Co-pyrolysis Of Lignocellulosic Biomass Research Articles

Synergistic interactions and co-pyrolysis characteristics of lignocellulosic biomass components and plastic using a fast heating concentrating photothermal TGA system

Co-pyrolysis of lignocellulosic biomass (LCB) with plastic has gained significant attention recently. Studying the pyrolysis kinetic behavior of LCB and plastic is beneficial for developing a framework for designing and improving biofuel production. The co-pyrolysis behavior, synergistic interactions and kinetic triplet parameters of the three main LCB components, i.e., cellulose, hemicellulose and lignin, and two plastics (polyethylene terephthalate [PET] and polyvinyl chloride [PVC]) were evaluated using a fast heating concentrating photothermal TGA system. The maximum decrease in mass loss rate with increasing heating rates was observed for cellulose with PET (1.23–0.94%/°C) and with PVC (1.05–0.62%/°C). The mechanism of synergistic interaction between hemicellulose and PET proceeded with polymer degradation and conversions of monomer units into excess volatiles in the higher heating rate regime. Distributed Activation Energy Model [DAEM] and Coats-Redfern [CR]) were used to calculate the kinetic parameters. DAEM results confirmed that mixed samples required lower activation energy to start the reaction. Using the CR method, the first degradation phase showed the best synergistic effect for lowering the PET and PVC activation energy, particularly with hemicellulose and lignin.

Experimental investigation of thermal performance, kinetic triplets, and synergistic effect for bamboo-waste plastic (PP & PE) blends using thermogravimetric analyser in N2 atmosphere

Co-pyrolysis of lignocellulosic biomass with other feedstock can improve the pyrolysis process of biomass due to synergistic effect and it also has the potential to minimize the carbon footprint. In India, bamboo is abundantly available which can be considered as a potential source of energy. On the other side, plastic waste management is a major concern. Therefore, co-pyrolysis of bamboo with polyethylene and polypropylene are investigated in a thermogravimetric analyser to investigate the synergistic effect. Experiments are carried out in the temperature range from 298 to 973 K with variable heating rates of 10 to 40 K/min. It is illustrated that the co-pyrolysis of 75% biomass with 25% polypropylene (B75_PP25) and 75% biomass with 25% polyethylene (B75_PE25) exhibit maximum synergistic effect. Model-free methods (Friedman, OFW, and KAS) are used to estimate the kinetic parameters. Minimum average activation energy is estimated for B75_PP25 and B75_PE25 samples from all three kinetic methods. For example, the average activation energy for B75_PP25 and B75_PE25 are 116.7 kJ/mol and 128.05 kJ/mol respectively from KAS method. Finally, the reaction mechanisms are identified using Criado’s master plot method. Statement of NoveltyStudies on co-pyrolysis of bamboo and waste plastics are barely reported in the literature. This investigation deals with the kinetics and synergistic behaviour of co-pyrolysis of waste plastics and bamboo from North-Eastern region of India. Additionally, the findings of this study also include the optimum blending ratio of bamboo and waste plastics for the co-pyrolysis process. This investigation would be useful for the researchers in designing and scaling-up the reactor for the thermal treatment of plastic and bamboo.

Co-pyrolysis of lignocellulosic biomass with other carbonaceous materials: A review on advance technologies, synergistic effect, and future prospectus

Due to the continuous rise in population, modernization, and industrialization, the demand for energy is increasing day by day, resulting in serious issues such as fossil fuel depletion, pollution, and power shortages. As a result, there is an urgent need to investigate alternate energy sources. Lignocellulosic biomass pyrolysis has been shown as the most promising feedstock for the production of sustainable and renewable biofuels. Unfortunately, the fuel characteristics of bio-oil generated from biomass pyrolysis are still insufficient to meet petroleum products ASTM standards. To address these challenges, co-pyrolysis of lignocellulosic biomass with other carbonaceous materials (e.g., plastic waste, Tyre garbage etc.) is emerging as one of the most promising approaches. Various experimental studied have been conducted on lignocellulosic biomasses co-pyrolysis with other carbonaceous materials such as plastic waste, tire waste, coal, algae and sewage sludge. The present manuscript aims to review and establish the scope of co-pyrolysis of lignocellulosic biomass with various carbon rich feedstocks for renewable production of high-quality renewable fuels. The synergistic effect between lignocellulosic biomass and other carbonaceous materials has been explored in detail. Furthermore, recent advances in co-pyrolysis process along with the reaction affecting parameters are also summarized in brief. Consequently, this review demonstrates both highlights of the remarkable achievement of co-pyrolysis and the milestones that are necessary to be garnered in the future.

