**1.1. Growth and development of cashew in Nigeria**

The world production of cashew crop, according to the Food and Agriculture Organization (FAO), was around 2.7 million tons per annum. The major raw cashew producing countries with their production figures in 2005 (as per the United Nation's Food and Agriculture Cashew Nut Shell Oil — A Renewable and Reliable Petrochemical Feedstock http://dx.doi.org/10.5772/61096 5

**1. Introduction**

4 Advances in Petrochemicals

as a raw material for the petrochemical industry.

is known as cashew nut shell liquid (CNSL) [3].

**1.1. Growth and development of cashew in Nigeria**

that suitably controls soil erosion.

rounding the kernel.

tropical plant (shrub) found within the region between 23°

tree crop in Nigeria, with evergreen leaves, all year round.

Cashew Nut Shell Oil (CNSO) is a versatile component of the Cashew fruits' nut. The oil which is a dark reddish-brown in colour is resident in a soft honeycomb shell, that is the pericarp of the nut. It is a natural resin that could serve as a valuable raw material for multiple applications. Rapid growth in the world population and increasing standard of living has overstretched petroleum resources as petrochemical feedstock. This among other factors, has culminated in the fast depletion of global petroleum reserves. Therefore, to maintain the standard of living and continuity of industrial sector which is paramount to human survival this decade and beyond, there is a need to find alternative sources of fuel and petrochemical feedstock. Cashew nut shell, a by-product of the cashew industry, is an embodiment of a useful chemical serving

Cashew (*Anacardium Occidentale* L.), a well-known species of the Anacardiceae family [1], is a

drought resistant tree crop grown successfully in areas with annual rainfall of 50–350 cm. Its height is above 12 m and has a spread of about 25 m. It has an extensive root system which makes it adaptable to a wide range of moisture levels and soil types [2]. On the commercial scale, it is best grown on well-drained, sandy loam soils. Today, it is an economically valuable

The cashew tree consists of the cashew nut fruit (which is a curved edible seed, housed in a honeycomb-like shell), the apple, leaf and bark. The fruit consists of an outer shell, inner shell and the kernel. The thickness of the cashew nut shell is about 1/8 in. (0.32 cm). The soft honeycomb matrix, in between the outer and inner shell, contains a dark brown liquid, which

The Cashew plant is of great economic significance to Nigeria and other tropical countries due to its valuable products. These products are utilized in food, medicine, chemical and allied industries. In addition to providing shade, the cashew tree is an embellished ornamental plant

Usually, it takes about 3-4 years from planting time before fruiting. Thereafter, the tree can live up to 40 years and more. The cashew fruit (figures 1 and 2) is unusual in comparison with other tree nuts since the nut is outside the fruit. The cashew apple which is about 10 cm long is an edible false fruit, attached to the externally born nut by a stem. Its color ranges from yellow to red, fibrous in nature, very juicy, sweet, pungent and high in vitamins A and C. In its raw state, cashew nut shell (CNS), which is leathery in nature, contains the vesicant oily liquid (CNSL). The shell is separated from the kernel by the testa which is a thin skin sur‐

The world production of cashew crop, according to the Food and Agriculture Organization (FAO), was around 2.7 million tons per annum. The major raw cashew producing countries with their production figures in 2005 (as per the United Nation's Food and Agriculture

N and 23°

S of the equator. It is a

Figure 2. The cashew nut cross section **Figure 2.** The cashew nut cross section

Organization) were Vietnam (960,800 tons), Nigeria (594,000 tons), India (460,000 tons), Brazil (147,629 tons) and Indonesia (122,000 tons). India ranks first in area utilized for cashew production, though its yields are relatively low. Collectively, Vietnam, India and Brazil account for more than 90% of all cashew kernel exports [4,5]. Figure 2. The cashew nut cross section **1.1 Growth and Development of Cashew in Nigeria**

