Bi-objective mathematical model for choosing sugarcane varieties with harvest residual biomass in energy cogeneration

Sugarcane crop occupies an area of about 23.78 million hectares in 103 countries,and an estimated production of 1.66 billion tons,adding to this volume more than 6%to 17%concerning residual biomass resulting from harvest.The destination of this residual biomass is a major challenge to managers of mills.There are at least two alternatives which are reduction in residue production and increased output in electricity cogeneration.These two conflicting objectives are mathematically modeled as a bi-objective problem.This study developed a bi-objective mathematical model for choosing sugarcane varieties that result in maximum revenue from electricity sales and minimum gathering cost of sugarcane harvesting residual biomass.The approach used to solve the proposed model was based on theε-constraints method.Experiments were performed using real data from sugarcane varieties and costs and showed effectiveness of model and method proposed.These experiments showed the possibility of increasing net revenue from electricity sale,i.e.,already discounted the cost increase with residual biomass gathering,in up to 98.44%.

Utilization of Acai Berry Residual Biomass for Extraction of Lignocellulosic Byproducts

According to the National Company of Supplying(CONAB)in 2017 alone,the national production of acai pulp reached 219855 t,equating to 180 million dollar(USD).Almost 85%of the weight of fruit is constituted by residual biomass,even though researches have highlighted important applications for this biomass,most of it is discarded as organic waste.Thus,it is relevant to envisage in-depth studies about how to use these residues,particularly regarding the environmental impact of its target destination.Nanocrystalline cellulose(CNC)and lignin are organic derivatives obtained through the physical-chemical treatment of lignocellulosic biomass.Both are abundant and currently considered as biopolymers because of their structural characteristics and their diverse applications in food and the medical field.This work presents the mass yields achieved and the physical-chemical characteristics of the lignocellulosic derivatives extracted from the fiber of the acai berry.A statistical design was used to define the influence of process variables as temperature,reaction time and fiber size on the yield of these byproducts.A maximum yield close to 64%of type I CNC,with 45%of crystallinity degree was achieved at the minimum condition of temperature and fiber size.Additionally,through rheological analysis,it was possible to predict the nanocrystal aspect ratios,ranging from 71 to 125.The extracted lignin was rich in methoxy groups,p-coumaryl alcohol and p-coumaric acid,and its structural unit’s low state of aggregation can be an indication of low molecular weight,which envisions an appropriate use for this lignin to produce commodity chemicals.

Use of residual lignocellulosic biomass for energetic uses and environmental remediation through pyrolysis

This study analyzes the potential of an agricultural residue,hazelnut shells,as raw material in a combined ther-mochemical process to obtain pyro-gas and biochar for environmental remediation.The novelty of this study relies on the definition of a pyrolytic polygeneration process to simultaneously attain an energy-type product and abiochar to maximize the versatility of the products and their usage.To this aim,the heating value of the gas and its potential to feed a micro combined heat and power(micro-CHP)system was evaluated.Additionally,the resulting biochar was chemically activated and tested as adsorbent for the removal of contaminants from an aqueous solution.Results show that the pyro-gas from the shell-type residue was suitable to be used as feed stream in a micro-CHP unit,which was able to operate near the full-load(91.9%)with electrical and thermal efficiencies of 27.6%and 57.9%,respectively.In the case of the biochar fraction,poor results were found for the char prior to activation.Instead,once it was activated with KOH,the resulting activated carbon presented high effectiveness as adsorbent and complete removal of the measured compound(methylene blue)was achieved.

Valorisation of industrial hemp (Cannabis sativa L.) residues and cheese whey into volatile fatty acids for single cell protein production

The production of single cell protein(SCP)using lignocellulosic materials stands out as a promising route in the circular bioeconomy transition.However,multiple steps are necessary for lignocellulosics-to-SCP processes,involving chemical pretreatments and specific aerobic cultures.Whereas there are no studies that investigated the SCP production from lignocellulosics by using only biological processes and microbial biomass able to work both anaerobically and aerobically.In this view,the valorisation of industrial hemp(Cannabis sativa L.)biomass residues(HBRs),specifically hurds and a mix of leaves and inflorescences,combined with cheese whey(CW)was investigated through a semi-continuous acidogenic co-fermentation process(co-AF).The aim of this study was to maximise HBRs conversion into VFAs to be further used as carbon-rich substrates for SCP production.Different process conditions were tested by either removing CW or increasing the amount of HBRs in terms of VS(i.e.,two and four times)to evaluate the performance of the co-AF process.Increasing HBRs resulted in a proportional increase in VFA production up to 3115 mg HAc L^(-1),with experimental production nearly 40%higher than theoretical predictions.The synergy between HBRs and CW was demonstrated,proving the latter as essential to improve the biodegradability of the former.The produced VFAs were subsequently tested as substrates for SCP synthesis in batch aerobic tests.A biomass concentration of 2.43 g TSS L^(-1) was achieved with a C/N ratio of 5.0 and a pH of 9.0 after two days of aerobic fermentation,reaching a protein content of 42%(g protein per g TSS).These results demonstrate the overall feasibility of the VFA-mediated HBR-to-SCP valorisation process.