Gheorghe LAZAROIU. Lucian MIHAESCU, Gabriel NEGREANU, Constantin PANA, Ionel PISA, Elena POP UNIVERSITY POLITEHNICA OF BUCHAREST

Transcription

1 Gheorghe LAZAROIU Lucian MIHAESCU, Gabriel NEGREANU, Constantin PANA, Ionel PISA, Elena POP UNIVERSITY POLITEHNICA OF BUCHAREST

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3 BIOENERGY FUEL from animal waste The leather sector comprises about enterprises and generates a turnover of 48 billion euros. A quarter of the production waste from the leather industry is generated in Europe Fats, which can be used as the input fuel for diesel engines (in crude state or as biodiesel), represent 10 % of this animal waste, while the rest are proteins that can be used to generate biogas through anaerobic digestion. Animal fats are an important secondary product of the leather industry about 10% leather finished and proteins over 30% They have high energy potential owing to their good combustion properties; hence, they are suitable fuels for internal combustion engines and steam or hot water generator. Removal of animal fats through incineration or storing have high associated costs of /tonne.

4 Animal fats have high heating value (H i ) and are used either as raw fats (under special conditions) or as biodiesel obtained through transesterification with alcohol. In the next table some properties of animal fat oils are reported and compared with the properties of diesel fuel Compostion [wt %] Properties Raw cow fats Diesel fuel* MEGA EEGA C H O Ash Heating Value Hi [MJ/kg] Cetane Number CN [-] Density [kg/m3] Viscosity at 40 C [m2/s] 46.37** Ignition Point [ C] * diesel fuel used for comparison is produced by American company Phillips 66; MEGA methyl ester of beef fat; EEGA ethyl ester of beef fat. **The viscosity of raw animal fats is high (up to 10 times that of diesel fuel), and raw animal fats contain a large quantity of lipids, free fatty salts, phospholipids, stearins, and wax.

5 1.1. EXPERIMENTAL INVESTIGATIONS: DIESEL ENGINES FUELLED WITH ANIMAL FATS The experimental results of the combustion mix between diesel and animal fat on a CFR-IT9-3M engine for x c animal fat weight in blend with diesel fuel between [kg animal fat/kg diesel fuel] The experimental installation is: The experimental engine was modified with an upgraded instrumentation, such as the Anstalt für Verbrennungskraftmaschinen List Engineering Company (AVL) in-cylinder pressure transducer line, Kubler speed incremental transducer, real-time AVL data acquisition system for processing and storage of measured data, and AVL gas analyser and smoke meter for diesel engines. Thermo-resistances were used to determine the temperatures of the cooling liquid of the engine and the engine diesel and inlet air, and thermocouples were used for determining the temperature of the exhaust gas. The experimental investigations were repeated twice for each engine operation regime, and the obtained results did not exceed a maximum deviation of 1%.

6 The following methodology was used: initially, the equipment and all instruments were calibrated. In order to prepare the animal fat-diesel fuel blends, both fuels were heated at temperatures over 40 C, the temperature at which animal fats are in the liquid state and are perfectly soluble in diesel fuel. The engine was firstly fueled with diesel fuel, and then with different diesel fuelanimal fat blends [kg animal fat/kg diesel fuel] For each experiment, the auto ignition delay, engine compression ratio, injection timing, pressure diagrams, concentration of the emitted pollutant, exhaust gas temperature, cooling liquid temperature, lubricant oil temperature, and inlet air temperature were recorded. 2 cases were analyzed : In the first case, the engine parameters such as injection timing (β = 13 CA, crank angle), compression ratio (ε = 13.74), and the values corresponding to a diesel fuel auto ignition delay of 13 CA were kept constant. In the second case, the engine parameters were adjusted in order to maintain the combustion process starting at TDC (top dead centre).

7 THE RESULTS OBTAINED IN THE FIRST CASE Constant engine parameters, such as: injection time - β = 13 CA (rotation angle); compression ratio - ε = 13.74; values of a delayed auto-ignition of diesel fuel by 13 CA. Maximum gas pressure vs. different substitute ratios x c Indicated mean pressure, p i, vs. different substitute ratios x c

8 THE RESULTS OBTAINED IN THE SECOND CASE The engine parameters were adjusted in order to maintain the combustion process starting at TDC (top dead centre) Variation in the maximum pressure with the fat percentage in the blend with diesel fuel - different substitute ratios xc Variation in injection timing with the fat percentage in the blend with diesel fuel - different substitute ratios