kernel

Cashew production in Nigeria dates back to the 15th century when it was introduced by Portuguese explorers [4,5]. The plant was then, purposefully planted for afforestation schemes in the now defunct Eastern Nigeria. Cashew became a popular commercial crop in 1953, when planted on a large scale principally for the nuts, afforestation and erosion prevention pro‐ grammes in the escarpment areas of Dui, Mbala, Oghe, Oji, Isuochi and Kingie in Eastern Nigeria by the defunct Eastern Nigeria Development Corporation. In Western Nigeria, the first planting of cashew started in the 16th century at Agege in Lagos [4]. Commercial cultivation actually started in the 1950s at Iwo, Eruwa and upper Ogun in the defunct Western Nigeria by the then Western Nigeria Development Corporation. **1.1 Growth and Development of Cashew in Nigeria** The world production of cashew crop, according to the Food and Agriculture Organization (FAO), was around 2.7 million tons per annum. The major raw cashew producing countries with their production figures in 2005 (as per the United Nationʹs Food and Agriculture Organization) were Vietnam (960,800 tons), Nigeria (594,000 tons), India (460,000 tons), Brazil (147,629 tons) and Indonesia (122,000 tons). India ranks first in area utilized for cashew production, though its yields are relatively low. Collectively, Vietnam, India and Brazil account for more than 90% of all cashew kernel exports [4,5]. The world production of cashew crop, according to the Food and Agriculture Organization (FAO), was around 2.7 million tons per annum. The major raw cashew producing countries with their production figures in 2005 (as per the United Nationʹs Food and Agriculture Organization) were Vietnam (960,800 tons), Nigeria (594,000 tons), India (460,000 tons), Brazil (147,629 tons) and Indonesia (122,000 tons). India ranks first in area utilized for cashew production, though its yields are relatively low. Collectively, Vietnam, India and Brazil account for more than 90% of all cashew kernel exports [4,5]. Cashew production in Nigeria dates back to the 15th century when it was introduced by Portuguese explorers [4,5]. The plant was then, purposefully planted for afforestation

Cashew was thereafter, introduced into the Middle Belt and Northern Nigeria from Eastern and Western Nigeria. These cashew nuts were mainly of the medium nut-size biotype, which according to ISO-6477 standards, fall within the W320 category. This cashew biotype therefore constitutes the main cashew species in Nigerian cashew plantations. This biotype, which was from the Asian continent, attracts low premium in the international market. However, Cocoa Cashew production in Nigeria dates back to the 15th century when it was introduced by Portuguese explorers [4,5]. The plant was then, purposefully planted for afforestation schemes in the now defunct Eastern Nigeria. Cashew became a popular commercial crop in 1953, when planted on a large scale principally for the nuts, afforestation and erosion prevention programmes in the escarpment areas of Dui, Mbala, Oghe, Oji, Isuochi and schemes in the now defunct Eastern Nigeria. Cashew became a popular commercial crop in 1953, when planted on a large scale principally for the nuts, afforestation and erosion prevention programmes in the escarpment areas of Dui, Mbala, Oghe, Oji, Isuochi and Research Institute of Nigeria (CRIN) which was established in 1962, commenced research on the cultivation, uses and economy of cashew around 1972. The crop then rapidly spread to all agro-ecologies of Nigeria [6]. This brought about the cultivation for erosion control and the afforestation schemes of the Brazilian cashew biotype (jumbo nut-size), which is now being grown by cashew farmers [6]. This species mature within a year in contrast to the local wild varieties which take about 3 to 5 years to mature.

Today, cashew grows almost everywhere in Nigeria but its cultivation is concentrated primarily in the south and middle belt regions both in small holder farms and plantations [2]. Major cashew growing areas in Nigeria include Abia, Abuja, Anambra, Benue, Cross river, Enugu, Ebonyi, Ekiti, Kogi, Kwara, Kebbi, Nasarawa, Niger, Oyo, Osun, Ondo, Ogun, Sokoto, and Taraba states. High quality cashew nuts, suitable for export, are produced from the south west and south east regions of Nigeria. Figure 3 shows the spread of cashew production in Nigeria as published by National Cashew Association of Nigeria.

Establishment of the Premier Cashew Processing Factory in Oghe, Enugu State early in the 1980s marks the turning point in industrial processing of cashew in Nigeria. The primary objective of government then was to process the harvest from the government-owned 650 ha cashew plantation as well as to serve other small land holding farmers in and around the States of Kogi and Benue.

**Figure 3.** The spread of cashew cultivation in Nigeria

In 2002, Nigeria produced about 30,000 tons of cashew nut from the total holdings of 50,000 ha, which were mostly under small holdings. The average growth of cashew nut production increased to 55,000 tons in 2004. In 2010, Nigeria ranked third among the top 10 world cashew nut-producing countries with a total production of 594,000 tons [7]. This stride improved to second worldwide in 2011 with a production of 835,000 metric tons, constituting 19.5% of the world's production according to FAOSTAT data 2013 [7]. The world production of cashew nuts is presented in Figure 4.

