PLAKAT
PRODUCTION OF BIOETHERS OF GLYCEROL ( fuel second generation) FROM CRUDE GLYCEROL – THE BY-PRODUCT OF BIODIESEL MANUFACTURE
Jan Gąsiorek
Department of Environment Protection
Institute of Natural Fibres
ul. Wojska Polskiego 71 b; 60-630 Poznan / Poland/
fax: +48 (0-61) 8417830 e-mail:
Abstract: The innovative procedure and system for bio-ethers of glycerol from crude glycerol wastes – the by-product of biodiesel production (patent application PL No 382 733) has been developed at “Energo-Eko” Company with INF participation in the study.
The known technological processes of bio-diesel (bio-esters) production, especially for one`s use at rural communities, demand simple and technologically uncomplicated methods of management for crude glycerol formed at bio-diesel production. The procedure of bio-ethers of glycerol production according to the invention consist in catalytic treatment of crude glycerol. In this conversion process of liquid, stable and quasi-stable glycerol wastes converts to ethers of glycerol (fuel second generation) and fertilizer with 29,8%K2O (% weight in dry mass). The ethers of glycerol has combusted (heat of combustion 29 185 kJ/ kg) to electricity for four years at the “ENERGO – EKO” Company.
Key words: biodiesel, glycerol wastes recovery
1. Introduction
Since the introduction of biodiesel /Fatty Acid Methyl Esters/ in South Africa prior World War II work has been done to increase its viability as a fuel substitute. In recent years; efforts in this area has been renewed due to environmental and economic pressures. Another pressing problem, which will be created with even modest production of biodiesel, is the overproduction of glycerol. The glycerol phase contains a considerable amount of methanol and soluble methyl esters.
Biodiesel is an alternative fuel which is produce by transesterification of oils/fats with methanol[1]. There are various methods for transesterification with use of various catalyst including alkali, acid and lipase[2]. The alkali – catalyzed method is a mostly common one in the world. Glycerol cannot be added directly to fuel and must be modified to derivatives of glycerol has an analogy in petrol. One potential solution, which may alleviate sonic of the on biodiesel, is the use of glycerol derivatives as fuel additives and fuel second generation.
In Poland and few UE country members legislative rules lags behind accepted directives of European Parliament 2003/30/EC and European Council from 8th of May 2003 year[3,4]]concerning to using biodiesel directions or other renewable fuels in transport increasing by 2 % till 30th of December 2005 with later growth of this fuels participation to 5,75 % at 31st of December 2010 and to 20 % in 2020.
Going forward to energetic expectation, Environmental Protection Department at Institute Natural Fibres in cooperation with company “ENERGO – EKO” from Poznan worked up new, originally technology of glycerol wastes recovery processing. This glycerol wastes came from bio-ester production can be sources for fuel oil and potassium-organic fertilizer production in catalytic etherification process. This catalyst is protected by patent application PL No 382 733. Etherification process of glycerol wastes was demonstrated in pilot scale by “Energo – Eko” company.
Presently not used glycerol wastes makes ecological problem, they rise production costs of biodiesel and makes it unprofitable. Bio fuels producers in Poland are absolved from excise tax which are regulate by rules (Dz. U. nr 29 poz. 603 from 26 April 2004).
This problem will assess the available quantities of waste oil, suitable for the production of biodiesel and in particular used frying oils (UFOs) and will perform economic evaluation of setting up a collection system of waste oils from restaurants. In addition, their collections/handling systems aspects specification for collection bins, in liner and trucks and concerning the contact studies about engineering of cleaning facility UFOs will be covered. Particularly in the Mediterranean See basin countries.
Management of glycerol wastes which are created during biodiesel production from vegetable oils and animal fats on diesel oil (FAMA – methyl ester upper fat acids) allows to get some extra products: heating glycerol oil – heating value 46,2 MJ/kg and mineral – organic fertilizer with 30 % K2O contents. To equal UE energetic specifications, Poland has to change sawing structure and agronomic production to increase rape plant seeding area to 1 million ha means 7,5 million ha with harvest growth by 2,5 – 3,0 Mg/ha. Then it will be possible to calculate that rape production for energetic purposes will be circa 2 millions tons. That kind of production will cover present diesel oil consumption in Poland over 10 % towards to actually production size.
2. Background on biodiesel fuel
Technology of biodiesel production, from vegetable oils for example rape and also from oils and wastes fats with management of glycerol wastes which came from that production is designed for farmers, farmer associations, country communes which want to product fuel for their own needs i.e. for tractors, agronomic machines, dryer rooms and heat installations.
3. Manufacturing biodiesel
Biodiesel production is based at oil processing from oil vegetable plants seeds or from wastes oils and animal fats[5]. Receiving process of methyl bio-esters upper fat acids is conducted in
30-70oC temperature with using alkaline catalyst. This technology is directed to future little country production plants of 500 tons fuel production in the year.
Glycerol wastes processing recovery
Processing technology of glycerol wastes to heat oil or fuel for Diesel engine and potassium – organic fertilizer is passing “cold” in room temperature till 30 oC with using catalyst which composition is patented (patent application PL No 382733)). Processing technology is directed to present and future bio-fuels producers.
Technology description
Method and installation for production of heat oil from glycerol wastes makes well known ways of producing bio-esters from rape oil pressed from seeds or used vegetable or animal fats more attractive in direction of getting fuel, so called biodiesel and glycerol heat oil.
