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Jatropha Curcas: A Climate Resilient Plant

Energy supply and its security have emerged as significant global concerns over the past decade. The utilization of liquid fuels through combustion generates energy, playing a pivotal role in a nation’s economic growth and prosperity. However, fossil fuels, which are major sources of this energy, emit greenhouse gases and other air pollutants, contributing to environmental degradation. An encouraging development is the increasing accessibility of biodiesel in the transportation sector, achieved through blending with traditional diesel fuel. This shift towards biodiesel is fueled by a confluence of factors, including growing environmental awareness, depleting petroleum reserves, and our nation’s dependence on an agriculture-based economy.

Biodiesel presents itself as a sustainable liquid bioenergy option that holds the potential to substitute diesel fuel effectively. It offers the advantage of reducing emissions of pollutants and can seamlessly be used in compression ignition engines without requiring modifications. In essence, biodiesel stands as a promising alternative fuel, possessing qualities comparable to those of traditional diesel fuel. Trans-esterification is the process of turning large, branching triglycerides into smaller, straight-chain methyl esters in the presence of a solvent, employing an alkali, acid, or enzyme as a catalyst.

India is a developing nation and depends mostly on fossil fuels for energy requirements. The government has set a goal of 5 % blending of biodiesel by 2030. In this regard, the biodiesel derived from nonedible oil seeds and waste cooking oil are encouraged to use as a feedstock for biodiesel. Many works have been done on the production of biodiesel from Jatropha and its utilization as diesel engine fuel.

Jatropha curcas: A Versatile Plant with Unique Characteristics

Selective focus shot of beautiful pink jatropha integerrima flowers
Beautiful pink jatropha integerrima flowers

Jatropha curcas, known by various names such as Jungli arandi, Ratanjot, and Amari jot in different parts of India, is a compact shrub primarily utilized as a hedge plant in rural Indian communities. Belonging to the spurge family, Euphorbiaceae, it encompasses around 170 succulent plant species, shrubs, and trees, with distinct male and female flowers. Another commonly used term for it is nettlespurge. These plants are remarkably resilient, thriving in arid conditions and infertile soils, making them invulnerable to grazing by cattle. In our childhood, we used to create bubbles using its sap.

This flowering plant, Jatropha curcas, stands out in the Euphorbiaceae family for its potential as a renewable energy source due to its adaptability to subpar soils and its ability to produce substantial oil yields per hectare. With its rapid growth and seed generation lasting up to 50 years, it emerges as a distinctive tropical plant promising numerous advantages for sustainable energy development. It holds the distinction of being the top contender in terms of both tangible and intangible environmental benefits.

Jatropha curcas presents a cost-effective biodiesel feedstock with superior fuel properties and a higher oil content compared to other species. Being non-edible, it doesn’t impact food prices or fuel-versus-food debates. Moreover, its emissions are less polluting than diesel, and it can be effectively used in diesel engines without compromising performance. Additionally, Jatropha curcas significantly contributes to improving rural livelihoods, offering an oil yield of up to 40% per seed based on weight.

Like many Euphorbiaceae family members, Jatropha contains highly toxic compounds. Traditionally utilized in basket-making, tanning, and dye production, the species gained attention in the 2000s for biodiesel production and medicinal applications as lamp oil. Despite its potential, caution is essential as the seeds contain the highly poisonous toxalbumin curcin and the carcinogenic phorbol. Even though some of the toxicity is reduced through roasting, ingestion of just three untreated seeds can be fatal to humans. The sap of Jatropha is also a skin irritant.

Also read: Potential of Multi-Purpose Tree Species (MPTs)

Jatropha Initiatives in India

India’s ambitious aim of achieving energy independence by 2018 includes a pivotal focus on Jatropha incentives. Derived from the seeds of the resilient Jatropha curcas plant, Jatropha oil presents a promising avenue for producing high-quality biodiesel. This plant is well-suited to thrive in the wastelands scattered across India, offering a sustainable source for biofuel production.

