Source Of Feedstock Research Articles

From Fossil Fuels to Renewable Biogas Production from Biomass Based Feedstock – A Review of Anaerobic Digester Systems

Three-quarters of the global energy consumption is expected to come from fossil fuels by 2040 despite many drawbacks to the world’s reliance on fossil fuels. The primary drawback of fossil fuels is in procuring, transporting, refining, and combusting them which generates pollution biproducts, global warming, which in turn generate a plethora of associated problems. Biomass as a renewable resource and its conversion into renewable fuel products can offset use and drawback of fossil fuels.
 Anaerobic digestion is known since the 10thcentury BC has become today a versatile tool to produce renewable energy in form of biogas from many biomass-based feedstock sources. These sources can be agriculturally based such as livestock waste, energy crops, plant (lignocellulosic) based, forest residues, or industrial and municipal waste such food waste, wastewater treatment sludge, distiller grains and food product residues. Feed stocks can be used in anaerobic fermentation processes as single or co-digest feedstock. Each feedstock represents a challenge on its own for anaerobic digestion processes in order achieve good operational stability and good biogas production.
 Selecting a suitable anaerobic fermentation process from today’s available technical sound processes described in this review is essential for future fossil fuel independence.

Advances in nutrient management make it possible to accelerate biogas production and thus improve the economy of food waste processing

ABSTRACT Foodwaste (hereinafter, FW) is the most voluminous solid waste and its amount is growing rapidly all over the world. The turning of FW into biogas via anaerobic fermentation is widely recognized as an environmentally responsible and economically reasonable option. Based on the knowledge obtained from agricultural biogas stations, the current methods of FW fermentation management are based on balancing the ratio of total carbon and nitrogen. However, it was repeatedly and independently reported that the stability of this process is low, resulting in many concessions in terms of prolonged hydraulic retention time or reduced biogas yield. Hence, biochemical as well as economic performance of the process is balanced by mixing of FW with agricultural residues. FW samples of various origin were collected and biochemically analyzed. The data indicate that FW originating from homes and luxury restaurants tends to be lignocellulose-based, whereas the levels of crude fiber (25% up to 27%) are higher than those from agricultural feedstock (18%). In contrast, FW from school canteens and inexpensive restaurants tends to be starch-based with high levels of amyloids (21% up to 23%) and fat (5% up to 7%). A novel method better reflecting the bioavailability of carbon and nitrogen to anaerobic consortia is proposed. It is demonstrated that the previous optimization methods could somehow reflect the availability of nutrients in agricultural feedstock, as carbonaceous and nitrogen sources are relatively equally biodegradable. Nevertheless, the biodegradability of FW is considerably different, which is why higher amounts of proteins and lipids lead to increased levels of ammonia and sulfide, resulting in an inhibitory effect on the metabolism of anaerobic consortia. Optimizing the anaerobic fermentation of FW by the new method outperforms the previous technique and makes it possible to process FW more intensively, or, more precisely, with higher profitability and lower proportion of ballast agricultural feedstock.

Recent progress on engineering microbial alginate lyases towards their versatile role in biotechnological applications.

Biomass feedstock is an efficient and harmless source of energy. There are various sources of feedstock, such as plant, microbial, macro, and microalgae, and agricultural waste. The major component in biomass feedstock material is a polysaccharide, such as cellulose, cellobiose, starch, and alginate. Alginate is mainly found in macroalgae as one of the significant polysaccharide components. It is made up of β-d-mannuronate (M) and α-l-guluronate (G) blocks. Alginate lyase is an enzyme that degrades alginate by breaking the glycosidic linkage between the poly M and G blocks to liberate oligosaccharides. Several organisms, including bacteria, fungi, viruses, and algae can produce alginate lyases. The species of bacteria, such as Bacillus, Vibrio, Pseudomonas, and Microbulbifer, are some of the important sources of alginate lyases. They are industrially essential enzymes used in food, biofuel, and biomedical industries. There are various assays available to determine the alginate lyase activity qualitatively as well as quantitatively. Qualitatively, different dyes like Gram's iodine, cetyl pyridinium chloride, and rutanium red can be used to visualize the zone formed due to the alginate lyase activity. DNS assay, UV absorption, and the Somogyi-Nelson method help to determine the alginate lyase activity quantitatively. Since the alginate lyase production in the native organisms is relatively lower, the genes encoding alginate lyases are heterologously cloned and expressed in E. coli to maximize the production and to characterize the enzyme. Different chromatographic techniques like size exclusion, affinity, gel permeation, and ion-exchange chromatography are used to purify the protein. In this paper, the source of alginate and alginate lyases, the mechanism of action of the enzyme, the engineering approaches to enhance the enzyme production, its purification strategy, and the potential applications of alginate lyases has been discussed.

