Techno-Economic Appraisal of Biodiesel from Jatropha Curcas: An Egyptian Case Study by
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Techno-Economic Appraisal of Biodiesel
from Jatropha Curcas:
An Egyptian Case Study
by
Prof. Guzine I. El Diwani, Prof.Dr.Shadia Rageb, Prof.Dr. Salwa
Hawash , Dr. Nahed Kamal ,
National Research Centre, Egypt
Chemical Engineering and Pilot Plant Department
Email corresponding author:geldiwani@yahoo.com
And
Prof.Dr. Ihab Farag
Univer. Of New Hampshire, USA
1. Introduction 1- Biodiesel is a fuel made from any vegetable oil including oils pressed straight from the seeds (virgin oils) such as soybean, sunflower, canola, coconut and Jatropha Curcas (JC). 2-It can be produced from any material that contains fatty acids.
3- Thus, various vegetable fats and oils, animal fats, waste greases, and edible oil processing wastes can be used as feedstock for biodiesel production. 4- The choice of feedstock is based on several variables such as local availability, cost, government support and performance as a fuel.
5-Biodiesel as a fuel runs in any unmodified diesel engine and it has been shown to give engine performance generally comparable to that of conventional diesel fuel while reducing engine emissions of particulates, hydrocarbons and carbon monoxide . 6- It has been reported that when biodiesel was used, CO was reduced by 8.6%, hydrocarbons by 30.7%, and particulate emissions by 63.3%. However, CO2 emissions were increased by 2.6%and NOx emissions were increased by 5%.
7- Biodiesel is typically mixed with regular diesel in blends between 5% and 50% (designated by a B followed by the percentage of biodiesel in the blend). 8- Any biodiesel blend (even B100) can be used in standard diesel engines without modification to the engine .
9- There are several benefits for using biodiesel as a blended fuel in diesel engines such that most major car and equipment manufactures have issued statements certifying that blends up to B20 are acceptable for use in their diesel engines without loss of warranty. 10- The economics of biodiesel production from several oil seeds in general and from JC in particular have been published in several reports issued worldwide. 11- This work is concerned with the techno-economic appraisal of biodiesel production from JC in Egypt.
12- Although several articles and reports have addressed the issue, appraisal under Egyptian conditions is highly needed for application in the country in addition to providing guidelines for adoption under similar conditions worldwide. 13-The first section includes the technical aspects as obtained through an extensive R&D program.
14- It is then followed by simulation and basic engineering of the crushing, extraction, transesterification and purification stages. 15-The third section includes the financial aspects and analysis through the formulation and assessment of several scenarios taking into consideration the productivity of seeds per unit area and the extent of recovery of raw oil from the JC seeds.
2. Basis of Technical Aspects 2.1. Jatropha Curcas Plantation in Egypt. Jatropha plant is cultivated in different places in Upper Egypt and in Egyptian deserts. Jatropha trees were irrigated with municipal wastewater primary treated. Average productivity for Jatropha fruits was 3.7 tons fruit /4000 m2 (acre) with average oil recovery of 25% by weight from seeds.
Luxor 350 Feddans Start 2002
Sohag 250 Feddans Start 2003
Suez 400 Feddans
New Valley 100 Feddans Start 2006
4000 Feddans Start 2009
Abu Rawash 2 Feddans Start 2006
(as study)2.2. Optimum biodiesel production conditions from Jatropha plant. Through extensive experimental work on bench and pilot scale, optimum operating conditions for Jatropha oil and biodiesel production have been obtained and are taken as the basis for this work as outlined below.
2.2.1. Jatropha oil Extraction The extraction process essentially comprises fruit dehulling, seed crushing to 2 mm, extraction of oil using hexane as solvent at ratio 1:5 seeds to hexane and separation of hexane from oil by hexane evaporation under vacuum at 40°C.
2.2.2. Transesterification Conditions for transesterification include: • Use of methanol as alcohol for transesterification at molar ratio of 6:1 alcohol :oil. • Use of sodium hydroxide as catalyst at a 0.75% or potassium hydroxide at a 1% based on oil weight. • Mix the reaction mixture at 60 rpm for 10 minutes and continue mixing for one hour at a temperature 65ºC to complete the reaction.