Amidst a backdrop of stagnant domestic crude oil production and an ever-growing demand for oil, India is strategically exploring alternative energy sources to bridge this gap, emphasizing both economic and environmental advantages. Ethanol, derived from sugarcane, stands out as a viable substitute, blending seamlessly with petrol/gasoline for transportation needs. Additionally, biodiesel, harnessed from oil-rich seeds of specific plants and blended with diesel, presents another promising option. In the West, biodiesel production often relies on field crops like Rapeseed, Sunflower (in Europe), Soybean (in the US), Palm Oil (Malaysia), and Jatropha curcas (Nicaragua).

The adaptability of Jatropha curcas is a remarkable attribute, thriving in various rainfall conditions ranging from 250 to over 1,200 mm annually. The plant can endure temperatures within the range of 20 to 26°C and exhibits preference for well-drained, well-aerated soils with pH levels between 5.0 and 6.5. In fact, it flourishes in low-nutrient, marginal soils, shedding its leaves during dry spells. Plantation patterns of 2 m × 2 m, 2.5 m × 2.5 m, and 3 m × 3 m, as recommended by Heller, prove effective in yielding higher fruit harvests. Typically, fruit production begins in the second year of cultivation, stabilizing into optimal economic output by the fourth or fifth year.

Projections for Jatropha Curcas oil production are optimistic, anticipated to reach 1,590 kg/ha. The fruits of the Jatropha Curcas plant resemble trilobite ovoid capsules, characterized by three cells and dimensions measuring 23–30 mm in length and 28 mm in width. The seeds of Jatropha Curcas possess a thin shell and an oblong shape with a dark back color, measuring approximately 2.12 cm in length when mature, making oil extraction a feasible and efficient process.

A Traditional Approach to Oil Extraction

Mechanical pressing, a time-honored method of oil recovery, is favored by small businesses due to its cost-effectiveness and safety compared to solvent extraction, requiring minimal maintenance. The process involves a helical body (worm) spinning within a confined area to exert pressing force. This can be achieved using either hydraulic presses or screw presses (press chamber).

In the evolution of this technique, hydraulic presses have given way to continuous screw presses, requiring less manual labor. A vertical feeder and a horizontal screw, with an increasing body diameter, apply pressure on the oilseeds along the length of the press. The barrel of the screw is slotted, allowing the growing internal pressure to release air and subsequently drain the oil through the barrel. At the end of the screw, the de-oiled cake is discharged, and the Jatropha Curcas oil is collected in a trough below the screw.

The key advantage of a screw press lies in its capacity to process substantial amounts of Jatropha Curcas seeds with minimal effort, enabling continuous oil extraction. This method presses seeds and nuts through a chamber using high friction and pressure, generating heat (60-100°C) due to the friction but does not add additional heat to the process. Once the seeds are crushed, the oil is extracted, leaving behind a pressed mass of seeds, often used as animal feed.

The cold-pressed technique involves using an oilseed press to extract oil from the seeds with minimal heat generation. The seeds are crushed in the press to obtain the oil. This process can operate at significantly lower temperatures (around 50°C) compared to an expeller press. Prior to pressing, oilseed materials undergo various pre-treatments, including washing, conditioning, heating, flaking, and dehulling, to enhance oil volume and quality recovery from the raw material.

Efforts to enhance oil extraction efficiency from screw presses have involved advancements in machine design and materials used in their construction. Seed preparation significantly impacts oil extraction efficiency and quality. While intact seeds exhibit high reproductivity, crushed and deshelled seeds create less stable pressing conditions. Research into mechanical extraction of Jatropha Curcas using a screw press expeller has explored oil yield under varying operating conditions such as extraction temperature, screw rotating speed, and nozzle diameter at the end of the press.

Optimal results were achieved at the highest examined temperature (90°C), nozzle diameter of 11 mm, and a rotating speed of 40 rpm. This mechanical screw oil extraction press is versatile and can be used for other feedstocks like Calophyllum Inophyllum. With a moisture percentage of 14.4%, kernels yielded approximately 78% of oil production. Mechanical screw presses are most suitable for higher oil yield feedstocks, retaining about 8-14% of oil in the cake and residual material. However, for low oil yield feedstocks, solvent extraction would be a more suitable alternative.

