Final Report Organisation Name The Wales Environment Trust / Sustainable Energy Project name Biodiesel production from waste cooking oil (WCO) Reference Number B/1649 (934032.053) 1 Summary This document reports on the work undertaken during the course of this project to produce biodiesel from waste cooking oil (WCO). A production plant was designed and built to produce sufficient biodiesel to fuel eight vehicles in the C&D Oil fleet. The fuel production process was constantly monitored and assessed in order to make modifications to improve energy efficiency of the process and the resultant fuel quality. A fleet of vehicles was used to trial the biodiesel fuel and the fuel usage and vehicle mileages were recorded so that fuel economy could be calculated. Approximately 30 tonnes of WCO was diverted from the waste stream and converted into a high value transport fuel. 2 Introduction Diesel fuels have an essential function in the post-industrial economy of our daily life. They are used as transport fuels in almost all transport vehicles, during start-up of large coal power stations or for flame stabilisation and supporting fuel purposes in high temperature incinerators. Consumption of diesel fuels increases year on year worldwide and this trend is set to proceed into the future. However, as with all other fossil fuels diesel fuel reserves are only available in a finite quantity with estimated R/P-ratio1 of about 40 years. Mining crude mineral oil and refining it enables us to get kerosene, petrol, diesel and other refinery derivatives from mineral oil, which is currently the most important primary energy carrier. Renewable substitutes or alternatives for mineral oil and its derivates must be found ensuring the ability to satisfy the increasing demand for diesel fuel and thereby reducing the environmental pressure through a short and closed carbon cycle, less harmful exhaust gases and particulates. Therefore, alongside other possible alternatives vegetable oil has become the subject of intensive research. As far back as 1900 Rudolph Diesel, the inventor of compression ignition engines, used vegetable oil used during a presentation of his engines. Vegetable oils are easily biodegradable, have very low sulphur contents and emit less PM102, CO, HC and SO2 during combustion. The carbon savings biodiesel is about 75–85% when derived from neat vegetable oil. It would be energetically favourable to use vegetable oils instead of fossil diesel fuel, however it is too viscous and its volatility too low for it to be a reliable fuel in modern light-duty diesel engines. Problems such as incomplete combustion followed by carbon deposits at injectors, coking of nozzle and piston ring sticking and fuel build up in lubrication oil of the crankcases have been reported. The EU-aim of achieving the objective for replacing 2% of the consumed motor fuels in 2005 by biofuels supports the research of looking into possibilities for reducing the viscosity and increasing the volatility of the vegetable oil. Micro emulsions with short chain alcohol, dilution with traditional diesel or transesterification with a monohydric alcohol into fatty acid alkyl esters (biodiesel) of the corresponding alcohol and fatty acids involved are potential methods. Transesterification of triglycerides like vegetable oils and fats may be done by different process layouts like acid, lipase or alkaline catalysed. This study refers to the last process, as it is the ease of this process, which makes it more favourable and commonly used. The overall transesterification reaction can be written as 1 Reserve/Production rate 2 10 micron equivalent diameter The total reaction consists of a sequence of three reversible reactions to diglyceride (DG), monoglyceride (MG) and finally to glycerol. Each step produces one ester chain and the reaction shows that stoichiometric 3 mole alcohol is used to transesterify 1 mole triglycerides into the esters. However, under the current market conditions it is only in certain circumstances economically feasible to produce biodiesel from food-grade and neat oils where climate, agricultural policy, geography and infrastructure play together in a synergic manner. Presently in the UK, when compared directly on a cost basis, biodiesel made using new vegetable oil cannot compete without substantial fiscal support measures. Sourcing