Co-pyrolysis of lignocellulosic biomass and plastics: A comprehensive study on pyrolysis kinetics and characteristics

Co-pyrolysis of biomass with plastics is an interesting research trend in improving both the yield and quality of oil products toward taking advantage of flexible material resources and sustainable fuel development. This study investigated the kinetic behaviors using thermogravimetric analysis and pyrolysis characterization for the co-pyrolysis of biomass (bamboo and oak wood) with plastics (polypropylene [PP] and polystyrene [PS]) in a fixed-bed reactor. The kinetic triplet for feedstocks was determined using the isoconversional method, compensation effect, and master plot method. The addition of 20 wt% plastics into biomass decreased the activation energy, with the most distinct positive synergistic effect for the bamboo/PS blend. In addition, the effect of co-pyrolysis temperature and biomass/plastic ratio on pyrolysis characteristics was investigated. Through biomass pyrolysis and biomass/plastic co-pyrolysis, the positive changes in distributions and physical-chemical properties of the products (i.e., char, oil, and gas) were observed using various analytical methods. Especially in the case of biomass/PS blends, the synergistic effect of co-pyrolysis was shown due to the difference in the actual and theoretical yields of the products. The liquid yields of the co-pyrolysis were 50.95, 50.17, 55.15, and 56.16 wt% for bamboo/PP, bamboo/PS, oak wood/PP, and oak wood/PS, respectively. The highest HHV of 28.22 MJ/kg was obtained for oil derived from the co-pyrolysis of bamboo/PS. Furthermore, co-pyrolysis chars have high HHVs in the range of 30.73–32.41 MJ/kg, suggesting that they can be used as solid fuels.

Co-pyrolysis of biomass and polyvinyl chloride under microwave irradiation: Distribution of chlorine

Co-pyrolysis of sophora wood (SW) and polyvinyl chloride (PVC) was conducted in a microwave reactor at different temperatures and different mixing ratios, and the transformation and distribution of chlorine in pyrolysis products were investigated. Microwave pyrolysis is a simple and efficient technique with better heating uniformity and process controllability than conventional heating. Compared with PVC pyrolysis, the addition of SW significantly reduced CO2 yield and greatly increased the yield of CO. The yield and quality of pyrolysis oil were effectively improved by SW, and the content of chlorine-containing compounds in the oil was suppressed to <1% at low temperatures (<550 °C). Co-pyrolysis of SW and PVC reduced the chlorine emissions from 59.07% to 28.09% and promoted the retention of chlorine in char (from 0.33% to 4.72%). Cellulose, hemicellulose, and lignin were co-pyrolyzed with PVC to investigate their effects on chlorine distribution. The experiments demonstrated that lignin had the most significant effects on reducing gas phase chlorine emission and achieving chlorine immobilization, and chlorine mainly existed in the form of sodium chloride in the char of lignin-PVC co-pyrolysis. Hence co-pyrolysis of lignocellulosic biomass and PVC provides a practical pathway for utilization of PVC waste in an environmentally friendly manner, realizing efficient chlorine retention and significantly reducing chlorine-related emissions.

Synergistic effects from co-pyrolysis of lignocellulosic biomass with low-rank coal: A perspective based on the interaction of organic components

A methodological approach towards synergistic effects from co-pyrolysis of lignocellulosic biomass with low-rank coal was proposed. The main maceral group from low-rank coal and primary organic components from biomass were selected to investigate the interaction of organic components. Thermal behavior and kinetic analysis on the co-pyrolysis of cellulose with acid-washed low-rank coal/vitrinite/inertinite were explored via TGA combined with iso-conversional method. The results indicated that the maceral group from low-rank coal showed different synergistic effects on the pyrolysis parameters and product distribution. The synergistic effect of vitrinite on the yield of volatile was closely related to its mass ratio. Positive and negative synergistic effects were observed when the mass ratio of vitrinite was 25% and 75%, respectively. Inertinite inhibited the formation of volatiles during co-pyrolysis and overall exhibited a negative synergy. No obvious synergy was observed for acid-washed low-rank coal when the heating was 10 °C·min−1 and 20 °C·min−1, while positive synergistic effects were found at a high mass ratio and heating rate. The integrative action of maceral groups played a significant role during the co-pyrolysis process.

