Renewable Energy in Agriculture in Egypt Technological Fundamentals of  Briquetting Cotton Stalks as a BiofuelEhab El Saeidy112345252.12.1.167892.1.210112.1.3122.22.2.11314372#22315472#3272.2.216459#260413#274172.2.318192.32.3.1436#2932021445#2862.3.2222.42.4.123242524#232624#23604#80327408#3082.4.22824#41293031157#373313.132520#32433571#3563.2870#4624334.134486#29335541#33636472#29437501#3134.238395395.14041870#3575.24243295#20444297#195392#2765.2.145464#2745.2.24647464#2585.2.348468#2795.2.449457#2595.35.3.150435#26251311#2985.3.252169#53386#2535.453396#57854204#3395524#23551#3005.55.5.1565.5.2316#25257445#2775.5.355#4458347#2775.6595.760458#309616616.16.1.162535#33463443#2756.1.2416#23764393#2356.1.365466#29066468#2726.1.467467#292482#3016.2686.369419#27970466#293516#3226.4716.572475#2967364#516.674468#2916.77576454#283388#23377420#2616.87879533#331557#346576#35980565#342572#357557#346817817.1827.283454#28384501#3117.385487#30486480#2997.487541#3347.588454#283501#3137.689492#3078898.1908.28.2.18.2.1-191604#7868.2.1-28.2.28.2.2-1928.2.2-28.2.2-38.2.38.2.3-1938.2.3-28.2.3-38.2.3-4948.2.48.2.4-18.2.4-28.2.4-3958.2.4-48.2.4-5968.38.3.1978.3.28.3.3988.3.48.499100516#321575#3911011029102103104105106ReferencesAcknowledgementsUnits24#2324#2317#21SummaryAppendix627#854627#606Eidesstattliche ErklärungenTable of contentsHelp Socio-economic assessments of briquetting cotton stalks

Introduction

An economic analysis was conducted in order to assess and compare the different alternative ways of producing energy sources. This assessment is important because from the farmer's perspective, the adoption of technologies for producing energy sources depends on their economic competitiveness compared with conventional energy sources.

A comparative cost-analysis approach was chosen to identify the competitiveness of energy carriers made of cotton stalk residues compared with traditional energy sources. The gross margins for each process were also calculated to determine the profits of potential alternatives. From these calculations, the specific energy costs were calculated and used as the main criteria for comparison. The specific energy costs determine the costs of producing one unit of energy (LE/kWh). The analysis compared the costs of the different alternatives to show which would have the lowest economic costs, but it also took into consideration the indirect costs such as the harmful impact of the worms on the harvest and ecological impacts.

Production lines

In order to perform the required economic analysis, a diagram showing the different energy production technologies was constructed (Figure 8.1). The diagram shows all possible alternatives and the processes involved in them. Four alternatives were chosen for study in this work. These are the most used in addition to the new technological alternatives, which are economically, ecologically, and environmentally friendly.

Stalk burning line Collection of the stalks

After the harvest operation the farmers must prepare the fields very quickly for the next crop. As irrigation water is available all the year round, continuous cropping is practised, with an average of two crops per year. The farmers cut the stalks down (near the roots) using a small axe. Then they collect the stalks in piles on the field by hand. These stalks are transported for storage at the head of the field or on the roof of the farmer's house. They are used later as a domestic fuel for cooking and heating throughout the year.

Fig. 8.1: Production lines for the energetic use of cotton stalks

Burning of the stalks

Because of the infestation by cotton worms, the stalks were to be burned immediately after the harvest operation according to a law issued by the Egyptian Ministry of Agriculture. The stalks were cut and collected in piles then; the farmer put some drops of kerosene on the pile and burns it with matches. This operation was usually done under supervision of the inspectors of the Ministry of Agriculture.

Stalk storing line Collection of the stalks

See (8.2.1-1).

 Transporting of the stalks

In former times farmer tied the piles after cutting and transporting them for storage and later use as fuel. Farmers used their own donkey or camel for this operation, renting or borrowing more animals if a huge amount had to be carried or if the field had to be prepared very quickly for the next crop. The stalks were transported to the head of the field, or to the farmer’s house.