cheaper feedstock materials is necessary in order to compete with diesel fuel. As alternatives, used vegetable oil and tallow are promising feedstocks for biodiesel production. These arise in the main from restaurants, fast food outlets, food industry, heavy steel working industry3, slaughterhouses or cull-actions. The current market outlet for waste cooking oil (WCO) is as an animal feed product. However, the European Union (EU) has completed an Animal By-Products Regulation, which bans the use of WCO in animal feedstuffs. The UK government, through DEFRA, applied for and was granted a two year derogation period to allow time for the simultaneous phasing out of WCO in animal feed and emergence of alternative markets. The derogation period expires in November 2004. Hence, the EU’s move to ban WCO in animal feed provides a suitable and cost effective alternative to new vegetable oil for biodiesel producers. Without the emergence of a biodiesel industry that uses WCO, there is the danger that once banned in animal feed, the material may be landfilled. The competitiveness of biodiesel to fossil diesel will ultimately depend on its price: the costs of biodiesel production mainly comprising capital investment, input raw materials, labour, consumables and energy consumption during production. This study aims to quantify the energy consumption of a small- scale biodiesel production facility and consequently implement and assess the impacts of energy-efficiency measures. 3 Used as a machinery lubricant 3 Plant design and installation The plant was designed to be suitably sized for the fuel required by the C&D Oil fleet (details of the fleet are given in section 6). The total fuel consumption of the vehicles within the fleet taking part in the trials was approximately 1,500 litres per week. This equates to about 75 tonnes per annum. The plant was designed and built with the following specification: All electrical items to be E-Exd for flameproof operation (required due to the handling of methanol). Sodium methoxide production 1 off 160 litre stainless steel mixing tank with single speed agitator; 1 off 720 litre stainless steel mixing tank with single speed agitator; 1 off 2,200 litre stainless steel settling tank. The tanks are interconnected by a series of 25mm steel piping with associated valves for retaining and transferring fluids. Transfer of liquids from storage containers (such as IBCs for the WCO and 205 litre drums for methanol) was made via flexible plastic pipework. Gear pumps (E-Exd) were used to transfer fluids between the various tanks. The outlet of the settling tank used a three-way valve provide separate pipework through which the glycerine and the esters (biodiesel) were drained. Glycerine was drained into a 205 litre drum directly below the settling tank outlet, and the esters were piped into IBCs. Figure 1 is a representation of the physical set-up of the biodiesel plant; and Figure 2 is a photograph of the completed plant. Heater An electric oil immersion heater was fitted into the side of the reactor tank. The heater had thermostatic control to ensure that the esterification reaction could take place at the optimum temperature. Pumps The gear pumps were sized to transfer between 50 and 100 lpm of liquid between tanks (depending on the viscosity and density of the liquid). For example, it would take around 10 minutes to transfer 500 litres of relatively high viscosity WCO from an IBC into the reactor tank. Agitators Both the sodium methoxide mixing tank and the main reactor tank are fitted with electrically driven, single speed, E-Exd agitators. Electrics All of the electrical connections were E-Exd compliant. The installation consisted of 3-phase connections of the pumps, mixers and heater. Each appliance was operated by its own switch mounted on the switch panel on the front of the main reactor tank unit. Settling tank Main NaOH reactor tank Sodium methoxide tank Biodiesel WCO Glycerine Me-OH Figure 1: Diagram showing the biodiesel plant arrangement Figure 2: Photograph of the biodiesel production plant The plant was installed at the premises of C&D Oil Ltd within an industrial unit of floor size 10 x 9 m. It is supplied with 240V 1-phase a.c. and 415V 3-phase a.c. electricity. The unit has a personnel door and a manually operated loading door along the front wall and