Co-production Of Biochar Research Articles

An integrated biorefinery of Madhuca indica for co-production of biodiesel, bio-oil, and biochar: Towards a sustainable circular bioeconomy

The advancement of non-waste biorefinery technology has proved beneficial in effectively using waste biomass resources. The potential of various biorefinery designs to transform biomass into a range of commercially viable products and bioenergies has piqued attention worldwide among the several scenarios proposed to commercialize biofuels. This paper describes the biorefinery of Madhuca indica (M. indica) seeds to generate biochar, bio-oil, and biodiesel. Pyrolization was used on the de-oiled cake to produce charcoal and bio-oil. The M. indica seed's biochar was utilized as a useful supporting particle to immobilize the enzyme. Through transesterification, the immobilized enzyme transformed the oil extracted from the seed into biodiesel. Using an optimum methanol-to-oil ratio of 7.5:1, 3 % (w/w) of catalyst, and 16 % (v/v) of water content, the method yielded a maximum fatty acid methyl ester (FAME) conversion of 93.4 %. Diesel and 20 % biodiesel have been assessed in terms of performance and emissions analysis. Comparing a 20 % blend of biodiesel to commercial diesel at full load, the emissions of carbon monoxide (CO) were reduced by 21.2 %, hydrocarbon (HC) emissions by 18.02 %, and nitric oxide (NO) emissions by 4.33 %. In addition, the capital flow of the suggested biorefinery was assessed using a techno-economic analysis. The biorefinery process payback period for the biodiesel, bio-oil, and charcoal made from M. indica was determined to be 3.1358 years using the Aspen Plus Economic Analyzer. Techno-economic studies reveal that the biorefinery process is highly lucrative and practical. The current study therefore shows methods to use the Madhuca indica seed biorefinery to produce sustainable energy and byproducts with no net emissions of carbon.

Interconnected pyrolysis and activation with in-situ H3PO4 activation of biochar from pear wood chips in a pilot scale dual fluidized bed

Interconnected pyrolysis and activation is a novel technology for combustible gas and biochar production in dual fluidized bed (DFB). The study proposed one-step and two-step methods for pyrolysis and activation of biomass in a pilot scale DFB with capacity of 100 kg/h. Physical and chemical activation occurred simultaneously in DFB system by phosphoric acid (H3PO4) impregnation pretreatment of pear wood chips, and flowing hot flue gas and steam. Stable operating parameters were observed for both methods. The one-step method was superior to the two-step method in terms of the pyrolysis gas quality, biochar pore distribution, micro- and meso-pores structures of biochar, while one-step method reduced the biochar yields. As an activation agent, H3PO4 increased the yields of biochar and pyrolysis gas, promoted formation of micropores and enriched the surface functional groups of biochar with increasing ratio of H3PO4. H3PO4 to biomass ratio of 1:5 reached the maximum biochar yield of 42.3 wt% and highest iodine adsorption value of 648.5 mg/g, increasing by 70.6 % and 90.3 % compared to the biochar without H3PO4 pretreatment, respectively. This DFB system facilitated the diversified use of fluidized beds and the co-production of biochar and product gas with energy saving and CO2 emission reduction.

Co-production of biochar and carbon nanotube from sewage sludge in a two-stage process coupling pyrolysis and catalytic chemical vapor deposition

Co-production of biochar and carbon nanotube from sewage sludge in a two-stage process coupling pyrolysis and catalytic chemical vapor deposition

Effect of air equivalence ratio on the characteristics of biomass partial gasification for syngas and biochar co-production in the fluidized bed

In order to explore the characteristics and mechanism of biomass partial gasification for biochar and syngas co-production in the fluidized bed, a study on the influence of gasification performance and biochar characteristics after partial gasification with different air equivalence ratios was carried out in a self-built small atmospheric bubble fluidized bed. The results indicate that when the air equivalence ratio rises from 0.07 to 0.16, the lower calorific value of wet producer gas keeps decreasing, and the maximum value can reach 9.16 MJ/Nm3. The biochar yield shows a declining trend, and the maximum value is 18.07 %. In addition, when the air-equivalence ratio is lower than 0.14, the rising of air equivalence ratio makes biochar more disordered due to the newly formed C–O structures, and the total Raman intensity will thereby continue to increase.