Obtained heat oil can be combust in Diesel engines with auto-ignition or prototype burner of 1 MW power initiated in “ENERGO-EKO” company and used for bio-electricity production.
Transesterification process which is shown in Fig.1 (STAGE I) carried out in 70oC temperature under normal pressure with catalyst I. This process is going in two major stages shown on following diagram.
Catalyst preparation (KOH in methanol).
The catalyst is injected to esterification reactor. The catalyst amount is controlled and measured for receiving of maximum yield of reaction. Average amount : 25 kg KOH is solution in 150 dm3 of methanol.
Used waste of fats needs making to liquefied. In that reason they are put in tank and warmth to process temperature and then pumped to reactor.
Esterification reaction
Reaction is carried out in thermal isolated reactor and equipped with mechanic stirrer.
Substrates are put to reactor from top. At first is inducted rapeseed oil or melted fat and then catalyst is added with 5-15 dm3/min speed. Optimal ratio of catalyst to wastes vegetable oils is 0,02-0,5 to 1 and depends on quality of used product (oil or fat). Received ester after separation is shipment to fuel tank.
Waste glycerol recovery (Stage II)
4. Etherification process
Glycerol phase (solid, quasi-solid and liquid) is treating on etherification process[6] in separate reactor with catalyst II which composition is protected of patent claim. Etherification process could be carried out in open reactor where glycerol wastes are mixed with catalyst II. Reaction result is ether of glycerol which can be used as the heat oil and mineral – organic salt sediments which can be used in agriculture as an potassic fertilizer[7].
Phase separation
Upper layer of glycerol ethers (second generation of fuel) is pumped to barrels and lower layer runback to etherification process.
Received in this technology biodiesel fulfills quality conditions which are described in Dz. U. nr 218 position 1845 from 19th October 2005 year (annex nr 2).
In table 1 are compared same physical properties of diesel and bio-diesel
Table 1. Parameters of fuel
Properties / Rape oil / Ethyl esters rape oil(bio-diesel) / Methyl esters rape oil
(bio-diesel) / Fossil fuel (diesel)
Density
20oC (g/dcm3) / 0,916 / 0,876 / 0,884 / 0,81-0,89
Octane number / 36 / 50,5 / ̴ 50 / 45-51
Viscosity
20oC (mm2/s) / 78,7 / (40oC) 4,53 / 6,8 / 9,5
Solidification point (oC) / -14 / -23 / -1,1 / -15
Blocking point of filter (oC) / -2 / -12 / -6 / -7
Destylation
(oC) / ≥260 / 250-350 / 320-350 / 180-350
Table 2. Comparison of costs production and profits for two methods: A- with rapeseeds oil, B – with waste oils /used frying oils/(with market price accordingly of 2007 year ;1€ = 3,6 zł)
A / BEstimated cost of production 1 bio-ester ton:
1.Seed: 4Mg x 825 zł/Mg = 3300 zł
2.Metanol: 175 dm3 x 1,9 zł/dm3 = 332,5 zł
3.Catalyst KOH: 20,23 kg x 3,3 zł/kg = 66,8 zł
4.Energy of pressed oil costs: 840 zł
TOTAL : 4539,3 zł / 1.Waste oil: 1,43 Mg x 0 zł/Mg = 0 zł
2.Methanol:143 dm3 x 1,9 zł/dm3 = 271,7 zł
3.Catalyst I (KOH): 20,42 kg x 3,3 zł/kg = 67,4 zł
4.Catalyst II:25,12 kg x 0,15 zł/kg = 3,77 zł
5.Electricity: 39,32 zł
TOTAL: 382,2 zł
Estimated profit:
1.Bioester: 1 Mg x 3,48 zł/kg (diesel oil – retail price) = 3480 zł
2.Glycerol heat oil: 446 kg x 1,2 zł/kg = 535,20 zł
3.mineral fertilizer: 32,18 kg x 2,5 zł/kg = 80,45 zł
4.Seed husks: 3 Mg x 550 zł/Mg = 1650 zł
TOTAL: 5745,65 zł (without pos. 2 and 3 ; 5130,0 zł) / 1. Bio-ester: 1 Mg x 3,48 zł/kg (diesel oil – retail price) = 3480 zł
2.Glycerol heat oil: 446 kg x 1,2 zł/kg = 535,20 zł
3.mineral fertilizer: 32,18 kg x 2,5 zł/kg = 80,45
TOTAL: 4095,65 zł
Profit: 5749,30 – 4539,3 zł = 1206,35 zł
(without pos. 2 and 3) 5130 zł – 4539,3 zł = 590,7 zł / Profit: 4096,15 – 382,2 = 3713,45 zł
Conclusions
West glycerol obtained by bio-diesel production (FAME) can be recovered to ether of glycerol and then can be used as a fuel oil for electricity, heating and transportation. Etheryfication process turns increase in economic profits of bio-diesel production.
Biodiesel and bioether are a domestically produced, renewable fuel that can be used in place of petroleum diesel. Use of biodiesel reduces greenhouse gas emission of carbon dioxide and particulate matter that are associated with major health impacts, including cancer. Biodiesel and bioether also reduces hydrocarbon emission that contribute to the formation of ground level ozone, as well as carbon monoxide, a poisonous gas associated with fuel combustion. In addition to the environmental and health benefits of the fuel, biodiesel and bioether also help the reduce the country`s dependence on foreign oil imports.