a fire exit on the rear wall. 4 Small-scale biodiesel experimentation Laboratory-scale experimentation of biodiesel production required specialist equipment. A list of the main items is given below: Hotplate Hotplate stirrer High-speed mixer/blender Measuring cylinders Glass beakers Electronic scales Electronic pH meter Electronic thermometer Storage beakers The chemicals that were used are listed below: Biodiesel raw materials Other chemical New vegetable oil Distilled/deionised water Waste cooking oil Sulphuric acid Methanol pH probe storage solution Sodium hydroxide pH probe calibration solution The experimentation followed procedures for biodiesel production found by researching the ‘worldwide web’ and publications such as From the Fryer to the Fuel Tank by J & K Tickell. The experimentation researched a number of parameters such as: 1. Methanol quantity; 2. Catalyst quantity; 3. Temperature; 4. Mixing duration; 5. Settling duration. The results from the experiments were used as a guide for the production of biodiesel using the large-scale equipment. 5 Large-scale test batches The results of the small-scale experimentation were used to develop a procedure to use on the large-scale rig. The procedure can be found in full in Appendix A. Plant operators were trained in the health and safety aspects of handling the materials used in the production process. 6 Fleet fuelling and consumption analysis After the glycerine was removed from the settling tank, the biodiesel was transferred under gravity into IBCs. When full, each IBC was transported by forklift truck to the two outside fuel storage tanks. By raising the tanks above the inlet height of the fuel tanks, the IBCs could also be emptied by gravity. Biodiesel storage tanks and metering Each of the two biodiesel fuel storage tanks has a capacity of 2,600 litres. There is a shared connection pipe to the metered fuel delivery pump. Sight tubes alongside each tank indicated the fuel level. Calibration tests of the analogue fuel meter showed that the meter reading was consistently 2% higher than the actual fuel delivered. Biodiesel blend At the beginning of the project, biodiesel was added to the vehicles as a blend with diesel fuel and ramped up to biodiesel-only over the first few weeks to check for any problems. The blends were successively 25%, 50% and then 100%. Fuel and mileage recording method All of the vehicles were fuelled at the start of the day, and a record of the fuel added (uncorrected for the 2% error) was kept on a log sheet by each driver. The vehicle mileages were recorded from the drivers’ tachographs, thereby allowing the fuel consumption to be calculated for each vehicle during the course of the project. Glycerol residue Every two weeks the fuel filter of each vehicle was checked for evidence of contamination caused by the running on biodiesel. On one of these checks a fine build-up of glycerol was discovered lining the filter mesh on one particular vehicle. The cause of glycerol remaining within the biodiesel was determined to be an insufficient ester/glycerol separation period inside the settling tank. Up until this time, the biodiesel was drawn out of the tank after 24 hours settling – and subsequent to the discovery of the glycerol in the fuel filter, the separation period was extended to 72 hours. The vehicle checks continued until the end of the project and the no further noticeable glycerol residue was discovered. Total fuel consumption Two ‘total’ amounts of biodiesel fuel are presented. The first is the Fuel total 1 which is the amount of biodiesel consumed by the ‘fleet’ and K811 tractor unit from the start of April until the end of the project (seven months). From the figures given in Appendix B, it is calculated as: Fuel total 1 = (0.98 x 1011) + (0.98 x 3935) + 25,749 + 3048 = 33,644 litres Therefore, during the project 30 tonnes of WCO was converted from a waste material into a high value transport fuel, replacing an equivalent amount of fossil derived diesel fuel. The second is Fuel total 2, which is the amount that was used to calculate the fuel economy figures. It comprises the fuel consumed by the ‘fleet’ only over the period 1st June to 30th October (end of project), and is given in Appendix B as: Fuel total 2 = 25,749 litres. Fleet mileage There are three total mileages relating to the project, each