Co-production of biochar and electricity from oil palm wastes for carbon dioxide mitigation in Malaysia

Power and heat production is the leading cause of greenhouse gas emissions in Malaysia, contributing to over 30% of total emissions. The transition from fossil to biomass resources in the power industry is an essential step towards achieving carbon neutrality in Malaysia. Oil palm wastes are the most abundant biomass resources in Malaysia because of the thriving oil palm industry. Consequently, two scenarios: (1) co-production of biochar and electricity, and (2) electricity generation, were proposed and simulated in Aspen Plus. A comprehensive evaluation system for mass and energy balances, techno-economic analysis, and life-cycle assessment was established to assess the two scenarios quantitatively. The results indicated that Scenario 1 achieved better economic and environmental benefits, the payback period was 6.12 to 8.89 years, and the global warming potential ranged from −885.23 to −1311.95 kg CO2-eq/t. The state-level spatiotemporal trajectory of oil palm waste resources and CO2 emission reduction potentials and economic benefits were analyzed. Theoretically, fully utilizing oil palm wastes in Scenario 1 would create economic benefits of 35.36 billion USD and mitigate CO2 emissions by 131.97 million tons in 2021. This study provides useful guidance for exploiting oil palm wastes to achieve carbon neutrality in Malaysia.

Techno-Economic Feasibility of Biomass Gasification for the Decarbonisation of Energy-Intensive Industries

The current climatic and geopolitical situation leads to strong decarbonisation policies in several industries worldwide. Moreover, the European Union is pushing intensive industries to achieve a 55% reduction in CO2 emissions towards 2030. Among them, the steel manufacturing sector is at the lead of alternative projects that can help achieve this ambitious target. Co-production of syngas and biochar is one potential solution for this sector. Herein, a techno-economic analysis is provided to evaluate the economic feasibility and the effect of the most influential parameters for a successful deployment. A bibliographic review has been carried out to establish a clear baseline for such an analysis in terms of investment costs at several scales for gasification projects. Additionally, the cost evolution for coke, natural gas, and CO2 emission credits on the profitability of these projects are given. The case scenario processing 20,000 tbiomass/y is the most feasible solution, with a payback of around three years and a net present value (NPV) of around 15 million EUR, showing that biomass gasification can be an up-and-coming alternative in the mid-term.

Carbon-negative co-production of methanol and activated carbon from bagasse pyrolysis, physical activation, chemical looping, and methanol synthesis

Methanol is regarded as an important chemical precursor in the chemical industry and has huge potential to replace gasoline and diesel as vehicle fuel. Biomass to methanol is a sustainable and green production method, but its economic and environmental viability is contingent on production technologies and geographic context. This study proposed a carbon-negative methanol production method that integrated four modules of bagasse pyrolysis, physical activation, chemical looping, and methanol synthesis in the context of China. Three scenarios, including co-production of methanol and biochar, co-production of methanol and activated carbon, and co-production of methanol and activated carbon with extra hydrogen, were put forward and simulated in Aspen Plus. An evaluation system was established to quantitatively assess the carbon and energy efficiencies and economic and environmental benefits of the three scenarios. The results suggested that the addition of hydrogen effectively increased the methanol yield in Scenario 3, leading to high carbon and energy efficiencies. Scenarios 1 and 2 exhibited better economic and environmental performance with low payback periods of 6.53 and 5.80 years and low global warming potentials of −1631.18 and −710.28 kg CO2-eq/t methanol. However, Scenario 3 would be economically and environmentally feasible by decreasing hydrogen production costs and implementing green hydrogen production methods in the foreseeable future. This study provides a viable approach for sustainable methanol production in China, thereby aligning with the current imperative of achieving carbon neutrality.

