Numerical investigaton for predicting diesel engine performance and emission using different fuels

The study focused on the numerical investigation for predicting engine performance and emission for a diesel engine using different fuels. The study reviewed recent literature on the effect of biofuels blend for maximizing the emission reduction for a sustainable environment. The key issues with the existing fuels have been briefly discussed in this article. The study investigated performance and emission characteristics using ethanol 85% blend denoted as E85 and Decane as an alternative fuel and compared the results with petroleum diesel fuel. The important physio-chemical fuel properties have been studied and compared with that of the commercial diesel fuel. The engine specification and other relevant information have been presented. The study investigated engine performance numerically by software tool by varying engine speeds at 1200 rpm, 1600 rpm, 2000 rpm and 2400 rpm at full load condition. The result presents the engine performance (such as BP, BSFC, BTE) and emission characteristics (CO, CO2, HC, NOx) using E85 and Decane and compared them with diesel at the same operating conditions. The study found that E85 fuel significantly reduces emission compared to Decane and diesel, however, it shows a poor performance. The numerical results were validated by experimental results and the reliability of the finding was discussed with an error analysis. Finally, the study recommended for more study on those fuels running at varying different engine operating conditions and using fuel blends

A Comparison of Ionic Liquids and Organic Solvents on the Separation of Cellulose-Rich Material from River Red Gum

With the aim of separating cellulose-rich material from river red gum, it was pre-treated with three ionic liquids (ILs), i.e. 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]), 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]) and 1-butyl-3-methylimidazolium acetate ([Bmim][OAc]) as well as with two organic solvents, i.e. methanol and ethanol. All ILs and organic solvents were able to remove more than 20% lignin. The [Emim][OAc] was found to be the most effective IL in removing lignin (i.e. 26.2 wt% lignin was removed) amongst all pre-treatment studies. Noticeable structural differences were observed in the cellulose-rich materials obtained from IL and organic solvent pre-treatments and several analytical instruments such as XRD, FTIR, TGA and SEM were employed for their detailed understandings. ILs, in contrast to organic solvents, produced porous and low crystalline cellulose-rich material. This was believed to be due to the transformation of crystalline cellulose I to amorphous cellulose II during IL pre-treatment. The exciting findings of producing high porosity and low crystallinity cellulose-rich material along with the removal of lignin using IL treatment have the potential to transform the future bio-processing and bio-refining industry. More than 80% IL recovery was achieved in this investigation. A minor structural alteration was observed in the recovered [Bmim][Cl] while no structural change was observed in the recovered [Emim][OAc] and [Bmim][OAc], and this was confirmed by FTIR spectroscopic analyses. This establishes the recyclability and reusability of ILs in the cost effective pre-treatment of biomass

Investigation of Reaction Mechanism and the Effects of Process Parameters on Ionic Liquid–Based Delignification of Sugarcane Straw

The delignification of sugarcane straw (SCS) was investigated using 1-ethyl-3-methylimidazolium acetate, [Emim][OAc], varying three process parameters such as temperature, residence time, and stirring rate. The maximum degree of delignification was around 63.9% at 90 °C for a stirring rate of 1400 rpm and a residence time of 5 h. The 23 full factorial statistical model was well-fitted with the experimental results. Among the 26 solid-liquid reaction mechanisms studied in this study, Zhuravlev, Lesokhin, and Templeman diffusion (i.e., shrinking core/product layer) model was found to be the most suitable model for describing the delignification mechanism of SCS using [Emim][OAc]. When compared with other process parameters, higher temperatures produced low crystalline and low thermally stable recovered cellulose-rich material with high porosity and BET surface area due to higher degree of crystalline cellulose I to amorphous cellulose II transformation. The recovered lignin was of low molecular structure with high content of phenolic OH− groups and syringyl units. The recovery of [Emim][OAc] was > 85% with no structural changes. [Figure not available: see fulltext.]