• 94 – 98% reactant oil conversion to biodiesel is achieved and the overall reaction product is left to settle in a clarifier for two hours. • Glycerol is obtained as byproduct at a rate of about 10% of produced biodiesel and settled as the lower phase in the reaction product at 50% purity. • This lower phase is separated and purified using phosphoric acid to obtain glycerol 85% purity.
2.2.3. Seed cake evaluation • a- Seed cake obtained form oil extraction which constitutes about 55- 75% of the seed, is dried at 60ºC to eliminate hexane traces; positive results for use as fertilizer have been obtained. • b- Dried seed cake is also tested animal fodder and proved successful when substituting conventional rabbit fodder by 7.5% and by 30% for gaats. It is to be noted that the content of phorbol ester of 0.085%, which is the cause of toxicity, can be removed by special treatment. Further investigations are to be undertaken for treating the seed cake and testing for use as animal fodder.
2.2.4. Treatment and recovery of side – streams The basic processing steps for biodiesel
Figure (1) Material Balance based on pilot-scale experimental results
3. Techno-economic Aspects for Biodisel Production under Egyptian Conditions 3.1. Capacity of Production Facilities • Biodiesel is produced in large capacities on the commercial scale in US and Europe. • Plants up to 85 million gallons / year (about 275 thousand tons/year) production are in operation in the US. • Conversely, in developing countries, biodiesel production is still on small-scale.
• Within the scope of this work an economic model and indicators for two nominal annual capacities namely 8000 and 50000 metric ton have been developed. The optimum process conditions, as developed in our laboratory, and outlined in last section are adopted.
3.2. Simulation and Basic Engineering • Simulation and basic engineering of extraction/transesterification of raw oil for the two proposed capacities has been conducted .
• Simulation has been conducted using ASPENPLUS from Aspentech which is the most powerful simulation software on the market. • The software from Haas has been used as a basis after introducing necessary modifications to adopted for the raw materials, process conditions and capacities proposed in this work. • The simulation includes the following section: crushing, extraction, transesterification, biodiesel purification and glycerol purification.
• Simulation output including material and energy balance and specifications of essential components marked on Figure (2) are outlined in Table (1) for the 50000 tons/yr production capacity. • Results have been used for the cost estimation of capital costs for the two proposed capacities respectively.
a. Methanol Recovery Column:- b.Biodiesel purification column:-
Component Fractions Component split fractions
Outlet streams MEOHREC EST1 Outlet Stream
Methanol .94000 .59999e-01 Meohwat Biodiesel Oilrec
Oil .35236e-02 .99648
Biodiesel .18283e-14 1.0000 methanol .93710 .62903e-01 .28201e-13
Glycerol .18901e-15 1.0000 oil .14329e-04 .35854e-02 .99640
NaOH .11422 .88578 biodiesel .63795e-03 .97293 .26429e-01
Water .11422 .88578 glycerol .11152 .85827 .30212e-01
Summary of key results naoh .93417 .65830e-01 .95110e-15
Number of stages 7 water .93417 .65830e-01 .95110e-15
Top stage temperature c 29.2638
Bottom stage temperature c 65.4330 *** summary of key results***
Top stage liquid flow kmol/hr 73.5179 number of theoretical stages 8
Bottom stage liquid flow kmol/hr 36.8265 top stage temperature c 154.101
Bottom stage vapor flow kmol/hr 56.9743 bottom stage temperature c 287.394
Molar reflux ratio 2.00000 top stage liquid flow kmol/hr 23.6998
Molar boilup ratio 1.54710 bottom stage liquid flow kmol/hr 0.79661
Condenser duty (w/o subcool) kw -775.115 top stage vapor flow kmol/hr 1.39521
Reboiler duty kw 768.907 bottom stage vapor flow kmol/hr 104.632
molar reflux ratio 0.94817
Oil feed pump:- molar boilup ratio 131.346
Input data:- condenser duty (w/o subcool) kw -2,055.33
Outlet pressure bar 4.00000 reboiler duty kw 2,519.85
Driver efficiency 1.00000
*** Results ***
c. Glycerol column:-
Volumetric flow rate cum/hr 8.31471
Component split fractions
Pressure change bar 3.80000
outlet streams
Npsh available meter 2.33736
watmeoh glycerol
Fluid power kw 0.87766
methanol 1.0000 .45499e-05
Brake power kw 2.23315
biodiesel .36749 .63251
Electricity kw 2.23315
glycerol .17395e-01 .98260
Pump efficiency used 0.39302
water 1.0000 .15490e-08
Net work required kw 2.23315
Summary of key results
Head developed meter 44.4806
top stage temperature c 68.9594
bottom stage temperature c 269.036
top stage liquid flow kmol/hr 65.8132
bottom stage liquid flow kmol/hr 7.68049
bottom stage vapor flow kmol/hr 76.0203
molar reflux ratio 2.00000
molar boilup ratio 9.89785
condenser duty (w/o subcool) kw -1,216.86
reboiler duty kw 1,364.40
Table 1 Material & Energy Balance and Specification Of Essential Components(2) Flowsheet of the complete crushing/extraction/transesterification process
3.3 Basis of Estimates for the Economic Model:
Option I In this option I it is assumed that each of the essential processing stages namely plantation, crushing & extraction, and transesterification & purification could be considered as a sub- project and financed separately.
