Cashew Industry Research Articles

High Performing Biobased Ionic Liquid Crystal Electrolytes for Supercapacitors

Production and storage of energy in a highly efficient and environmentally sustainable way is a demand of the current century to meet the growing global energy requirement. Design and development of novel materials and processes that allow precise control over the electrochemical behavior and conductivity of electrolytes is necessary for acquiring such targets. Development of ionic liquid crystals with ordered domains endowed with enhanced ionic conductivity from renewable resources is receiving much interest in this respect. In this paper, we report a unique strategy for the preparation and utilization of ionic liquid crystalline electrolyte derived from a renewable resource: cashew nut shell liquid; an abundantly available waste byproduct from cashew industry. We have prepared imidazolium-based ionic liquid crystal (PMIMP) from cardanol and studied its structure and liquid crystalline phase formation by various techniques. The symmetrical supercapacitor fabricated with mesoporous carbon electrodes emplo...

Analysis of opportunities for greenhouse emission reduction in the global supply chains of cashew industry in West Africa

Global supply chains (GSCs) have become common for industries, and companies seek to reduce their environmental impact, particularly greenhouse gas (GHG), through their GSCs. Guided by ISO 14044, we measure and compare GHG emission of 1000 kg of cashew kernels in 12 GSCs scenarios of West Africa cashew industry, and identify opportunities for reduction. The results show that transportation, cashew processing operation and nutshells waste management produce significant proportion of the total GHG emission. Such results highlight the fact that alternatives in process units and flows in life cycle systems can reduce GHG emission of a product. Thus, limitation of transportation of raw cashew nuts for primary processing, the use of energy-efficient processing methods, and processing on large-scale gives options to supply chain managers and decision makers in the industry to reduce GHG emission. Again, making use of co-product (nutshells) reduces cashew kernels GHG emission much more than it may have been considered by most stakeholders. The challenges of measuring and comparing GHG emission in the industry's GSCs such as non-existing or inadequate quality databases are also discussed.

From cashew nut shell wastes to high value chemicals

Abstract The amount of waste generated in cashew nut processing factories has caused serious problems for a long time. However, this situation is about to change because they are being turned into an opportunity by a variety of bio-based chemicals. Todate, cashew nut shells (CNS) have proven to be among the most versatile renewable resource as they produce cashew nut shell liquid (CNSL). CNSL which is a dark reddish brown viscous liquid (ca. 30–35 wt%) is extracted from the soft honeycomb of the CNS. The shells have been regarded as a by-product of the cashew industry though now it is a cheaper source of natural unsaturated phenols. CNSL offers a multitude of interesting possibilities for the synthesis of speciality chemicals, high value products and polymers. Our recent research efforts have demonstrated that its constituents can be transformed into diverse functional chemicals. This paper reports some key results on how cashew nut shells (an agro waste from cashew nut processing factories) have been employed to produce several functional materials and chemicals. The materials that are highlighted include the synthesis of 3-propylphenol from cardanol and anacardic acid, some polymers prepared from CNSL components, heterogeneous catalysts prepared using CNSL as a templating agent and anacardic acid capped chalcogenide nanoparticles.

Cardanol grafted natural rubber: A green substitute to natural rubber for enhancing silica filler dispersion

ABSTRACTNatural rubber (NR) usage is wide‐spread from pencil erasers to aero tyres. Carbon black and silica are the most common reinforcing fillers in the rubber industries. Carbon black enhances the mechanical properties, while silica reduces the rolling resistance and enhances the wet grip characteristics. However, the dispersion of polar silica fillers in the nonpolar hydrocarbon rubbers like natural rubber is a serious issue to be resolved. In recent years, cardanol, an agricultural by‐product of the cashew industry is already established as a multifunctional additive in the rubber. The present study focuses on dispersion of silica filler in natural rubber grafted with cardanol (CGNR) and determination of its technical properties. The optimum cure time reduces and the cure rate increases for the CGNR vulcanizates as compared to that of the NR vulcanizates at all loadings of silica varying from 30 to 60 phr. The interaction between the phenolic moiety of cardanol and the siloxane as well as silanol functional groups present on the silica surface enhances the rubber–filler interaction which leads to better reinforcement. The crosslink density and bound rubber content are found to be higher for the silica reinforced CGNR vulcanizates. The physico‐mechanical properties of the silica reinforced CGNR vulcanizates are superior to those of the NR vulcanizates. The CGNR vulcanizates show lower compression set and lower abrasion loss. The dynamic‐mechanical properties exhibit less Payne effect for silica reinforced CGNR vulcanizates as compared to the NR vulcanizates. The transmission electron photomicrographs show uniform dispersion of silica filler in the CGNR matrix. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43057.