Investigating co-production of syngas, biochar, and bio-oil from flax shives biomass by pyrolysis and in-line catalytic hybrid reforming

Investigating co-production of syngas, biochar, and bio-oil from flax shives biomass by pyrolysis and in-line catalytic hybrid reforming

Biomass-powered thermal weeding in wine farms: An environmental and economic assessment

The energy transition in agriculture must be accompanied by agronomic practices that shift production towards organic regimes. Among the energy consuming processes that today find resistance in organic conversion there is certainly the removal of weeds from crops, that is mainly carried out through herbicides. This analysis evaluates the economic and environmental implications that the introduction of innovative thermal weeding systems, powered by biomass gasification, can have in the substitution of traditional chemical and mechanical weeding technologies. The comparison is carried out through a combination of cost–benefit analysis, environmental analysis and sensitivity analysis applied to the case study of vineyard management in northern Italy. The results show that the biomass-powered weeding system is economically feasible when it can benefit from economic incentives that reward organic production. In all cases, biomass-powered weeding system provides for a reduction in equivalent CO2 emissions which reaches −75% in the case of replacement of glyphosate-based chemical weeding methods. The analysis points out that gasification-powered weeding process can also achieve carbon neutrality through the co-production of biochar, which should lead policy makers to support this practice under the environmental objectives at national and European level.

Co-production of biooil and biochar from microwave co-pyrolysis of food-waste and plastic using recycled biochar as microwave susceptor

Microwave (MW) co-pyrolysis of food-waste (FW) and plastic with recycled biochar as MW susceptor was investigated for co-production of biooil and biochar. Effect of biochar recirculation (3–10 wt%) was analysed on end product yield and properties and compared with conventional MW susceptor (Granular Activated Carbon, GAC). Highest biooil yield (52 wt%) along with 30 wt% of biochar yield were obtained with 7 wt% biochar recirculation. pH and density of biooil were 4.12 and 1.09 g/mL, respectively. Increase in biochar recirculation caused substantial reduction in phenols, acids, alcohols, furans and oxygenated compounds in biooil due to rapid feedstock volatilization, end-chain β-scission and/or disengaging of the long carbon chain of FW and LDPE and transference of oxygenated functional groups into the gaseous phase. Similarly, with increased biochar recirculation, biochar showed decrease in volatile matter (by 47 %) with a simultaneous increase in fixed carbon (by 10 %), carbon (by ∼ 6 %), higher heating value (by ∼ 27 %) and morphological properties. 70 % of biooil energy yield and 45 % of biochar energy yield (obtained with 7 wt% biochar recirculation) accounted for the highest net energy efficiency of 115 %, which was comparable to that of GAC (117 %).

Negative emission power plants: Techno-economic analysis of a biomass-based integrated gasification solid oxide fuel cell/gas turbine system for power, heat, and biochar co-production—part 2

In our previous work (Part I), we evaluated the thermodynamic models of the biomass-fed integrated gasification solid oxide fuel cell system with a carbon capture and storage (BIGFC/CCS) unit. In this work (Part II), the techno-economic analysis of the proposed negative emission power plants is carried out. Levelized cost of electricity, net present value (NPV), payback period, internal rate of return (IRR), and levelized cost of negative carbon (LCNC) are the key economic parameters evaluated. The results of a series of sensitivity analysis show the impact of gasification agents and stepwise increase in biochar co-production on the performance of the system. The total overnight cost is estimated to be 6197 $/kW and 5567 $/kW for the air and steam-oxygen gasification BIGFC/CCS systems, respectively. Steam-oxygen gasification is found to be more economically beneficial than air gasification one for all of the cases studied. Economically viable biochar co-production cases are identified to ascertain the influence of capital cost, operating cost, biomass cost, plant capacity factor, and tax. Moreover, the effect of the carbon credit scenario on the economic indicators is also reported. The results show that the most effective economic performance from the steam-oxygen gasification case reported an NPV of 3542 M$, an IRR of 24.2%, and a payback period of 3.3 years, with an LCNC of -322.5$/t of CO2. Compiling the results from Part I and Part II shows that it is easier to achieve negative emission using the steam-oxygen gasification of a BIGFC/CCS system. These results are expected to be helpful for stakeholders in identifying appealing negative emissions power plant projects for near and long-term future investments.