defined below: Mileage total 1 – total mileage of the ‘fleet’ from June to October that is used to calculate fuel economy; Mileage total 2 – total mileage of the ‘fleet’ from April to October (including the period during April and May when vehicles were using 25 and 50% biodiesel blends); Mileage total 3 – total mileage of the ‘fleet’ and tractor unit K811 from April to October (i.e. total mileage with at least a 25% biodiesel content in the fuel). Mileage total 1 = 122,258 km (76,411 miles); Mileage total 2 = 122,258 + 15,817 + 10845 = 148,920 km (93,075 miles); Mileage total 3 = 148,920 + 9,955 = 158,875 km (99,297 miles). Fuel consumption/economy Average fuel economy (F.E.ave) for the fleet over the period from June to the end of October was calculated using the following: F.E.ave = Mileage total 1 / Fuel total 2 = 122,258 / 25,749 = 4.75 km/l (13.3mpg). A comparison was made between the fuel economy achieved on biodiesel and diesel fuel. Vehicle T312 was taken off biodiesel for one week and the mileage and diesel fuel used during this period was recorded. Table 1 compares the respective fuel economy figures returned by T312 for both biodiesel and diesel fuel. These figures indicate a 3.7% reduction in fuel economy when using biodiesel. Average fuel economy (km/l) Vehicle Difference Diesel fuel Biodiesel T312 5.17 4.98 -3.7% Table 1: Fuel economy comparison for biodiesel vs diesel fuel However, although this exercise gives a useful indication of the effects of running on biodiesel, the figures need to be evaluated whilst considering the following variables: 1. Vehicle loads vary. The amounts of collected oil transported by T312 would not have been consistent during the exercise; 2. Vehicle routes vary. The collection points for T312 would have varied on a daily basis, therefore some days may have seen more motorway driving whilst others may have seen more city centre driving; 3. Driver styles vary. T312 would have been driven to a number of drivers, each of whom could have had a different driving style (early/late gear changes, passive vs aggressive driving, leaving engine idling for prolonged periods etc); 4. The duration of the test was unequal. The diesel fuel test was conducted over one week, whilst the biodiesel test was conducted over a 21 week period. The significance of number 4 is that the biodiesel test would have ‘smoothed out’ the extremes of variables 1 to 3 described above within its average, whereas the diesel fuel test may have been skewed towards one of the extremes of one or more of these variables, i.e. the biodiesel fuel economy range was between 4.36 and 5.81 km/l on a monthly basis (accounting for the 2% metering error). Between June and October it is realistic to assume that T312 would have encountered a full range of vehicle loads, routes and driving styles which accounted for the variation in returned fuel economy figures. However, the same assumption cannot be made over a short period of just one week, as conducted for the diesel fuel test. Hence, the figures returned may reflect an extreme condition of one or more particular variable. 7 Process energy assessment The energy expenditure during the production process was all through the use of electrical equipment for heating, mixing and fluid transfer. Where possible gravity was used to transfer liquids such as in the case of the glycerine and esters removal transfer from the settling tank to storage vessels. Pumps The specification of the 4 identical pumps is as follows: Type: rotary gear pump Size: 1.1 kW (1.5hp) RPM: 1420 Construction: Body and covers: Cast iron Rotors: Carbon steel Shafts: Nitrided steel Motor: EEXD, totally enclosed fan cooled, IP55 Supply: AC 415V, 3 phase, 50 Hz Agitator A This agitator is used to mix the methanol and catalyst inside the premixer tank. Specification as follows: Size: 0.37kW (0.5hp) RPM: Via reduction gearbox gives 206 rpm shaft speed Motor: EEXD, totally enclosed fan cooled, IP55 Supply: AC 415V, 3 phase, 50 Hz Agitator B This agitator is used to mix the WCO and sodium methoxide inside the main reaction tank. Specification as follows: Size: 0.75kW (1 hp) RPM: 1400 rpm via reduction gearbox to 206 rpm shaft speed Motor: EEXD, totally enclosed fan cooled, IP55 Supply: AC 415V, 3 phase, 50 Hz Heater Type: Industrial incoloy 825 sheathed immersion heater Size: 406 mm Rating: 6 kW