Synthesis of cardanol oil building blocks for polymer synthesis

This review proposes a platform approach for the synthesis of various building blocks from cardanol in one- or two-steps syntheses. Cardanol, which is a natural phenol, is issued from cashew nutshell liquid, a non-edible renewable resource, co-produced from the cashew industry in large commercial volumes. Cardanol is non-toxic and particularly suitable for the addition of aromatic renewable resources in polymers and materials. Various routes were used for the synthesis of di- and poly-functional building blocks used thereafter in polymer syntheses. Phenolation was used to dimerize/oligomerize cardanol in order to increase its functionality. Thio-ene was used to synthesize new reactive amines. Epoxidation and (meth)acrylation were also used to insert oxirane or (meth)acrylate groups in order to synthesize polymers and materials.

Biosynthesis of tannase from cashew testa using Aspergillus niger MTCC5889 by solid state fermentation

The use of better carbon sources and efficient production strains were deemed as promising strategies to economize tannase production. A novel agro-residue, cashew testa, was tested for the production of tannase under solid-state fermentation (SSF) using Aspergillus niger CEPC 11. CEPC 11 was identified by 18S rDNA typing as Aspergillus niger and deposited in International depositing Authority under MTCC number 5898 and NCBI accession number KM516789. The enzyme was purified 11 fold to obtain tannase with a specific activity of 10.22 U/mg and final yield of 48 %. SDS-PAGE analysis of purified enzyme gave a single band of 89.9KDa. The optimal temperature was found to be 40 °C, with an active range of 25–60 °C. The optimal pH was 5.5, and the enzyme was inactive at pH 8.0. The enzyme was identified through MALDI-TOF-MS tandem mass spectrometry as tannase. Km and Vmax were recorded at 0.1133 M (substrate concentration) and 44.79 μmol/min respectively. Heavy metals (Cadmium, Nickel, Lead, and Copper) in tannery effluent were analyzed before and after treatment with enzyme by AAS (Atomic Absorption spectroscopy). Gallic acid is also determined as an inter-mediatory by-product of this technology. Treatment with tannase enzyme improved the quality of fruit juices. This is the first report on production of tannase by Aspergillus niger under SSF with cashew industry by-product cashew testa as the substrate. The use of residues is an alternative to solve pollution problems that can be caused by an incorrect environmental disposal.

ANALYSIS OF CARBON BLACK–REINFORCED CARDANOL-MODIFIED NATURAL RUBBER COMPOUNDS

ABSTRACT Carbon black is advantageous for rubber as a reinforcing filler. Carbon blacks at higher loadings require process aids for easier processing and improved filler dispersion. Aromatic oils have been used so far in the rubber industry as plasticizer and process aids. The presence of polycyclic aromatic hydrocarbons in these oils has raised concerns, and they have been banned. Rubber industries are looking for alternate sources of process aids from renewable resources. Cardanol (m-pentadecenyl phenol), an agricultural by-product of the cashew industry, is cheap and abundantly available. It was proved recently to be a plasticizer and a multifunctional additive. The dispersion of carbon black in natural rubber (NR) grafted chemically with cardanol (CGNR) is investigated and compared with that of oil plasticized natural rubber. The physico-mechanical properties of the carbon black–filled CGNR vulcanizates are better than that of the aromatic oil plasticized NR vulcanizates. The cross-link density and bound rubber content are higher and the Payne effect is lower for the carbon black–filled CGNR vulcanizates as compared with oil plasticized NR vulcanizates. Dispersion of carbon black in the CGNR matrix is uniform and better than the aromatic oil plasticized NR.

