Reviewing research on the synthesis of CALB-catalyzed sugar esters incorporating systematic mapping principles.

Rigorous evidence reviews must follow specific guidelines designed to improve transparency, reproducibility, and to minimize biases to which traditional reviews are susceptible. While evidence synthesis methods, such as systematic reviews and maps, have been used in several research fields, the majority of reviews published in the realm of chemical engineering are nonsystematic. In this study, we incorporated principles of systematic mapping to conduct a literature review covering research on the synthesis of sugar fatty acid esters (SFAE) with Candida antarctica lipase B (CALB). Our results showed that the simple monosaccharides were the most cited sugars among studies we conducted. The direct use of renewable raw materials and frequently available resources to produce alternative sugar esters (SE) was scarcely reported in our data set. We found that free fatty acids (FFA) were the most commonly cited acyl donors amongst all publications, with lauric, oleic, and palmitic acids accounting for ∼43% of the occurrences. Tertiary alcohols (ter-butyl alcohol (T-but) and 2-methyl-2-butanol (2M2B)) and ionic liquids were the most used solvents to synthesize SE. The co-occurence analysis of keywords involving solvent terms showed that most of the papers evaluated different solvents as reaction media (mostly in the form of a bisolvent system), also investigating the impact of their choice on sugar ester productivities. Given the potential of reviews informing us of research decisions, this article reveals trends and spaces across CALB-catalyzed SE synthesis research, in addition to introducing a new methodological perspective for developing reviews in the field of chemical engineering.

Proposal of an open-source computational toolbox for solving PDEs in the context of chemical reaction engineering using FEniCS and complementary components.

In this contribution, an open-source computational toolbox composed of FEniCS and complementary packages is introduced to the chemical and process engineering field by addressing two case studies. First, the oxidation of o-xylene to phthalic anhydride is modelled and used as a FEniCS' proof-of-concept based on a comparison with the software Aspen Custom Modeler (ACM). The results show a maximum absolute error of 2% and thus a good FEniCS/ACM agreement. Second, synthetic natural gas (SNG) production through CO2 methanation is covered in further detail. In this instance, a parametric study is performed for a tube bundle fixed-bed reactor employing a two-dimensional and transient pseudo-homogeneous model. An operating window for critical variables is evaluated, discussed, and successfully contrasted with the literature. Therefore, the computational toolbox methodology and the consistency of the results are validated, strengthening FEniCS and complements as an interesting alternative to solve mathematical models concerning chemical reaction engineering.

CFD study and experimental validation of low liquid-loading flow assurance in oil and gas transport: studying the effect of fluid properties and operating conditions on flow variables.

Low liquid-loading flow frequently occurs during the transport of gas products in various industries, such as in the Oil & Gas, the Food, and the Pharmaceutical Industries. Even small amounts of liquid can have a significant effect on the flow conditions inside the pipeline, such as increased pressure loss, pipe wall stresses and corrosion, and liquid holdup along the pipeline. However, most studies that analyze this type of flow only use atmospheric pressures and horizontal 1-in or 2-in pipes, which do not accurately represent the range of operating conditions present in industrial applications. Therefore, this study focused on modeling low liquid-loading flow in medium-sized (6-10 in) pipes, using CFD simulations and experimental data from the University of Tulsa, and then applying it to real operating conditions from a Colombian gas pipeline. An acceptable difference was observed between experimental and CFD data, both for the liquid holdup (18%) and for the pressure drop (12%). Variables like pressure drop and wall shear stress increase with phase velocity, operating pressure, and pipe inclination. Liquid holdup increases with liquid velocity but decreases with all other factors. The relation of flow variables with phase velocities is of particular interest: Doubling the gas velocity decreased holdup 70% and increased pressure drop tenfold. On the other hand, the presence of the liquid phase seems to be more influential on process variables than its exact flowrate; the introduction of the liquid phase to a single-phase gas causes an increase in pressure loss by a factor of three, but doubling the liquid velocity only increases the pressure loss by a further 30%.

Supply chain and environmental assessment of the essential oil production using Calendula (Calendula Officinalis) as raw material.