Towards enhanced understanding of synergistic effects in co-pyrolysis of pinewood and polycarbonate

Utilization of biomass and plastic wastes has drawn growing attention in recent years as it offers promising pathway for simultaneous energy production and waste disposal. In this paper, the co-pyrolysis of pinewood and polycarbonate was performed in a fixed bed reactor with focus on determining the extent of synergistic effects and unraveling the underlying synergistic mechanism. The extent of synergistic effects was quantified via direct comparison of the results from co-pyrolysis of pinewood-polycarbonate mixture with the weighted average values from individual components pyrolysis. The observed synergistic effects were further deconvolved into different component interactions (such as volatiles-volatiles interactions, volatiles-feedstocks interaction, and catalytic effects of chars) using tailored feedstock configurations to gain more insights into the synergistic mechanism. The results showed that co-pyrolysis enhancedH2 by 33%, CO by 26%, and total syngas yields by 19% as compared to their weighted values from individual pyrolysis. Co-pyrolysis also exhibited superiority in energy recovery as the overall energy efficiency was noticeably promoted from 42.9% to 48.6%. Deconvolution of synergistic effects revealed that volatiles-volatiles interactions were the primary contributor for the enhancement of H2 and CO. Examination of volatiles-feedstock interactions indicated that the highly reactive pinewood volatiles facilitated polycarbonate degradation, while polycarbonate volatiles were relatively stable and unable to promote pinewood decomposition. Furthermore, pinewood char catalytically enhanced polycarbonate degradation. This paper provides a deconvolved understanding of synergistic effects in co-pyrolysis of lignocellulosic biomass and polycarbonate wastes, which is very helpful in designing clean and efficient energy recovery systems from these waste resources.

Influence of Char Intermediates on Synergistic Effects During Co-Pyrolysis of Pinewood and Polycarbonate

Abstract Combined use of plastic and biomass wastes offers promising pathway for simultaneous energy production and waste disposal. In this article, the co-pyrolysis of pinewood and polycarbonate (PC) was performed in a fixed bed reactor to quantify their synergistic interaction on the product output and determine the effect of char intermediates on the synergistic effects. The extent of synergistic effects was obtained via a direct comparison of results from co-pyrolysis of pinewood–polycarbonate mixture with the weighted average values from pyrolysis of individual components. The observed synergistic effects were further examined from the influence of char intermediates using tailored feedstock configurations to gain more insights into the synergistic mechanism. The results showed co-pyrolysis resulted in enhancement by 33% in H2, 26% in CO, and 19% in total syngas yields compared to their weighted values from individual pyrolysis. Co-pyrolysis also exhibited superiority in energy recovery with the overall energy efficiency promoted from 42.9% to 48.6%. Deconvolution of synergistic effects revealed that pinewood char catalytically enhanced PC degradation, while the effect of PC char on pinewood pyrolysis was minimal. This article provides results on deconvolved understanding of synergistic effects in co-pyrolysis of lignocellulosic biomass and PC wastes, which is very helpful in designing clean and efficient energy recovery systems from these waste resources.

Integrating Anaerobic Digestion of Pig Slurry and Thermal Valorisation of Biomass

The feasibility of coupling the anaerobic digestion of pig manure and co-pyrolysis of its digestate with milk thistle as lignocellulosic biomass was studied. Kinetic analysis was performed along with an evaluation of energy recovery attained from a combined approach Pig slurry was digested under mesophilic semi-continuous conditions. Digestate was dried and submitted to thermogravimetric analysis under inert atmosphere along with milk thistle samples. Kinetic evaluation was carried out using non-isothermal methods. Assessment of the energy obtained from the combined digestion and pyrolysis process was performed. Digestion resulted in a yield of 308.5 ± 18.2 mL CH4/g VS. The evaluation of co-pyrolysis of mixtures at different contents of milk thistle showed no interactions between the two materials during pyrolysis. The energy need associated with thermal drying of digestate was 476 MJ/m3 of pig slurry. Co-pyrolysis of lignocellulosic biomass and digestate [25% content of digestate (w/w)] resulted in a lower char production, associated with the lower ash content of the former. The extra supply of energy needed for thermal drying of the digestate might be obtained from co-pyrolysis with biomass. This approach presented an energy recovery of about 29.4%