ECONOMICS OF CASHEW PROCESSING TECHNOLOGY IN INDIA

The by-products of cashew viz., cashew nut shell liquid (CNSL), shell cake, testa and cashew apples are commercially exploitable. The method of processing technology affects the outturn, quality of the output, health of the workers, quality of by-products and the cost of production. The adoption of appropriate methods of processing technology can bring efficiency in the form of higher outturn, better quality kernels and cashew nut shell liquid. To use these by-products economically and to create awareness on the business opportunities in cashew processing, the present study attempts to find out the economic feasibility of cashew nut and oil (CNSL). The overall cost of production of kernels has been found to be Rs. 4784.11 and 4616.63 per quintal of raw nuts processed in steaming and drum roasting methods, respectively. The cost of raw material has been the major component in the cost of production of kernels, constituting 86.64 and 86.86% of the total cost of production of kernels in steaming method and drum roasting methods, respectively. The total sale proceeds from the sale of cashew kernels, shells and testa have been Rs. 5347.53 and the profit per quintal of raw nuts processed has been Rs. 563.43 in the steaming method, whereas in the drum roasting method the total sale proceeds has been Rs. 4693.62 and the profit per quintal of raw nut has been Rs. 76.99. Thus it is concluded that the steam processing method realized better returns than drum roasting method due to the adoption of latest technology in the cashew processing methods in India. Cashew nut shell liquid (CNSL), a by-product of the cashew industry has always been credited with words such as ‘versatile raw material’. The two methods of extraction of CNSL viz., kiln method and expeller method are adopted by farmers/processors. The BCR and IRR analysis worked out to 1.13 and 41.2% in kiln method, whereas, they have been 1.15 and 45.27% in expeller method. The solutions to the problems confronting cashew nut processing lies in intensifying research in order to develop cost-effective, eco-friendly technology to boost efficiency and productivity and to reduce costs of processing.

CASHEW INDUSTRY IN INDIA

Cashew (Anacardium occidentale L.) often referred to as ‘wonder nut’, is one of the most valuable processed nuts traded on the global commodity markets and is also an important cash crop. In India cashew is cultivated an area of 9, 23,000 ha with production of 613,000 MT and productivity of 0.7 MT/ha (Indian Horticulture Database, 2010). Maharashtra is leading in cashew production (198,000 MT) with 32.3% share. It is cultivated widely throughout the tropics for its kernels. In India, it is grown in the west coast, east coast and in a few plain areas in Karnataka and Madhya Pradesh. The highest productivity is noticed in Maharashtra. India is the largest producer of cashew in the world with 25.52% share in world production. In India each metric ton of raw cashew seed produced and processed, yields about 230 kg (23%) of exportable grade kernels. Cashew generates employment in the processing and agrarian sector of India employing over 3 lakh persons with more than 95% of them being women (DCCD, Cochin). Cashew is mainly cultivated in Asia, Africa and Latin America. The global area harvested under cashew increased by 665%, from 516,550 ha in 1961 to 3,953,175 ha in 2007 (FAO). The annual growth rate during this period was 4.55% with variations ranging from 8.22 to 20.08%. India is the premier exporter of cashew kernels and earns a sizeable amount of foreign exchange. India is the second largest exporter after Vietnam, accounting for 34% of the world’s export of cashew kernels. During 2009 India exported 446 million kg of cashew kernels. The cashew tree plays an important role in maintaining the ecological balance of the dry regions, the cashew tree is multi-functional: apart from exportable cashew nuts, it supplies timber, firewood, medicines, fodder, etc. By-products from cashew offer opportunities for development of local industry, the world market for cashews is dynamic, with sustained growth rates of approximately 10% per year and the nuts produced could receive the “organic” label as they are chemical free and get premium price. Various value added products such as juice, fenny, wine, dried cashew apple, syrup and jam can be prepared from cashew apple which paves the wave for the development of cashew based industry and economic development of our country. In major cashew growing areas of our country, natural farming is followed. It is estimated that not more than 20% of cashew holdings in India use chemical fertilizers or pesticides (Sivaraman and Hubballi, 2002; Shalini Yadav, 2010). This facilitates adoption of organic farming practices over a period of time without additional efforts. Thus, there is a vast potential of bringing these areas under organic farming practices to exploit the available marketing avenues.