Biomass has been considered a potential source of value-added products and energy vectors. Most biomass studies have researched the best pathways or processes to upgrade this renewable raw material through stand-alone processes or biorefineries. The biomass supply chain is a crucial aspect in the economic analysis of biomass upgrading since most of the raw materials need to be transported. A supply chain analysis gives an idea about the availability, real costs, and storage conditions of the raw material to guarantee an accurate feasibility analysis and a standardized production process. Calendula (Calendula Officinalis) is an aromatic plant used to produce valuable extracts in the cosmetic and pharmaceutical industries. Nevertheless, high amounts of exhausted biomass (more than 95% w/w) are produced and wasted. Theseresidues represent an environmental issue to be solved through the implementation of valorizing options. This paper analyses the supply chain and environmental impact of essential oil production using Calendula (Calendula Officinalis) as a raw material in the Colombian context. The case study comprises a single-objective optimization of the calendula supply chain to produce essential oil and the life cycle assessment (LCA) of the process through a cradle-to-gate approach in the Colombian context. The results showed the best locations to upgrade Calendula in Colombia (i.e., Manizales and Bucaramanga), supplying 1.1 % of the total product demand. The optimal product flow to customers was 0.32 tons/year, and the required feedstock from suppliers was 162 tons/year. The agricultural stage of essential oil production represented the highest environmental impact of the supply chain. In particular, plastic sheets, organic fertilizers, and chemical fungicides were the main contributors to this impact.

Sizing of reactors by charts of Damköhler's number for solutions of dimensionless design equations.

The reaction kinetic rate and mass transport play an important role in the sizing and scale-up of reactors. The Damköhler's dimensionless number ( D a ) is the quotient of these effects. A new interpretation of D a as a local property is introduced D a ( x , y , z , t ) . A new graphical methodology is proposed for the sizing and scale-up of unidirectional flow reactors and CSTRs. The partial differential equation (PDE) and algebraic that describe the continuity within these reactors transform into dimensionless variables, and the conversion at the output is expressed as a function of the conditions at the input D a 0 . The operating conditions as volumetric flow, residence time; design variables as reactor volume; and intrinsic reaction rate are involved in D a 0 . The equations are solved numerically to develop the design charts D a 0 vs X. The design volume is linear with D a 0 , and the conversion is obtained from the charts ( D a 0 vs X) or vice versa. Using these charts avoids the analytical or numerical solution of the PDE that governs the unidirectional flow reactors becoming an easy tool for scale-up. The article portrays how to use these diagrams. Reactors with D a 0 < 0.1 have a low conversion per pass, the charts also allow estimating the number of recirculations required as a function of the overall conversion. Reactors with the same conversion have the same D a 0 , both laboratory and industrial scale. Then, the D a number is presented as a fundamental parameter for design and scaling-up these reactors.

Catalytic assessment of solid materials for the pyrolytic conversion of low-density polyethylene into fuels.

Pyrolysis techniques provide an interesting way of recycling plastic wastes (PW) by transforming them into liquid fuels with high calorific values. Catalysts are employed in PW pyrolysis in order to favor cracking reactions; in that regard, cheap and abundant natural resources are being investigated as potential catalyst precursors. This article explores the pyrolysis of low-density polyethylene (LDPE) in a semibatch reactor under a reduced pressure of 300 torr and temperatures in the range of 370 °C-430 °C. Three different solid materials, an activated carbon (AC1), a commercial Fluid cracking catalyst (FCC) and an aluminum- pillared clay (Al-PILC), were tested as catalysts for the pyrolysis process. Thermogravimetric analyzes were previously performed to select the most catalytically active materials. AC1 displayed very low catalytic activity while FCC and Al-PILC displayed high activity and conversion to liquid products. Hydrocarbons ranging from C5 to C28 were identified in the liquid products as well as significant changes in their composition when FCC and Al-PILC catalyst were used. Differences in the catalytic activity of the 3 solid materials are ascribed mainly to differences in their acid properties.

Effectiveness of the mixture of nopal and cassava starch as clarifying substances in water purification: A case study in Colombia.

Aluminum sulfate is one of the most used chemical coagulants in the world, but research has shown that high concentrations of aluminum in the body are associated with neuropathological conditions. Because of this, different alternatives have been evaluated such as natural coagulants, which are considered safe for human health and contain fewer contaminants than chemicals due to their biodegradation properties. The main objective of this study was to evaluate the efficiency of mixing nopal mucilage and cassava starch for turbidity removal in water purification. In this paper, test jars and the treatment equipment (TA-scale FQ-005/PE manufactured by Generatoris SA de CV of Mexico) was applied in order to measure turbidity and pH parameters before and after the process of coagulation-flocculation, which was applied to water from the Magdalena River in Colombia. Samples from two sampling periods were assessed. One was evaluated during the rainy season and the other was evaluated without precipitation (drought) with initial turbidities of 316 NTU and 80 NTU, respectively. It was found that aluminum sulfate as a coagulant reference obtained better turbidity removal results (up to 99%) as compared to nopal (up to 60.4%), and nopal-starch combination of cassava (up to 67%), indicating that this mixture increases the effectiveness of natural coagulants used individually. Our results indicate that this should be considered as an alternative in the water purification process.

