Olive Pomace and Alperujo: Complete Guide on Valorization, Prices and Market Opportunities

Olive pomace and alperujo represent the main by-products of the Spanish olive oil industry, generating approximately 4 million tonnes of material annually that has evolved from being considered a problematic waste to becoming a high-value resource for the circular economy. Spain, as the world's leading olive oil producer with approximately 50% of global production and a forecast of 1.26 million tonnes in the 2024/25 season, faces both the challenge and opportunity of efficiently managing these by-products generated during the campaign months between October and March.

The technological transformation of the olive oil sector, especially the widespread adoption of two-phase extraction systems in over 90% of Spanish olive mills, has significantly modified the characteristics and volume of alperujo generated. This material, rich in organic matter, residual oil and bioactive compounds, offers multiple valorization pathways ranging from energy production through biomass and biogas, to olive pomace oil extraction, composting for agricultural use, and obtaining high-value compounds such as polyphenols and antioxidants. The alperujo market shows marked seasonality, with significant price variations depending on fat content, moisture, geographical location and energy demand, making it a key element for the economic sustainability of olive mills and valorization companies.

Technical differences between three-phase pomace and two-phase alperujo

The olive oil extraction system fundamentally determines the characteristics of the resulting by-product. In the traditional three-phase system, used until the 1990s, three separate products were obtained: olive oil, solid pomace with low moisture (30-40%) and alpechin as liquid effluent. This system, although generating more manageable pomace due to its lower water content, required large quantities of process water and produced highly polluting alpechin that had to be managed in specific ponds.

The two-phase system, massively adopted in Spain since the late 1990s, uses a maximum of 10% water relative to the olive input and generates only two fractions: olive oil and alperujo. The latter presents very different characteristics from traditional pomace, with a moisture content of 60-70%, generating approximately 80 kg of alperujo per 100 kg of processed olives. Its fat content ranges between 1.9-2.5% in residual oil, although this figure can vary significantly depending on the extraction efficiency of the mill. The composition of alperujo includes remains of skin, pulp and olive pit mixed with vegetation waters, resulting in a semi-solid material with high content in organic matter (approximately 91%) and acidic pH.

Production and generation of alperujo in Spain

Spain generates annually between 3.5 and 4 million tonnes of alperujo, a figure directly related to olive oil production. Considering that between 4 and 5.78 kg of alperujo are produced per liter of olive oil, the 2024/25 campaign with an estimated production of 1.26 million tonnes of oil will generate a considerable volume of this by-product. Andalusia concentrates more than 80% of national production, followed by Castilla-La Mancha and Extremadura, making these regions primary hubs for the development of valorization infrastructure.

Seasonality is a fundamental characteristic of alperujo. The olive oil campaign is concentrated between October and March, with production peaks between November and January, generating significant logistical challenges for olive mills that must manage large volumes in short periods. This temporal concentration directly influences prices, transport availability and the capacity of valorization plants to process the material. Outside the campaign, some extraction plants work with stored alperujo or imported from other producing countries to maintain their activity throughout the year.

Alperujo pricing: determining factors and market ranges

The alperujo market in Spain has experienced significant changes in recent years, evolving from a model where extraction plants purchased the material to situations where they charge a fee for its collection. Alperujo prices depend on multiple interrelated factors that make this market particularly complex and variable.

Fat content is the most determining factor in price. Alperujo with a higher percentage of residual oil is more attractive to extraction plants, allowing better profitability in olive pomace oil production. Typical values range between 1.5% and 3% on wet matter, although they can reach higher levels depending on the mill's efficiency and type of olive processed. Moisture represents the second critical factor: alperujo with moisture above 70% requires greater energy investment for drying and processing, reducing its commercial value. Mills that perform second centrifugation or reprocessing of alperujo obtain a more de-stoned material but with lower fat content.

Geographical location significantly influences commercial conditions. In areas with high concentration of olive mills but scarce valorization plants, such as in some districts of Jaén or Córdoba, alperujo may have negative value, meaning mills must pay for its removal. Conversely, in areas with higher energy demand or proximity to biomass plants, the material can reach positive values. Transport costs are determining factors, especially considering that alperujo contains 60-70% water, making transport economically unviable over long distances exceeding 100-150 km.

During the 2024 campaign, the market situation has shown great heterogeneity. While some large extraction plants have established variable collection fees between 5 and 15 euros per tonne charged to mills, other biomass and biogas facilities offer to purchase the material, especially if it presents favorable characteristics. Orujillo (de-stoned and dried alperujo after passing through the extraction plant), used as biofuel, is traded in ranges of 40 to 80 euros per tonne depending on its calorific value and residual moisture, being comparable in price with other biomass fuels such as pellets or almond shells.