Hydrothermal carbonisation of raw and dewatered paunch waste: Experimental observations, process modelling and techno-economic analysis

In this study, dewatered and raw paunch waste, with 15 and 3 wt% total solids respectively, generated at abattoirs was hydrothermally carbonised under subcritical water conditions. Higher solids content was found to produce higher hydrochar yield (i.e. 53% for 15 wt% compared to 33.5% for 3 wt%) at similar operating conditions of 10 bar and 240 °C for 5 min. The morphological differences were noted via Scanning Electron Microscopy (SEM) in the hydrochar samples, and the surface area for processing raw paunch waste was found to be 68.1 m2 g−1 compared to 10.8 m2 g−1 in case of dewatered paunch waste. The light bio-oil was mostly composed of phenolic compounds while the heavy bio-oil mainly contained long chain fatty acids and their esters. Following the experimental work, a full-scale ASPEN Plus process model was developed for a typical abattoir generating 27 tonne dry paunch waste per day. Pre-heater and hydrochar dryer contributed to 73% and 57% of the total energy for processing raw and dewatered paunch waste, respectively, because of the high moisture content of the feedstock and hydrochar. After the equipment sizing and estimation of capital and operating costs, the discounted cash flow analysis was performed using the Nth-Plant financing assumptions. It was concluded that treating dewatered paunch waste is preferable as it: needed a smaller reactor i.e. lower overall initial investment, was less sensitive to bio-oil price, and improved the net present value over a period of 30 years to $2.8 MM. Besides the liquid hourly speed velocity, its commercial viability is highly sensitive to internal rate of return and existence of hydrochar dryer

Thermogravimetric Analysis of biosolids pyrolysis in the presence of mineral oxides

Biosolids, the treated and stabilised sewage sludge, was pyrolysed in the presence of naturally occurring minerals in a Thermogravimetric Analyser (TGA). The results were then compared with a synthetic catalyst (i.e., 5% Co/Al2O3). Higher mass loss was observed in TGA in the presence of both minerals and the metal oxide based catalyst when compared to biosolids' alone pyrolysis. The scanning electron microscope (SEM) images confirmed significant morphological changes in the produced biochars while Fourier Transform Infrared (FTIR) spectra corroborated noticeable chemical changes in their structure. The kinetic analyses conducted using a hybrid approach consisting of model-fitting and model-free methods, suggested that there was a reduction in activation energy in the presence of minerals and the catalyst. Overall, it is concluded that minerals despite their low catalytic activity, offer various process and morphological advantages

Dissolution reaction kinetics and mass transfer during aqueous choline chloride pre-treatment of oak wood

Lignocellulosic biomass processing employing ionic liquids is of recent research interest for the biorefinery industry. The data on biomass dissolution kinetics in ionic liquids is important for designing scale-up pre-treatment reactor design. In this study, the reaction mechanism and kinetics of oak wood dissolution in aqueous choline chloride was investigated. In an extended effort, a correlation of dimensionless numbers was developed for the estimation the mass transfer coefficient. The analyses suggested that oak wood dissolution in choline chloride occurred in two stages. The diffusion of ionic liquid through the product layer was the dominating rate-controlling step in the first stage of dissolution followed by the surface chemical reaction in the second stage. The diffusivity of choline chloride into the oak wood matrix was ranging between 2.96E−14 and 2.84E−13 m2/s. The activation energy of the diffusion controlled stage and surface chemical reaction controlled stage was approximately 24.2 and 40.3 kJ mol−1, respectively. The proposed mathematical correlation for mass transfer coefficient fitted well with the experimental mass transfer coefficient values

Ergonomic considerations for designing truck drivers' seats: The case of Bangladesh

Objectives: The purpose of this work was to investigate the fitness of the existing truck seats for Bangladeshi truck drivers and suggest a guideline for drivers' seats based on their anthropometry. Methodology: In this study, eight anthropometric measurements of 120 Bangladeshi truck drivers and seven seat dimensions of ninety trucks of three brands namely, TATA, ASHOK LEYLAND, and ISUZU were considered for investigating the considerable mismatch between seat dimensions and drivers' anthropometry. The data were analyzed using two-sample t-tests to identify the relationship between existing seat dimensions and drivers' anthropometry. Results: The results showed a mismatch in seat dimensions and anthropometric measurements for nearly all truck brands and the existing seat dimensions were found to be inappropriate for Bangladeshi drivers. For all the truck brands, the percentage mismatch of seat height, seat depth, seat width, backrest height, and steering wheel clearance varied between 71% and 98%, 23% and 79%, 33% and 84%, 28% and 65%, and 53% and 100% respectively. Subsequently, an attempt was made to provide ergonomically correct seat dimensions for Bangladeshi truck drivers. Further, generalized equations to design the appropriate seat dimensions were developed using the least square regression technique. The recommended seat height, depth and width, backrest height, and steering wheel clearance were found to be appropriate for 82%, 79%, 76%, 98%, and 100% of drivers respectively. Conclusion: The analysis and results of this study can be useful in developing guidelines for design and manufacture of truck driver seats in Bangladesh

