BDI technology successfully helps in the modernisation of an existing plant

ENVIEN Group is one of the largest firms involved in the production of biofuels in the CEE countries and it also plays a vital role in the agricultural sector. The company has been investing in next-generation technology and has been operating an innovative BDI RepCAT process plant since the beginning of this year. ENVIEN purchased a running biodiesel plant in Hungary and two weak points within the plant soon became evident. Firstly, the feedstock flexibility was limited to used cooking oil only. Customers’ requests for additional supplies of biodiesel could not be met because of the extremely poor quality of waste oils and fats with a high FFA content. Additionally, there was no by-product line installed to process the glycerin phase from the transesterification line. G-phase and soapy water had to be disposed of resulting in valuable glycerin as well as methanol and fatty acids being lost. Consequently, there was room for improvement as well as increased profitability at the plant.

New partnership

A competent partner was sought for the construction of an additional new production line with overlapping glycerin processing. The aim was to utilise the latest technology in order to prepare the facility for the future and to recycle the maximum possible from the G-phase. BDI was invited to take on the project and it started work according to its eight- step retrofit programme. The initial technical discussions with BDI’s experts included an evaluation of the plant as well as lab tests and technical meetings.

The conclusion was that the modernisation of the existing plant would not be an efficient and goal-oriented solution. The result of this preengineering phase was the construction of a new multi- feedstock biodiesel plant with BDI’s RepCAT technology. This technology allows the catalyst to be reused within the process, significantly reducing operating costs. Another very notable benefit is that the technology for operating high-risk fats has been approved in Europe. Since the RepCAT process does not require a separate glycerin line, the final concept included a separate new G-phase processing unit for the existing line. The aim of the G-phase unit is to produce 80% glycerin at the same time as recycling the methanol and soap liquor contained in the G-phase. In addition, the soaps contained in both streams are split and reused as feedstock in the new RepCAT process. For this reason, RepCAT was chosen for the new process line – it allows the processing of feedstock with unlimited FFA content. Technology The concept of BDI’s G-phase unit is based on the separate processing of G-phase and soapy water in order to obtain the necessary process flexibility in both streams. The G-phase is heated up and continuously neutralised with acid to gain a neutral pH. This stream feeds the first de-methanolisation column, where methanol is distilled to high purity. The recycled methanol that is obtained is then reused in the existing biodiesel plant.

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The de-methanolised glycerine phase is further acidulated in a continuous mixing vessel in order to split all soaps. Salt formation is avoided by applying special process conditions. After acidulation, two phases are formed, which are separated into a FFA-phase and a glycerine phase. The glycerine phase is neutralised and dried in a dewatering column, resulting in a minimum concentration of 80%. Soapy water is also heated up before it enters a de- methanolising column. The distilled recycled methanol is buffered in the recycled-methanol buffer tank. The de-methanolised water is pumped into an existing storage tank for disposal. Project schedule After the delivery of comprehensive permission data and acquisition of the relevant approvals, the project kicked off in early 2020. Managing and executing this type of project during the pandemic required special measures. In addition to the sudden relocation of engineers to work from home along with the establishment of new ways of collaboration, the management of suppliers in particular required the utmost attention. It is unquestionable that proper and tight supplier management was the key to avoiding project delays under such unfavourable conditions. During the construction and commissioning of the G-phase unit, special focus was placed on training the operating personnel on site. Consequently, the acceptance test was successfully carried out in mid-2021.

BDI RetroFit programme – eight important steps to ensure project success Every biodiesel plant is unique.

Standardised solutions for improving individual parameters such as yield, product quality or feedstock flexibility are therefore not effective. To achieve optimum results, it is necessary to develop an individual overall concept for each plant and to implement the most suitable technical solutions. The range of services offered by the BDI RetroFit programme includes all necessary steps for a successful plant optimisation.

Status evaluation
Determination of customer requirements
On-site expert evaluation of the existing plant
Preparation of preliminary concepts including first cost estimates

Pre-engineering
Preparation of concepts, including planning of layout and integration in the existing process
Feasibility study based on mass and energy balances

Proposal preparation
Definition of scope of supply
Project and implementation plan
Binding offer with detailed cost structure

Authorisation procedure
Preparation of data required by the authorities
Assistance throughout the authorisation process
Preparation of risk analyses (e.g., HAZOP studies)

Engineering and delivery
Basic and detailed engineering
Supplier management
Efficient project management for shorter project times

Implementation
Technical on-site support during mechanical installation
Shortest possible downtimes achieved by efficient planning during installation phase

Commissioning
Functional plant testing and start-up
Optimisation of plant parameters and stabilisation of processes
Sustainable realization of guaranteed values
Training of plant personnel; Plant handover

Customer Service
Regular maintenance support
Spare part supply and service
24-hour technical service hotline
Further training and workshops.

With this eight-step retrofit programme, BDI forms the missing link between biodiesel plants that have been in operation for many years (regardless of whether they have been operated with BDI or third-party technology) and state-of-the-art technologies. By implementing this programme, companies can optimise existing plants according to their customers’ needs. The addition and modernisation of certain essential process steps leads to an increase in feedstock flexibility, an increase in plant capacity, a minimization of energy and operating-material consumption and a consistently high quality of fuel produced.