PROSPECTS OF CASHEW CULTIVATION IN KARNATAKA

Cashew (Anacardium occidentale L.) is an evergreen important money spinner crop of waste, marginal and degraded lands of many states in India. India being the largest producer (60%) and exporter of cashew kernels in the world has 9,23,000 ha area and produces 6,13,000 t of cashew with an average national productivity of 695 kg/ha. Karnataka is a prominent state in cashew production occupying 5th position in area (1,18,000 ha) ranking 6th in production (53,000 t) with an average productivity of 461 kg/ha which is much less than the national average. Dakshina Kannada district has the highest area of cashew in Karnataka, followed by Udupi, Belgaum, Chickballapur, Uttara Kannada, Kodagu and Kolar. The average productivity of Udupi (2,080 kg) and Uttara Kannada (2,050 kg) is almost three times the national productivity. However, in other districts the productivity is on par with the national average. The state is bestowed with many research stations working on cashew including the Directorate of Cashew Research, Puttur, Horticulture Research Station, Ullal and AICRP on Cashew at Chintamani dedicated for research, establishment and growth of cashew industry in Karnataka by releasing several high yielding cultivars suitable for both coastal and plain regions. The cultivars recommended for cultivation in Karnataka have longer bearing season with better kernel yield (28-33%). The average yield of these cultivars ranges between 9-21 kg/tree/year after 10 years of planting, producing medium sized (6-9 g) nuts. Reasons for lower yields in Karnataka include old and senile orchards, seedling originated farms, waste and degraded soils and poor production technologies. There is an urgent need to orient farmers about profitability, economics, scientific production technologies like use of improved cultivars, high density planting, integrated management of nutrition and pests, advanced postharvest handling and processing technologies, etc. Karnataka has an area of 4.15 lakh ha of marginal and waste land apart from 21,217 ha of mined area which rightly suits the cultivation of cashew that is being extensively cultivated in degraded soils. Thus, cashew is an excellent crop that may be promoted to grow profitably, especially in the mined areas of Tumkur, Koppal, Bellary, Chitradurga and Raichur districts.

Mechanical, chemical, and curing characteristics of cardanol–furfural-based novolac resin for application in green coatings

The present research work focuses on the mechanical, chemical, and curing characteristics of novolac resin based on renewable resource materials such as cardanol and furfural. Cardanol, a metasubstituted phenol, is a renewable organic resource obtained as a byproduct of the cashew industry. Furfural, an aromatic aldehyde, is also a renewable resource obtained as an agricultural waste product. Novolac resin has been synthesized by the condensation of cardanol with furfural in the presence of an oxalic acid catalyst and using varied molar proportions of the reacting monomers. The reaction was performed at 120°C. The progress of the reaction was monitored by determining the free formaldehyde and free phenol content. The prepared cardanol–furfural-based novolac resins were further characterized by various techniques such as infrared and nuclear magnetic resonance spectroscopic analysis. The resins were cured using the most suitable agent, hexamethylenetetramine. The differential scanning calorimetric technique was used to investigate the curing behavior of the prepared samples. The cured film samples were used for the determination of mechanical properties such as adhesion, flexibility, scratch hardness, gloss, and impact resistance; these cured film samples were also used to observe the effect of various chemicals and solvents (chemical resistance properties) such as sulfuric acid, acetic acid, sodium hydroxide, sodium carbonate and methanol, methyl ethyl ketone, xylene, and deionized water, respectively, on the surface of the film. The resulting coatings based on prepared cardanol–furfural resin were found to have excellent mechanical and chemical resistance properties.

Synthesis and Characterisation of Coumarins from H-Cardanol

A facile conversion of H-cardanol (side-chain hydrogenated cardanol, 3-pentadecylphenol; renewable fine chemical from the cashew industry) into value added 3-acylcoumarins, including those incorporating (+) menthol or cholesterol, has been achieved. The H-cardanol coumarin hybrid compounds were low melting, lipophilic and soluble in hydrocarbon solvents. They exhibit UV characteristics typical of 7-alkyl-3-acylcoumarins.