Thermal behavior and gas evolution characteristics during co-pyrolysis of lignocellulosic biomass and coal: A TG-FTIR investigation

Co-pyrolysis characteristics of cornstalk with two types of coal (lignite, bituminous coal) were investigated using thermogravimetry coupled with Fourier transform infrared spectrometry (TG-FTIR). Pyrolysis thermal behaviors of biomass and coal samples and their blends in different blending ratios were revealed by TG and DTG profiles, and an online monitoring of gas products evolved was realized by FTIR measurement. In order to explore potential synergistic effect, characteristic values of TG and DTG curves were identified for all blended and parent samples. In the meantime, evolution characteristics of CO2, CO, CH4, H2O and formic acid were identified by FTIR profiles against temperature. Slight synergistic effects were approved by both TG and FTIR analysis, which resulted in higher char yields and influences on volatile evolution during co-pyrolysis. 0.3∼7.4 % higher final residual yields than expected were confirmed in co-pyrolysis. TG results showed that thermal behavior of biomass was remarkably influenced with the presence of coal in blended samples at 286–306 °C. FTIR profiles also indicated that the evolution of formic acid was affected according to the releasing characteristics of CO and C–O groups at the same temperature region. SEM images and BET analysis of residual char provided further information about synergy. Disparity of thermal behaviors and void spaces between parent biomass and coal brought favorable conditions for adsorption and coking of both biomass and coal volatiles, which led to different gas-solid interactions and significantly changed the surface morphology and porous structure of co-pyrolyzed char particles.

Investigation on co-pyrolysis of lignocellulosic biomass and amino acids using TG-FTIR and Py-GC/MS

Co-pyrolysis of lignocellulosic biomass and microalgae could greatly improve bio-oil quality. In order to understand the interaction, nitrogen transformation mechanism, and better use lignocellulosic biomass and microalgae, co-pyrolysis of lignocellulosic biomass (bamboo waste (Ba)) and amino acids (glutamic acid (Glu) and aspartic acid (Asp)) was performed by TG-FTIR and Py-GC/MS technique. Results showed that individual pyrolysis of Glu and Asp formed 52% pyrrolidinone and 75% maleimide through intramolecular dehydration reactions, respectively, with the releasing of CO2, CO and NH3. Besides, co-pyrolysis of Ba with Glu and Asp decreased the biomass decomposition temperature largely. Furthermore, co-pyrolysis greatly increased the yield of CO2 and NH3, and promoted the formation of phenols, O-containing species (but oxygen yield decreased), while inhibited the generation of N-species (decreased about 50%) in bio-oil, through strong Maillard reaction, ketonization, deamination, and decarboxylation reactions. At last, the possible reaction pathways of co-pyrolysis of lignocellulosic biomass and amino acids were proposed. In conclusion, co-pyrolysis of lignocellulosic biomass and amino acids could significantly improve the quality of bio-oil, and effectively control the nitrogen transformation into bio-oil.

A comparative study on co-pyrolysis of lignocellulosic biomass with polyethylene terephthalate, polystyrene, and polyvinyl chloride: Synergistic effects and product characteristics

Co-pyrolysis of waste biomass and plastics was investigated to find out whether the quality of pyrolysis products was improved. For the sake of yield and compositional comparison, three polymers (polyethylene terephthalate, polystyrene, and polyvinyl chloride) and two biomasses (walnut shells and peach stones) were tested in a fixed bed reactor. The maximum bio-oil yield was obtained at 500 °C as 20.81 wt % for walnut shell and 18.30 wt %, for peach stone pyrolysis, then co-pyrolysis experiments were performed at 500 °C. Based on the experimental findings, blending of polyethylene terephthalate, polystyrene, and polyvinyl chloride into biomass affected product yield substantially. To gain more insight into the effect of polymers, liquid and solid products were analyzed by various analytical techniques. Results showed a significant modification on the chemical structure tars after co-pyrolysis, and tar yield increased up to 49.80 wt%. Meanwhile, modifying the structures and enhancing the quality of the tars and chars seemed possible by co-pyrolysis.