Option II In this option II it is assumed that the whole project is integrated i.e. seeds from the plantation stage are delivered directly to the extraction stage with no profit. Similarly, the raw oil is delivered directly to the transesterification stage. All other assumptions are similar to Option I except for some consequent assumptions such as decrease in working capital and operating costs corresponding to no direct profits for seeds or raw oil. The Basic assumptions for both cases are presented below.
Table (2) Alternative assumptions for high and average productivities of fruits and seeds
Item High Productivity Average Productivity
Ton Fruits Per 4000 m2 (acre) 5.58 3.43
Tons Seed per 4000 m2 (acre) 3.2 2.0Raw Materials-Intermediate Products & Products/Prices:
Table (3) Estimated prices of Raw Materials and Products
Item Price $/ton Basis of Estimates
Hexane 791 Market Price
Methanol 818 Market Price
NaOH 455 Market Price
H3PO4 729 Market Price
Seeds 145-230 Actual production costs *1.25 to account for profits
for the plantation stage)
Raw Oil 300-625 Prices that ensure a Simple Rate of Return on
Investment () for the crushing /extraction stage of 12-
15%
Biodiesel 945 US price (November 2010)
Cake 145 Market Price of equivalent product used as animal
fodder
Glycerol 545 Market PriceCapital Investments The capital investments for the process components have been estimated as follows
Table (4) Basis of Estimates of Capital Costs Item % Relative to Fixed Capital Purchased Equipment 100 Purchased Equipment* Equipment Setting 30 Purchased Equipment Piping 15 Purchased Equipment Civil 15 Purchased Equipment Steel 15 Purchased Equipment Instrumentation 10 Purchased Equipment Electrical 10 Purchased Equipment Insulation 8 Purchased Equipment Paint 8 Purchased Equipment Other 10 Purchased Equipment Engineering 10 Total Fixed Capital Contract Fee 5 Total Fixed Capital Contingencies 10 Total Fixed Capital Working Capital 25 Annual Operating Costs * Prices of Equipment have been estimated from reported sources
Operating Costs: In addition to raw materials costs as estimated according to actual consumption from pilot experimental results and prevailing costs, other components of operating costs are presented in Table (5).
Table (5) Basis of estimates of operating costs others than raw materials Labour $/Annum Engineers 4364 Supervisors 3273 Adminstration 2182 Labourer 1091 Maintenance 2% of Capital Others 5% of Total Annual Operating Cost
4 Scenarios have been assumed for each
Option as depicted in Figure (3)I II
High Productivity Average Productivity
(5.58 ton fruit/acre) (3.43 ton fruit/fed)
High Recovery High Recovery
(45% oil ) (45% oil )
IV III
Average Productivity High Productivity
(3.43 ton fruit/acre) (5.58 ton fruit/acre)
Average Recovery Low Recovery
(35% oil ) (25% oil )
Figure (3)Scenarios for the Two Capacities:
8000 & 50000 tons/yr4. Results and Analysis 4.1 Area Requirements:- The area requirements for the assumed Scenarios are presented in Figure (4).