Storing of stalks

Farmers stored the stalks at the head of the field. The storage area was lost to the cultivated area. The other alternative was to transport these stalks and store them on the roof of the house. In both cases these methods of storage were harmful to the environment and human health, and represented an economic loss. Farmers carried out this operation with the help of their family or labourers.

Stalk chopping line Collection of the stalks

See (8.2.1-1).

 Transporting of the stalks

See (8.2.2-2).

 Storing of the stalks

See (8.2.2-3).

 Chopping the stalks

Such work must be performed on the field. It makes transporting of the chips easier and more economical. The machine recommended for this operation is a GSZ 242 produced by SÜDHARZER Maschinenbau (Germany). It is a mounted machine and is driven by the tractor P.T.O. It needs about 12 kW and cuts stems up to 12 cm thick. The chips are then transported and stored for subsequent use as explained in 6.2.2-2 and 6.2.2-3.

Stalk briquetting line Collection of the stalks

See (8.2.1-1).

 Transporting of the stalks

See (8.2.2-2).

 Storing of the stalks

See (8.2.2-3).

 Chopping the stalks

See (8.2.3-4).

 Briquetting

This operation is the technologically, ecologically and environmentally friendly alternative compared with the other methods of handling cotton stalks. It depends on the use of a mobile hydraulic press machine. This machine is mounted on the tractor. It takes its power from the tractor P.T.O. and the hydraulic system and is preferably operated by the same tractor as the chopping machine. KAHL (Germany) has developed another type of briquetting machine. Depending on the type, briquette diameter, and throughput, the machine needs from 3 to 400 kW power. This machine may be expensive for the farmer, but he can rent it from the machine station.

To collect the empirical data, structured questionnaires were used (see Appendix). The questionnaires employed for the survey have been summarized (see Appendix). The survey was conducted in Egypt. During the survey, the farmers responsible for handling the cotton stalks were the key informants.

For data entry and management, a data bank containing all the information gathered from the interviews was constructed using MS Excel software. The databank was tested and verified to eliminate all errors. This was done by comparing the information entered into the databank with the information in the questionnaires. All other statistical analyses and calculations were also made using the same software.

Costs

As shown in Figure 8.1 there are several production lines that could be used in order to handle the cotton stalks and produce energy resources. The most potential and important alternatives were chosen for the comparative cost analysis. These alternatives are:

Stalk burning line

This line was chosen because it was the official process used in Egypt, but now it is still used illegal. The Egyptian Ministry of Agriculture prefers this line as it ensures complete destruction of the harmful cotton worms, their eggs and larvae from the last season. This process involves only collection of the stalks from the fields, followed by storing on the field until the time of burning. This operation is also carried out on the field without transportation anywhere else. The cotton stalks are collected in piles on the field by hired labourers and burned. This operation takes about 72 man-hours/feddan. The labour costs 12 LE/day (1.5 LE/hour). The gross margin is –138.00 LE/fe because the production value of this alternative is zero, as it involves no production. The specific energy costs with this alternative are 0.058 LE/kWh. This method prevents the farmer from tapping a free source of energy (about 7500 kWh/fe). As a consequence, the farmer must buy substitute energy from a fossil fuel source.

Stalk storing line

This line is the most favourable for the farmers as it provides a free source of domestic fuel that the farmer’s family can use for domestic purposes. It involves the collection of the stalks and transport for storage on the field or on the house roof for later use as a fuel. The farmer’s house is usually not far from his field. The maximum distance is about 2 km. This line requires about 20 man-hours/feddan and about 9 m3 to store the stalks of one feddan. The costs of this operation are about 20-30 LE/feddan. The stalks can also be transported to the operating place by farm animals such as donkeys and camels, which may be owned, borrowed or rented by the farmer. This will then cost 10 LE/day (8 hours).

Storing of the stalks on the field also means a high capital demand. It involves the collection of the stalks, transport, and storage of these stalks. The gross margin is positive (62.87 LE/fe) as the stalks are used for the energy demand of the farmer’s family. The specific energy cost is 0.031 LE/kWh. It is the lowest of all.