Energy Return on Investment (EROI) and Life Cycle Analysis (LCA) of biofuels in Ecuador.

In Ecuador, the net energy contribution of biofuels is unknown or unnoticed. To address this issue, we determined the Energy Return on Investment (EROI) for bioethanol and biodiesel. The selection of raw materials relied on their productive capacity, export and import records, and historical yields. Consequently, the scope included three raw materials for ethanol (sugar cane, corn, and forest residues) and four for biodiesel (African palm, pinion, bovine fat, and swine fat). Using a method based on the Life Cycle Analysis (LCA) of each biofuel, we assessed the entire production chain through statistical processing of primary and secondary information. Then we calculated the calorific values in the laboratory, compared energy inputs/outputs, and finally obtained the energetic returns. EROIs for bioethanol were: 1.797 for sugarcane, 1.040 for corn, and 0.739 for wood. The results for biodiesel were: 3.052 for African palm, 2.743 for pinion, 2.187 for bovine fat, and 2.891 for swine fat. These values suggest feasibility only for sugarcane in the case of ethanol. In contrast, biodiesel has better prospects because all the feedstocks analyzed had EROIs higher than two. Nevertheless, biodiesel is not available for trading in Ecuador because energy policy has overlooked systems based on higher energy return. Future studies should consider more comprehensive variables such as climate change, land use, and water management.

Kinetic modeling of the alkaline deproteinization of Nile-tilapia skin for the production of collagen.

A new phenomenological model, based on a second order dissolution kinetics, was developed for the alkaline removal of non-collagenous protein (NCP) from the skin of Nile tilapia (SNT). This model allows estimating the liquid concentration of NCP in terms of temperature, skin size, NaOH concentration and time. This model was fitted with 135 experiments averaging a R2 of 0.99. The root-mean-square deviation and the mean-absolute-percentage error of the model were 0.0041 and 3.15%, respectively. The Arrhenius-activation energy was 15-122 kJ mol-1. Multi-objective optimization led to the highest NCP extraction (NCPE) of 24.3% and to the lowest loss of collagen (LC) of 1.3%, with R2 coefficients of 0.98 and 0.92, respectively. Ultimately, SNT deproteinized under optimal conditions was subjected to acid extraction and purification. FTIR and SEM analyses indicated that the product was a Type I collagen that could be used in the pharmaceutical industry.

Turpentine valorization by its oxyfunctionalization to nopol through heterogeneous catalysis.

Turpentine is a mixture of monoterpene hydrocarbons obtained as a by-product in the paper industry. In this contribution we present its transformation process towards an alcohol named nopol, that is an important household product and fragrance raw material. Reaction conditions were established for the oxyfuntionalization of crude turpentine oil over Sn-MCM-41 catalyst for the selective conversion of ß-pinene to nopol. Synthesized materials were characterized by XRD, N2 adsorption, FT-IR, TEM and chemical absorption. The reaction was tested in 2 mL glass reactor with a sample of commercial turpentine with α-pinene (55.5% w/w) and ß-pinene (39.5% w/w) as main components and scaled up into a 100 mL Parr reactor, getting 92% conversion of ß-pinene and a nopol selectivity of 93%. The reusability tests showed that the catalyst can be reused 4 times without loss of activity. The results showed that 86% less solvent and 37.5% less paraformaldehyde can be used with turpentine, compared to the conditions used with ß-pinene for getting similar catalysts activity.

Formulation of a fermentation substrate from pineapple and sacha inchi wastes to grow Weissella cibaria.