**Figure 4.** Main producer countries of cashew nuts

Figure 4. Main producer countries of cashew nuts Recently, a cashew export programme was initiated in Lagos, Nigeria by the Nigerian Export Promotion Council (NEPC), the National Cashew Association of Nigeria (NCAN) and USAID/Nigeria Expanded Trade and Transport (NEXTT). The move is to expand further the production of cashew nut for export purposes. The National Cashew Association of Nigeria (NCAN) is the umbrella body for the Nigerian cashew industry. It is actively Recently, a cashew export programme was initiated in Lagos, Nigeria by the Nigerian Export Promotion Council (NEPC), the National Cashew Association of Nigeria (NCAN) and USAID/ Nigeria Expanded Trade and Transport (NEXTT). The move is to expand further the produc‐ tion of cashew nut for export purposes. The National Cashew Association of Nigeria (NCAN) is the umbrella body for the Nigerian cashew industry. It is actively involved in developing a strategy and action plan to improve the quality of raw nuts, to increase the coordination in the sector and to improve the business climate for processing.

involved in developing a strategy and action plan to improve the quality of raw nuts, to increase the coordination in the sector and to improve the business climate for processing. India is a leading exporting country of cashew nuts. Its production volume stems from the skilled labour force and technology deployed at the processing stage. The popularity of cashew nuts arose from its applicability as natural vitamin pills [(balita.ph/…/cashew‐nuts‐ gain‐popularity‐as‐natures‐vitamin‐pill/)]. Cashew kernels on the other hand, have high India is a leading exporting country of cashew nuts. Its production volume stems from the skilled labour force and technology deployed at the processing stage. The popularity of cashew nuts arose from its applicability as natural vitamin pills [(balita.ph/.../cashew-nuts-gainpopularity-as-natures-vitamin-pill/)]. Cashew kernels on the other hand, have high protein content (about 19.5%), which accounted for its use in place of soybean meal in broiler chickens [8], whereas the nuts serve a major source of alkenyl phenolic compounds [9].

### protein content (about 19.5%), which accounted for its use in place of soybean meal in broiler chickens [8], whereas the nuts serve a major source of alkenyl phenolic compounds **1.2. Processing**

Research Institute of Nigeria (CRIN) which was established in 1962, commenced research on the cultivation, uses and economy of cashew around 1972. The crop then rapidly spread to all agro-ecologies of Nigeria [6]. This brought about the cultivation for erosion control and the afforestation schemes of the Brazilian cashew biotype (jumbo nut-size), which is now being grown by cashew farmers [6]. This species mature within a year in contrast to the local wild

Today, cashew grows almost everywhere in Nigeria but its cultivation is concentrated primarily in the south and middle belt regions both in small holder farms and plantations [2]. Major cashew growing areas in Nigeria include Abia, Abuja, Anambra, Benue, Cross river, Enugu, Ebonyi, Ekiti, Kogi, Kwara, Kebbi, Nasarawa, Niger, Oyo, Osun, Ondo, Ogun, Sokoto, and Taraba states. High quality cashew nuts, suitable for export, are produced from the south west and south east regions of Nigeria. Figure 3 shows the spread of cashew production in

Establishment of the Premier Cashew Processing Factory in Oghe, Enugu State early in the 1980s marks the turning point in industrial processing of cashew in Nigeria. The primary objective of government then was to process the harvest from the government-owned 650 ha cashew plantation as well as to serve other small land holding farmers in and around the States

In 2002, Nigeria produced about 30,000 tons of cashew nut from the total holdings of 50,000 ha, which were mostly under small holdings. The average growth of cashew nut production

varieties which take about 3 to 5 years to mature.

of Kogi and Benue.

6 Advances in Petrochemicals

**Figure 3.** The spread of cashew cultivation in Nigeria

Nigeria as published by National Cashew Association of Nigeria.

[9]. **1.2 Processing** Basic physical operations before extraction are required on the samples of cashew nuts to ensure a high degree of purity and the quality of the product. These operations constitute the

Basic physical operations before extraction are required on the samples of cashew nuts to ensure a high degree of purity and the quality of the product. These operations constitute the basic pretreatment on samples and include washing, drying, shelling and size reduction. Sometimes, washing may involve the use of detergents to remove likely contaminants.

basic pretreatment on samples and include washing, drying, shelling and size reduction. Sometimes, washing may involve the use of detergents to remove likely contaminants.

Drying is purposely to make the nuts moisture-free. Both sun- and oven-drying have been found effective. Size reduction creates a better contacting surface area for the shell and solvent to enhance removal of the CNSL.

Traditionally, the kernel is removed for the CNS manually. However, to improve the deshel‐ ling process, several methods have been adopted [1,8,10], which include, among others, soaking the nuts in water to improve the moisture content thereby reducing the scorching and cracking tendencies during roasting. Roasting the nuts makes the shell brittle and loosens the kernel from the shell easily. Also, CNSL is released during the roasting [10]. Figure 5 shows the nut-processing stages.