Stalk chopping line

This line was chosen because it is one of the best alternatives that could reduce the harmful impacts of the worms. It involves the collection of the stalks from the fields, followed by storage on the field. This is followed by chopping these stalks into small chips and then transporting and storing them for subsequent use. The stalks can be chopped by a chopping machine as presented in 6.2.3-4. This costs 10 LE/hour. This operation also takes 9 man-hours/feddan, i.e. three hired labourers for 3 hours per feddan. The total costs of this operation are about 45 LE. After the cutting operation, the farm animals transport the product to the operating place. This operation also takes about 15 hours per feddan. The calculated specific energy cost in this case is 0.045 LE/kWh. The chopping line has a high capital demand compared with other lines in this alternative, as it involves the chopping of the stalks as well as the transport and storage of the chips. The gross margin is still a minus figure (-17.63 LE/fe), but it is higher than that for burning because the chips produced can be used as fuel or an energy resource in the household or for other purposes. The specific energy cost is 0.045 LE/kWh. It is lower than for the burning of the stalks.

 Stalk briquetting line

This is one of environmentally and ecologically favoured alternatives, as it will provide many benefits. It will ensure the complete destruction of the worms and provide an environmentally friendly energy resource that can be used by the farmer and his family. It involves the collection of stalks from the fields, followed by storage on the field. This is followed by chopping and briquetting. The briquettes are then transported and stored for subsequent use. The stalks are cut manually and collected by hired labourers, then transported for cutting and pressing. The processed briquettes are transported to the farmer’s house, where they can be used as an energy source for domestic purposes. The costs of the different operations such as stalk collection, storage, or transportation are similar to those in the former alternatives. The additional costs here are due to briquetting, which is preferably done by a mounted hydraulic press machine driven by the P.T.O. and the hydraulic system of the tractor. That means this operation is carried out directly on the field. The briquetting line with chopping of the stalks has the highest capital demand compared with other operations. The gross margin is higher than for burning, but still lower than for chopping. The specific energy cost is the highest at 0.062 LE/kWh. It is higher than other lines because it involves the additional operation of briquetting, which requires additional costs.

The costs of each step in these chosen lines are calculated to enable a comparison between them. The results are described in Tables 8.1, 8.2, 8.3, and 8.4. For each alternative, Figure 8.2 is constructed to illustrate the costs of each operating step.
Discussion of costs

As shown in the tables 6.2.1, 6.2.2, 6.2.3 and 6.2.4, it is clear that the lines with more processes display more costs because they involve more processes that require additional capital. Therefore briquetting of the stalks shows the highest costs as it involves the highest number of processes and modern technology. Its specific energy costs (LE/kWh) were only 5 % higher than the burning line including the costs of the purchasable fuel. It is also 35% higher in its specific energy costs than chopping line and double the costs of the storing line.

Economically briquetting is the most costly line, but considering the agronomic and ecological benefits that can be gained it is preferred to the chopping alternatives because it allows for complete destruction of the harmful worms. This will reduce the costs of pest control measures and increase the yield as well. It is much preferred to burning, as it allows the reduction of smoke pollution, one of the main causes of the formation of black clouds over Cairo in the autumn. The difference between the costs of the kerosene and the briquettes produced is also small and could be made even smaller by adopting more cost-effective machines and processes in the production of these briquettes.

Compared with stalk burning, the specific energy cost of briquetting is the highest. Both of these methods are suitable for eliminating the harmful cotton worms. Briquetting costs are high because of using the machine in these processes. These machines are usually imported and thus increase the costs. If these machines were collected or manufactured in Egypt, that would certainly reduce the costs of briquetting and make this the more useful and cheaper process. Labour in Egypt is cheap. Figure 8.2 and Figure 8.3 illustrates the costs of various production lines for the utilization of cotton stalks in Egypt.

Generally, for all lines, the most labour-intensive processes are the collection of the stalks from the field, transportation, and storage. Other processes require lower labour because they depend more on machines. As for the capital demand, chopping and briquetting have the highest capital demand.

