energies-logo

Journal Browser

Journal Browser

Valorization of Waste Products to Biofuel: Current Trends and Technological Challenges

A special issue of Energies (ISSN 1996-1073). This special issue belongs to the section "A4: Bio-Energy".

Deadline for manuscript submissions: closed (30 June 2021) | Viewed by 1942

Special Issue Editors

Prof. Dr. Mette Hedegaard Thomsen
E-Mail Website
Guest Editor
Department of Energy Technology, Aalborg University, 6700 Esbjerg, Denmark
Interests: biomass fractionation; extraction; fermentation; halophytes; biofuels; biochemicals
Special Issues, Collections and Topics in MDPI journals
Department of Energy Technology, Aalborg University, 6700 Esbjerg, Denmark
Interests: biorefineries; process modeling; biomass pretreatment; biofuels; bioenergy; anaerobic digestion; biogas; fermentation; process simulation

Special Issue Information

Dear Colleagues,

A major concern with liquid biofuels for the transportation sector is the sustainability of such fuels with respect to actual GHG reduction potential, land-use-change issues, and biomass availability. Secondly, cost competitiveness with current fossil fuels is a major barrier for the deployment of current technologies for the production of biofuels. The environmental and economic sustainability of producing liquid biofuels is largely dependent on the feedstock used for the process. Feedstocks that are easily processed into biofuels are the 1st Generation (1G) feed stocks such as oil from oil crops; sugar cane juice; and starch from cereal grains, but these feed stocks have a high price and are face challenges in the form of environmental sustainability and the food-versus-fuel dilemma. On the other hand, 2nd Generation (2G) feed stocks such as agricultural waste and municipal solid waste have a lower price, are abundantly produced, and are sustainable to use as biofuels feedstock, as they are CO2 neutral and do not compete with food production. However, conversion to biofuels is challenged by the complex composition and/or recalcitrant nature of the waste. This Special Issue will cover all aspects related to biological, thermos, and catalytic routes for the conversion of waste to fuels, focusing on current trends and technological challenges.

Prof. Dr. Mette Hedegaard Thomsen
Dr. Tanmay Chaturvedi
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Energies is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • conversion of agricultural waste into fuels
  • conversion of municipal solid waste into fuels
  • thermochemical conversion of waste into fuels
  • catalytic conversion of waste into fuels
  • biological conversion of waste into fuels
  • waste biorefinery concepts

Published Papers (1 paper)

Order results
Result details
Select all
Export citation of selected articles as:

Research

11 pages, 743 KiB  
Article
A Study on the Feasibility of Anaerobic Co-Digestion of Raw Cheese Whey with Coffee Pulp Residues
Energies 2021, 14(12), 3611; https://doi.org/10.3390/en14123611 - 17 Jun 2021
Cited by 5 | Viewed by 1546
Abstract
In this paper, a study on the feasibility of the treatment of raw cheese whey by anaerobic co-digestion using coffee pulp residues as a co-substrate is presented. It considers raw whey generated in artisanal cheese markers, which is generally not treated, thus causing [...] Read more.
In this paper, a study on the feasibility of the treatment of raw cheese whey by anaerobic co-digestion using coffee pulp residues as a co-substrate is presented. It considers raw whey generated in artisanal cheese markers, which is generally not treated, thus causing environmental pollution problems. An experimental design was carried out evaluating the effect of pH and the substrate ratio on methane production at 35 °C (i.e., mesophilic conditions). The interaction of the parameters on the co-substrate degradation and the methane production was analyzed using a response surface analysis. Furthermore, two kinetic models were proposed (first order and modified Gompertz models) to determine the dynamic profiles of methane yield. The results show that co-digestion of the raw whey is favored at pH = 6, reaching a maximum yield of 71.54 mLCH4 gVSrem−1 (31.5% VS removed) for raw cheese whey and coffee pulp ratio of 1 gVSwhey gVSCoffe−1. The proposed kinetic models successfully fit the experimental methane production data, the Gompertz model being the one that showed the best fit. Then, the results show that anaerobic co-digestion can be used to reduce the environmental impact of raw whey. Likewise, the methane obtained can be integrated into the cheese production process, which could contribute to reducing the cost per energy consumption. Full article
Show Figures

Graphical abstract

Back to TopTop