Enhancing photosynthetic production of glycogen-rich biomass for use as a fermentation feedstock.

Current sources of fermentation feedstocks, i.e. corn, sugar cane, or plant biomass, fall short of demand for liquid transportation fuels and commodity chemicals in the United States. Aquatic phototrophs including cyanobacteria have the potential to supplement the supply of current fermentable feedstocks. In this strategy, cells are engineered to accumulate storage molecules including glycogen, cellulose, and/or lipid oils that can be extracted from harvested biomass and fed to heterotrophic organisms engineered to produce desired chemical products. In this manuscript, we examine the production of glycogen in the model cyanobacteria, Synechococcus sp. strain PCC 7002, and subsequent conversion of cyanobacterial biomass by an engineered Escherichia coli to octanoic acid as a model product. In effort to maximize glycogen production, we explored the deletion of catabolic enzymes and overexpression of GlgC, an enzyme that catalyzes the first committed step towards glycogen synthesis. We found that deletion of glgP increased final glycogen titers when cells were grown in diurnal light. Overexpression of GlgC led to a temporal increase in glycogen content but not in an overall increase in final titer or content. The best strains were grown, harvested, and used to formulate media for growth of E. coli. The cyanobacterial media was able to support the growth of an engineered E. coli and produce octanoic acid at the same titer as common laboratory media.

Assessing the wood sourcing practices of the U.S. industrial wood pellet industry supplying European energy demand

BackgroundAs the demand for wood pellets has increased in EU member states, so has a multi-pronged examination of the environmental effects of establishing a transatlantic trade in wood pellets between the U.S. and Europe. However, the nature of industrial wood pellet supply chains is poorly understood or little known. This work aimed to understand the feedstock sourcing strategies being used by the wood pellet industry in the southeast U.S., commonly applied approaches to documenting sustainability of these feedstocks, and drivers operating behind related developments.MethodsThis study used structured interviews of sustainability managers and procurement staff at pellet mills comprising 75% of the U.S. industrial pellet sector. The industry was classified into types of supply chains, based on the role of loggers, wood dealers, sawmills, and other wood product facilities in the supply chains. Additional classifications examined feedstock types and origins, number and type of suppliers, contractual relationships with suppliers, applied procurement systems, risk assessment and due-diligence methodologies, risk mitigation procedures, and supply chain certifications.ResultsThree main types of supply chains were identified within the U.S. industrial pellet sector, differentiated based on features of feedstock procurement, risk assessment procedures, and risk management. The study observed a slight shift toward using a higher proportion of wood residuals as feedstock in some of the larger pellet mills. Policy requirements, customer orders, and external pressures were driving the sector’s adoption of sustainability programs, with risk assessments and wood procurement procedures aligned to policy requirements.ConclusionsThe strength of a risk-based approach to sustainability documentation depends on the quality of source data on risks within a sourcing area, scale of analysis, and integration of risk assessments into procurement practices. Some risk categories are more difficult to assess and control. Challenges increase with increasing number and diversity of supply chain actors and depend on the nature of agreements between these entities for the conveyance of feedstocks to pellet mills. Fiber procurement is similar to pulpwood-using industries, but extending the risk assessment to residuals is complicated and challenging to the sector. The study identified a number of strategies in use within pellet mill supply chains for dealing with these challenges.

Recent advances in biochar application for water and wastewater treatment: a review.

In the past decade, researchers have carried out a massive amount of research on the application of biochar for contaminants removal from aqueous solutions. As an emerging sorbent with great potential, biochar has shown significant advantages such as the broad sources of feedstocks, easy preparation process, and favorable surface and structural properties. This review provides an overview of recent advances in biochar application in water and wastewater treatment, including a brief discussion of the involved sorption mechanisms of contaminants removal, as well as the biochar modification methods. Furthermore, environmental concerns of biochar that need to be paid attention to and future research directions are put forward to promote the further application of biochar in practical water and wastewater treatment.

