PLASMA-CHEMICAL TECHNOLOGY OF OBTAINING ADDITIONAL AMOUNT OF LIQUID FUEL FROM A MIXTURE OF FUEL OIL AND TORF

Objectives of plasma-chemical (PC) technology for obtaining additional amount of liquid fuel from a mixture of fuel oil and peat

  • Estimation of efficiency of application of PC technology to increase the yield of liquid fuel from a mixture of fuel oil and peat in relation to the input liquid fuel in the form of fuel oil.
  • Obtaining the maximum amount of bio-oil from liquid fuel.
  • Evaluation of applicability and characterisation of the obtained bio-oil. Approximate calculation of economic indicators.
  • Schematic diagram of the installation for PC treatment of HC mixtures
    The discharge (plasma) zone is in direct contact with the HC feedstock to be treated, which is fed continuously. Under the influence of high-energy electrons and ions of the plasma, HC molecules, which are part of the feedstock, undergo degradation and are divided into lower molecular compounds.
    The effective residence time of HC in the plasma is 12 microseconds.

Main features of plasma chemical processes

The main feature of plasma chemical processes is that in plasma many reactive particles - excited molecules, electrons, molecular ions and free radicals - are formed in higher concentrations than under normal conditions of chemical reactions, which initiate and cause new types of chemical cracking reactions.

Advantages of plasma chemical processes

  • The main advantage of energy conversion under low-temperature plasma (LTP) conditions is the high rates of the cracking reaction. Intensification of cracking processes occurs under the short-term influence of high temperature with possible addition of necessary catalysts and high specific power of plasma, which leads to formation of high concentration of active radicals, ions and electrons.
  • The electron energy at LTP is about 10 eV, which allows to split hydrocarbons by C-C (6.2 eV) and C-H (5.5 eV) bonds.
  • The impact of LTP on hydrocarbons causes many chemical reactions leading to the destruction of their high-molecular compounds, which increases efficiency compared to thermal cracking.

Block diagram of the PC processing of the initial product

Material balance of fuel oil and peat processing, kg

Refined products and energy balance

  • At atmospheric distillation of 1000 kg of a mixture of fuel oil and peat up to 360°C, treated according to the PC method, containing about 700 kg of organic compounds is released, kg: about 580 kg of organic liquid products; up to 47 kg of water; up to 116 kg of gaseous compounds (CO, CO2, H2S, hydrocarbons C1-C4 and others). The yield of liquid organic products is about 83% of the theoretically possible.
  • At atmospheric distillation of the same mixture without PC treatment only 15% of organic liquid products can be obtained.
  • The total energy consumption for PC processing is about 32 kW per tonne of feedstock (including 6.16 kW for the operation of the PC reactor). The calculation does not include energy consumption for condensation of liquid fractions and separation of solid residue from the treated feedstock.

Structural diagram of the equipment

Approximate calculation of economic indicators at the capacity of the complex of 15 tonnes per day

Conclusions
  • At atmospheric distillation, PC of treated mixture of fuel oil and peat, to 360°C boils out about 58% of distillate, produces about 28-29% of solid mineral residue, 11-12% of hydrocarbon non-condensable gases and 4-5% of water. A second distillation of the distillate (58%) can produce a petrol fraction of 5-6%, a diesel fraction of 38-39% and a liquid residue of 10-11%.Mineral part of peat can be extracted from the product of peat and fuel oil mixture processing at thermolysis on the known equipment, but at temperatures up to 360°С. The heat of combustion of the solid residue is 6950 kcal/kg.
  • Electricity consumption directly for PC treatment of 1000 kg of fuel oil and peat mixture is about 6.16 kW.
  • Simplified economic calculation shows that with initial equipment costs of about 46.8 million rubles and equipment productivity of 15 tonnes/day the payback period of the project is less than 2 years. At the same time, the resulting hydrocarbon non-condensable gas is used to heat a mixture of fuel oil and peat, and the solid residue in the form of semi-coke can be used in the form of fuel pellets (these revenues were not taken into account in the economic calculations).
  • Experimental production unit
    in a container
Technical characteristics of the experimental production unit
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