Gold honey variety pineapple wastes and sacha inchi sub-products (SIS) were characterized in their elemental, physical, and chemical form in order to formulate a supplemented fermentation substrate (SFS) for the growth Weissella cibaria. The peels and fresh cores of the pineapple (FPP, FPC) were dried and ground (PPP, PPC) and then mixed (MCPP). The following procedures were then undertaken: a physicochemical characterization (moisture, aw, pH, acidity, and soluble solids) of the SIS, FPP, FPC, PPP, and PPC; a proximal characterization of he FPP, FPC, SIS, and SFS; and an elemental analysis (C-N2-H2-O2-S) of the MCPP, SIS, and W. cibaria, which allowed the stoichiometric equation to be defined and the SFS to be formulated. We then evaluated the effect that homogenization and heating to boiling point had on the concentration of reducing sugars in the SFS (g L-1). Finally, W. cibaria´s kinetic fermentation parameters were evaluated in the SFS and in a commercial substrate (control). The results showed FPP and FPC yields of 26.02 ± 0.58 and 14.69 ± 1.13%, respectively; a higher total sugar content in FPC (7.21%) than in FPP (6.65%); a high crude protein content in SIS (56.70%), and a C:N2 ratio of 6.50:1.00. Moreover, the highest concentration of reducing sugars (4.44 ± 0.29 g L-1) in the SFS was obtained with 5 h of hydrolysis under homogenization pre-treatments and heating until boiling. The SFS allowed the adaptation of W. cibaria, and there was a biomass production of 2.93 g L-1 and a viability of 9.88 log CFU mL-1. The formulation of an unconventional fermentation substrate from -Agro-industrial wastes of pineapple and sacha inchi to produce valuable products (such as lactic acid biomass through fermentation), is an excellent perspective for large-scale application.

Chrysotile asbestos treated with phosphoric acid as an adsorbent for ammonia nitrogen.

The purpose of this study was to find an alternative application for chrysotile asbestos, given that there is a complete structure of extraction and production of this class of serpentine minerals, but its use is banned for many applications. The idea was to obtain a compound that could immobilize phosphate by triggering a reaction between the magnesium oxide and hydroxide contained in the mineral, without causing phosphate leaching. To this end, chrysotile (Mg3SiO5(OH)4) was treated with phosphoric acid (H3PO4) in a molar ratio of 1:3 in an aqueous medium at 85 °C until the solvent evaporated, resulting in two different solid compounds, which were prepared in a similar manner. The first compound (cri/H3PO4 1:3)1, was obtained by rinsing and then heat-treating it at 150 °C for 6 h, while the second one, (cri/H3PO4 1:3)2, was rinsed after the heat treatment. Compound (cri/H3PO4 1:3)1 underwent partial leaching, while compound (cri/H3PO4 1:3)2 showed a mass increase of 48%, with the formation of crystalline magnesium pyrophosphate mixed with amorphous SiO2. The latter compound adsorbed N-NH3 at pH 10, following the pseudo-first-order model (activation energy = 8329 ± 1696 J mol-1). Equilibrium experiments, which were performed following Hill's sigmoidal type S2 isotherm model, indicated that the adsorption phenomenon was governed by two processes, i.e., complexation up to the inflection point (KH between 10.0 mg L-1 at 40 °C and 13.6 mg L-1 at 25 °C) followed by adsorption. The qmax varied from 18.0 to 19.6 mgN g-1 and the adsorbent was reusable, maintaining its initial adsorbent capacity during its first reuse. This material, which was tested on real effluents, presented a N-NH3 removal rate similar to that shown by the test solutions. The treatment of chrysotile with H3PO4 conducts it to a composite that adsorbs ammoniacal nitrogen at pH 10 and it is reusable maintaining the adsorption capacity.

Evaluation of low-cost alternatives for water purification in the stilt house villages of Santa Marta's Ciénaga Grande.

Water purification is indispensable to guarantee safe human consumption and to prevent diseases caused by the ingestion of contaminated water. This requires a series of water treatment processes which require investment. However, the economic limitations of rural communities hinder their ability to implement such water-treatment systems, as is the case in Ciénaga Grande of Santa Marta ("Large Swamp", in English) in Colombia. Low-cost systems can be used instead as simple and safe alternatives. Therefore, the objective of this work was to evaluate non-conventional, low-cost water processes to purify the water from the collection point of two stilt house villages in Ciénaga Grande of Santa Marta. These include: 1) Using two natural coagulants, Moringa Oleifera and Cassia Fistula; 2) filtration through a biosand filter and a carbon activated filter; and 3) disinfection through UV-C Radiation and through solar disinfection. The results showed a turbidity values reduction between 52% and 96% using the two natural coagulants; both turbidity and total coliforms achieved reductions of 98.4% and 76.9%, respectively in the filtration process; and removal of total coliforms up to 98.8% in the disinfection process. Despite the high rates of reduction in the different parameters, the water does not comply with the recommended limits for safe drinking water.

