The effects of different additives on the compost of Camellia oleifera shell were characterized and a maturity evaluation system for the obtained compost was established. Four treatments were designed as C. oleifera shell with C. oleifera seed meal (A1), with C. oleifera seed cake (A2), with sheep manure (A3), and with spent mushroom substrate (A4). A3 had the longest thermophilic phase (over 50 °C) and shortest cooling phase. Compared with A1, the thermophilic phase of A2 was postponed 11 days due to the high lipid content, but terminated almost at the same time. The temperature of A4 increased slowly and took longer time to reach ambient. C/N, pH, E4/E6, and NH₄⁺-N decreased along with composting process, while TN, GI, and NO₃⁻-N were opposite. Based on the Pearson correlation analysis with the Solvita maturity index as a reference, the result indicated that TN, C/N, GI, NH₄⁺-N, and pH can be used for the maturity evaluation.

The present research focuses on the analyzing the characteristics of bio-oil derived from intermediate pyrolysis of Aegle marmelos (AM) seed cake and its suitability for C.I. engine adaptation. Owing to the high volatile matter content of 73.69%, Aegle marmelos biomass was selected as the feedstock for this research. The intermediate pyrolysis was carried out at 600 °C in a 2-kg fixed bed type pyrolysis reactor at a heating rate of 10 °C/min and the obtained bio-oil was characterized by different analytical methods. As per American Society for Testing and Materials (ASTM) standards, physicochemical properties of the bio-oil were tested and it was observed that bio-oil is a highly viscous fluid with low calorific value. Analysis of bio-oil through FT-IR and GC-MS examination confirmed the presence of phenol, esters, alkyl, and oxygenated compounds. The performance and emission testing of direct injection diesel engine were conducted with various bio-oil blends and the results were compared with baseline diesel fuel. The experimental results showed that the addition of bio-oil decreased BTE (%) while increasing the BSEC (MJ/kW-h). At the same time, increasing the bio-oil ratio with diesel decreases dangerous emissions such as carbon monoxide and oxides of nitrogen emissions in the engine exhaust. According to engine test result, it was suggested that up to 20% of AM bio-oil (F20) can be employed as engine fuel for better engine operating characteristics.

This research focuses on the detailed experimental assessment of compression ignition (CI) engine behavior fuelled with Aegle marmelos (AM) seed cake pyrolysis oil blends. The study on effects of engine performance and emission a characteristic was designed using L₂₅ orthogonal array (OA). These multi-objectives were normalized through gray relational analysis (GRA). Likewise, the principal component analysis (PCA) was performed to assess the weighting values respective to every performance and emission characteristics. The variability induced by using the input process parameters was allocated using analysis of variance (ANOVA). Hence, GRA-coupled PCA were employed to determine the optimal combination of CI engine control factors. The greater combination of engine characteristics levels were selected with F₅ and W₅. The higher brake thermal efficiency (BTE) have been obtained for F20 fuel as 22.01% at peak engine load, which is 11.43% for diesel. At peak load condition, F20 fuel emits 14.99% lower HC and 18.52% lower CO as compared to diesel fuel. The improved engine performance and emission characters can be attained by setting the optimal engine parameter combination as F20 blend at full engine load condition. The validation experiments show an improved average engine performance of 67.36% and average lower emission of 64.99% with the composite desirability of 0.8458.

In this work, fodder radish seed cake (FRSC) was pyrolyzed in a rotary kiln reactor at 0, 3, and 6 rpm, at final temperature of 500 °C. Maximum biochar yield was observed at 0 rpm (≈ 26 wt.%). Increase of the rotary speed decreased the volatile matter content and increased the ash content of the biochars. Biochars exhibited alkaline pH (≈ 9.0), low electrical conductivity (< 105.6 dS m⁻¹), and high cation exchange capacity (69 to 78 cmolc kg⁻¹), as well as high nitrogen contents (≈ 80 g kg⁻¹). FTIR analysis presented biochars with similar spectra, with carboxyl and carbonyl groups within the structure, along with aromatic rings and nitrogen containing functions (amides). Biochar incubation experiments in an acrisol at different biochar doses (5 g L⁻¹ soil to 40 g L⁻¹ soil) were performed in order to evaluate changes in soil fertility parameters caused by FRSC biochar application. Results indicated that most of macro (N, P, K, Ca, Mg) and micronutrients (S, Cu, Zn, Mn, B, Na) increased with increase of the dosage, along with the decrease in Al and H+ Al contents. An increase in pH (from 4.25 to 5.33) was also observed, in electric conductivity (from 30.0 to 45.7 dS m⁻¹), and a decrease in soil real density (from 3.67 to 2.99 kg L⁻¹) at the dosage of 40 g char L⁻¹ soil.

The highly unbalanced nature of bio-oil composition poses a serious threat in terms of storage and utilization of bio-oil as a viable fuel in engines. So it becomes inevitable to study the variations in physicochemical properties of the bio-oil during storage to value its chemical instability, for designing stabilization methodologies. The present study aims to investigate the effects of storage stability of bio-oil extracted from pyrolyzing Calophyllum inophyllum (CI) deoiled seed cake on the engine operating characteristics. The bio-oil is produced in a fixed bed reactor at 500 °C under the constant heating rate of 30 °C/min. All the stability analysis methods involve an accelerated aging procedure based on standards established by ASTM (D5304 and E2009) and European standard (EN 14112). Gas chromatography-mass spectrometry was employed to analytically characterize the unaged and aged bio-oil samples. The results clearly depict that stabilizing Calophyllum inophyllum bio-oil with 10% (w/w) methanol improved its stability than that of the unstabilized sample thereby reducing the aging rate of bio-oil to 0.04 and 0.13 cst/h for thermal and oxidative aging respectively. Engine testing of the bio-oil sample revealed that aged bio-oil samples deteriorated engine performance and increased emission levels at the exhaust. The oxidatively aged sample showed the lowest BTE (24.41%), the highest BSEC (20.14 MJ/kWh), CO (1.51%), HC (132 ppm), NOx (1098 ppm) and smoke opacity (34.8%).

This paper aims to analyse the characteristics and properties of the fractions obtained from slow pyrolysis of non-edible seed cake of Calophyllum inophyllum (CI). The gas, bio-oil and biochar obtained from the pyrolysis carried out at 500 °C in a fixed bed batch type reactor at a heating rate of 30 °C/min were characterized by various analytical techniques. Owing to the high volatile content of CI biomass (72.61%), it was selected as the raw material in this present investigation. GC-MS and FT-IR analysis of bio-oil showed the presence of higher amount of oxygenated compounds, phenol derivatives, esters, acid and furans. The physicochemical properties of the bio-oil were tested as per ASTM norms which imply that bio-oil is a highly viscous liquid with lower heating value as compared to that of diesel fuel. The chemical composition of evolved gas was analysed by using GC testing which revealed the presence of combustible components. The FT-IR characterization of biochar showed the presence of aliphatic and aromatic hydrocarbons whereas the elevated amount of carbon in biochar indicates its potential to be used as solid fuel. The performance and emission characteristics of CI engine were assessed with different CI bio-oil blends and compared with baseline diesel fuel. The results showed that addition of bio-oil leads to decreased brake thermal efficiency and increased brake specific energy consumption. Meanwhile, increase in blend ratio reduces harmful pollutants such as oxides of nitrogen and smoke in the exhaust. From the engine testing, it is suggested to employ 20% of CI bio-oil blends in CI engine to obtain better operation.