A Solvent-Based Approach to Oil Extraction

Leaching, a solvent-based method, entails the extraction of the soluble fraction (solute or leachate) from Jatropha Curcas seeds using a liquid solvent. Chemical extraction has gained prominence in the oil extraction industry due to its ability to yield a high percentage of oil and the potential to produce top-quality oil. The choice of solvent in the solvent extraction process can impact oil yields due to the polar nature of the Jatropha Curcas seeds. Commonly employed oil extraction solvents include hexane, propane, ethane, tetrahydrofuran (THF), ethanol, dichloromethane, methanol, and the methanol-water binary system.

Despite the advantages of high purity and oil yield associated with solvent use, there’s an expenditure of energy during the lengthy extraction process. An experiment utilizing Soxhlet extraction applied Response Surface Methodology (RSM) for optimizing crude oil extraction. The analytical parameters considered were the solvent-to-seed ratio, reaction temperature, and extraction duration. n-Hexane was employed as the solvent, with solid-to-solvent ratios of 3:1, 5:1, and 7:1 (v/w), and three distinct extraction times: 4, 5, and 6 hours. The reaction temperature varied between 60 and 70°C.

Interestingly, petroleum ether demonstrated superior efficacy in oil extraction, yielding 35.3-44.3% of oil, compared to hexane which produced 34.8-42.3% oil yield. Solvent extraction proves to be a significantly more efficient method for recovering oil from oilseeds compared to mechanical extraction, as it involves dissolving oil by bringing oilseeds in contact with a liquid solvent. Factors such as oilseed preparation, temperature, mode of operation, and equipment design all influence oil recovery efficiency. However, this method presents challenges in separating the oil-solvent mixture, making it more suitable for small-scale manufacturing plants.

Jatropha Curcas: Unveiling the Potential and Challenges

Reports highlight that Jatropha Curcas, a hardy plant, thrives in underutilized areas with minimal water and poor soil conditions. It has the ability to yield oilseed as early as the first year, albeit on a modest scale. However, questions arise regarding the feasibility of large-scale commercial cultivation of Jatropha Curcas in fertile lands, potentially replacing other essential food and income crops in tropical regions.

Considering an annual yield of 2000 kg from mature trees, the estimated yearly operational expenses for cultivating 1 hectare of Jatropha Curcas stand at approximately USD 200. A significant portion of these expenses is attributed to picking and post-harvest processing. Hence, the annual expenditures are intricately tied to production levels. The labor-intensive nature of Jatropha Curcas cultivation poses a challenge in achieving and sustaining economic viability.

A promising approach to enhance the economic potential of Jatropha Curcas involves intercropping with annuals, perennials, or trees. This strategy not only boosts soil productivity but also acts as a soil cover, providing additional revenue to farmers. Particularly when Jatropha Curcas production is low or nonexistent, and expenses for land maintenance persist, intercropping becomes crucial. However, it’s important to note that as Jatropha Curcas plants cover more soil with reduced spacing between rows for intercrops, the output of intercrops diminishes over time. This dynamic relationship doesn’t always correspond to an increase in Jatropha Curcas yield.

Analyzing the energy dynamics, biodiesel production from the Jatropha Curcas system is considered viable when the net energy ratio exceeds one, indicating that more energy is generated than consumed. However, based on specific economic criteria, biodiesel production from Jatropha Curcas is currently not deemed economically feasible.

To achieve economic viability, substantial research efforts should focus on attaining a seed yield of 3,250 kg/ha per year. Thus, future research endeavors should prioritize inventing, developing, and enhancing technologies for seed gathering, seed processing, oil extraction, and biodiesel manufacturing processes. Moreover, a comprehensive investigation into agronomic performance, water and nutrient requirements, and susceptibility to pests and diseases of Jatropha is essential for fostering commercial and economically successful production.

