Funded project – Innovative almond waste digestion systems for nutritional fertilizer production
This project conducted pilot trials using a modular digestion vessel to transform almond waste into nutritional fertiliser. Greenhouse crops, such as wheat and tomatoes were part of various fertiliser recipes testing. The goal was to establish the scale-up efficacy of this system and to evaluate the commercial feasibility of the nutrient-rich fertiliser.
Background
Select Harvests is one of Australia's largest almond growers, packers, and processors. They face a significant waste issue due to the almond hull and shelling process, with approximately 65% of the delivered field weight becoming waste.
Addressing the fire risk associated with managing almond hull waste and exploring more beneficial waste recovery methods were crucial priorities for Select Harvests. Given the strong capabilities of the organisation and the expertise within its robust team, Select Harvests was well-positioned to tackle this challenge and identify innovative solutions.
Select Harvests has demonstrated their success by implementing a world-class biomass power station, which stands as the only one of its kind worldwide, effectively utilising almond hull and shell as fuel. Furthermore, their commitment to sustainability is evident through the establishment of a state-of-the-art composting facility that operates on a closed-loop process, incorporating the biomass ash, hull, and shell.
Leveraging their expertise and proven track record, Select Harvests is dedicated to pursuing innovative solutions and continually advancing their sustainability initiatives.
Objectives
- Validate the effectiveness of urea digestive systems in upcycling almond waste products to produce nutrient-rich organic fertilisers at a larger scale.
- Conduct pilot studies to assess the commercial viability and scale-up requirements for digesting almond waste nutrients into organic fertilisers suitable for broad acre, horticultural, and other applications in Victoria.
- Develop a new commercial product that enhances the lifespan and worth of almond waste in Victoria, generating economic, environmental, and social benefits.
Process
Select Harvests initiated the process by acquiring the necessary equipment for installation and commissioning at the site.
Pilot plan design and engineering
- Collaborating with external consultants, conducting trials and develop a comprehensive flow sheet for the process. The design included key components such as a vertical agitator, mono-pump, and filter press.
- To ensure the protection of intellectual property, the process went through several phases, including reviews and the collection of additional data prior to proceeding to the filing phase. The unique nature of both the process and product made them eligible for consideration as novel inventions.
During the initial trial phase, Select Harvests undertook the following steps
- Conducting small-scale trials using various chemicals to evaluate the outcomes.
- Based on the results, Select Harvests identified a process incorporating urea as the optimal choice due to the composition of the final product.
The lab-based trial process involved the following key steps
- Conducting experiments to evaluate the impact of modifying the product sizing on the final extraction, allowed Select Harvests to determine the optimal size that would yield the desired results.
- Performing agitation of the product to assess the extraction and reaction rates. Through careful observation, Select Harvests sucessfully determined the ideal level of agitation that maximised the extraction efficiency.
- Adjusting the process timing to determine the most effective duration for achieving the desired outcomes. By combining variables Select harvest identified that a smaller product size, combined with optimal agitation, resulted in the best extraction efficiency within a shorter period of time.
The final phase focused on product assessment and marketing
- External stakeholders, including experts and industry partners, conducted glasshouse trials to assess and validate the effectiveness of the products. These trials provided concrete evidence of the product's efficacy in real-world conditions, further supporting its value.
- Select Harvest undertook a comprehensive marketing assessment to evaluate the market potential for their products. The assessment confirmed that there is a substantial and well-established market demand for their products, indicating a promising opportunity for its successful commercialisation.
Challenges
Equipment delivery
- During the construction and commissioning phases, Select Harvests encountered challenges related to equipment performance. As a result, they decided to replace the mono-pump with a diaphragm pump, which ultimately facilitated steady operation of the plant.
- Overseas delivery delays disrupted the project's timeline, requiring adjustments to accommodate late equipment arrival.
- Refinement of other deliverables and advancement of non-dependent project components mitigated the impact of equipment delay.
- Select Harvest extended the project time frames due to equipment delivery delays, necessitating schedule adjustments.
- Lessons learned emphasised on the need for improved equipment supplier selection and consideration of location to mitigate delivery risks in future projects.
- COVID-19 and other external risks partially contributed to the equipment delivery challenges, highlighting the potential for similar delays in the future.
Equipment selection
- Dual-purpose circulating pump: The selected pump served both circulation and filtration functions, leading to pump blockages.
- Limited consultation with suppliers: The Original Equipment Manager (OEM) completed the pump selection was solely, without seeking advice from other suppliers, potentially contributing to the inadequate selection.
- To address future challenges, the team will explore multiple designs and request quotations from various suppliers. Providing options for comparison, if suppliers recommend different equipment, further investigation will be conducted to understand their reasons.
Insights
Through rigorous product assessments and market evaluations, Select Harvests gained valuable insights into the product's performance and market potential. These findings reinforced their confidence in the product's viability and ability to meet customer needs.
The results led to the successful development of a highly scalable process that generates valuable fertiliser outputs, establishing an environmentally sustainable circular economy for almond hull and shell. The final report encompasses the entire project journey, including research and development, product assessment and marketing, lab-based trials, design and engineering, IP protection, and plant commissioning and operation.
Select Harvest acquired valuable insights during the project, particularly regarding supplier relations and equipment selection. For businesses undertaking similar endeavours, it is crucial to thoroughly evaluate and select the appropriate equipment. Additionally, patience and perseverance are essential when venturing into uncharted territory, as unique projects often involve significant learning curves. Thus, maintaining patience and persisting in the face of challenges are key to achieving success.
Outcomes
- In partnership with the Almond Board of Australia, Select Harvests organized an onsite event to showcase several important circular economy initiatives. The event attracted 44 attendees, and 17 individuals took part in the site tour.
- Interviews conducted on-site, featuring the Almond Board of Australia, helped raise awareness of the project and its initiatives to a larger audience.
- Optimisation of recipes to maximise the value extracted from the product.
- Construction, installation, and successful commissioning of a plant, marking a ground-breaking achievement for Select Harvests Engineering Coordinator and the organisation.
- Mitigation of hull management risks through the implementation of an alternative reuse project.
- Demonstration of the effectiveness of the product through glasshouse trials.
Impact
A media shoot featured Select Harvests and the Almond Board of Australia, highlighting their sustainability efforts, including the hull digestion project.
Visits and tours by representatives from the California Almond Board demonstrated an interest in the technology and solutions implemented by Select Harvests.
What’s next?
Looking ahead, the team aims to convert 10,000 tonnes per annum (tpa) or more of waste into a valuable organic fertiliser that enhances performance and reduces soil mobility. There is a compelling case for commercialisation to utilise this fertiliser within the Select Harvests facility to increase local production.
Select Harvests is actively collaborating with external partners to identify potential opportunities for expanding the supply of the product and further optimising the recipes. The plan is to produce a significant quantity of the product to gather additional data on its agronomy performance. Once a stable production is achieved, Select Harvests intends to incorporate the product on a wide scale in their orchards.
Furthermore, Select Harvests aims to explore the possibility of supplying the product to a prominent waste recycler in Australia for trial purposes, both in liquid and solid form. The goal is to establish a strong market presence that can support the scaling of this innovative process, thereby creating a new business avenue for Select Harvests.
From the grantee
“The grant from Sustainability Victoria has enabled us to fast track a scaled-up process of a novel and innovative design and understand the benefits that can be achieved through waste recycling. The funding helped us produce a valuable fertilizer product to use in our orchards and we were able to accomplish this project earlier than it would have otherwise been."
More information
Learn more about Select Harvests