Research progress on levoglucosan production via pyrolysis of lignocellulosic biomass and its effective recovery from bio-oil

Production of high value biochemicals from lignocellulose biomass via pyrolysis, particularly levoglucosan (LG) has received immense attention in recent years. LG production via fast pyrolysis has recorded a continuous development over the past years, which demands a state-of-the-art review, covering the LG recovery methods and commercial feasibility analysis of the process. This paper provides an in-depth review of the progress and current status of bio-LG production with a focus on formation mechanisms, influential variables, recovery methods and techno-economic prospects. Based on the experimental findings of the previous studies, this review concluded that the LG yield from biomass via pyrolysis could be proposed as a function of biomass structural properties, cellulose content, inorganic minerals content as well as pyrolysis process conditions. An essential aspect of maximising the overall efficiency of LG production process is the adoption of efficient in-situ or post-pyrolysis LG extraction techniques, which has been critically reviewed for the first time. The paper also summarises the techno-commercial assessment studies of LG facility, highlighting the limiting factors towards the economic attractiveness of the process. Finally, the review highlights the knowledge gaps and provides future recommendations, which will be helpful for the improvement of productivity and economic feasibility of bio-LG production process

Investigations into distribution and characterisation of products formed during hydrothermal carbonisation of paunch waste

Paunch waste is the wet waste generated from the cattle/sheep yard, paunch material, skin-shed, boning rooms, blood stream and rendering plant in an abattoir. It contains around 3% solids. It mainly consists of grass, grain, grease, fat, protein, blood, intestinal content, manure and cleaning products. In this study, paunch waste was treated under hydrothermal carbonisation conditions at different temperatures (160 to 240°C), residence time (5-150 min) and initial N2 pressure (10-30 bar) in a laboratory scale 600 mL Parr reactor system. The main objective of this study was to quantify the product distribution and further characterise the products produced from the hydrothermal carbonisation of paunch waste. The product distribution results reveal that higher bio-oil yield was obtained at relatively mild hydrothermal carbonisation conditions which is mainly attributed to fragile nature of paunch waste, higher water, volatile matter and carbohydrate content, and lower lignin and ash content. The resultant hydrochar was found to have higher HHV (∼24.48 MJ kg-1) and BET surface area (68.1 m2g-1) which demonstrates their suitability as a coal substitute (in energy generation processes) or a porous medium (in soil conditioning, remediation or catalysts applications). Biodiesel-like compounds were found in the heavy bio-oil with the HHV of around 38 MJ kg-1. Higher bio-oil production and excellent physico-chemical properties of hydrochar at milder hydrothermal carbonisation conditions have demonstrated significant improvement in the commercial viability of hydrothermal carbonisation of the paunch waste

Recycling biosolids as cement composites in raw, pyrolyzed and ashed forms: A waste utilisation approach to support circular economy

Ongoing management of biosolids has emerged as a major economic challenge for wastewater treatment facilities around the world. To tackle this challenge, it becomes imperative for the researcher community to identify various applications for this waste material, simultaneously supporting the government's closed-loop circular economy initiative. This research investigates the use of biosolids in raw, pyrolyzed (biochar), and ashed (bioash) forms as cement replacement materials. Detailed material characterization was carried out on the raw cementitious material followed by that on the hydrated cement composites using X-ray fluorescence, X-ray diffraction, energy-dispersive X-ray spectroscopy, scanning electron microscopy, carbon, hydrogen, nitrogen, and sulfur (CHNS) analysis, Xray micro-computed tomography and compressive strength test to identify their mechanical and physicochemical properties. The results show that the addition of 10% biosolids in the blended cement composite increased its total porosity by more than 21 times and decreased its compressive strength by 80% at 28 days of curing, indicating its potential use as an air-entraining admixture for the low-density concrete. However, the addition of 10% biochar brought about a strength improvement of ~278% and a reduction in its total porosity by ~87% compared to that of the biosolids blended cement composites. Partial replacement of cement with 10% bioash (ash form) showed ~66% reduction in its total porosity and 11% reduction in the 28-day compressive-strength compared to that of the biochar blended cement composites. Overall, this study demonstrates that the different forms of biosolids (raw, biochar, and bioash) can potentially be used as cement replacement materials with varied benefits in the cement and concrete industry. The recommendation for the future work is to carry out long-term durability studies on these blended cement composites for the ready uptake of this waste material by the construction industry