Techno-economic analysis of aniline production via amination of phenol.

The purpose of this research is to demonstrate through a techno-economic assessment that aniline can be industrially produced using a profitable and inherently safer process than the ones currently employed. The aniline production process was designed using process simulation software. From this, the mass and energy balances were determined, the equipment sizing was performed and the net present value (NPV) was calculated to be USD 93.5 million. Additionally, a heat integration analysis was carried out in order to improve process profitability, obtaining a new NPV of USD 97.5 million. The economic sensitivity analysis showed that the process could withstand fixed capital investment changes of up to +89%, weighted average cost of capital changes between 16-24% and a decrease in cyclohexylamine demand of up to 44%. The conceptual design is still profitable when aniline price is varied in a range of 1224-1840 $/t and phenol cost in a range of 815-1178 $/t.

Data driven methodology for model selection in flow pattern prediction.

The determination of multiphase flow parameters such as flow pattern, pressure drop and liquid holdup, is a very challenging and valuable problem in chemical, oil and gas industries, especially during transportation. There are two main approaches to solve this problem in literature: data based algorithms and mechanistic models. Although data based methods may achieve better prediction accuracy, they fail to explain the two-phase characteristics (i.e. pressure gradient, holdup, gas and liquid local velocities, etc.). Recently, many approaches have been made for establishing a unified mechanistic model for steady-state two-phase flow to predict accurately the mentioned properties. This paper proposes a novel data-driven methodology for selecting closure relationships from the models included in the unified model. A decision tree based model is built based on a data driven methodology developed from a 27670 points data set and later tested for flow pattern prediction in a set made of 9224 observations. The closure relationship selection model achieved high accuracy in classifying flow regimes for a wide range of two-phase flow conditions. Intermittent flow registering the highest accuracy (86.32%) and annular flow the lowest (49.11%). The results show that less than 10% of global accuracy is lost compared to direct data based algorithms, which is explained by the worse performance presented for atypical values and zones close to boundaries between flow patterns.

Kinetic triplet of Colombian sawmill wastes using thermogravimetric analysis.

The potential of sawmill wastes as a raw material in pyrolysis process is presented in this study. Non-isothermal thermogravimetric analysis (TGA and DTG) and isoconversional methods were employed to determine triplet kinetic (activation energy, reaction model and pre-exponential factor). Through TGA and DTG, the conversion degree is described as a function of temperature for five heating rates (10, 20, 30, 40 and 50 o C/min) and four model-free methods (Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), Friedman, and Vyazovkin) with temperatures ranging from 25 to 1000 ° C were employed. Isoconversional lines were built for every method at different isoconversional degrees α ∈ [ 0,1 ] . The activation energy E was found as a function of α in the interval χ I I = [ 0.2 , 0.7 ] where each isoconversional methods were in agreement and the estimated error was sufficiently small. Findings show the same activation energy profile independently of the isoconversional method. In particular the total variation of E in χ I I was as follows: 209.909-228.238 kJ/mol (FWO); 211.235-229.277 kJ/mol (KAS); 223.050-188.512 kJ/mol (Friedman), and 211.449 kJ/mol-229.512 kJ/mol (Vyazovkin). The reaction model of the process in χ I I matched with a two-dimensional diffusion ( D 2 ) by using a master-plot analysis. The calculated and reported parameters are fundamental information for the pyrolysis reactor design using Sawmill wastes as feedstock.

Predictive analysis of urban waste generation for the city of Bogotá, Colombia, through the implementation of decision trees-based machine learning, support vector machines and artificial neural networks.

This study presents an analysis of three models associated with artificial intelligence as tools to forecast the generation of urban solid waste in the city of Bogotá, in order to learn about this type of waste's behavior. The analysis was carried out in such a manner that different efficient alternatives are presented. In this paper, a possible decision-making strategy was explored and implemented to plan and design technologies for the stages of collection, transport and final disposal of waste in cities, while taking into account their particular characteristics. The first model used to analyze data was the decision tree which employed machine learning as a non-parametric algorithm that models data separation limitations based on the learning decision rules on the input characteristics of the model. Support vector machines were the second method implemented as a forecasting model. The primary advantage of support vector machines is their proper adjustment to data despite its variable nature or when faced with problems with a small amount of training data. Lastly, recurrent neural network models to forecast data were implemented, which yielded positive results. Their architectural design is useful in exploring temporal correlations among the same. Distribution by collection zone in the city, socio-economic stratification, population, and quantity of solid waste generated in a determined period of time were factors considered in the analysis of this forecast. The results found that support vector machines are the most appropriate model for this type of analysis.