Bioavailability and speciation of Cadmium in contaminated paddy soil as alleviated by biochar from co-pyrolysis of peanut shells and maize straw

BackgroundBiochar is an important material for remediation of Cd in contaminated paddy soils. However, different biochars have variable effects on bioavailability of Cd while single biochar cannot properly amend immobilized Cd. Co-production of biochar from peanut shells and maize straw at different mass mixing ratios (1:0, 1:1, 1:2, 1:3). The characteristics, properties and effects of co-pyrolysis biochars on amendments of Cd polluted paddy soil was evaluated.ResultsOur research revealed that yield, ash, elemental contents and specific surface area of co-pyrolysis biochars have variable amendment effects compared with single biochar. The co-pyrolysis biochars have produced rich oxygen-containing functional groups and crystal structure, especially 1P3M (co-pyrolysis biochar produced from peanut shell and maize straw in mass ratios of 1:3). The addition of biochar has significantly enhanced pH and EC value, however, content of available Cd during incubation was significantly reduced compared with control treatment. The efficiency of biochars have reduced available Cd in order of 1P3M > M > 1P1M > 1P2M > 2P1M > 3P1M > P after incubation. The 1P3M was most effective in reducing CaCl2-extractable Cd concentration up to 43.97%. The BCR sequential extraction method has produced lowest exchangeable fraction Cd content and highest residual fraction Cd content in 1P3M among all biochar amended treatments.ConclusionsIt is concluded that 1P3M has a much greater potential to decreased the bioavailability of Cd in contaminated paddy soil. And 1P3M was highly effective for transporting Cd from soluble form to less toxic stable forms in polluted paddy soils.Graphical

Negative Emission Power Plants: Thermodynamic Modeling and Evaluation of a Biomass-Based Integrated Gasification Solid Oxide Fuel Cell/Gas Turbine System for Power, Heat, and Biochar Co-Production—Part 1

This article is the first of a two-part series presenting the thermodynamic evaluation and techno-economics of developing negative-emission power plants. The aim of this research is to evaluate the potential of biochar co-production in negative-emission power plants based on biomass-fed integrated gasification solid oxide fuel cell systems with carbon capture and storage (BIGFC/CCS) units. The influence of two gasification agents, namely, air and steam-oxygen, on the proposed system is investigated. In Part I, we present the thermodynamic models. A sensitivity analysis is carried out to investigate the system response to stepwise increase in biochar co-production (up to 10% by weight). Providing a secondary oxy-combustor in the steam-oxygen gasification case has been shown to be a solution to meet the heat requirements of the allothermal gasification process. A comprehensive exergy analysis indicated significant efficiency improvement for the steam-oxygen gasification case. The results show that the biomass steam-oxygen gasification yields the higher electrical exergy efficiency (48.3%) and combined heat and power (CHP) exergy efficiency (54.6%) for the similar rates of biochar co-production. The specific power output per unit of CO2 stored is 2.65 MW/(kg/s) and 3.58 MW/(kg/s) for the air and steam-oxygen gasification cases, respectively, when the biochar is co-produced at 10% by weight for the given biomass flow of 20 kg/s. Moreover, the total CO2 stored due to the proposed system is calculated as 133.9 t/h, and it is estimated to remove 1.17 Mt of CO2 from the atmosphere annually (when the biochar-based carbon storage is also considered). The models are used for the techno-economic analysis presented in Part II of the series.

An economic and environmental assessment of biofuel produced via microwave-assisted catalytic pyrolysis of forest residues

The conversion of forest residues into biofuels will enhance the decarbonization of the transportation sector and help the world reach its net-zero targets. Microwave-assisted catalytic pyrolysis (MACP) is an emerging thermo-catalytic conversion technology which, when coupled with low-carbon electricity, will result in negative emissions. The work described here assessed the economic feasibility and environmental impact of a novel MACP system for co-production of upgraded biofuel and high-quality biochar from forest residues. The cradle-to-gate (CTG) carbon intensity of MACP biofuel ranged from −57.3 to 27.4 g CO2-eq/MJ respectively when using either low-carbon electricity or carbon-intense electricity. Compared to petroleum fuels, a 43% to 162% reduction of GHG emissions could be achieved depending on electricity mix and methods to treat biochar co-product. The use of electricity to produce MACP biofuel as compared to directly charge electric vehicles was justified as a preferred use based on the finding that the advanced utilization of waste biomass via MACP could contribute significantly to GHG reduction of transportation fuel without sacrificing the travel distance of vehicles. The minimum selling price (MSP) of MACP biofuel was $1.02/L in the absence of any policy support and could be reduced to a comparable price of petroleum fuels at $0.53/L or increased to $1.32/L depending on the co-product revenue from biochar’s higher or lower-value applications. MACP biofuel could also be priced competitively with petroleum fuels by as early as 2026 under the planned carbon tax schedule in Canada. This co-production of upgraded biofuel and value-added biochar could bring flexibility to the biorefinery to seek the highest possible economic and environmental benefits facing the changing market and policy.