Biodiesel production and characterisation of poppy (Papaver somniferum L.) seed oil methyl ester as a source of 2nd generation biodiesel feedstock

One of the challenging tasks for the researchers is to identify alternative renewable energy feedstocks which can be used as a substitute for fossil fuel to meet the increasing demand for energy, reduce the depletion of fossil fuel reserves and eliminate the increasing concerns of environmental impact. The 2nd generation poppy (Papaver somniferum) seed oil (PSO) can be considered as one of the feedstocks which would be low cost and does not compete with food crops for biodiesel production. In this study, biodiesel production was conducted in 2 stage processes which consist of acid and base–catalysed esterification and transesterification to reduce the free fatty acid (FFA) content of poppy seed oil (PSO) and to increase the yield of poppy seed oil methyl ester (PSOME), respectively. To determine the maximum yield of methyl ester, different parameters that influence the production of methyl ester, namely the molar ratio of methanol to oil (5.0:1–7.0:1), catalyst loading (0.5–1.5 wt.%), reaction temperature (40–80 °C) and time (60–120 min) were investigated under the transesterification reaction. The results found that methanol to oil molar ratio of 6.0:1, catalyst loading of 1.0 (wt.%), reaction temperature of 60 °C and reaction time of 90 min were observed to be the optimum process parameters for maximising the yield of PSOME at a constant speed of 720 rpm. In these conditions, the maximum methyl ester yield was found to be about 93 %. The gas chromatography (GC) analysis was conducted to evaluate the fatty acid methyl ester (FAME) composition of the PSOME. Furthermore, the physico-chemical properties of the PSOME were evaluated and characterised using ASTM and EN standards for biodiesel. It was found that PSO can be used as a potential feedstock for biodiesel production as most of the physico-chemical properties are within the ASTM and EN standards.

Hydrochars production, characterization and application for wastewater treatment: A review

Hydrothermal carbonization (HTC) of wet solid wastes has been pointed out as an eco-friendly, flexible and highly efficient technology for the sustainable valorization of multiple sourced wastes. In this review paper, most recent studies on hydrochars (solid residue of the HTC process) production, characterization and application for wastewaters treatment was summarized and deeply discussed. The role of initial feedstock source nature and characteristics as well as the HTC experimental conditions including the temperature, the residence time and the pH media was assessed. Physical and chemical activation methods including the use of oxygen, steam, microwave, acids, alkaline, organics and salty solutions for the improvement of the physicochemical properties of the produced hydrochars are compared. The efficiency of these raw/modified hydrochars along with the involved mechanisms during organic (dyes) and mineral pollutants (heavy metals and nutrients) removal from aqueous solutions is also reviewed. Finally, this paper addresses the main challenges and also demonstrates insights on new directions for hydrochars research and development in the future.

Bioethanol Producing Equipment Prototype Using Cassava Peel Using Microcontroller-Based Destilation Principles

Bioethanol is a biochemical liquid in the process of fermentation of sugars from carbohydrate sources using the help of microorganisms followed by the distillation process. Bioethanol can be used as a substitute for fuel oil depending on its purity. Bioethanol with 95-99% content can be used as premium substitution (gasoline), while 40% content is used as a substitute for kerosene. Cassava peel obtained from cassava plant products (Manihot esculenta Cranz or Manihot utilissima Pohl) is the main food waste in developing countries. Each kilogram of cassava can usually produce 15-20% of tuber skin. The cassava skin starch content is quite high, allowing it to be used as a source of bioethanol feedstock. In this research, the distillation process to produce bioethanol is carried out by controlling the temperature and pressure in the distillator so that the bioethanol produced can be maintained.