9 Results for NOx and Smoke NOx emission level Variation in smoke concentration with fat percentage in the blend with diesel fuel xc= 0 [ kg animal fat / kg diesel fuel ] xc= 0.05 [ kg animal fat / kg diesel fuel ] xc= 0.10 [ kg animal fat / kg diesel fuel ] xc= 0.15 [ kg animal fat / kg diesel fuel ] 0 xc= 0 [ kg animal fat / kg diesel fuel ] xc= 0.05 [ kg animal fat / kg diesel fuel ] xc= 0.10 [ kg animal fat / kg diesel fuel ] xc= 0.15 [ kg animal fat / kg diesel fuel ] NOx [ ppm ] Case 1 NOx [ ppm ] Case 2 K - smoke number [ 1/m ] Case 1 K - smoke number [ 1/m ] Case 2

10 In Conclusion: Analysis of the obtained experimental investigation results showed that the advantages of using the raw animal fats are the reduction in NO x emission level, smoke emission level, the maximum pressure of gases, and the maximum pressure rise rate during combustion. The disadvantages of using the raw animal fats are the reduction in indicated mean effective pressure, and the increase in auto ignition delay, indicated specific energy consumption, and the CO and HC concentration. These disadvantages impose limitations on the percentage of raw animal fats in the blend with diesel fuel. Comparison of the experimental results for the two working cases shows that by modifying the fuel injection timing, the negative effects of autoignition delay (the increase in the delay with the increase in the percentage of animal fats in the blends with respect to the autoignition delay for diesel fuel) are eliminated.

11 1.2. EXPERIMENTAL PILOT PLANT FOR ANIMAL FATS MIXED WITH LIQUID HYDROCARBONS COMBUSTION EFFICIENCY The experimental researches and validation were conducted on a pilot boiler, Multiplex CL 50 model, manufactured by Thermostahl Company. Experimental pilot boiler equipped with the burner Anyo-12

12 The used burner is equipped with a mechanical spray pump for a maximum pressure of 22 bars, with a spray nozzle flow rate in the return setting and with a swirl of air. The burner has embedded an electric heater to preheat the fuel spray to 75 o C 1. Boiler; 2. Combustible tank; 3. Liquid combustible burner; 4. Multilyser burned gases analyzer; 5. Cooling water flow meter; 6. Radiation pyrometer; 7. Cold water thermometer; 8. Hot water thermometer; 9. Burned gases thermometer

13 Thermocouple temperature mixing vessel Thermocouple for temperature inside the boiler Flue gas analyzer MAXILYZER NG

14 PILOT PLANT OPERATION Burner starting: Checking the operating status of the control and protection elements on the boiler and setting their value; The separating valve; The main switch engages; Liquid fat is gradually dosed into fuel, for mass ratios of 10, 20 and 30 %. The mixing can be done in the preheater mounted before the burner. Preheating temperature for burner is set between o C, in order to allow the total fats flow and pump power back burner (melting temperature of the fat previously determined in around 42 o C). Air needed for combustion was taken from the room where the boiler is placed and had a value of 30 o C. Fat solid phase is mixed with diesel and then heated until it is perfectly soluble. The flame had a completely bright aspect.

15 The flame had a completely bright aspect. There was noted the emergence soot, not in the flame and into the chimney as shown in Figure. Air needed for combustion was taken from the room where the boiler is placed and had a value of 30 o C. Flame shape visualized by eye observation placed over outbreak

16 10% fat flame test 20% fat flame test 30% fat flame test

17 The boiler efficiency (yield) varies between 69 and 72.6%, depending on the variation of excess air between 2.66 to 3.56, and the temperature of the exhaust gas in the chimney was between o C. The main pollutant emission was the CO, with CO value between to %. The NO x emission was insignificant, the average being around 26 ppm. The pollution limits achieved by burning technology have been in normal targets, so the burning technology can be used at large scale.

18 CONCLUSIONS Animal fat burning technology by mixing them with liquid hydrocarbons has been developed as an application for leather wastes which are in significant quantities. It has been developed a technology with a slight burning application, spray mechanical fuel heated in two stages. Pre-heating temperatures depend on the quality of the animal fat and the characteristics of the burner. The experimental tests have demonstrated quality combustion and emissions to an acceptable level.