Jatropha’s Economic Potential and Environmental Benefits

Jatropha holds promising potential for generating economic benefits at both local and national levels. With proper management, it can flourish in arid, marginal lands that are unsuitable for traditional agriculture, allowing villagers and farmers to utilize non-farm land for income generation. Furthermore, increased production of Jatropha oil brings substantial economic gains to India on a broader scale by reducing the nation’s reliance on fossil fuel imports for diesel production, a primary transportation fuel in the country. This reduction minimizes India’s expenditure of foreign currency reserves on fuel, enabling the country to bolster its reserves for strategic industrial investments and production.

An additional economic advantage stems from the carbon-neutral nature of Jatropha oil. Large-scale production of this biofuel contributes to an improved carbon emissions profile for the country. Unlike other biofuels, such as corn or sugar cane ethanol, or palm oil diesel, Jatropha does not compete with food production. This aspect makes it a politically and morally acceptable choice among India’s current biofuel options. It alleviates concerns about diverting farmland from food production, a critical consideration in a country like India, which sustains a massive population with significant food needs.

Comparing the economics of Jatropha biodiesel production to fossil diesel, the procurement cost of Jatropha seeds emerges as a crucial component. Greenhouse gas (GHG) mitigation perspectives and the potential to earn certified emission reductions (CERs) further underscore the importance of promoting biofuels as a sustainable energy option. However, a notable challenge is the availability of marginal land for Jatropha production. To mitigate the adverse effects of highly volatile crude oil prices on the Indian economy, promoting renewable bio-energy options needs to be integrated with employment opportunities within a comprehensive social framework.

Versatility of Jatropha curcas: A Multifaceted Plant

Hedge castor (jatropha curcas) green leaf
Jatropha curcas green leaf

Jatropha curcas, a highly versatile plant, offers a multitude of applications, making it a prime contender for future biodiesel production. The oil derived from Jatropha curcas finds its main use in the production of biodiesel, effectively powering diesel engines. Beyond biodiesel, the residual cake from oil extraction, rich in protein, can serve as valuable fish or animal feed (following detoxification). Moreover, this plant proves to be an excellent biomass feedstock, utilized for generating electricity in power plants or producing biogas, as well as a high-quality organic fertilizer.

The potential of Jatropha curcas doesn’t stop at biodiesel and biomass. Extracts from this plant hold promise for the development of novel drugs, particularly targeting pain relief and potentially combatting breast, liver, and lung cancers. Furthermore, biomass derived from Jatropha curcas presents a viable solution for water purification, particularly in tackling contamination by heavy metals like Copper and Zinc.

The use of biosorbents derived from waste of Jatropha curcas stands as a viable method for removing heavy metal ions from water, addressing a critical concern of water contamination in various industrial settings. Conventional methods for heavy metal removal often prove effective but can be cost-prohibitive, especially for developing countries and rural areas. Thus, the research focuses on leveraging natural and cost-effective biosorbents, offering an urgent and ecological solution to water pollution challenges.

Interestingly, Jatropha curcas also possesses analgesic properties, acting as a potent painkiller. The plant’s methanolic leaf extract exhibits significant analgesic capabilities, potentially operating through both peripheral and central pain mechanisms. Additionally, the stems find utility in basket-making, while the plant’s extracts serve the purpose of tanning leather and producing a red dye, highlighting the various dimensions of its usability and potential.

National Biodiesel Mission: India’s Quest for Energy Independence

In December 2009, the Indian government launched the National Biodiesel Mission (NBM), designating Jatropha as the prime candidate for biodiesel production to work towards achieving a proposed biodiesel blend of 20% with conventional diesel by 2017. The ambitious target aimed to satisfy 20% of India’s diesel demand through plant-derived fuel, requiring an allocation of 140,000 square kilometers of land.