Fig. 8.2: Costs of each process step of the production lines analysed

Fig. 8.3: The costs of various production lines for the utilization of cotton stalks in Egypt

Gross margin

 

 

 

Process steps

Unit

Amount

%

Collection of the stalks

LE/fe

108.00

82%

Storage of the stalks on the field

LE/fe

30.00

18%

Burning of the stalks on the field

LE/fe

0.00

0%

Total variable costs

LE/fe

138.00

100%

Production value

LE/fe

0.00

 

Gross margin

LE/fe

-138.00

 

Labour productivity

LE/h

-1.50

 

Land productivity

LE/fe

-138.00

 

Capital productivity

LE/LE

-

 

 

 

 

 

 

 

 

 

Total costs per feddan

 

 

 

Process steps

Unit

Amount

%

Collection of the stalks

LE/fe

108.00

82%

Storage of the stalks on the field

LE/fe

30.00

18%

Burning of the stalks on the field

LE/fe

0.00

0%

Total costs

LE/fe

138.00

100%

Energy content of stalks

kWh/fe

7500

 

Energy costs of fossil fuel

LE/kWh

0-04

 

Substitute costs of fossil fuel

LE/fe

293.87

 

Total costs (including the purchasable fuel)

LE/fe

431.87

 

Specific energy costs

LE/kWh

0.058

 

Specific energy costs

€/kWh

0.008

 

 

 

 

 

 

 

 

 

Total costs per ton (DM)

 

 

 

Process steps

Unit

Amount

%

Collection of the stalks

LE/t

72.00

78%

Storage of the stalks on the field

LE/t

20.00

22%

Burning of the stalks on the field

LE/t

0.00

0%

Total costs

LE/t

92.00

100%

Energy content of the stalks

kWh/t

5000

 

Energy costs of fossil fuel

LE/kWh

0.04

 

Substitute costs of fossil fuel

LE/t

195.91

 

Total costs (including the purchasable fuel)

LE/t

287.91

 

Specific energy costs

LE/kWh

0.058

 

Specific energy costs

€/kWh

0.008

 
Table 8.1: Burning line (1)

Gross margin

 

 

 

Process steps

Unit

Amount

%

Collection of the stalks

LE/fe

108.00

47%

Storage of the stalks on the field

LE/fe

30.00

13%

Stalk transport

LE/fe

45.00

19%

Stalk storage

LE/fe

48.00

21%

Total variable costs

LE/fe

231.00

100%

Stalk storage

t/fe

1.50

 

Energy content of the stalks

kWh/t

5000

 

Specific energy price

LE/kWh

0.039

 

Production value

LE/fe

293.87

 

Gross margin

LE/fe

62.87

 

Labour productivity

LE/h

0.41

 

Land productivity

LE/fe

62.87

 

Capital productivity

LE/LE

-

 

 

 

 

 

 

 

 

 

Total costs per feddan

 

 

 

Process steps

Unit

Amount

%

Collection of the stalks

LE/fe

108.00

47%

Storage of the stalks on the field

LE/fe

30.00

13%

Stalk transport

LE/fe

45.00

19%

Stalk storage

LE/fe

48.00

21%

Total costs

LE/fe

231

100%

Energy content of the stalks

kWh/fe

7500

 

Specific energy costs

LE/kWh

0.031

 

Specific energy costs

€/kWh

0.004

 

 

 

 

 

 

 

 

 

Total costs per ton (DM)

 

 

 

Process steps

Unit

Amount

%

Collection of the stalks

LE/t

72.00

47%

Storage of the stalks on the field

LE/t

20.00

13%

Stalk transport

LE/t

30.00

19%

Stalk storage

LE/t

32.00

21%

Total costs

LE/t

154.00

100%

Energy content of the stalks

kWh/t

5000

 

Specific energy costs

LE/kWh

0.031

 

Specific energy costs

€/kWh

0.004

 
Table 8.2: Stalks storing line (2)

Gross margin

 

 

 