Control: Thermostat from 20 to 80°C Supply: AC 415V, 3 phase, 50 Hz Production process operating times The duration for which each of the four pumps operates during the production of a 450 litre batch of biodiesel is given below: Pump 1 methanol in: 2 mins Pump 2 WCO in: 18 mins Pump 3 sodium methoxide in: 2 mins Pump 4 settling tank in: 10 mins Agitator A sodium methoxide 20 mins Agitator B esterification 60 mins Heater: 15 to 60°C: 100 mins Energy usage Energy costs are determined by calculating the kWh consumption of the equipment. The pumps on average operate at 80% of their rated capacity, and the agitators operate on average at 75% of their capacity. Pumping costs = ((2+18+2+10)/60) hours x 1.1 kW x 80% =0.47 kWh; Mixer A costs = (20/60) hours x 0.37 kW x 75% =0.09 kWh; Mixer B costs = (60/60) hours x 0.75 kW x 75% =0.56 kWh; Heater costs = (110/60) hours x 6 kW x 100% =11 kWh; Total = 12.1 kWh Energy cost The cost of electricity is approximately 7p/kWh. Therefore: the total energy cost of producing a 450 litre batch of biodiesel 84.7p. equating to 0.19p per litre of biodiesel. Energy efficiency The relative proportion of the energy expenditure of each electrical item used in the production process is shown in Figure 3. It shows that the heater accounts for almost 91% of the energy usage, with the pumps and mixers accounting for only 9.2% combined. The most effective way to reduce energy costs was to improve the efficiency of the heater. The main reaction vessel into which the heater was fitted is a single skin stainless steel tank. There would have been significant heat losses through the vessel walls, therefore it was decided to insulate the tank with ‘Rockwool’ 50mm duct wrap insulation in order to retain as much heat as possible and reduce the heating time. The insulation was wrapped around the circumference of the tank and the bottom cone, with the top of the tank left uninsulated to allow access to the viewing hatch. The heating times of 450 litre batches inside the main reaction tank were logged with the insulation in place and it was found that the heating time to 60° had reduced from 110 minutes to 63 minutes. The percentage reduction provided by the insulation was 42.7%. New heater costs = (63/60) hours x 6 kW x 100% =6.3 kWh; The effect on the energy expenditure pie chart can be seen in Figure 4, which shows the total energy costs reduced by 36.3%. The new energy costs with the insulated reaction tank are therefore: the total energy cost of producing a 450 litre batch of biodiesel 53.9p; equating to 0.12p per litre of biodiesel. Pump 1 0.2% Pump 2 2.2% Pump 3 0.2% Heater Pump 4 90.8% 1.2% Agitator A 0.7% Agitator B 4.6% Figure 3: Breakdown of energy expenditure during biodiesel production Savings 36.3% Pump 1 0.2% Pump 2 2.2% Pump 3 0.2% Pump 4 1.2% Agitator A 0.7% Agitator B Heater 4.6% 54.5% Figure 4: Breakdown of energy expenditure after energy efficiency measures 8 Vehicle emissions results During the course of the project, two of the vehicles had to undergo an MOT test. The opportunity was taken to test the particulate emissions (the only emission tested on diesel in an MOT). Copies of the emission results can be found in Appendix C. The first emission test was conducted using biodiesel, then after the test the fuel tank was drained and the tank part-filled with ULSD. The vehicle was then driven for about 20 miles to ensure that all of the biodiesel was purged through the fuel system and engine. It was then resubmitted to the same testing station and tested under the same condition with the same equipment. The results are summarised in Table 2 and show that both of these vehicles passed the emission test with considerable ease – indicating that they are well- maintained vehicles. However, it is evident that they both emitted less particulates (expressed as parts per million – ppm) when fuelled with biodiesel rather than ultra low sulphur diesel (ULSD) fuel. Vehicle Pass limit ULSD Biodiesel Reduction Reduction Identification (ppm) (ppm) (ppm) (ppm) (%) T312 3.00 0.39 0.32 0.07 17.9% N649 3.00 0.28 0.20 0.08 28.6% Table 2: Particulate emission test results 9 Conclusions This project was carried out to investigate the cost effectiveness of biodiesel production by a batch process using the esterification reaction. A breakdown of the costs (expressed as per litre of biodiesel