Oxygen-enriched Combustion Characteristic Of Oily Sludge And Design Research Of The Boiler Heating Surface

Oily sludge is the waste produced in the process of the exploitation and processing of crude oil.In order to realize the harmless,reduction and resource treatment of oily sludge.Based on the oxygen-enriched combustion technology,a new technology of oily sludge treatment is put forward,which can realize the harmless treatment of oily sludge,and directly capture high concentration CO₂ for oilfield oil-driving,and sulfuric acid and nitric acid can be resource recovery.The pollutant emission characteristics of oily sludge combustion will be changed under the oxygen-enriched combustion.SO₂ and NO emission characteristics of oily sludge combustion in oxygen-enriched atmosphere was studied in a horizontal tubular electric heating furnace,and factors such as combustion atmosphere and combustion temperature were considered.The results show that SO₂ and NO are released in the form of unimodal during oily sludge combustion in O₂/CO₂ atmosphere.As the oxygen concentration increases,the curve of release peak of SO₂ and NO increases,and the time of SO₂ and NO completely release is shortened and the total amount of SO₂ and NO increases.With the increase of temperature,the curve of release peak of SO₂ and NO occurred earlier and higher,and the time of SO₂ and NO completely release is shortened,and the total amount of SO₂ and NO increases,and the biggest increase of SO₂ and NO is at the temperature?800⁹00??.Comparing the production amount and conversion rate of SO₂ and NO in air atmosphere and 21%O₂/79%CO₂ atmosphere,the production amount and conversion rate of SO₂ and NO decrease in 21%O₂/79%CO₂atmosphere.The effects of temperature and atmosphere on trace element migration characteristics of oxygen-enriched combustion was studied in the horizontal tube furnace.The results show that the release rate of Hg is close to 100% at the combustion temperature above 700? and the change of combustion temperature and combustion atmosphere has no effect on the release of Hg.The release rates of As,Pb and Zn increased with the increase of combustion temperature in O₂/CO₂ atmosphere.The release rate of Pb increases with the increase of oxygen concentration,and the release rate of As decreases with the increase of oxygen concentration.and the release rate of Zn shows atrend of decrease after the first increase with the increase of oxygen concentration.The release rate of As,Pb and Zn in air atmosphere is greater than that in 21%O₂/79%CO₂atmosphere at the same temperature.Taking a 200t/d fluidized bed oily sludge incinerator as an instance,detailed thermal calculation and analysis of pure oxygen,instead of air,used in the incineration system of a fluidized bed are carried out.According to the energy balance,a conceptual design of oxygen-enriched burning oil sludge fluidized bed boiler is carried out from aspects of heating surface of dense segment,heating surface of dilute segment and heating surface in tail section etc.The design parameters and structure layout of fluidized bed boiler are studied.The results show that the heat in the furnace increases and convection heat tail flue releases,the heat transfer in the furnace is much larger than the convective heat transfer on the condition of oxygen-enriched combustion.Adequate heating surface is required to be arranged in the dense phase zone to absorb the heat in the furnace.As bubbling bed incineration oily sludge need small fluidizing air rate,low fluidizing air speed.Pure oxygen can meet the requirements of fluidizing air speed,and don not need flue gas recirculation system.Finally,an economic analysis was carried out for the oxygen-enriched combustion boier with 200t/d of oily Sludge.The results show that using a fluidized bed boiler with200t/d of daily disposal ability,73 000 t of oily sludge is treated per year,so 73 million yuan of sewage charge can be saved per year;The steam output of the boiler is about 177000 t per year.In addition,5.56 t sulfuric acid with 40% of mass fraction and 0.708 t nitric acid with 37% of mass fraction can be recovered per day,and 99 000 t CO₂ can be recovered per year.