The conversion of biomass into renewable jet fuel

Producing renewable jet fuels from solid waste contributes greatly on circular economy with respect to the energy, environment and economics. The feedstock sources are resolved, the solid wastes are re-used, the pollution from aircrafts are reduced and the air energy is renewed. In this study, the rice husk biomass, which has been a headache agriculture waste in Taiwan, was turned into products similar to traditional jet fuel through fluidized bed fast pyrolysis, hydro-processing and hydro-cracking/isomerization, in which significant increases in normal alkanes, iso-alkanes and cycloalkanes were found. The final product from hydro-cracking/isomerization contained appropriate amount of normal, iso-, and cyclo-alkanes, which made it suitable to be the replacement for jet fuel.

Biodiesel fuel production from brown grease produced by wastewater treatment plant: Optimization of acid catalyzed reaction conditions

Periodic spikes in crude oil prices have led to a need in alternative energy sources. A major potential source of biodiesel feedstocks is brown grease, a byproduct of wastewater treatment. A recent brown grease sample from this contained 60 % FOG (fats, oils, and greases), 25 % water, and 15 % biosolids by mass. This study is focused optimizing the reaction conditions (i.e., quantities of Methanol, Sulfuric Acid, Fe2(SO4)3, and time) to maximize the yield of esters, with minimal residual free fatty acid (FFA), in the shortest residence time. Response Surface Methodology (RSM) was used to evaluate the correlation between the process variable and the response. The significance of quadratic model of each response was determined by analysis of variance, where all models indicated sufficient significance with p-value < 0.0001. Using a basis of 40 g brown grease, optimized conditions were 35 ml MeOH, 1.3 ml H2SO4, 0 g Fe2(SO4)3 and reaction time of 120 min, resulting in a biodiesel yield of 99.70 %. The results showed efficient biodiesel production under the optimum conditions.

Synthesis of Bio-Oilphenol-Formaldehyde Resins under Alkali Conditions

In the present study, bio-oil produced from vacuum pyrolysis of woody biomass has been investigated as a source of chemical feedstock. Bio-based resins were produced using the bio- oil with phenol substitutions ranging from 10 to 30 wt%. The conventional GC/MS analysis was carried out for the evaluation of the chemical composition of bio-oil. TGA, DSC and FT-IR analyses were used in order to characterize the bio-oil-phenol-formaldehyde (BPF) resins. The bonding quality of wood samples bonded with the BPF resins was investigated under different pre-treatment conditions. The highest shear strength was observed for the control samples bonded with the laboratory PF resin. As the amount of bio-oil was increased up to 30 wt%, the shear strength of the samples decreased from 12.08 to 11.76 N/mm2. The bonding performance was not negatively affected by the combination of bio-oil under dry conditions. According to TS EN 12765 standard, the relevant performance requirements for bonded samples under dry conditions must be at least 10 N/mm2. Relating to the standard, all samples bonded with BPF resins obtained the requirements for durability class C1. Under wet conditions, the bonding performance was negatively affected by the addition of bio-oil. However, the BPF resins fulfilled the durability requirements for C1, C2, and C3 specified in EN 12765 (2002).

Transforming waste vegetable oils to biodiesel, establishing of a waste oil management system in Albania

Nowadays, food wastes contribute to a significant part of the total world wastes’ data, having a direct impact on the environment and economic losses. Use of Vegetable Oils for frying and other food-chain services studied for their potential as a feedstock source for biodiesel production. Development of the processing technologies has exploited their use as a valuable economic resource despite their status as food by-products. Recently in Albania, a private enterprise has oriented the investments in the frying waste vegetable oils by establishing a collecting network and their use for biodiesel production. In the first phase, is established the management system and collection network of Waste Vegetable Oil in restaurants, catering, and Fast-food chain in the Tirana-Durresi region. The results during the first year have shown that the collected amount reached 400 tons. Waste Vegetable oil collected data have reached approx 100 t per month. On a five-year strategic plan, the company aims to reach a collection of 15–20% of total waste vegetable oils, generated in-country, or potentially 6000–8000 tons per year. The contracts are organized bilaterally, between the end-point user and the company. Legislative enforcement to ban their disposal to the sewage system, or surface waters, are in action. Plant pilot experiments have successfully produced biodiesel using waste vegetable oils.

