CASE STUDY
Innovative wastewater treatment at gunvor biofuel huelva
As water resources become scarcer and the value of recycling wastewater grows, there is a pressing need for effective wastewater treatment technologies. This case study explores the adoption of an Anaerobic Membrane Bioreactor (AnMBR) system at Gunvor Biofuel Huelva (GBH), highlighting its sustainability benefits and contribution to a circular economy.
Conventional wastewater treatment technologies often fall short due to their energy-intensive nature and operational complexities. The AnMBR offers a promising solution, by combining anaerobic bioreactors with membrane filtration. This integration allows for separate control over hydraulic and solid retention times, enhancing the system’s efficiency in handling higher organic loads and biomass concentrations.
The AnMBR technology outperforms traditional systems by addressing the limitations posed by fats, oils, grease (FOG), suspended solids (TSS), and salinity. Key benefits include
To align with environmental regulations and enhance wastewater quality for discharge, Gunvor Biofuel Huelva (GBH) implemented the AnMBR technology. This system not only ensures the discharge quality but also maximizes renewable energy production through biogas, contributing to the plant’s sustainability goals. The process integrates biothane anaerobic biological treatment with ultrafiltration membranes, resulting in a compact, efficient, and low-energy anaerobic treatment system that converts wastewater into biogas. This biogas, a mix of methane and carbon dioxide, can be utilized as a renewable energy source, potentially making the plant energy neutral or even a renewable energy producer.
Wastewater streams originating from various processes such as glycerine purification, biodiesel cleaning and drying are initially filtered through a coarse sieve before being gathered in a homogenization tank. This tank is engineered to mitigate fluctuations in both flow and concentration, and it has ample capacity to allow for the necessary residence time needed for preacidification, which aids the degradation process in the subsequent anaerobic reactor. A soda dosing system is also implemented to control preacidification.
To safeguard downstream pumping equipment and membranes from blockages, fine screening and a specialized pumping tank equipped with pumping machinery are positioned before the anaerobic reactor’s entrance.
Following these preparatory stages, the wastewater is directed to the AnMBR, where anaerobic biological conversion transforms the organic content into methane, carbon dioxide, and a minimal amount of biomass, which remains suspended through agitation. Biomass is periodically removed from the reactor to a sludge processing system, which includes a polyelectrolyte treatment followed by centrifugal dewatering. The processed sludge is then recycled to the beginning of the treatment
process, while the excess is stored in a designated tank. There is a permeate line that sends all the water removed from the anaerobic reactor to an ultrafiltration membrane and then to the existing aerobic wastewater treatment plant. Biogas generated during this process is captured at a slight overpressure in the reactor’s head zone and purified of water and particulates before storage in a gasometer. This gas then undergoes desulfurization in a chemical scrubber before it can be used.
Implementing this project at the Gunvor Biofuel Huelva facility aims to strengthen the circular economy through the generation of renewable biogas, which in turn helps reduce the worldwide CO2 footprint by cutting down dependency on fossil fuels. Adhering to regional regulations and taking advantage of incentives, this initiative allows the conversion of biogas into biomethane, which can then be supplied to the gas grid, demonstrating a dedication to producing sustainable energy.
Water consumption
Gunvor’s operational sites are significant water users, integral to various aspects of their production processes. The utilization of fresh water is essential in several stages of their operations, such as feedstock pretreatment, steam generation, and the cooling of processed refinery products.
In 2023, Gunvor’s total water consumption across its operations was 1.51 million cubic meters, a reduction from the 1.85 million cubic meters recorded in 2022. This decrease in water usage was primarily due to the closure of Gunvor Petroleum Antwerp and a scheduled maintenance turnaround at Ingolstadt refinery (GRI).
Biodiversity and ecosystems
Consideration of biodiversity and ecosystems in strategy and business
As a trading company with limited operational activities, Gunvor has no significant direct impact on biodiversity or ecosystems. However, consideration of such aspects in the value chain as Gunvor buys raw materials like gas, liquid fuels or metals, which are produced by other actors, perhaps also in regions where protection of biodiversity or ecosystems could be relevant. In order to meet the future CSRD requirements, Gunvor will assess these aspects in a resilience analysis. The outcome will be used to determine whether changes in the strategy and business model are required and what the transition plan should be in such cases. This work is planned for 2025.
List of operational sites
The following table provides a list of our operational sites, where Gunvor has operational control. The table includes information on local biodiversity sensitive areas and the potential impacts.
This is based on a preliminary assessment, as explained in the next section.
According to our preliminary assessment, the emissions from the production sites do not have a significant negative affect on the biodiversity and, to our knowledge do not affect threatened species.
See the illustration to get an impression of the distance between one of our sites (Gunvor Energy Rotterdam) relative to the nearest biodiversity preservation area (Natura 2000).
Identification of biodiversity impacts, risks, opportunities
In order to meet the future CSRD requirements, Gunvor will describe and execute a process to identify impacts, risks, dependencies and opportunities in relation to biodiversity and ecosystems. This work is planned for 2024-2025.
Biodiversity protection actions and resources
The sites in Rotterdam and Ingolstadt are large and many species make use of these sites as nesting or feeding place. We facilitate this as much as practically possible.