19 3. EXPERIMENTAL DETERMINATIONS CONCERNING THE RECOVERY OF PROTEINS FROM LEATHER WASTE A system was developed and tested in a multi-stage technology based on the anaerobic digestion process of tanning products. This system was characterized by C / N 5. The process requires an acclimation period for anaerobic organisms because of high ammonia (NH + 4 / NH3) concentrations exceeding 9000 mg / l. Ammonia was determined according to ISO : 2800 and DR 2991 spectrophotometer special kits, 650 nm, by identifying the ammonia produced by the reaction of ammonium ions and hypochlorite in the presence nitrozopentacianferatului salicylates (III) and sodium (sodium nitroprusside). It was developed and tested an anaerobic digester with hydrolysis cascade acidogenesis and methanogenesis protein in the leather industry. Related control system maintains optimum ph values of 4.7 and 7.2 in the reactor acidogenesis of methanogenesis reactor by adding hydrochloric acid or sodium hydroxide. Average flow of biogas pilot plant was about 1 l / h biogas, with a conversion rate of 16-17%. The biogas obtained for different sorts of animal protein had a composition in limits: CH4: 40% - 65%; CO2: 56% - 28%; H2: 0.9% - 1.1%; H2: 0% - 1%; N2: 3.1% %. Lower calorific power: about kj / Nm3

20 Biogas was burned and the gases were analyzed with an analyzer as shown in the next figure. These analyzes confirmed indirectly previous data and especially lower calorific power Research on the use of biogas energy are underway by research team.

21 BIOENERGY FUEL from crude vegetable oils It was studied burning crude vegetable oils mixed with diesel as an alternative fuel use of organic farmers. Romania has great potential crop of vegetable oils from rapeseed and sunflower. If rape is for biofuels for internal combustion engines, sunflower oil will be used to develop the purpose of producing energy. In research conducted were used samples of these oils in the rough, not chemically modified. Dosage mixture of crude oil and liquid fuel classical was reported in mass units (without taking into account the ratio of calorific values). Dosing was carried out by mixing the previously weighed quantity and homogenization resulted from mixing. We have found a very high degree of homogenization, proving that these substances are perfectly compatible.

22 Mixtures were made in the following proportions: 10%, 20% and 50% vegetable oil. Perfectly homogeneous mixtures result. For mixing it was considered light liquid fuel (CLU) and oil Samples of liquid fuel additive classics with emulsified vegetable oil without precipitate without mechanical impurities or sediments. For direct burning feature is the viscosity. The addition of vegetable oils viscosity fuel oil falls, volatility increases and decreases the number of coke and asphaltenes. Lower calorific value (LHV) of crude vegetable oils is slightly lower than heavy oil or light liquid fuel. Vegetable oils with high flash point between Celsius degrees, and this values are much higher than of the diesel (about 81 degrees Celsius).

23 Kinematic viscosity [m 2 / s] for different types of vegetable oil, depending on the temperature is shown in Figure Sunflower Soy Corn Temperature, Celsius degrees = 40 Temperature, Celsius degrees = 60 Temperature, Celsius degrees = 80 Temperature, Celsius degrees = 100

24 Kinematic viscosity [m 2 / s] for different types of vegetable oil, depending on the temperature is shown in Figure Oil fuel and 20% vegetable oil2 Oil fuel and 20% vegetable oil 100 % vegetable oil CLU and 50% vegetable oil CLU and 20% vegetable oil 5 0 Temperature, Celsius degrees = 50 Temperature, Celsius degrees = 80 Temperature, Celsius degrees = 100

25 Experimental research concerning the pulverization of vegetable oils The experimental stand for the study of pulverization The image of an injector attached to the conduit of vorticity air

26 Experimental research on the operation of combustion technology of vegetable oils to energy plants of average power The research was aimed to determine the combustion performance for the most appropriate constructive solutions for burners of average power for crude vegetable oils. For this research was used boiler pilot of UPB, shown in the next figure. The boiler produces steam and is a reference in the field with a maximum thermal power of 2 MW. Boiler pilot was equipped with a first burner with rotating cup and later with a mechanical spray grill, both burners being specially designed and built to burn crude vegetable oils. Cup burner type rotary spraying allows a maximum flow rate of 90 kg / h of vegetable oil. To start, the burner has been fitted with a natural gas burner with a flow rate of 3 Nm3/h. Cup rotating speed was 6,000 rpm, speed usual for such a burner. Flue gas monitoring was done MAXILYZER NG, multifunctional device with embedded computing functions.