Process steps

Unit

Amount

%

Collection of the stalks

LE/fe

108.00

35%

Storage of the stalks on the field

LE/fe

30.00

10%

Chopping of the stalks

LE/fe

74.00

24%

Chip transport

LE/fe

51.50

17%

Chip storage

LE/fe

48.00

15%

Total variable costs

LE/fe

331.50

100%

Chips yield

t/fe

1.50

 

Energy content of the chips

kWh/t

5000

 

Specific energy price

LE/kWh

0.039

 

Production value

LE/fe

293.87

 

Gross margin

LE/fe

-17.63

 

Labour productivity

LE/h

-0.11

 

Land productivity

LE/fe

-17.63

 

Capital productivity

LE/LE

-0.25

 

 

 

 

 

 

 

 

 

Total costs per feddan

 

 

 

Process steps

Unit

Amount

%

Collection of the stalks

LE/fe

108.00

32%

Storage of the stalks on the field

LE/fe

30.00

9%

Chopping of the stalks

LE/fe

97.50

29%

Chip transport

LE/fe

51.50

15%

Chip storage

LE/fe

48.00

14%

Total costs

LE/fe

335

100%

Energy content of the chips

kWh/fe

7500

 

Specific energy costs

LE/kWh

0.045

 

Specific energy costs

€/kWh

0.006

 

 

 

 

 

 

 

 

 

Total costs per ton (DM)

 

 

 

Process steps

Unit

Amount

%

Collection of the stalks

LE/t

72.00

32%

Storage of the stalks on the field

LE/t

20.00

9%

Chopping of the stalks

LE/t

65.00

29%

Chip transport

LE/t

34.33

15%

Chip storage

LE/t

32.00

14%

Total costs

LE/t

233.30

100%

Energy content of the chips

kWh/t

5000

 

Specific energy costs

LE/kWh

0.045

 

Specific energy costs

€/kWh

0.006

 
Table 8.3: Chopping line (3)

Gross margin

 

 

 

Process steps

Unit

Amount

%

Collection of the stalks

LE/fe

108.00

30%

Storage of the stalks on the field

LE/fe

30.00

8%

Chopping of the stalks

LE/fe

74.00

20%

Briquetting

LE/fe

51.47

14%

Briquette transport

LE/fe

51.50

14%

Briquette storage

LE/fe

48.00

13%

Total variable costs

LE/fe

362.97

100%

Briquettes yield

t/fe

1.50

 

Energy content of the Briquettes

kWh/t

5000

 

Specific energy price

LE/kWh

0.039

 

Production value

LE/fe

293.87

 

Gross margin

LE/fe

-69.10

 

Labour productivity

LE/h

-0.36

 

Land productivity

LE/fe

-69.10

 

Capital productivity

LE/LE

-0.48

 

 

 

 

 

 

 

 

 

Total costs per feddan

 

 

 

Process steps

Unit

Amount

%

Collection of the stalks

LE/fe

108.00

24%

Storage of the stalks on the field

LE/fe

30.00

7%

Chopping of the stalks

LE/fe

97.50

21%

Briquetting

LE/fe

124.38

27%

Briquette transport

LE/fe

51.50

11%

Briquette storage

LE/fe

48.00

10%

Total costs

LE/fe

459.38

100%

Energy content of the Briquettes

kWh/fe

7500

 

Specific energy costs

LE/kWh

0.061

 

Specific energy costs

€/kWh

0.009

 

 

 

 

 

 

 

 

 

Total costs per ton (DM)

 

 

 

Process steps

Unit

Amount

%

Collection of the stalks

LE/t

72.00

23%

Storage of the stalks on the field

LE/t

20.00

6%

Chopping of the stalks

LE/t

66.67

22%

Briquetting

LE/t

82.92

27%

Briquette transport

LE/t

34.33

11%

Briquette storage

LE/t

32.00

10%

Total costs

LE/t

307.92

100%

Energy content of the Briquettes

kWh/t

5000

 

Specific energy costs

LE/kWh

0.062

 

Specific energy costs

€/kWh

0.009

 
Table 8.4: Briquetting line (4)