Measurement of Transport Properties of Woody Biomass Feedstock Particles Before and After Pyrolysis by Numerical Analysis of X-Ray Tomographic Reconstructions

Lignocellulosic biomass has a complex, species-specific microstructure that governs heat and mass transport during conversion processes. A quantitative understanding of the evolution of pore size and structure is critical to optimize conversion processes for biofuel and bio-based chemical production. Further, improving our understanding of the microstructure of biochar coproduct will accelerate development of its myriad applications. This work quantitatively compares the microstructural features and the anisotropic permeabilities of two woody feedstocks, red oak and Douglas fir, using X-ray computed tomography (XCT) before and after the feedstocks are subjected to pyrolysis. Quantitative analysis of the three-dimensional (3D) reconstructions allows for direct calculations of void fractions, pore size distributions and tortuosity factors. Next, 3D images are imported into an immersed boundary based finite volume solver to simulate gas flow through the porous structure and to directly calculate the principal permeabilities along longitudinal, radial, and tangential directions. The permeabilities of native biomass are seen to differ by three to four orders of magnitude in the different principal directions, but we find that this anisotropy is substantially reduced in the biochar formed during pyrolysis. The quantitative transport properties reported here enhance the ability of pyrolysis simulations to account for feedstock-specific effects and thereby provide a useful touchstone for the biorefining community.

Co-production of phenolic-rich bio-oil and magnetic biochar for phosphate removal via bauxite-residue-catalysed microwave pyrolysis of switchgrass

Bauxite residue (BR) was tested as a low-cost microwave absorber and catalyst for microwave-assisted pyrolysis for producing phenolic-rich bio-oil, along with magnetic biochar that can be used as an adsorbent for capturing excess nutrients, such as phosphates, from eutrophic water or wastewater. Mixing BR alone with switchgrass (SG) did not enhance SG microwave absorption, while mixing 10 wt% clinoptilolite and 20 wt% BR (10Clino–20BR) with SG increased the heating rate by 382% in comparison with 10Clino alone, due to the formation of good microwave absorbers (i.e. maghemite and magnetite) on the biochar surfaces, confirming their synergistic effects. The addition of BR reduced the acidity of the bio-oil by up to 47%, and increased the production of aromatics and alkylated phenols by up to 180% and 319%, respectively, compared with 10Clino alone. Biochar produced from 10Clino–20BR had magnetic properties, which are very important for facilitating the separation of spent biochar from P-contaminated aqueous solutions in industrial applications. Using the magnetic biochar for phosphorus adsorption, the highest adsorption capacity of 64.4 mg PO43−/g (21 mg PO43--P/g) was measured for the biochar produced using 10Clino–20BR at pH 4, and the adsorption isotherm was fitted by the Freundlich model very well. The magnetic biochar showed a high adsorption capacity for phosphate removal. In addition, the P-loaded biochar could be marketed as a balanced fertilizer to increase soil fertility, converting BR into a valuable product, instead of a waste material.

Multi-objective optimization of an integrated biomass waste fixed-bed gasification system for power and biochar co-production

In this work, an integrated biomass waste gasification combined heat and power (CHP) system is simulated and analyzed based on a multi-scale first-principles numerical model, which consists of a 1D fixed-bed gasifier model and a 1D hybrid peripheral fragmentation and shrinking-core biomass particle model. The simulations are based on a 15kW gasification CHP system and the numerical model is validated by two different groups of experimental data, and the maximum deviation is 2.56% in syngas H2 composition prediction. A multi-objective optimization framework of the integrated biomass waste gasification CHP system is formulated that considers 3 objectives: economic benefit, greenhouse gas emission, and potential health impact caused by PM emission. The best-compromised solution from the Pareto front leads to $142.8/day economic benefit, 694.3 kg CO2eq/day mitigation, and 57.67 Singapore Pollutant Standards Index score. The impacts of the three objectives on decision variables (i.e., feedstock flowrate, feedstock moisture content, and equivalent ratio) are analyzed by investigating 21 different weighted single-objective problems.