Biodegradation of Cashew Nut Shell Liquid byDelftia AcidovoransandPseudomonas AeruginosaIsolated from Marine Environment

Cashew Nut Shell Liquid or CNSL is a versatile byproduct of the Cashew Industry. CNSL is widely used in paints, varnishes, enamels, laminating resins, rubber compounding resins, cashew cement, polyurethane based polymers and epoxy resins. Biodegradation of paints is a threat to the marine paint industry. CNSL is an eco-friendly antifouling agent widely used in marine paints that prevents fouling of microorganisms to the hull of the ships and boats. Our aim was to isolate, identify and optimize the effectiveorganism that degrade CNSL and phenol, which would be helpful in developing new paint products that resists these organisms. By enrichment culture technique, a mixed population of microorganisms was obtained. By screening all the plants, it was found that Delftia acidovorans and Pseudomonas aeruginosa play a significant role in the degradation of CNSL. Degradation of CNSL was estimated spectrophotometrically by Folins-Ciocalteau method at 650 nm. These strains can also be used for bioremediation purposes in CNSL contaminated soils in cashew industries.

Novel environmentally sustainable cardanol-based plasticizer covalently bound to PVC via click chemistry: synthesis and properties

Cardanol, a famous renewable organic resource of the cashew industry, was covalently linked to PVC chains as a natural internal plasticizer using the click reaction. The modified PVC exhibited decreased Tg and near-zero migration.

Performance Emission and Economic Analysis of Preheated CNSL Biodiesel as an Alternate Fuel for a Diesel Engine

In the present work, CNSL (cashew nut shell liquid), a byproduct of cashew industry, has been considered as an economically viable alternate source for producing biodiesel. Further, the feasibility and economic viability of using CNSLME (cashew nut shell liquid methyl ester or CNSL biodiesel) directly in a diesel engine has been analyzed. CNSL is trans-esterified in double stages due to its high free fatty acid content and instead of using produced CNSLME in blend with diesel; it was directly used in a single cylinder diesel engine by preheating it. By this measure, the higher viscosity of biodiesel is reduced and the experimental investigation tends to show that both the performance and emission of preheated CNSLME has been improved. At an inlet fuel temperature of 80°C, the CNSLME discerns a 20% increase in BTE (brake thermal efficiency), 66% and 52% decrease in CO and HC emission, respectively, than unheated CNSLME. To purport the economic viability of CNSL, a detailed economic analysis has been conducted. From the analysis, it is inferred that CNSL is a low cost feedstock for biodiesel production among the other existing edible and non-edible oils considered so far.

Sustainable Preparation of Cardanol-Based Nanocarriers with Embedded Natural Phenolic Compounds

In this article, the environmentally friendly preparation of “green nanocarriers” based on the combination of natural renewable materials is described. Cardanol (CA), obtained as the major byproduct of the cashew industry, and cholesterol (CH) have been used to encapsulate chlorogenic acids (CQAs), a class of natural phenolic compounds extracted from two different rowanberries (Sorbus Americana and Vaccinium sp.). The chlorogenic acid extracts and cardanol-based vesicular nanodispersions have been characterized, respectively, by ultra-high performance liquid chromatography (UHPLC), transmission electron microscopy (TEM), and dynamic light scattering (DLS).

Synthesis and characterization of novel vinylester prepolymers from cardanol

A novel thermosetting vinylester (VE) resin was prepared form cardanol, coming from cashew nut shell liquid (CNSL), a renewable resource and waste of the cashew industry. A VE cardanol‐based prepolymer was synthesized by reacting commercial cardanol diepoxy and methacrylic acid. The VE cardanol‐based prepolymer was polymerized by free radical polymerization to yield a thermoset resin with different monomers used as reactive diluents such as styrene (ST), isobornyl methacrylate (IBOMA), dibutyl itaconate (DBI), butanediol dimethacrylate (BDDMA), and hexanediol dimethacrylate (HDDMA). The resulting VE resin was characterized by TGA, DSC, and DMA analyses and compared to diglycidyl ether of bisphenol A (DGEBA)‐based VE resin. Cardanol‐based VE resins exhibit interesting mechanical and thermal properties for composite materials. The Tg value is 86°C with 40% by mass of ST and 116°C with 40% by mass of IBOMA. Around 70°C of Tg are lost compared to DGEBA‐based VE resin, whereas with an oil‐based VE resin the loss of Tg value is around 150°C.Practical application: The acrylated cardanol‐based monomer described in this contribution, that is, acrylated cardanol from CNSL, provided new biobased aromatic building blocks for further free radical polymerizations with various reactive diluents. The obtained VE materials are partially biobased and may be used as binders in composite applications.Biobased vinylester prepolymer (VE) was synthesized by acrylation of commercial di‐epoxy cardanol (Cardolite NC514), coming from CNSL. Vinylester materials were synthesized by free radical polymerization of VE with various monomers. Mechanical and thermal properties of obtained materials showed that synthesized vinylester material could lead to binders for composite application.