Influence of magnetic field on barium sulfate incrustation from aqueous solutions.

The formation of scales in the petroleum industry, such as those composed of calcium and barium sulfates, may reduce productivity since these sediments can partially or totally obstruct the pipes. The mitigation of these inorganic precipitates can be accomplished by using scale inhibitors or by non-intrusive physical technologies. Here, we investigated the influence of magnetic field on the incrustations of barium sulfate by analyzing the concentration of barium and sulfate ions, the solution flow rate, the capillary tube geometry, and the magnetic field intensity in a homemade experimental unit supported on the monitoring of the dynamic differential pressure. The results show that the saline concentration and the flow rate of the solutions and the geometry of the capillary tube have a significant influence on the dynamics of barium sulfate incrustation. The presence of the magnetic field tends to prolong the induction time of the barium sulfate precipitation. A semi-empirical model was used to describe the effect of the studied variables on the barium sulfate incrustation behavior. The X-ray diffraction data of the precipitated particles analyzed using the Rietveld method suggest that the use of the magnetic field favor the formation of more crystalline particles and with smaller crystallite size than those formed in the absence of a magnetic field. Optical and scanning electron microscopy measurements also corroborate with these findings. The results from this study suggest that magnetic fields can be of interest in practical crystallization processes of barium sulfate and successfully applied to decrease the speed of barium sulfate incrustation in pipelines.

A comparative study on the treatment of gelatin production plant wastewater using electrocoagulation and chemical coagulation.

Effluents from gelatin production plants are highly complex and difficult to treat by conventional methods. The Electrocoagulation (EC) technique was evaluated to treat effluents that contain a heavy load of Chemical Oxygen Demand (COD) and a large quantity of suspended solids. This paper presents results of laboratory scale studies that compare the performance of Chemical Coagulation (CC) with aluminum salts and EC with aluminum electrodes. The heavy organic load and suspended solids in this kind of wastewater lead to low performance in the secondary treatment. SEM-EDS were used to analyze the sludge formed in the EC process and the removal mechanism of pollutants from the wastewater. The structure and composition of the precipitates at different operation conditions, such as pH, show that EC has increased efficiency of COD removal, compared to CC with the same dose of aluminum (Al+3) as coagulant. The efficiency of COD removal was 73.6% with EC and 55.6% with CC. The in-situ formation of zeolites in the EC process explains the high efficiency of this treatment compared to the CC process. The zeolite formation during the EC process in the wastewater of the gelatin production plant has not been reported until now.

Phosphorus as a promoter of a nickel catalyst to obtain 1-phenylethanol from chemoselective hydrogenation of acetophenone.

Two catalysts were prepared using monodisperse pre-synthetized nanoparticles of metallic nickel and nickel phosphides with the same average diameter. Both nanoparticles species were deposited on the same support: mesoporous silica nano-spheres of MCM-41. This support is suitable to inhibit agglomeration and sintering processes during preparation steps. Therefore, two supported and activated catalysts with the same average nanoparticles diameter were obtained. They differ only in the nature of the active species: metallic nickel and nickel phosphides. The effect of the presence of a second element (phosphorus), more electronegative than nickel, on the activity and selectivity in the chemoselective hydrogenation of acetophenone was studied. The reaction conditions were: H2 pressure of 1 MPa, 80 °C using n-heptane as solvent. With the aim to understand the catalytic results, nanoparticles, support and catalysts were carefully characterized by X-ray diffraction, diffuse light scattering, transmission electron microcopy, high resolution transmission electron microcopy, selected area electron diffraction, scanning electron microcopy, Fourier transformer infrared spectroscopy, N2 adsorption at -196 °C, atomic absorption, H2 and CO chemisorption and volumetric oxidation. Considering these results and geometric and electronic characteristics of the surface of both active species, a change in the adsorption intermediate state of acetophenone in presence of phosphorus is proposed to explain the hydrogenation chemoselectivity of nickel phospides.