Sodium carbonate-based post combustion carbon capture utilising trona as main sorbent feed stock

In the pursuit of shifting technology towards sustainable, environmentally benign processes, post-combustion carbon capture technology is recognised to be a timely mitigation option. This paper presents the development of a novel sodium carbonate-based post combustion carbon capture process utilising the carbonate mineral trona (trisodium hydrogendicarbonate dihydrate) as main sorbent feedstock source. The energy penalty, the fraction of energy sacrificed to capture CO2 relative to the net energy produced serves as main performance indicator. Investigations on the correlative relationship between energy penalty as a function of capture efficiency are carried out by retrofitting the process to a 600 MW reference coal-fired power plant. The energy penalty of the global system features a distinct local minimum of 3.99%, corresponding to a CO2 capture efficiency of 90.00% and a CO2 outlet purity of 99.90%. The Specific Primary Energy Consumption for CO2 Avoided (SPECCA) index corresponding to this minimum is evaluated to be SPECCA = 0.514MJkgCO2-1. Sensitivity analyses on the effect of increasingly high SO2 flue gas volume fractions ySO2 show that the capture efficiency is virtually unimpaired for calcination temperatures of 190 ⩽T⩽280 °C and ySO2 ranging from 0.50 to 0.70%. Whilst commercially available CO2 capture technology is energy intense and prone to sorbent degradation, the process developed retains high capture efficiencies of calcium oxide-based looping cycles at low operating temperatures and eliminates the predisposition of amine-based sorbents utilised in scrubbing capture schemes to deplete due to the presence of SO2 in the inlet flue gas stream. It can be concluded that sodium carbonate based post-combustion capture processes are a competitive alternative to existing CO2 capture technologies.

Predicted annual biomass input to maintain soil organic carbon under contrasting management

AbstractCorn (Zea mays L.) residue is an important source of lignocellulosic feedstocks for meeting the US renewable energy goals. However, there is uncertainty in how much biomass can be sustainably harvested. The objectives of this study were to (i) simulate soil organic carbon (SOC) dynamics in the 0–20, 20–30, and 0–30 cm soil depths for the 2005–2015 study period using CQESTR, a process‐based C model; (ii) establish trends in SOC with residue removal and tillage management over the predictive period of 2016–2035; and (iii) recommend practices to maintain SOC stocks in a corn–soybean (Glycine max L. [Merr.]) rotation with corn residue removal in western Minnesota. The residue removal treatments in the conventional tillage since 1995 (CT95) and no tillage since 1995 (NT95) were initiated in 2005, and in 2006 for the no tillage since 2005 (NT05). Corn residue removal treatments were none, cob removal, ∼50% removal, and ∼75% removal (R0, RCob, R50, and R75, respectively). Only R0 in NT05 increased SOC (0.32 Mg C ha−1 yr−1) stocks in the top 30 cm soil depth by 2035 with annual aboveground biomass input of 6.30 Mg ha−1 yr−1. It was concluded that only the NT05 field has the potential to maintain SOC at the current rate of biomass addition, and a minimal annual aboveground C (MSC) input of 3.75 Mg C ha−1 yr−1 is required to maintain SOC until 2035. These simulation results indicate that caution should be used in removing residue especially under conventional tillage.

Comparison of Microstructural Response to Heat Treatment of Inconel 718 Prepared by Three Different Metal Additive Manufacturing Processes

Optimization of metallic components fabricated from age hardenable alloys relies on the use of effective heat treatments. As additive manufacturing (AM) is taking its place as “another tool in the toolbox” for fabrication of metallic components, numerous processes are under development differing mainly by the starting feedstock and heat source. In parallel with these efforts is the optimization of the post-processing heat treatment to obtain the required properties. Due to differences in the various processes, it is expected that different microstructures will form in the AM specimens possibly affecting the mechanical behavior. To address optimization of heat treatments requires an understanding of how the starting microstructure responds to heat treatments. This study looks at inherent differences in the response of Inconel 718 to heat treatments developed for wrought 718. Three different AM processes were used to fabricate the samples in this study.

Algae-Powered Sustainable Community Design Life Cycle Assessment and Techno-Economic Analysis

Microalgae as a feedstock source for biofuels have been researched extensively over the last decade as the renewable energy community strives to find an environmentally responsible and economically...