27 Results of performance tests of burning the untreated sunflower oil in the 2 MWt boiler Heat = 900 [ kw ] Boiler efficiency [ % ] Heat = 850 [ kw ] Air excess Temperature flue gas exhaust chimney [Celsius degrees] Oil flow [ kg/h ] Heat = 650 [ kw ]

28 Results of performance tests of burning the untreated sunflower oil in the 2 MWt boiler Chart Title Heat = 900 [ kw ] Heat = 850 [ kw ] Heat = 650 [ kw ] SO2 [ mg/m3 ]2 NOx [ mg/m3 ] CO [ mg/m3 ] CO2 [% ] O2 [ % ]

29 INNOVATIVE BIOENERGY FUEL HYDROGEN SOLID BIOMASS This innovative energy carrier biomass combined positive effect on carbon emissions and those of hydrogen as a clean fuel. The researches focus on the development of an innovative efficient technology for co-combustion of solid biomass with hydrogen enriched gas (HRG), produced by an electrolytic system. The combustion of various types of solid biomass like sawdust, chopped wood, straw briquette, ropes of wine, cobs corn, and energy willow with and without HRG is analyzed. The biomass represents the third major source of primary energy worldwide, after coal and oil. Wood represents the main source of biomass. The biomass with high energy potential includes the agricultural and wood related residuals. The residuals of forestry activities (exception the fire wood) represents about 65 % of the biomass energy potential, while 33 % originates from the agricultural residuals.

30 Experimental installations The combustion of solid biomass with hydrogen in a tunnel or in a combustion chamber to a experimental boiler Biomass burning crumbled solid (<10 mm) with hydrogen or HRG in ERPEK 30 kw boiler

31 The HRG is generated by an industrial portable apparatus placed in the furnace vicinity. This apparatus is provided with a sensor for HRG external detection and with an anti-explosion valve. The HRG supply to the furnace is continuous, that means that is no need of storage. The electrolytic system keeps the fluid in a permanent flow and produces a quasi-stoichiometric gaseous blend of oxygen and hydrogen. The electrolytic production of HRG HRG in the primary air injection Construction of the hydrogen supply and pneumatic air dam

32 The research was conducted for the following types of biomass: 1- sawdust; 2- chopped wood; 3-briquetted straw; 4- wine ropes; 5- cobs corn; 6- energy willow. 1- sawdust; 2- chopped wood; 3-briquetted straw 4- wine ropes; 5- cobs corn; 6- energy willow.

33 Biomass tests are conducted by the research team for over 10 years. The energy characteristics of the most common type of solid biomass (The lower heat value -LHV, The total moisture in the initial state - Wt, and ash in the initial state, Ai) are Biomass type Parameter LHV [kj/kg] Wt [ % ] Ai [% ] 1- sawdust chopped wood briquetted straw string vine cobs corn energy willow

34 Results of experimental tests Experimental tests for monitoring the combustion of solid biomass with HRG in an outbreak with a constant thermal power installed 400 kw. The experimental tests were carried out in two cases: no injection and injection of HRG (15 liter / 1 kg biomass). The analysis of gas components from the furnace in the final stage of combustion was carried out with a gas analyzer HORIBA type PG250. The Horiba PG-250 is a compact, lightweight and fully portable gas analyzer that can simultaneously measure up to five separate gas components. It is a highly reliable and versatile gas analyzer for compliance testing of NO x, SO 2, CO, CO 2, and O 2. The PG-250 is capable of intermittent or continuous measurement of the five components simultaneously. The analysis was done flue gas analyzer NG MAXILYZER provided with a double filter system (moisture and dust), with measuring cells for O2, CO, NO, NO2, SO2. Calculated parameters are: CO in the air, excess air, CO2, efficiency and heat loss in flue gases. For temperature measurements, we used 2 thermocouples, type S, highly accurate, available in two temperature range of -35 C to 400 C, respectively -30 C to 180 C.

35 Appearance of the flame combustion of the six types of biomass with and without injection of HRG. without HRG with HRG

36 Efficiency [ % ] Without HRG With HRG sawdust 2- chopped wood 3-briquetted straw 4- wine ropes 5- cobs corn 6- energy willow

37 CO concentration [ ppm ] Without HRG With HRG sawdust 2- chopped wood 3-briquetted straw 4- wine ropes 5- cobs corn 6- energy willow

38 SO2 concentration [ ppm ] Without HRG With HRG sawdust 2- chopped wood 3-briquetted straw 4- wine ropes 5- cobs corn 6- energy willow

39 NOx concentration [ ppm ] Without HRG With HRG sawdust 2- chopped wood 3-briquetted straw 4- wine ropes 5- cobs corn 6- energy willow

40 Conclusions: Improved combustion efficiency in all cases analyzed CO concentration decreases significantly which shows an improvement of combustion Certain species of biomass concentration is somewhat higher NOx. One possible explanation may be higher temperature measurement in the table due to mismatch between HRG and biomass

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