Figure (4) Area Requirements (4000 m2)
80000
70000
60000
50000
8000 ton/yr 40000
50000 ton/yr 30000
20000
10000
0
SC I SC II SCIII SCIVFigure (5) Distribution of annual operating cost
for SCIII - 50000ton/yr
Labour
1%
Maintenance Others
1% 5%
Raw Materials
94%Figure (7) Financial Indicators for 50000
Ton/Yr Biodiesel
160
Total Capital
140 Investments Millions
$
120
100 Total Production
USD ($)
Costs Millions $
80
60
Total Profits
40 Millions$
20
Average SRR%
0
SC I SC II SC III SC IV4.2.3 Distribution of Capital Costs over Processing Stages The distribution of capital costs for the two capacities is demonstrated in Figures (8) and (9). Plantation represents the major cost component.
Figure(8) Distribution of Capital Costs
Over Processing Stages % 8000 Ton/yr
80
70
60
50 P l a nt a t i on
40
C r u sh i n g /
Ex t r a c t i o n
30
T r a n se st e r i f i c a t i o n
20
10
0
I II III IVFigure (9) Distribution of Capital Costs
Over Processing Stages % 50.000 Ton/yr
80
70
60 P l a nt a t i on
50
C r u sh i n g /
40 Ex t r a c t i o n
30 T r a n se st e r i f i c a t i o n
20
10
0
I II III IVFigure (10) SRR % for Transesterification at
constant biodiesel Price $945/ton
200
150
8000 ton/y r
100
50000 ton/y r
50
0
SC I SC II SCIII SCIV4.2.5 Prices of Biodiesel for a value of SRR of
10%. (national interest rate)Table (6) Specific Biodiesel Price for Transesterification (SRR 10%)
SC I SC II SCIII SCIV
Capacity $/ton
8000 ton/yr 459 674 575 781
50000 ton/yr 425 642 541 746
Capacity $/liter
8000 ton/yr 0.41 0.61 0.52 0.70
50000 ton/yr 0.38 0.58 0.49 0.674.3 Financial Indicators for Option II In this option II it is assumed that the whole project is integrated i.e. seeds from the plantation stage are delivered directly to the extraction stage with no profit. Similarly, the raw oil is delivered directly to the transesterification stage. All other assumptions are similar to Option I except for some consequent assumptions such as decrease in working capital and operating costs corresponding to no direct profits for seeds or raw oil.
Table (7) Economic Indicators for Integrated Scheme – Option II
Annual Biodiesel Production 8000 Tons
SC I SC II SC III SC IV
Total Capital Inv estments $ 11.9 17.6 18.1 21.1
Total Production Costs $ 1.2 1.2 5.5 5.9
Total Profits $ 5.3 4.2 6.3 4.9
Av erage SRR% 44.5 24.0 35.1 23.5
Annual Biodiesel Production 50000 Tons
Item/Scenario SC I SC II SC III SC IV
Total Capital Inv estments Millions $ 65.1 65.1 97.4 119.7
Total Production Costs Millions $ 6.7 6.7 33.9 36.5
Total Profits Millions $ 34.0 27.7 39.8 31.2
Av erage SRR% 52.2 28.4 23.5 26.1Table (8) Prices of Biodiesel for SRR 10%-Integrated System- Option II
SC I SC II SCIII SCIV
Capacity $/ton
8000 ton/yr 435 656 380 610
50000 ton/yr 396 607 357 584
Capacity $/liter
8000 ton/yr 0.41 0.61 0.52 0.7
50000 ton/yr 0.38 0.58 0.49 0.67• The SRR varied between 19& 36% and 22 &44 % for 8000 and 50000 ton/annum respectively. Positive economic indicators have also been obtained if it is assumed that all stages are considered as an integrated project. • The price of biodiesel that provides a SRR of 10 % was in the range of $ 0.3-0.7/liter for the different assumed scenarios which is lower than the prevailing price of biodiesel (about $1/liter)
• Thus, in view of experimental results and economic assumptions, there are positive prospects for production of biodiesel from Jatropha Curcas under Egyptian conditions.
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