Export performance of Indian cashewnut – An analysis

The Indian Cashew industry provides employment to more than 5 lakh people both directly and indirectly, particularly in the rural areas and it thus plays a very vital role in the economy. Today nuts constitute an important part of diet in several countries of the world. In Indian cashew processing factories, over 95% of the workers are women. The total export earnings from export of cashew kernel and cashew nut shell liquid has increased from 447.80 crores in 1990–91 to 4390.68 crores in 2011–12. India is facing tough competition from Vietnam and Brazil in the exports of Cashew Kernels. The NPC for the period 2004 under exportable hypothesis was 0.98, which also revealed that the domestic prices received by the farmers were lower than the international prices, which also implied that the domestic producers were disprotected or rather taxed compared to a situation prevailing under free trade condition. USA was one of the most stable countries among major importers of Indian cashew kernel as indicated by the high retention probability of 70.49%. India could not retain the previous export share to Singapore. The major competitors for India in the world market are Vietnam, Brazil, Indonesia and Tanzania. A dependency on one or two export market would increase the trade risk in the near future. Hence, appropriate export promotion strategies are to be evolved to diversify the geographical concentration.

Jobs, Votes and Legitimacy: The Political Economy of the Mozambican Cashew Processing Industry's Revival

This article seeks to explain the revival of the Mozambican cashew processing industry after it was virtually wiped out by liberalisation policies at the turn of the millennium. Over the last decade state, private and external actors have cooperated to rehabilitate cashew processing with a concerted industrial policy and rents generated by protection. It is argued that such rent creation is a political process and that theories of ‘good governance’ and ‘developmental neopatrimonialism’ are unable to explain political support to the cashew sector in Mozambique. The ‘developmental state’ literature is a more useful guide not only to how the industry was rehabilitated, but also to where the political ‘will to develop’ originated in other contexts. Following from this discussion, it is argued that in Mozambique an elite ideology of nationalism, modernisation and anti-imperialism paved the way for protection of the cashew industry, while more active support was a result of more immediate concerns around finely balanced elections, inadequate employment generation in the broader economy and the faltering legitimacy of the ruling party.

Synthesis of bio based low temperature curable liquid epoxy, benzoxazine monomer system from cardanol: Thermal and viscoelastic properties

This paper deals with the synthesis and characterization of cardanol based pre-polymers, one containing epoxy group and the other with a benzoxazine unit, obtained from cashew nut shell liquid which is a by product of cashew industry. Using these monomers a new curing system has been developed by varying the proportion of the monomers in the copolymer mixture. Differential scanning calorimeter was used to study and monitor the cure process of monomers as well as their copolymers. Decrease of onset of reaction and the peak exothermic temperature with increase of epoxy content in the copolymers was observed due to the catalytic effect of free phenolic group in the cardanol epoxy. The tertiary amine formed during benzoxazine ring opening found to catalyze the cross linking reactions. The viscoelastic properties, evaluated by dynamic mechanical thermal analysis indicated an increase in storage modulus and tanδ values with incorporation of benzoxazine in the copolymers. Thermal stabilities of the cured polymers were studied by thermo gravimetric analysis. Two stage decomposition was observed for all the copolymers owing to cardanol side chain degradation at low temperature and main cross linked polymer structure at high temperature. The copolymers displayed lower char yields compared to the pure homopolymers because of less ordered structure due to copolymerization. The cardanol derived functional monomers can be used with epoxy and benzoxazine resins to impart flexibility to the cross linked networks.