A Review of Intermediate Pyrolysis as a Technology of Biomass Conversion for Coproduction of Biooil and Adsorption Biochar

The agenda to utilize and efficiently convert biomass has been raised to alleviate environmental problems and pressure on the reliance on fossil fuel. Intermediate pyrolysis has the ability to treat different biomasses and coproduction of biooil and adsorption biochar. This review article aims to evaluate the appropriateness of intermediate pyrolysis for the coproduction of biooil and adsorption biochar. It was observed that coproduced biooil is of high quality, stable, and miscible that can be used directly to existing engines or be easily blended. The biochar coproduced is good for adsorption but is not stable for microbial attack and hence unsuitable in soil treatment but for hydrometallurgy. Since the process is capable of treating waste biomass, it is an opportunity for further investigations in areas where wastes are plenty and less utilized. To increase the effectiveness of this technology for coproduction, optimizing parameters, design of efficient reactors, and use of catalyst must be worked upon.

Local lignocellulosic biofuel and biochar co-production in Sub-Saharan Africa: The role of feedstock provision in economic viability

Bioenergy production in developing countries remains a contentious topic. We study feedstock provision costs in the context of a hybrid thermochemical-biochemical (HTB) lignocellulosic conversion process to co-produce ethanol and biochar in rural Sub-Saharan Africa. Using household-level and market data from Kenya, we examine the availability and cost of purchasing agricultural residues from smallholder farmers and transporting residues to a local-scale (10–20 Mg dry biomass per hour) HTB biofuel-biochar plant with integrated syngas-fermentation for ethanol production. We demonstrate that these costs depend significantly on regionally-specific agroecological and socio-economic conditions, such as crop yields, cropland density, and the value of crop residues to farmers. Only under the best-case scenario do we find that this integrated biofuel-biochar plant with 15 Mg of feedstock per hour capacity has positive net present value.

Effects of MgCl2 and Mg(NO3)2 loading on catalytic pyrolysis of sawdust for bio-oil and MgO-impregnated biochar production

For high-quality utilization of biomass resources, co-production of bio-oil and MgO-impregnated biochar from catalytic pyrolysis of Mg-loaded biomass samples is a prospective approach. In this study, the effects of MgCl2 and Mg(NO3)2 loading on catalytic pyrolysis of sawdust for production of high value-added bio-oil and biochar, as well as the catalytic pyrolysis process mechanism were explored. The thermal degradation process behavior and the pyrolysis products of non-condensable gas, bio-oil and biochar were obtained by thermogravimetric analyzer (TGA) and lab-scale fixed-bed reactor system. The product properties were analyzed and characterized by gas chromatography (GC), gas chromatography-mass spectrometry (GCMS), N2 adsorption-desorption, X-rays diffraction (XRD) and transmission electron microscopy (TEM). The obtained results indicated that the loading of Mg salts favored the thermal degradation process of catalytic pyrolysis due to the weakened hydrogen-bonding networks and disrupted the crystalline structures. The enhanced cross-linking and repolymerization reactions of pyrolysis intermediates by the catalytic effect of Mg resulted in the increased non-condensable gas and biochar yields and the decrease of bio-oil yield. The loading of Mg salts also resulted in the decreased CO yield and increased CO2 yield. The relative contents of ketones and furans increased, and the relative contents of phenols and sugars decreased for Mg-loaded SD samples in bio-oil. In addition, the Mg salts loading also favored the formation of developed pore structure and uniformly dispersed MgO nanoparticles in obtained biochar. In general, catalytic pyrolysis of MgCl2-loaded or Mg(NO3)2-loaded sawdust is a feasible method to obtain high value-added bio-oil and MgO-impregnated biochar products.