Nutrient recycle from algae hydrothermal liquefaction aqueous phase through a novel selective remediation approach

Algae have received increasing interest in the past several decades as a biofuel feedstock source. However, sustainable nutrient supply has presented algal biofuels with a major obstacle in the value chain. At a scale where algal biofuels would meet a significant portion of transportation fuel needs, the demand for nutrients, specifically nitrogen and phosphorus, would exceed current global agricultural production. One downstream conversion pathway, hydrothermal liquefaction (HTL), produces bio-crude oils from wet algal biomass with a waste aqueous phase (HTL-AP), containing a significant amount of carbon and nitrogen. While this stream is rich in organic content and nutrients, it also contains toxic components, which include heterocyclic nitrogen compounds and phenolic compounds. Thus, the recyclability and potential toxicity of HTL-AP need to be studied in detail. The feasibility of utilizing nutrients available in HTL-AP was experimentally determined for Chlorella vulgaris and Desmodesmus armatus monocultures. Our work focused on determining the tolerance of these algae species toward HTL-AP toxicity through varying dilutions. Nitrogen replacement in the growth media was varied from a low of 18% to a high of 141% across both species. The most notable of these results show that addition of a 100× dilution (35% nitrogen replacement) of untreated HTL-AP decreased growth in C. vulgaris by 47 ± 7% with respect to a control medium. Adsorption treatments, including activated carbon and various resins, were introduced to remediate the HTL-AP toxic effects. Treatment of the HTL-AP portion with an ion-exchange resin, Dowex 50WX8, supported C. vulgaris growth at a 100× dilution (35% nitrogen replacement) with no statistical change compared to the control. An in-depth molecular profiling demonstrated for the first time the selective removal of high‑nitrogen containing components by resin treatment. This work provides a foundation for studying the toxic components of HTL-AP and possible mechanisms by which treatments can remove these components.

Utilization of Lignin-Derived Small Molecules: Epoxy Polymers from Lignin Oxidation Products.

Much effort has been invested in developing methods for producing small molecules from lignin as a way to source feedstock chemicals from renewable sources. Significant progress is being made, and methods for deconstructing lignin are producing good yields of small, mononuclear aromatic products-sufficient amounts to enable studies of the potential use of these compounds as replacements for compounds currently produced from petroleum. To investigate the use of lignin products in epoxies, we begin with aromatic acids that can be produced from lignin, treat them with epichlorohydrin to make glycidyl ethers, and investigate the thermal and mechanical properties of cured mixtures of these compounds with a commercial epoxy resin (EPON 826) and an anhydride curing agent (NMA). While most of the lignin-modified epoxy polymers exhibit good physical and thermal properties, the polymer prepared from p-hydroxybenzoic acid (compound 6) has a higher glass-transition temperature (Tg = 159 °C) than do thermosets made with other lignin-derived materials, such as vanillic acid diglycidyl ether (compound 4) and matches the Tg of cured samples of the commercial EPON-826/NMA epoxy system. This is significant, as p-hydroxybenzoic acid is readily available by simple hydrolysis of several different lignins and functions as a drop-in replacement for 50% of the BPA-based material in this commercial system without significant degradation of material properties. The use of lignin-derived small molecules in high-value systems such as epoxies may help improve the economics of biorefineries.

Yield and Cost of Biochar Produced by a Locally Fabricated Reactor

Yield and Cost of Biochar Produced by a Locally Fabricated Reactor Akom, M., A. Fanyin - Martin, C. Oti-Boateng, E.Otoo1 and E. Dawoe Abstract This study examines the yield and cost of biochar produced using a locally developed reactor. Biochar yield of 540 kg was obtained from 1460 kg of wood shaving feedstock used. The average charring ratio and feedstock were 37% and122 kg respectively. A total of 988 kg of firewood was used to produce the biochar in 35 days. The total cost of production was GH¢ 1214.42 (USD 631.49) with an average of GH¢ 4.99 (USD 2.59), GH¢ 20.58 (USD 10.70), GH¢ 26.52 (USD 13.79) and GH¢ 19.95 (USD 10.37) spent on feedstock, firewood, transportation and labour per day respectively. It is suggested that locally manufactured reactor should address heat loss issues as well as improve heat capture system. The facility should also be sited near the source of feedstock as much as possible to reduce transportation cost. It is also recommended that the price of biochar should be subsidized once it has an established market. Full Text: PDF DOI: 10.15640/jaes.v9n2a1