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Biochar and biocarbons from biorefined grass clover pulp for feed and technical applications

Applications are invited for a PhD fellowship/scholarship at Graduate School of Technical Sciences, Aarhus University, Denmark, within the Animal Science/Process Engineering programme. The position is available from 1 November 2020 or later.

Biochar and biocarbons from biorefined grass clover pulp for feed and technical applications

Research area and project description:

Protein production from grasses and clover, otherwise known as ‘green protein’, is an emerging process undergoing commercialisation to make protein feed for monogastric livestock and humans alike. During protein production, a large fibre fraction, with high moisture content, remains that requires valorisation. Current applications include anaerobic digestion or silage for use as animal feed. This PhD proposes that this fibre fraction can be processed to supply process heat demand while producing a high value biochar/biocarbon. This biocarbon then will be developed as a toxin binder in animal feed. The use of biocarbon in feeds can bring about anti-inflammatory, antioedematous, antibacterial and antiviral effects on animals has gained increasing importance, particularly after the ban on antibiotic use in feeds as growth promoters within the EU.

Under convectional pyrolysis, high moisture grass fibre would not be considered an ‘ideal’ feedstock and as a result, only few studies are available on the topic. Nevertheless, the requirement for high temperature steam in the initial protein extraction process changes the process economies. In the research, high moisture grass fibre will undergo two stage combined steam drying and pyrolysis. In this process, the grass fibre will be evaporated under superheated steam. The dried grass fibre will then enter a rotary pyrolysis kiln where it will be heated in an inert atmosphere (most likely between 500 and 900 ºC), where it will undergo thermal decomposition yielding flammable volatiles and solid carbon (biochar/biocarbon). The volatile fraction is then combusted, heating the reactor and raising superheated steam. The superheated steam then dries the incoming grass fibre, with the energy within the superheated steam used to evaporate the moisture within the incoming feedstock, generating more steam. This resultant steam will then be used as the steam source for the grass protein extraction.

The aim of this proposal is to develop this pyrolysis process to (i) autothermally supply the heat demand for the grass protein process, and (ii) optimise the resultant biocarbon for use as a toxin binder in animal feed.

Experimental work
The project will centre on the incorporation of a demonstration scale unit into the Green Protein demonstration facility at Aarhus University Foulum. Experiments will therefore be undertaken at different scales from bench to demonstration scale. Initial work will be at bench scale and consist of a series of batch scale experiments with grass pulps different biochemical compositions, differing moisture contents and different pyrolysis temperature and retention times. The findings will be used to determine how reaction parameters influence the energy yields within the volatile fraction and the physical characteristics of the char. These initial findings will act as a parameter screening identifying required conditions for extrapolation to the demonstration plant.

To test biocarbon for use as a toxin binder the applicant will characterise existing feed additives to best understand their physical and chemical characteristics and enable comparison with above tests. In addition, the biocarbons produced under the different conditions will be tested for toxin binding properties including mycotoxins as zearalenone and ricin as a model for the toxin, verotoxin, produced by certain E-coli strains. The biochar will be tested for its mineral binding properties, as well as binding capacity for the fat soluble vitamins A (retinol), E (alfa-tocopherol) and certain carotenoids and compared to commercially available feed additives.

The PhD student will be part of a cross-departmental research team working in multi-disciplinary areas. This will include working with a number of different people with different backgrounds, including animal scientists, analytical chemists, chemical engineers and mechanical engineers from both academia and industry.

Qualifications and specific competences:
Applicants must have a relevant Master’s Degree within Biology, Engineering or Animal science.

Place of employment and place of work:
The place of employment is Aarhus University, and the place of work is Research Centre Foulum.

Applicants seeking further information are invited to contact:

Main supervisor: Professor Søren Krogh Jensen, Aarhus University, Dept. of Animal Science, e-mail: skj@anis.au.dk, tel.: +45 87158076.

Co-supervisor: Assistant professor Morten Ambye-Jensen, Aarhus University, Dept. of Engineering, e-mail: maj@eng.au.dk

Co-supervisor: Postdoc Aidan Mark Smith, Aarhus University, Dept. of Engineering, e-mail: aidan.smith@eng.au.dk

Application procedures

Before you apply

Information and attachments:

Please be aware that you must have all relevant appendices, attachments, addresses for referees, etc. ready when you apply, as the entire application must be uploaded to the system in one go.

Documentation of language skills:

The English language requirement at the graduate school is comparable to an “English B level” in the Danish upper secondary school (“gymnasium”).