produced) is as follows: Input Cost / litre biodiesel WCO 15p Methanol 7.6p Sodium hydroxide 0.52p Energy 0.12p Total 23.24p It can be seen that energy costs are insignificant compared to the material costs of the main feedstocks of WCO and methanol. However, even during the course of this project measures were conducted that reduced the total energy consumption by 36%. The biodiesel that was produced in the project performed well in the fleet of vehicles in which it was trialled. Over 33,000 litres of biodiesel was produced and consumed, displacing approximately the equivalent amount of fossil derived diesel fuel. The carbon dioxide saving was approximately 90 tonnes over the course of the project. More than 30 tonnes of WCO was converted into biodiesel, diverting it from a potential waste stream (once its banning as an animal feed is comes into force in November 2004). The particulate emissions of two fleet vehicles tested as part of their MOT showed significant reductions (28 and 18% respectively). A slight decrease in fuel economy was found for vehicle T312 when run on biodiesel compared to ULSD. The calculated reduction of 1.7% is within the range of errors caused by variables such as driving style, vehicle routes and vehicle loads during the trials. 10 Appendix A The biodiesel production procedure This section contains the production procedures for making biodiesel on the large-scale rig. BIODIESEL • Protective clothing • Production procedures: 1. UCO transfer 2. Preparing Sodium Methoxide 3. Mixing the Reactants 4. Transferring the Mixture to the Settling Tank 5. Removing the Glycerine and Biodiesel from the Settling Tank • Note 1: Calculating the Quantity of Methanol and Sodium Hydroxide Required. WEARING OF PROTECTIVE CLOTHING The chemicals used in the manufacture of biodiesel are extremely hazardous and must be treated accordingly. Before handling any of the methanol or sodium hydroxide YOU MUST READ THE HEALTH AND SAFETY NOTES FOR BOTH CHEMICALS. You are supplied with the following protective clothing to ensure that you are safe when handling these chemicals: • Safety goggles • Respirator and carbon filters • Rubber apron • Nitrile gloves. When handling the sodium hydroxide YOU MUST WEAR THE GLOVES AND THE GOGGLES AT ALL TIMES. When handling the methanol or sodium methoxide YOU MUST WEAR THE RESPIRATOR, APRON AND GLOVES AT ALL TIMES. If you inspect the UCO and sodium methoxide mixture inside the Reactor tank YOU MUST WEAR THE RESPIRATOR, APRON AND GLOVES AT ALL TIMES. Biodiesel Production Procedure: 1 UCO transfer 1. Weigh the IBC containing the UCO. 2. Ensure all valves are in the closed positions. 3. Connect camlock of UCO inlet pipe to UCO container OR position hose into the top layer of UCO through the top opening of the IBC. 4. Open valve in UCO container (if connected via this). 5. Zero the UCO flow meter. 6. Open valve in UCO inlet pipe. 7. Switch on Pump 1. 8. Switch off Pump 1 when required quantity of UCO is in the reactor. 9. Record the value on the UCO flow meter. 10. Close valve in UCO inlet pipe. 11. Close valve in UCO container (if connected via this). 12. Disconnect camlock from UCO container (if connected via this). 13. Reweigh the IBC containing the UCO to determine the exact quantity of UCO transferred to the reactor tank. 14. Measure and record the temperature of UCO in the reactor. 15. Switch on Heater 1. 16. Monitor UCO temperature at intervals and switch on Mixer 2 intermittently as required. 17. The UCO is ready when its temperature is at least 40°C. Biodiesel Production Procedure: 2 Preparing Sodium Methoxide 1. Calculate the quantity of methanol required by referring to Note 1. 2. Ensure all valves are in the closed positions. 3. Ensure the lid of the Methoxide tank is closed tight. 4. Wear the appropriate protective clothing (see Safety Notes). 5. Insert methanol probe into methanol drum. 6. Zero the Methanol flow meter. 7. If unsure of the Methanol flow meter calibration, use the dipstick to measure the methanol level. 8. Switch on Pump 2. 9. Switch off Pump 2 when the required quantity of methanol has been transferred into the Tank. 10. Remove the Methanol probe from the drum and replace the cap. 11. Open the plug in the top of the Methoxide tank and insert the funnel. 12. Switch on Mixer 1. 