Currently, fuel-yielding plants occupy a mere fraction, covering less than 5,000 square kilometers. The procurement of biodiesel commenced in 2014, and a pilot program was initiated in August 2015. Jatropha curcas was trialed in six Indian states during the 2000s, focusing on biofuel production and combating soil erosion in rural areas. The government, in collaboration with banks, provided initial financial support.

India holds immense potential for biodiesel production from Jatropha curcas, known as “Jangli arandi” in Hindi and “Kattukkotai” in Tamil, particularly abundant in forests and wastelands. However, due to a severe scarcity of Jatropha seeds, the government’s ambitious plan faced challenges. Consequently, various existing biodiesel plants shifted operations to utilize multiple feedstocks, including used cooking oils, animal fats, and imported crude vegetable oils. Private producers were encouraged to sell biodiesel directly to end-users, provided they adhered to the prescribed Bureau of Indian Standards (BIS) norms.

As of July 1, 2016, public sector Oil Manufacturing Companies (OMCs) in India procured 1.32 crore liters of biodiesel, showcasing progress in biodiesel adoption. Biodiesel production from diverse feedstocks reported 130 million, 135 million, and 140 million liters in the years 2014, 2015, and 2016, respectively. Projections indicated an upward trajectory, reaching an estimated 150 million liters in 2017 and an additional 10 million liters through 2018.

India’s endeavor to promote Jatropha cultivation is a pivotal part of its energy policy, aiming for energy independence by 2018 while reducing reliance on coal and petroleum to meet escalating energy demands. However, the promotion of the bio-fuel policy has faced scrutiny, prompting critical reviews in recent times. Vast expanses of wasteland earmarked for Jatropha cultivation offer a significant employment boost to India’s rural poor and present appealing business prospects.

The Indian government identified 400,000 square kilometers (98 million acres) of land suitable for Jatropha cultivation, envisioning it as a potential replacement for 20% of India’s diesel consumption by 2011. Life-cycle analyses have displayed favorable energy balances for Jatropha-based biodiesel production in India, indicating potential greenhouse gas emission savings of 33-42% compared to fossil-based diesel.

Implementation Efforts for Jatropha Cultivation in India

Jatropha
Jatropha Fence (PC – Author)

The potential of Jatropha as a source for biodiesel production gained significant attention in India, with notable figures like Dr. Abdul Kalam advocating for its cultivation. The Indian government launched the National Biofuel Policy in 2008, aiming to meet about 20% of the country’s diesel demand through biofuels, specifically emphasizing Jatropha-based fuels. To support this, initiatives were put in place to provide loans to farmers for Jatropha cultivation, and public entities like Indian Railways and various states took up projects for its plantation.

Indian Railways, seeking to reduce diesel purchasing costs, initiated Jatropha plantation on semi-arid land near railway stations to generate bio-diesel for its vehicles. Several states like Karnataka, Andhra Pradesh, Tamil Nadu, Rajasthan, and Maharashtra actively promoted Jatropha plantation due to its suitability for arid conditions and low water requirements.

In Karnataka, private companies like Labland Biodiesel have been actively involved in Jatropha research and development, utilizing Jatropha seeds in government buses. Similarly, Andhra Pradesh collaborated with Reliance Industries for Jatropha planting, aiming to cultivate it for high-quality bio-diesel fuel. Tamil Nadu aggressively promoted Jatropha plantation to aid farmers affected by irregular rains, involving several entrepreneurs and abolishing purchase tax on Jatropha. Rajasthan and Maharashtra also embraced Jatropha cultivation due to its water-efficiency and suitability for arid regions.

In Maharashtra, partnerships like Hindustan Petroleum Corporation Limited (HPCL) joining hands with the Maharashtra State Farming Corporation Ltd (MSFCL) for a Jatropha seed-based bio-diesel venture were established. Additionally, Chhattisgarh embarked on an ambitious plan to plant millions of Jatropha saplings, aiming to become a bio-fuel self-reliant state by 2015.

The efforts showcased the government’s commitment to harnessing Jatropha’s potential as a biodiesel source, not only for economic benefits but also for reducing dependence on traditional fossil fuels, setting the stage for sustainable energy practices in the future.

