For the R&D Biogas engineering department we are looking for interns! The following internships / graduation assignments are available. Apply using the apply button and select the (graduation) internship you are interested in.
Design of a chicken manure to combined bio-methane/L-CO2 plant
Suitable for BSc or MSc in Chemical Engineering / Mechanical Engineering / Sustainable Energy
Chicken manure is an intriguing feedstock for biogas production, presenting both opportunities and challenges. HoSt is currently investigating the feasibility of establishing a standalone chicken manure digester capable of processing 100,000 tons of chicken manure annually.
The process is as following. Chicken manure is fed into a digester where it undergoes anaerobic digestion, producing biogas. The biogas produced contains impurities like H₂S and VOCs, which are removed during the biogas cleaning process. The cleaned biogas is then upgraded to meet network requirements by removing CO₂. The separated CO₂ is liquefied for further use.
Chicken manure has high nitrate and salt concentrations. To address the nitrate issue, a stripper is used. The liquid from this process is recycled back into the digester to help dilute the manure. Despite nitrate reduction, the salt concentration remains high. One potential solution is to use an evaporator. The process involves separating solid materials from the digestate using centrifuges, potentially aided by a coagulant to enhance solid separation.
Several challenges and considerations are for example;
- Salt Concentration: High salt levels require effective dilution strategies. Evaporation -and condensation processes can help, but they must be optimized.
- Evaporator Types and Energy Sources: Different evaporators, using either steam or mechanical vapor recompression, can be employed. The choice depends on the availability of low-temperature heat, ideally sourced from a power plant, to minimize electricity loss in biomass-fired power plants.
- Key factors include the value of the produced biogas and the extent of CO₂ emissions reduction.
The goal is to develop an optimal design that balances cost-efficiency, environmental impact, and operational effectiveness. By addressing the specific challenges posed by chicken manure and leveraging innovative technologies and strategies, we can create a sustainable and economically viable biogas production system.
Your tasks:
- Making mass and energy balances;
- Overview of evaporaties;
- Calculate OPEX, CAPEX and economy;
- Influence of CO2 price and rules on gas price and value of CO2.
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Design of a Straw digester
Suitable for BSc or MSc in Chemical Engineering / Mechanical Engineering / Sustainable Energy
Design of a Straw digester
Straw, with its abundant availability, holds immense potential for biogas production in the EU and globally. In the EU alone, the digestion of straw could yield approximately 90 billion cubic meters of gas annually, which is about 300% of the current total usage. On a global scale, this potential increases nearly tenfold. Despite its potential, straw is notoriously difficult to digest. Based on extensive research conducted at the HoSt laboratory, it has been found that pre-treatment technologies can significantly enhance gas production from straw. However, these pre-treatments also impact the design of the digester itself;
- Process Efficiency: Pre-treatment can enhance the conversion rate of straw to biogas, influencing the overall retention time required in the digester.
- Capital Expenditure (CapEx): The design and complexity of the digester will vary depending on the pre-treatment used, affecting initial investment costs.
- Operational Expenditure (OpEx): The choice of pre-treatment also impacts ongoing operational costs, including energy consumption and maintenance.
Conclusion
Harnessing the potential of straw for biogas production can revolutionize energy supply in the EU and worldwide. By optimizing pre-treatment technologies and digester designs, HoSt aims to create efficient, cost-effective, and environmentally sustainable solutions for biogas production from straw. This endeavour not only promises a significant increase in renewable energy output but also contributes to a substantial reduction in greenhouse gas emissions.
Your tasks:
- Making mass and energy balances;
- Adapting the calculation program of HoSt for pretreatment technology (reaction velocity constant);
- Dimensions of main equipment the Hydrolysis, biogas unit, separator;
- Calculate OPEX, CAPEX and economy;
- Influence of CO2 price and rules on gas price and value of CO2.