13. Gradually pour the sodium hydroxide granules into the funnel. Do not pour too quickly (the granules must have time to dissolve into the methanol). 14. When all of the sodium hydroxide granules have been poured into the tank continue mixing for a further 10 minutes then switch off Mixer 1. Biodiesel Production Procedure: 3 Mixing the Reactants If Procedures 1 & 2 have been completed successfully: 1. Open the valve below the Methoxide tank. 2. Open the valve in the line to the Reactor tank. 3. Ensure the Reactor tank lid is securely fastened. 4. Switch on Mixer 2 for the Reactor tank. 5. Switch off Heater 1. 6. Switch on Pump 3. The flowrate is very high (50 l/min). Therefore operate Pump 3 intermittently to allow the Sodium Methoxide to fully mix with the UCO. 7. When the Methoxide tank is empty, switch off Pump 3 and close the valve below the Methoxide tank. 8. Close the valve in the line to the Reactor tank. 9. Continue mixing for 50 minutes, then switch off Mixer 2. Biodiesel Production Procedure: 4 Transferring the Mixture to the Settling Tank 1. Switch on the Settling tank heating elements at least 2 hours before transferring the mixture. 2. Open the valve below the Reactor tank. 3. Open the valve in the line downstream of Pump 4. 4. Switch on Pump 4. 5. When the Reactor tank has emptied Switch off Pump 4. 6. Close the valve in the line downstream of Pump 4. 7. Close the valve below the Reactor tank. Biodiesel Production Procedure: 5 Removing the Glycerine and Biodiesel from the Settling Tank 1. Allow the glycerine to settle out of the biodiesel for about 18 hours. 2. Take a sample of biodiesel by lower a sample vessel into the Settling tank via the top hatch OR via the sample tap on the side of the tank. 3. Open the Settling tank outlet valve to drain off the glycerine into a glycerine tank. 4. Close the valve when biodiesel appears. 5. Remove the glycerine tank. 6. Open the Settling tank outlet valve to drain off the biodiesel into a biodiesel IBC tank. 7. When the Settling tank is empty close the outlet valve. 8. Switch off the Settling tank heating elements. 9. Measure and record how much biodiesel was transferred into the biodiesel IBC tank. Note 1: Calculating the Quantity of Methanol and Sodium Hydroxide Required. A. Calculating the quantity of methanol The quantity of methanol required for a reaction is 20% of quantity of UCO that is used. For example, if 400kg of UCO was pumped into the Reactor tank, the volume can be calculated by: Volume of UCO (litres) = Mass of UCO (kg) ÷ 0.915 = 400 ÷ 0.915 = 437.2 litres Therefore, Volume of methanol (litres) = 0.2 x 437.2 = 87.4 litres. B. Calculating the quantity of sodium hydroxide The amount of sodium hydroxide (NaOH) needed is directly related to the quantity of UCO. Take the quantity of sodium hydroxide needed per litre of UCO (calculated in the Titration) and multiply by the number of litres of UCO used in the reaction by: Mass of NaOH (g) = Volume of UCO (litres) x Mass of NaOH per litre of UCO (g) 11 Appendix B Fleet mileage and fuel consumption The fleet mileage and biodiesel fuel usage data were tabulated for each fleet vehicle over the course of the project; Fuel consumption was calculated on a daily, weekly, monthly and project duration basis; It was during April and May that the fuel blend was ramped up from 25% biodiesel, through 50%, to 100%. Although the figures for April and May were recorded they have been summarised to totals in the table since fuel consumption figures are not valid for inclusion or comparison with those for 100% biodiesel which started for the whole fleet from June; Fleet totals are given for the period 1st June to 31st October 2002 (when all vehicles were running on 100% biodiesel; The ‘fleet’ is defined as the seven 7-tonne trucks used for collection of WCO by C&D Oil. A tractor unit (registration K811) belonging to C&D Oil was also run on biodiesel during the project, and its figures are presented alongside the ‘fleet’ figures, though not included ‘fleet’ totals; All figures for fuel usage are the unadjusted figures as recorded by the drivers throughout. Correction of the 2% meter error is made in the ‘June to October’ totals at the end of each column. Adjusted fuel economy figures (km/litre) were then calculated using the corrected fuel usage values. 12 Appendix C Comparison of particulate emissions: copies of MOT test data sheets for N649 and T312).