Sustainable Approaches to Incorporate Plant-Based Biomaterials in Power Generation
Round 1
Reviewer 1 Report
The review of alternative methods that have been developed to harness biomass compounds for power generation, with a particular emphasis on cellulose and plant-derived materials.
The review encompasses three different types of energy harvesting based on their origin: mechanical, osmotic, and thermal energy.
Throughout the manuscript, the latest developments in materials science pertaining to each approach are described, along with the reported performance. Additionally, hybrid approaches involving the combination of biomass materials with other components have been considered and compared to the performance achieved using biopolymers alone. The review also addresses the current limitations and opportunities in the field, providing an overview of the present landscape and indicating future directions.
It appears that figures play an important role in academic writing. However, if Figures 3-6 in your review are busy, not adequately described, or their necessity is unclear, there are guidelines you can follow to address these issues.
Minor editing of the English language is required, pay attention to maintaining consistency in your chosen language style.
Author Response
We would like to thank the reviewer for the positive comments on the manuscript. We have revised the paper, including the figures and English quality, and we hope our work is now up for publication.
Reviewer 2 Report
The authors review the progresses of plant-based biomaterials for power generation through three aspects: mechanical, osmotic, and thermal energy conversion. The topic is interesting and worthy of reviewing. Publication in Solids could be considered should the authors carefully address the following a few comments.
1. What are the advantages of plant-based biomaterials for power generation? I suggest to make the pros more clearly in the Introduction section.
2. I would like to suggest the authors compare the performances of biomaterials-based energy harvesters and that of traditional materials.
3. The positions of Figures are very strange. It is very hard for me to clearly view the Figures. Please modify them.
4. I would like to suggest the authors discuss the perspectives of potential applications of the biomaterials-based energy harvesters, including all the three different types the authors discuss in this manuscript.
5. There are a few typos and grammar issues. Please go through the whole manuscript and make necessary corrections.
There are a few typos and grammar issues. Please go through the whole manuscript and make necessary corrections.
Author Response
We would like to thank the reviewer for the positive comments on our manuscript. We have now revised the reviews, and we hope it is now up for publication.
- What are the advantages of plant-based biomaterials for power generation? I suggest to make the pros more clearly in the Introduction section.
We agree with the reviewer that the pros of using cellulose should be better outlined. We have now expanded on the advantages of cellulose, as a material that can be obtained from plants, that fix CO2, and has promising physical-chemical properties:
P2, L63. “On the contrary, a synthesis of plant-derived biomaterials could theoretically be achieved through “carbon negative” methods, which lead to a storage of CO2 from the atmosphere given the natural ability of plants to fix carbon. Thus, the incorporation of biomass-derived materials in the fabrication of these renewable energy devices shows a promising approach that could further save environmental and power costs, while overcoming the limitations of biomass combustion.
One of the most common biomass-derived materials is cellulose [6], which is pro-duced at a scale of 1.5 × 1012 tonnes per year [7]. This material is by far the most stud-ied biomass compound in energy research given its low-cost and chemical versatility, and it shows material shows advantages compared to traditional materials, which en-ables the incorporation in multiple applications. Cellulose gels show a high porosity and specific surface area, which can enhance the energy generation through surface phenomena such as triboelectricity. Moreover, it is a flexible material, with a good ion conductivity when hydrated, which improves the use in portable[], wearable devices compared with traditional materials. This material can be further modified chemically to enhance power generation through chemical oxidation or click chemistry among others.”
- I would like to suggest the authors compare the performances of biomaterials-based energy harvesters and that of traditional materials.
We agree that a comparison of cellulose with traditional materials on each application should be provided. We have expanded the descriptions of the materials used for each application besides cellulose, and included relevant figures on the table comparisons to offer an easier visualization by the reader. Changes have been highlighted in the manuscript (P5 L206, P9 L386, P14, P15 L578).
- The positions of Figures are very strange. It is very hard for me to clearly view the Figures. Please modify them.
We apologise for the formatting of figures. We have now re-sized and sharpened them, and we hope they are clearer now.
- I would like to suggest the authors discuss the perspectives of potential applications of the biomaterials-based energy harvesters, including all the three different types the authors discuss in this manuscript.
We agree with the reviewer that a discussion of perspectives would benefit the manuscript. This has now been included under the “Current limitations and opportunities” section”. Future applications of piezoelectric and triboelectic generators as wearable sensors are discussed, alongside potential applications of thermoelectric materials based on cellulose in energy harvesting from waste heat (P17, L669). In the case of osmotic energy generation, to date, the applications seem to be limited to energy generation from salinity gradients.
“Future developments in the field of power generation using biomass-derived materials will focus on the development of high throughput cellulose sources, that require a minimal processing to achieve a good performance. An example of a potential source is bacterial cellulose which, as observed, presents good physical-chemical properties given the high presence of nanofibrils, that enhance the surface area of materials. However, this method for cellulose generation is slow, and requires a high energy to maintain bacterial colonies.
Besides the chemical modification of cellulose biopolymers, the advantage of using vertically aligned nanocrystals has been described. This material can be used to achieve a high piezoelectric coefficient, leading to an enhanced power generation. Further developments in the manufacturing of thin nanocrystalline cellulose films could be incorporated into miniaturised and wearable sensors, that will make use of the power generation for battery-less health monitoring. In this context, cellulose films could be used both as a power source for low-power electronics, and as sensing materials. Piezoelectric and triboelectric properties of cellulose could be exploited to determine hand movement or muscle contractions among other applications while thermoelectric generators could be used as temperature sensors. Moreover, the mechanical versatility of cellulose thermoelectrics could be used in the harvesting of waste heat directly from the generating source. This could enable the recovery of power from small electronic parts such as electric wires directly, boosting the efficiency. “
- There are a few typos and grammar issues. Please go through the whole manuscript and make necessary corrections.
We would like to thank the reviewer for pointing this issue. The manuscript has now been revised, and the grammar has been amended.