Enhancing Biodiesel Production from Jatropha in India: Challenges and Opportunities

A major hurdle in ramping up biodiesel production in India is the limited availability of Jatropha seeds on a large scale. Despite considerable efforts to promote large-scale cultivation and enhance Jatropha yield through various means, the desired results have not been achieved. Many corporations, petroleum companies, and private entities have collaborated with state governments, aiming to promote Jatropha plantations on government-owned wastelands or through contract farming with small and medium-sized farmers. However, due to challenges such as poor Jatropha seed yield, limited availability of wasteland, and high plantation and maintenance costs, several biodiesel projects have turned unviable.

Trials involving High Yielding Varieties (HYVs) of Jatropha for biodiesel production have not yielded satisfactory results. Consequently, due to the limited availability and volatile prices of biodiesel, the pace of blending has been hindered. Reports indicate that Jatropha occupies only about 0.5 million hectares of low-quality wastelands across the country, with the majority being new plantations of less than three years. Unfortunately, many pilot initiatives have proven to be major failures due to various reasons, including the lack of a market for the product, disputes over buy-back agreements, heavy subsidies, and inadequate farmer ownership.

Furthermore, large-scale cultivation of Jatropha, with its extended gestation period (3–5 years), has been a significant challenge in implementing the biodiesel program. The longer payback period and lack of readily available state support present additional difficulties for farmers. The Jatropha-based biodiesel production program is grappling with obstacles such as slow progress in planting, suboptimal processing and marketing infrastructure, and underdeveloped distribution channels.

In recent years, some stakeholders from both the public and private sectors have been exploring alternative tree-borne oilseeds for biodiesel production. However, the sustainability of these alternatives still requires validation. While favorable government policies and active participation from local communities and private entrepreneurs can sustain the program in the short term, a robust long-term strategy is crucial. The current trajectory is likely insufficient in the long run, given the current feedstock choices, technological status, and policy landscape.

A significant research focus on the development of second and third-generation feedstocks is imperative to meet the country’s future bioenergy needs. The demand for biofuels is shifting towards developing countries, where policies favoring domestic biofuels markets are on the rise. The demand for biodiesel is expected to decline in the US and EU, thereby driving down the demand for vegetable oil as feedstock. Conversely, countries like Brazil, Argentina, and Indonesia will witness an increase in biodiesel demand due to favorable policies.

Considering the biodiesel production potential in India, urgent research efforts by public sector Oil Manufacturing Companies (OMCs) are needed to achieve higher feedstock yields, develop short-duration crops, and enhance Jatropha cultivation through planned varietal improvement programs, particularly in selected areas of the country.

In conclusion, the key policy changes required are a multi-feed feedstock approach, an attractive incentive mechanism at both the feedstock and biodiesel production stages, and substantial research and development to increase feedstock yields. Despite Jatropha’s abundance and use in reclamation and oil production, none of the Jatropha species have been fully domesticated, resulting in variable productivity and an unknown long-term impact on soil quality and the environment.

Notably, Jatropha biodiesel production demands significantly more water than other common biofuel crops, and initial yield estimates may have been overly optimistic. Addressing these challenges and leveraging opportunities is crucial for propelling India’s biodiesel production to greater heights.

Ravi S. Behera
Ravi S. Behera
Mr. Ravi Shankar Behera, PGDAEM, National Institute of Agricultural Extension Management (MANAGE), Hyderabad is an independent freelance Consultant and Author based in Bhubaneswar. He is an Honorary Advisor to grassroots Voluntary Organizations on Food Security, Forest and Environment, Natural Resource Management, Climate Change and Social Development issues. Ravi has lived and worked in various states of India and was associated with international donors and NGOs over the last twenty three years including ActionAid, DanChurchAid, Embassy of Sweden/Sida, Aide et Action, Sightsavers, UNICEF, Agragamee, DAPTA and Practical Action. He has a keen interest in indigenous communities and food policy issues.
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