from the engine testing using the blend fuel. The blend fuel has lower hydrocarbon emissions while oxides of nitrogen reduces by 19% and 26% compared to pure diesel and PPO respectively.

Energy Recovery from Waste Tires Using Pyrolysis: Palestine as Case of Study

The first industrial-scale pyrolysis plant for solid tire wastes has been installed in Jenin, northern of the West Bank in Palestine, to dispose of the enormous solid tire wastes in the north of West Bank. The disposable process is an environmentally friendly process and it converts tires into useful products, which could reduce the fuel crisis in Palestine. The gravimetric analysis of tire waste pyrolysis products from the pyrolysis plant working at the optimum conditions is: tire pyrolysis oil (TPO): 45%, pyrolysis carbon black (PCB): 35%, pyrolysis gas (Pyro-Gas): 10% and steel wire: 10%. These results are depending on the tire type and size. It has been found that the produced pyrolysis oil has a High Heating Value (HHV), with a range of 42 − 43 ( MJ / kg ) , which could make it useful as a replacement for conventional liquid fuels. The main disadvantage of using the TPO as fuel is its strong acrid smell and its low flash point, as compared with the other conventional liquid fuels. The produced pyrolysis carbon black also has a High Heating Value (HHV) of about 29 (MJ/kg), which could also encourage its usage as a solid fuel. Carbon black could also be used as activated carbon, printers’ ink, etc. The pyrolysis gas (Pyro-Gas) obtained from waste tires mainly consist of light hydrocarbons. The concentration of H2 has a range of 30% to 40% in volume and it has a high calorific value (approximately 31 MJ / m 3 ), which can meet the process requirement of energy. On the other hand, it is necessary to clean gas before the burning process to remove H2S from Pyro-Gas, and hence, reduce the acid rain problem. However, for the current plant, some recommendations should be followed for more comfortable operation and safer environment work conditions.

Pyrolysis of C3 energy plant (arundo donax): Thermogravimetry, mechanism, and potential evaluation

Pyrolysis of Arundo donax can provide renewable and sustainable energy, materials, and chemicals in a large scale. In this study, the pyrolysis mechanism and potential evaluation of biomass was revealed by thermogravimetric analysis, Fourier transform infrared spectroscopy, gas chromatography-mass spectrometry and a fixed bed pyrolysis setup. Up to about 150 °C, moisture in the sample was evaporated, resulting in mass loss. After drying, in the second stage, pyrolytic thermal decomposition reaction took place in the temperature range of about 150–375 °C at different heating rates ranging from 10 to 20 °C/min in inert atmosphere using the techniques of thermogravimetric analysis. The differential thermogravimetric curves could be divided into three fitting peaks corresponding to three key components of cellulose, hemicellulose, and lignin. Apparent absorbance peaks at 3590, 2950, 2182, 1786, and 1176 cm−1 were detected and indicated the main pyrolysis products of CO2, CH4, CO, and O-containing compounds (acids, alcohols and ketones/aldehydes). The main carbon numbers were C3, C4, C5, and C8 and the main compositions were acids, ketones/aldehydes, alcohols, and phenols. The output of an industrial scale plant (2000 t/d) was 28 MW power, 51.36 t/d bio-oil, 555.04 t/d vinegar, and 511.36 t/d biochar. In China, there are more than 0.3 million ha of marginal lands suitable for growing Arundo donax, which can provide 9 million tons of feedstock for industrial scale pyrolysis plants.

Techno-economics of Biochar and Biogas viability in Ghana

Biogas and voucher are technological solutions that deal with sanitation and other environmental problems. The technology for producing biogas from faeces is termed bio-toilet and production of biochar from the same human waste is by means of Sol-char toilet. The study evaluated economic benefits and costs of sol-char toilet and compared with empirical benefits and costs estimates of bio-toilet. Cost Benefit Analysis was used to judge welfare change attribution of investment into Sol Char Toilet and Bio Toilet. The pyrolysis plant was fed with 4000 tons of faeces for which Sol char toilet incurred Total capital cost of US$ 3,140,940.38, Net Present Value (NPV) of US$9,718,817.4788, Profitability Index (PI) of 4.0942381271 and 1.4 years payback period. Bio toilet values for a total of 4000 m3 (100 units of 40 m3 each) were; - Total capital cost of US$ 36,026.05, NPV of US$89,152.75, PI of 3.4746 and 3.46 years payback period. Sol char toilet is faced with high capital requirement challenges, compared with an advantage in smaller payback period and a marginal difference in PI. The study concluded that complementary roles of sol char toilet and bio toilet in the Ghanaian economy is preferred.Keywords: Biogas; Biochar; Cost Benefit Analysis; Profitability Index; Payback period.

Simulation of the Condensation and Fractionation Unit in Waste Plastics Pyrolysis Plant

The condensation and fractionation unit design affects the quantity and quality of the liquid products derived from the waste plastics pyrolysis. The oil products, if meet the standards requirements, can be used as an alternative fuel. Three configurations of this unit were studied: two condensers system with phase separators (2 CNDR), three condensers system with phase separators (3 CNDR) and as an unconventional solution in pyrolytic plant—the rectification column system (TOWR). Based on the chromatographic analysis and laboratory distillation results of the pyrolytic oil from industrial plant, the composition of the model oil was determined. This model oil was then used in simulations of the condensation and fractionation units, using ChemCad software. The comparison of the three tested configurations showed that the best separation of components was achieved in the TOWR system. Although in the simplest CNDR 2 system the desired heavy fraction yield was higher, its composition was least favourable in terms of oil properties (e.g., flash point), because more light components were condensed. Since the application of rectification column resulted in the best fractionation efficiency, the proposed TOWR configuration was examined in detail. The change of the rectification column process parameters (mainly the reflux ratio) allows for precise control of the oil fractions composition. The reflux ratio, and hence the distillate temperature, determines the heavy fraction yield. The yield and composition of the oil fractions practically do not depend on the feed stream temperature. By increasing the number of stages in the rectification column the separation of near-boiling components is improved, but the significant effect is noticeable only up to 10 theoretical stages.Graphic