Main applications and valorization chain

Olive pomace oil extraction

The main valorization pathway for alperujo is its processing in extraction plants or pomace industries to obtain olive pomace oil. These industrial plants receive fresh alperujo from olive mills and through drying, de-stoning and extraction processes with authorized solvents, obtain the residual oil that is subsequently refined for human consumption. This process additionally generates two highly valuable by-products: olive pit, used as high-quality biofuel, and exhausted orujillo. Spanish extraction plants process millions of tonnes of alperujo annually, representing an industrial sector that generates stable employment throughout the year, unlike the seasonality of olive mills.

Energy biomass and cogeneration

The energy use of alperujo through direct combustion or cogeneration has traditionally been an important valorization pathway. The calorific value of dried alperujo is around 4,000-4,500 kcal/kg, although its high moisture requires prior drying that consumes part of the obtainable energy. Separated olive pit presents higher values, reaching 4,500-5,000 kcal/kg with moisture below 10%. Numerous industrial facilities, especially in the ceramic, food and drying sectors, have incorporated biomass boilers that use orujillo as primary fuel, contributing to industrial decarbonization and reducing dependence on fossil fuels.

Biogas and biomethane production

Anaerobic digestion of alperujo to produce biogas and biomethane represents one of the most promising and growing applications. Although alperujo presents certain technical challenges due to its lignocellulosic nature and content of phenolic compounds that can inhibit microbiological processes, co-digestion with other organic substrates allows optimizing methane production. Recent projects in Andalusia have demonstrated the technical and economic viability of these facilities, which can process between 100,000 and 250,000 tonnes annually of alperujo, generating biomethane injectable to the gas grid or usable as transport fuel. These plants also contribute to the circular economy by generating digestate usable as fertilizer.

Composting and agricultural use

Alperujo presents appropriate characteristics for composting processes, although it requires mixing with other structuring materials and nitrogen sources to balance the C/N ratio. Various experiences in olive oil cooperatives have developed composting plants that process alperujo mixed with olive pruning remains, manure and other organic wastes, obtaining quality compost for agricultural use. The composting process requires approximately 20-30 weeks and investment in turning and temperature control infrastructure, but allows closing the cycle by returning to the field in the form of organic fertilizer the nutrients extracted during harvest. The resulting compost presents high content in potassium and organic matter, being especially valued in organic farming.

Extraction of bioactive compounds

Alperujo contains significant amounts of polyphenols, antioxidants and other bioactive compounds of high value for pharmaceutical, cosmetic and nutritional supplement industries. Hydroxytyrosol, one of the most potent antioxidants known, is found in significant concentrations in alperujo and can be extracted using advanced technologies. Although this valorization pathway requires significant investments in specialized equipment and purification processes, it offers the highest profitability margins per kilogram of processed alperujo. Some plants integrate the extraction of bioactive compounds with other valorization pathways in biorefinery schemes that maximize the utilization of the material.

Animal feed and other applications

The use of alperujo in animal feed is limited by its content of phenolic compounds that can be antinutritional, especially for monogastrics. However, after adequate drying and mixing processes with other ingredients, it can be incorporated in small proportions in rations for ruminants, although European regulations establish specific restrictions. Emerging applications include the production of bioplastics, obtaining industrial enzymes, developing natural colorants and producing second-generation advanced biofuels, although these pathways are mostly in research or pilot development phase.

Logistics and commercialization models

Logistical management of alperujo represents one of the main operational challenges during the olive oil campaign. Olive mills must daily evacuate large volumes of high-moisture material that cannot be stored for long periods without generating fermentation problems, leachates and bad odors. Commercialization models vary significantly depending on the region and size of the facilities.

Large cooperatives and groupings of olive mills usually establish annual contracts with extraction plants or valorization facilities that guarantee the removal of alperujo throughout the campaign under predetermined conditions. These agreements specify minimum material characteristics (fat content, maximum moisture), delivery conditions and applicable price or fee. Smaller olive mills may sell directly to local plants, although they frequently obtain less favorable conditions by not having volume negotiation capacity. The role of intermediaries that aggregate alperujo from multiple small mills to negotiate better conditions with valorization plants has gained importance in recent years.

Transport of alperujo, carried out mainly by tipper or dump trucks, represents a significant cost that can range between 0.03 and 0.08 euros per kilogram-kilometer depending on distances and volumes. Considering that more than 60% of the weight is water, optimizing collection routes and minimizing distances is fundamental for economic viability. Some olive mills make investments in pressing or additional centrifugation systems to reduce moisture before transport, although this implies lower fat content in the resulting material.

Regulatory framework and classification as by-product

Alperujo has experienced an important evolution in its legal consideration, transitioning from being considered waste to obtaining classification as a by-product when destined for specific uses. Order TED/92/2022, of February 8, establishes that fatty pomaces from olive mills destined for the extraction of crude olive pomace oil have by-product consideration meeting the requirements established in Law 7/2022, on waste and contaminated soils for a circular economy.