English language qualifications comparable to an “English B level” are documented by one of the following tests:

  • TOEFL test (internet-based), minimum score: 83. The graduate school does not accept the paper-based test, nor the TOEFL ITP test. Remember to ask the test center to send your test results to Aarhus University in order to enable verification of your test results. Aarhus University’s TOEFL code is 8935.
    Currently, the TOEFL iBT Special Home Edition test (available in selected areas) will also be accepted.
  • IELTS (academic) test, minimum average score: 7.0 points
    Please note, from 1 June 2020 the Graduate School of Science and Technology has split in two following the split of the faculty. For the two new schools, Graduate School of Natural Sciences and Graduate School of Technical Sciences, the minimum average score requirement for an IELTS test is 7.0 points (equivalent of a C1 level).
  • Cambridge English Language Assessment:
    Cambridge Certificate of Proficiency (CPE)
    Cambridge English: Certificate of Advanced English with grade A,B or C (CAE)
    Cambridge English: First Certificate with grade A (FCE)

When to take the test and how to upload the documentation:
The test result must not be more than two years old at the time of application.

The English language test should be taken before applying for admission and uploaded under “language skills documentation” in the online application form.

It is possible to apply for admission before you have taken the test. In this case documentation stating that you have signed up for a test (please state expected submission date) must be uploaded. If the test result is not part of the original application the test result is to be sent to gsts@psys.au.dk no later than one month after the application deadline.

The following applicants are exempted from documenting their English qualifications/taking a test:

  • Applicants with citizenship from the following countries: Australia, Canada, Ireland, New Zealand, the United Kingdom, the United States, or one of the Nordic countries (Denmark, Finland, Iceland, Norway or Sweden).
  • Applicants with a Bachelor’s or Master’s programme completed in Australia, Canada, Ireland, New Zealand, the United Kingdom, or the United States. In this case, please upload your Bachelor’s or Master’s diploma under the section ”Language skills documentation”.
  • Applicants with a Bachelor’s or Master’s programme completed at a Danish university for which the requirement was English B level at the time of admission. In this case, please upload your Bachelor’s or Master’s diploma under the section ”Language skills documentation”.

The programme committee may request further information or invite the applicant to attend an interview.

How to apply:

1)      Find the application form:
Go to https://phd.tech.au.dk/for-applicants/apply-here/ - Note, the online application system opens on 1 June 2020.
Choose August 2020 Call with deadline 1 August 2020 at noon (11.59 AM CEST).
You will be directed to the call, and must choose the programme “Animal Science”.

2)      Fill in the following information:

  • Personal information
  • Academic background
  • Admission
  • Financing (if any)
  • Study: In the dropdown menu you must choose the project: “Biochar produced from biorefined grass clover pulp for feed and technical purposes”
  • Source (how you found out about the call)

Next to some of the information fields you will find a number. Click on the number to get further directions on how to fill in the information field/what information is needed.

3)      Application attachments:
Please be aware that you cannot submit the application if one or several of these documents have not been uploaded.

If you wish to upload more than one document under each section, you must scan/merge all documents into one large PDF file and upload this. Please note that we reserve the right to remove scientific papers, large reports, theses and the like. Instead you can indicate a URL where the information is available.

All information in the application must be in English or Danish, preferably English. A certified English translation is required for documents written in languages other than English or one of the Scandinavian languages (i.e. Norwegian, Swedish or Danish) languages.

As a minimum all applications must include (pdf-files only, max. 20 MB, no zip):

  • One reference (template for references)
  • Curriculum vitae,
  • Motivation (max. 1 page)
  • Transcripts, grade point averages (weighted and unweighted), and diploma(s) for both Bachelor’s and Master’s degree. If the original documents are not in English or one of the Scandinavian languages (i.e. Norwegian, Swedish or Danish) then copies of the original documents as well as a certified English translation must be attached.
  • Project description (½-4 pages). For technical reasons, you must upload a project description. When - as here - you apply for a specific project, please simply copy the project description above, and upload it as a PDF in the application. If you wish to, you can indicate an URL where further information can be found. Please note that we reserve the right to remove scientific papers, large reports, theses and the like.
  • Documentation of language skills if required.

After submission of the application, you will receive a confirmation e-mail with an application ID, you should use for reference if needed.

The graduate school reserves the right to verify the authenticity of your educational diploma and transcripts:

  • Request additional information to verify an application.
  • Reject the application if it is proven, or if the University has reasonable belief, that the information provided is false or if the applicant refuses to provide the requested information, whether or not an offer has already been made. 
  • For further information on applying, assessment procedures, etc. please see the GSTS Application Guide.

Please note:

  • The programme committee may request further information or invite the applicant to attend an interview.
  • The project will only be initiated if final funding (from the graduate school/the faculty) is secured.

All interested candidates are encouraged to apply, regardless of their personal background.

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