Co-pyrolysis of lignocellulosic biomass with low-quality coal: Optimal design and synergistic effect from gaseous products distribution

Co-pyrolysis of lignocellulosic biomass and low-quality coal can alternate fossil fuel partially and utilize biomass on a commercial scale. Gaseous products from co-pyrolysis process can be widely applied in industries due to the advantage in transportation and compression. Thus, investigation of synergistic effect and optimal design about gas products is essential for efficiently and comprehensively design of the process. In this research, three model compounds of lignocellulosic biomass (cellulose, hemicellulose, lignin) and wheat straw were co-pyrolyzed with a kind of low-quality coal via a drop tube furnace. Based on the component insight of biomass and response surface methodology, synergetic effects from gas distribution were investigated. The influence of reaction condition (biomass ratio and pyrolysis temperature) on the yield and high heat value (HHV) of gaseous products were explored. Optimal result for the objective of the highest effective gas yield during co-pyrolysis were obtained. Results revealed that both positive and negative synergic effects on yields and composition of pyrolysis gas were presented. When pyrolysis temperature was 600 °C, both wheat straw and three model compounds promoted the formation of H2 and CO. Negative effects on CO2 were observed when co-pyrolysis of cellulose/wheat straw with coal at the temperature of 600 °C to 800 °C. Whether positive or negative synergy existed depended on the mixing ratio, temperature and combined action of lignin, hemicellulose, and cellulose. For coal and hemicellulose mixtures, the mixing ratio of 0.03 and temperature of 936 °C can get the highest yield of H2 (20.56 mmol/g). Moreover, the maximum yield of CO and CO2 was obtained at cellulose mixing ratio of 0.99 and 0.98 at 787 °C and 626 °C, respectively. Based on the view of biomass composition, the results can be used to optimize the gaseous products distribution during co-pyrolysis of coal and biomass.

Co-pyrolysis of lignocellulosic biomass and microalgae: Products characteristics and interaction effect

Co-pyrolysis of biomass has a potential to change the quality of pyrolytic bio-oil. In this work, co-pyrolysis of bamboo, a typical lignocellulosic biomass, and Nannochloropsis sp. (NS), a microalgae, was carried out in a fixed bed reactor at a range of mixing ratio of NS and bamboo, to find out whether the quality of pyrolytic bio-oil was improved. A significant improvement on bio-oil after co-pyrolysis of bamboo and NS was observed that bio-oil yield increased up to 66.63wt% (at 1:1) and the content of long-chain fatty acids in bio-oil also dramatically increased (the maximum up to 50.92% (13.57wt%) at 1:1) whereas acetic acid, O-containing species, and N-containing compounds decreased greatly. Nitrogen transformation mechanism during co-pyrolysis also was explored. Results showed that nitrogen in microalgae preferred to transform into solid char and gas phase during co-pyrolysis, while more pyrrolic-N and quaternary-N generated with diminishing protein-N and pyridinic-N in char.

Interactions of beech wood–polyethylene mixtures during co-pyrolysis

To investigate the interactions between beech wood (BW) and polyethylene (PE) during co-pyrolysis, they were pyrolyzed both individually and as their mixtures from ambient temperature to 650°C at a heating rate of 10°Cmin−1 using a thermogravimetric analyzer and a tube reactor. In the presence of PE, the production of levoglucosan (LG) and methoxyphenols with unsaturated alkyl side chains from BW was enhanced, resulting in maximum 1.65 and 1.55 times higher yields comparing with their expected yields from BW:PE (w:w)=40:60 mixture, respectively. It was due to the stabilization of the radical species of those by H-abstraction from the PE pyrolysates in the vapor phase. According to this, CO, CO2, C2-C3 compounds, and 5-membered ring compounds, which are LG decomposition products, showed 0.86, 0.85, 0.58, and 0.68 times smaller yields comparing with their expected yields. Methoxyphenols with saturated alkyl side chains, phenols, and catechols, also showed 0.77, 0.66, and 0.87 times smaller yields because they are mainly derived from methoxyphenols with unsaturated alkyl side chains. On the other hand, it was suggested that hydrogen radicals produced during the polyaromatization of BW stabilized PE radical species, resulting in products from PE with higher carbon numbers. Thus, the present work reveals that the interactions between BW and PE mainly involve H-exchange to stabilize radical species. These findings increase our understanding of the operative mechanism in the co-pyrolysis of lignocellulosic biomass and synthetic polymers, which will be useful in future for achieving pyrolysis reaction control and recovering desirable products from difficult-to-separate initial mixtures.