This classification implies that the material is not subject to waste regulations when destined for authorized valorization, simplifying administrative procedures and favoring the circular economy. However, olive mills must maintain chronological records of the quantities produced, destinations and characteristics of the generated alperujo. When alperujo is destined for uses such as composting, biogas production or direct soil application, additional requirements established in specific regional regulations must be met, such as Andalusia's Decree 4/2011 which regulates the use of olive mill effluents as fertilizer.

In the field of animal feed, alperujo is subject to the regulations on animal by-products not intended for human consumption, establishing strict limits and conditions for its use. Public aid for alperujo valorization infrastructure, such as those established within the framework of the Andalusia Rural Development Programme 2014-2022 with allocations exceeding 13 million euros, requires beneficiary companies to have participation of at least 30% of alperujo-producing entities in their share capital, thus promoting vertical integration of the sector.

Innovation and success stories in alperujo valorization

The Spanish olive oil sector has developed multiple innovative initiatives demonstrating the potential of alperujo in circular economy models. Comprehensive valorization plants process over 100,000 tonnes annually of alperujo through biorefinery schemes that combine oil extraction, pit separation for biomass, obtaining hydroxytyrosol and other polyphenols, and fertilizer production, maximizing the extractable value from each processed tonne and achieving the "zero waste" objective.

Biogas and biomethane projects in different regions have demonstrated capacity to process 40% of regionally generated alperujo, with investments exceeding 300 million euros that will produce over 1 TWh of biomethane annually, equivalent to the consumption of 200,000 households. These facilities use advanced technologies that increase biogas production potential by 20% through optimized alperujo pretreatments. Integration with other industries, such as green methanol production, renewable hydrogen and sustainable aviation fuels from captured biogenic CO2, represents the frontier of advanced valorization.

In the field of composting, experiences developed by olive mill groupings have established pilot plants that process thousands of tonnes of alperujo mixed with pruning remains and olive grove biomass, generating certified compost as organic amendment that is commercialized or distributed among member farmers, closing the production cycle. These projects have demonstrated technical viability and agronomic acceptance, although they require investment in infrastructure and process maturation period.

Challenges and future perspectives of the sector

Despite advances in valorization, the sector faces important structural challenges. The economic viability of traditional extraction plants is compromised when processing alperujo with fat content below 1.6% and moisture above 70%, especially after the progressive elimination of electricity cogeneration bonuses that supported part of the business model. This has led to situations where some plants have reduced activity or established collection fees that penalize olive mills.

The concentrated seasonality over 5-6 months generates production peaks that saturate the installed valorization capacity, especially in provinces like Jaén where production is concentrated. Developing safe alperujo storage capacities or establishing staggered collection calendars represents a need to optimize the operation of valorization plants that require continuous feeding throughout the year to make investments profitable.

Future perspectives of the sector point toward greater diversification of valorization pathways and development of biorefinery models that extract multiple high-value products before dedicating the remaining material to energy uses. Production of advanced biofuels, bioplastics, functional ingredients for food and cosmetics, and platform molecules for the chemical industry represent opportunities that will require investment in R&D and industrial scaling. Regulatory support through incentives for the circular economy, financing of innovative projects and administrative simplification for new valorization pathways will be determining for sector development.

Conclusions and commercial opportunities

Alperujo has definitively transitioned from being considered a problematic waste to being recognized as a valuable resource with multiple utilization pathways that contribute to the sustainability and profitability of the Spanish olive oil sector. The 4 million tonnes generated annually represent considerable energy, nutritional and chemical potential that the sector is learning to valorize through increasingly efficient and sustainable technologies.

For olive mills, optimizing the characteristics of generated alperujo through adjustments in extraction processes, second centrifugation or moisture reduction can transform a management cost into a complementary income source. Establishing stable commercial relationships with valorization plants through multi-year contracts provides operational security during the campaign. For valorization companies, diversification of products extracted from alperujo, from pomace oil to bioactive compounds and advanced biofuels, allows increasing margins and reducing dependence on energy bonuses.

The energy sector finds in alperujo and its derivatives (orujillo, olive pit, biogas) renewable energy sources that contribute to decarbonization objectives and industrial self-consumption. The agricultural sector can close cycles through the use of alperujo compost, reducing dependence on synthetic fertilizers and improving the health of olive grove soils. In this context, digital platforms specialized in the commercialization of agricultural by-products such as Biomket facilitate efficient connection between alperujo generators during the olive oil campaign and valorization companies with processing capacity, optimizing logistics, commercial conditions and contributing to the development of a true circular economy in the Spanish olive oil sector.