Internship: Design a PFR Digester

HoSt is currently looking for a insert who can preform a research and design a PFR digester. This will research focus on making a design of a PFR suitable to ferment organic material.

A digester can be seen as a CSTR; an ideally stirred tank. Organic material is added and converted to biogas. Because it is a CSTR and the residence time is relatively long (45 days), the conditions in the tank are stable, which is favourable for the process. However, with a CSTR you have the problem of leaching: if you add fresh material today, some of that fresh material will flow out again immediately, without being converted.

A PFR (Plug Flow Reactor) does not have this problem, which means that in the end a higher conversion of organic material can be achieved compared to a CSTR. However, in a PFR the conditions change continuously as the material slowly flows from start to finish. Also, digestate from the PFR will have to be actively recirculated to the beginning to start the digestion process.

Your profile:

  • Mechanical Engineering / Chemical Engineering;
  • Hbo / wo.

Your tasks:

  • Literature study on the use of a PFR type reactor as a digester;
  • Modelling of the substance flows in a PFR, making an analytical mass balance;
  • Determination of the amount and position of the recirculation flow;
  • Drafting of a PID (process and instrumentation diagram) of a PFR;
  • Drafting of a basic design including components of a pilot scale (100 m3) PFR digester.

What we offer:

  • Monthly fixed fee of €400 based on 40 hours per week;
  • Lots of responsibility and room for own initiatives;
  • Professional support, guidance and insights;
  • An internship in the renewable energy sector;
  • Interesting international environment which is only a 5-minute walk from the ‘Kennispark’ train station in Enschede;
  • Nice welcome package;
  • A dynamic, flexible and passionate team.

About HoSt

The HoSt Group is one of the world market leaders in bioenergy systems and technologies for converting organic residual flows into sustainable energy and raw materials. HoSt stands for working together on high-quality use of residual flows and a zero-waste society in which waste does not exist but is instead used as a reusable raw material. With over 240 employees spread over seven countries, HoSt develops, designs, manufactures, and maintains more than 300 innovative and proven systems since 1991. HoSt contributes to the success of a circular economy, industry, and society by producing renewable energy, solving the waste problem, and creating valuable end products from residual flows.

In addition to its headquarters in the Netherlands, HoSt has offices in the US, France, Latvia, Poland, Germany, and England and more than 300 built projects in more than 30 countries on four continents. For the systems supplied by HoSt, HoSt has 24/7 service and maintenance teams.


Mail your resume and motivation to [email protected]. General questions can be addressed to Mariëtte Huis in `t Veld, internship coordinator. For questions and more details about the internship please contact Gijs Olde Loohuis via +31 (0) 53 – 460 90 80.

Please do not make use of this vacancy as an acquisition opportunity.